Cut release 0.5.1

* Move to smart pointers and split out ParsedText class

* Cleanup ParsedText

* Fix clearCache functions and clear section cache if page load fails

* Bump Page and Section file versions

* Combine removeDir implementations in Epub

* Adjust screen margins

.clangd

@@ -0,0 +1,2 @@
+CompileFlags:
+    Add: [-std=c++2a]

README.md

@@ -36,7 +36,34 @@ This project is **not affiliated with Xteink**; it's built as a community projec
 - [ ] WiFi connectivity
 - [ ] BLE connectivity
 
-## Getting Started
+## Installing
+
+### Web (latest firmware)
+
+1. Connect your Xteink X4 to your computer via USB-C
+2. Go to https://xteink.dve.al/ and click "Flash CrossPoint firmware"
+
+To revert back to the official firmware, you can flash the latest official firmware from https://xteink.dve.al/, or swap
+back to the other partition using the "Swap boot partition" button here https://xteink.dve.al/debug.
+
+### Web (specific firmware version)
+
+1. Connect your Xteink X4 to your computer via USB-C
+2. Download the `firmware.bin` file from the release of your choice via the [releases page](https://github.com/daveallie/crosspoint-reader/releases)
+3. Go to https://xteink.dve.al/ and flash the firmware file using the "OTA fast flash controls" section
+
+To revert back to the official firmware, you can flash the latest official firmware from https://xteink.dve.al/, or swap
+back to the other partition using the "Swap boot partition" button here https://xteink.dve.al/debug.
+
+### Manual
+
+See [Development](#development) below.
+
+## Usage
+
+See [the user guide](./USER_GUIDE.md) for instructions on operating CrossPoint.
+
+## Development
 
 ### Prerequisites
 
@@ -58,24 +85,12 @@ git submodule update --init --recursive
 
 ### Flashing your device
 
-#### Command line
-
 Connect your Xteink X4 to your computer via USB-C and run the following command.
 
 ```sh
 pio run --target upload
 ```
 
-#### Web
-
-1. Connect your Xteink X4 to your computer via USB-C
-2. Download the `firmware.bin` file from the latest release via the [releases page](https://github.com/daveallie/crosspoint-reader/releases)
-3. Go to https://xteink.dve.al/ and flash the firmware file using the "OTA fast flash controls" section
-4. Press the reset button on the Xteink X4 to restart the device
-
-To revert back to the official firmware, you can flash the latest official firmware from https://xteink.dve.al/, or swap
-back to the other partition using the "Swap boot partition" button here https://xteink.dve.al/debug. 
-
 ## Internals
 
 CrossPoint Reader is pretty aggressive about caching data down to the SD card to minimise RAM usage. The ESP32-C3 only

USER_GUIDE.md

@@ -0,0 +1,78 @@
+# CrossPoint User Guide
+
+Welcome to the **CrossPoint** firmware. This guide outlines the hardware controls, navigation, and reading features of 
+the device.
+
+## 1. Hardware Overview
+
+The device utilises the standard buttons on the Xtink X4 in the same layout:
+
+### Button Layout
+| Location        | Buttons                                    |
+|-----------------|--------------------------------------------|
+| **Bottom Edge** | **Back**, **Confirm**, **Left**, **Right** |
+| **Right Side**  | **Power**, **Volume Up**, **Volume Down**  |
+
+---
+
+## 2. Power & Startup
+
+### Power On / Off
+
+To turn the device on or off, **press and hold the Power button for 1 full second**.
+
+### First Launch
+
+Upon turning the device on for the first time, you will be placed on the **Book Selection Screen** (File Browser).
+
+> **Note:** On subsequent restarts, the firmware will automatically reopen the last book you were reading.
+
+---
+
+## 3. Book Selection
+
+The Home Screen acts as a folder and file browser.
+
+* **Navigate List:** Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to move the selection cursor up 
+  and down through folders and books.
+* **Open Selection:** Press **Confirm** to open a folder or read a selected book.
+
+---
+
+## 4. Reading Mode
+
+Once you have opened a book, the button layout changes to facilitate reading.
+
+### Page Turning
+| Action            | Buttons                              |
+|-------------------|--------------------------------------|
+| **Previous Page** | Press **Left** _or_ **Volume Up**    |
+| **Next Page**     | Press **Right** _or_ **Volume Down** |
+
+### Chapter Navigation
+* **Next Chapter:** Press and **hold** the **Right** (or **Volume Down**) button briefly, then release.
+* **Previous Chapter:** Press and **hold** the **Left** (or **Volume Up**) button briefly, then release.
+
+### System Navigation
+* **Return to Home:** Press **Back** to close the book and return to the Book Selection screen.
+* **Chapter Menu:** Press **Confirm** to open the Table of Contents/Chapter Selection screen.
+
+---
+
+## 5. Chapter Selection Screen
+
+Accessible by pressing **Confirm** while inside a book.
+
+1.  Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to highlight the desired chapter.
+2.  Press **Confirm** to jump to that chapter.
+3.  *Alternatively, press **Back** to cancel and return to your current page.*
+
+---
+
+## 6. Current Limitations & Roadmap
+
+Please note that this firmware is currently in active development. The following features are **not yet supported** but
+are planned for future updates:
+
+* **Images:** Embedded images in e-books will not render.
+* **Text Formatting:** There are currently no settings to adjust font type, size, line spacing, or margins.

lib/EpdFont/builtinFonts/pixelarial14.h

@@ -0,0 +1,184 @@
+/**
+ * generated by fontconvert.py
+ * name: pixelarial14
+ * size: 8
+ * mode: 1-bit
+ */
+#pragma once
+#include "EpdFontData.h"
+
+static const uint8_t pixelarial14Bitmaps[1145] = {
+    0xFF, 0xFF, 0xFF, 0xC0, 0xFF, 0xFF, 0xFF, 0x1C, 0x63, 0x8C, 0xF7, 0x98, 0xCF, 0xFF, 0xFF, 0xDC, 0xE7, 0xFE, 0xFF,
+    0xFF, 0xFB, 0x9C, 0x63, 0x0C, 0x60, 0x30, 0xF3, 0xFF, 0xBF, 0x1F, 0x9F, 0x9B, 0x37, 0xEF, 0xFB, 0xE3, 0x00, 0x70,
+    0x67, 0xCF, 0x37, 0x61, 0xBB, 0x0D, 0xF0, 0x7D, 0x81, 0xDD, 0xC0, 0xDF, 0x07, 0x98, 0xFC, 0xC7, 0x66, 0x7B, 0xF3,
+    0x07, 0x00, 0x3E, 0x0F, 0xE1, 0x8C, 0x31, 0x86, 0x60, 0xFC, 0x1F, 0x07, 0xE4, 0xC7, 0x98, 0xF3, 0x0E, 0x7F, 0xF7,
+    0xE6, 0xFF, 0xF0, 0x37, 0x66, 0xCC, 0xCC, 0xCC, 0xCC, 0xC6, 0x67, 0x30, 0xCE, 0x66, 0x33, 0x33, 0x33, 0x33, 0x36,
+    0x6E, 0xC0, 0x6F, 0xF6, 0xFF, 0x08, 0x0E, 0x07, 0x03, 0x8F, 0xFF, 0xFC, 0x70, 0x38, 0x1C, 0x0E, 0x00, 0xFF, 0xC0,
+    0xFB, 0xFF, 0x80, 0xF0, 0x1C, 0x73, 0xCC, 0x30, 0xC7, 0x18, 0x61, 0x8E, 0x30, 0xC0, 0x7E, 0xFF, 0xC3, 0xC3, 0xC3,
+    0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xFF, 0x7E, 0x37, 0xFF, 0x33, 0x33, 0x33, 0x33, 0x30, 0x7E, 0xFF, 0xC3, 0xC3,
+    0x03, 0x03, 0x07, 0x0E, 0x1C, 0x38, 0x70, 0xFF, 0xFF, 0x7E, 0xFF, 0xC3, 0xC3, 0x03, 0x3F, 0x3F, 0x03, 0x03, 0xC3,
+    0xC3, 0xFF, 0x7E, 0x03, 0x03, 0x83, 0xC3, 0xE3, 0x31, 0x99, 0xCD, 0xC6, 0xC3, 0x7F, 0xFF, 0xE0, 0x60, 0x30, 0x7F,
+    0x7F, 0xE0, 0xC0, 0xFE, 0xFF, 0xC3, 0x03, 0x03, 0xC3, 0xC7, 0xFE, 0x7E, 0x7E, 0xFF, 0xC3, 0xC0, 0xC0, 0xFE, 0xFF,
+    0xE3, 0xC3, 0xC3, 0xC3, 0xFF, 0x7E, 0xFF, 0xFF, 0x07, 0x06, 0x06, 0x1E, 0x1C, 0x1C, 0x1C, 0x38, 0x30, 0x30, 0x30,
+    0x7E, 0xFF, 0xC3, 0xC3, 0xC3, 0xFF, 0xFF, 0xC3, 0xC3, 0xC3, 0xC3, 0xFF, 0x7E, 0x7E, 0xFF, 0xC3, 0xC3, 0xC3, 0xC7,
+    0xFF, 0x7F, 0x03, 0x03, 0xC7, 0xFE, 0x7C, 0xF0, 0x00, 0x3C, 0xF0, 0x00, 0x3F, 0xF0, 0x03, 0x03, 0x1E, 0x7E, 0xF0,
+    0xF0, 0x70, 0x7E, 0x1F, 0x03, 0xFF, 0xFF, 0x00, 0xFF, 0xFF, 0xFF, 0xC0, 0xC0, 0x70, 0x7E, 0x1F, 0x0F, 0x1E, 0x7E,
+    0xF0, 0xC0, 0x7E, 0xFF, 0xC3, 0xC3, 0x03, 0x07, 0x1E, 0x1C, 0x30, 0x30, 0x30, 0x30, 0x30, 0x3F, 0x87, 0xFE, 0xFF,
+    0x7D, 0xFB, 0xF1, 0xBF, 0x1B, 0xF3, 0xBF, 0xFF, 0xDF, 0xE6, 0x00, 0x7F, 0x03, 0xF0, 0x06, 0x01, 0xF0, 0x1F, 0x01,
+    0xF0, 0x1F, 0x03, 0xB8, 0x31, 0x87, 0xFC, 0x7F, 0xE7, 0xFE, 0xE0, 0x7C, 0x03, 0xC0, 0x30, 0xFF, 0x7F, 0xF0, 0x78,
+    0x3C, 0x1F, 0xFF, 0xFF, 0x83, 0xC1, 0xE0, 0xF0, 0x7F, 0xFF, 0xF0, 0x3F, 0x0F, 0xF3, 0x87, 0xE0, 0x3C, 0x01, 0x80,
+    0x30, 0x06, 0x00, 0xC0, 0x18, 0x0F, 0x87, 0xBF, 0xC3, 0xF0, 0xFF, 0x1F, 0xF3, 0x07, 0xE0, 0x3C, 0x07, 0x80, 0xF0,
+    0x1E, 0x03, 0xC0, 0x78, 0x0F, 0x07, 0xFF, 0xCF, 0xF0, 0xFF, 0xFF, 0xF0, 0x18, 0x0C, 0x07, 0xFF, 0xFF, 0x80, 0xC0,
+    0x60, 0x30, 0x1F, 0xFF, 0xF8, 0xFF, 0xFF, 0xF0, 0x18, 0x0C, 0x07, 0xFB, 0xFD, 0x80, 0xC0, 0x60, 0x30, 0x18, 0x0C,
+    0x00, 0x3F, 0x87, 0xFE, 0xE0, 0x7C, 0x03, 0xC0, 0x0C, 0x00, 0xC1, 0xFC, 0x1F, 0xC0, 0x3C, 0x03, 0xE0, 0x77, 0xFE,
+    0x3F, 0x80, 0xC1, 0xE0, 0xF0, 0x78, 0x3C, 0x1F, 0xFF, 0xFF, 0x83, 0xC1, 0xE0, 0xF0, 0x78, 0x3C, 0x18, 0xFF, 0xFF,
+    0xFF, 0xC0, 0x06, 0x0C, 0x18, 0x30, 0x60, 0xC1, 0x83, 0x07, 0x8F, 0x1F, 0xF7, 0xC0, 0xC0, 0x78, 0x3F, 0x0E, 0x61,
+    0x8C, 0x61, 0xBC, 0x3F, 0x87, 0xB8, 0xE3, 0x1C, 0x63, 0x0E, 0x60, 0xFC, 0x06, 0xC0, 0x60, 0x30, 0x18, 0x0C, 0x06,
+    0x03, 0x01, 0x80, 0xC0, 0x60, 0x30, 0x1F, 0xFF, 0xF8, 0xC0, 0x3E, 0x07, 0xE0, 0x7E, 0x07, 0xF1, 0xBF, 0x1B, 0xFB,
+    0xBD, 0xF3, 0xDF, 0x3D, 0xF3, 0xDF, 0x3C, 0x63, 0xC6, 0x30, 0xC1, 0xF0, 0xFC, 0x7E, 0x3F, 0x1F, 0xEF, 0x77, 0xBB,
+    0xC7, 0xE3, 0xF1, 0xF8, 0x7C, 0x18, 0x3F, 0x87, 0xFE, 0xE0, 0x7C, 0x03, 0xC0, 0x3C, 0x03, 0xC0, 0x3C, 0x03, 0xC0,
+    0x3C, 0x03, 0xE0, 0x77, 0xFE, 0x3F, 0x80, 0xFF, 0x7F, 0xF0, 0x78, 0x3C, 0x1E, 0x0F, 0xFF, 0xFE, 0xC0, 0x60, 0x30,
+    0x18, 0x0C, 0x00, 0x3F, 0x87, 0xFE, 0xE0, 0x7C, 0x03, 0xC0, 0x3C, 0x03, 0xC0, 0x3C, 0x03, 0xC0, 0x3C, 0x37, 0xE3,
+    0xE7, 0xFF, 0x3F, 0x70, 0xFF, 0x9F, 0xFF, 0x01, 0xE0, 0x3C, 0x07, 0x80, 0xFF, 0xFF, 0xFC, 0xC6, 0x18, 0xE3, 0x0E,
+    0x60, 0xFC, 0x06, 0x7F, 0x7F, 0xF0, 0x78, 0x3C, 0x07, 0xE1, 0xFE, 0x0F, 0x01, 0xE0, 0xF0, 0x7F, 0xF7, 0xF0, 0xFF,
+    0xFF, 0xC7, 0x03, 0x81, 0xC0, 0xE0, 0x70, 0x38, 0x1C, 0x0E, 0x07, 0x03, 0x81, 0xC0, 0xC1, 0xE0, 0xF0, 0x78, 0x3C,
+    0x1E, 0x0F, 0x07, 0x83, 0xC1, 0xE0, 0xF8, 0xEF, 0xE3, 0xE0, 0xC0, 0x3C, 0x03, 0xE0, 0x76, 0x06, 0x60, 0x67, 0x1E,
+    0x31, 0x83, 0xB8, 0x1F, 0x01, 0xF0, 0x1F, 0x00, 0x60, 0x06, 0x00, 0xC1, 0x81, 0xE1, 0xF0, 0xF8, 0xD8, 0xEC, 0x6C,
+    0x66, 0x36, 0x33, 0x1B, 0x19, 0xDD, 0xFC, 0x6C, 0x7C, 0x36, 0x3E, 0x1B, 0x1F, 0x0F, 0x8F, 0x03, 0x83, 0x01, 0xC1,
+    0x80, 0xC0, 0x7C, 0x3D, 0x86, 0x30, 0xC3, 0x30, 0x7E, 0x07, 0x80, 0xF8, 0x33, 0x0E, 0x71, 0x86, 0x70, 0xFC, 0x06,
+    0xC0, 0x3E, 0x07, 0x71, 0xE3, 0x18, 0x31, 0x83, 0xF8, 0x1F, 0x00, 0x60, 0x06, 0x00, 0x60, 0x06, 0x00, 0x60, 0x06,
+    0x00, 0xFF, 0xFF, 0xFC, 0x0E, 0x01, 0x80, 0x30, 0x0E, 0x07, 0x80, 0xE0, 0x30, 0x06, 0x01, 0xC0, 0x7F, 0xFF, 0xFE,
+    0xFF, 0x6D, 0xB6, 0xDB, 0x6D, 0xB7, 0xE0, 0xC3, 0x0E, 0x18, 0x61, 0x87, 0x0C, 0x30, 0xC3, 0x87, 0x1C, 0xFD, 0xB6,
+    0xDB, 0x6D, 0xB6, 0xDF, 0xE0, 0x30, 0xF1, 0xF3, 0xE7, 0xDD, 0xF1, 0x80, 0xFF, 0xFF, 0xFC, 0xCE, 0x73, 0x00, 0x7E,
+    0x7E, 0xC3, 0xC3, 0x3F, 0x7F, 0x63, 0xE3, 0xC7, 0xFF, 0x7F, 0xC0, 0xC0, 0xFE, 0xFE, 0xE3, 0xE3, 0xC3, 0xC3, 0xC3,
+    0xC3, 0xE3, 0xFF, 0xFE, 0x78, 0xFB, 0x1E, 0x3C, 0x18, 0x30, 0x60, 0xC7, 0xFD, 0xF0, 0x03, 0x03, 0x7B, 0x7F, 0xC7,
+    0xC7, 0xC3, 0xC3, 0xC3, 0xC3, 0xC7, 0xFF, 0x7F, 0x7E, 0x7E, 0xC3, 0xC3, 0xFF, 0xFF, 0xC0, 0xC0, 0xC3, 0xFF, 0x7E,
+    0x3D, 0xEF, 0xBF, 0x61, 0x86, 0x18, 0x61, 0x86, 0x18, 0x60, 0x7B, 0x7F, 0xC7, 0xC7, 0xC3, 0xC3, 0xC3, 0xC3, 0xC7,
+    0xFF, 0x7F, 0x03, 0xC3, 0xFF, 0x7E, 0xC0, 0xC0, 0xFE, 0xFE, 0xE3, 0xE3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3,
+    0xFF, 0xFF, 0xFF, 0xC0, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x3F, 0xE0, 0xC0, 0xC0, 0xC3, 0xC3, 0xC6, 0xDE,
+    0xFC, 0xF8, 0xFC, 0xEE, 0xC6, 0xC7, 0xC3, 0xFF, 0xFF, 0xFF, 0xC0, 0xF9, 0xEF, 0xDE, 0xE7, 0x3E, 0x73, 0xC6, 0x3C,
+    0x63, 0xC6, 0x3C, 0x63, 0xC6, 0x3C, 0x63, 0xC6, 0x30, 0xFE, 0xFE, 0xE3, 0xE3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3,
+    0xC3, 0x7E, 0x7E, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3, 0xFF, 0x7E, 0xFE, 0xFE, 0xE3, 0xE3, 0xC3, 0xC3, 0xC3,
+    0xC3, 0xE3, 0xFF, 0xFE, 0xC0, 0xC0, 0xC0, 0xC0, 0x7B, 0x7F, 0xC7, 0xC7, 0xC3, 0xC3, 0xC3, 0xC3, 0xC7, 0xFF, 0x7F,
+    0x03, 0x03, 0x03, 0x03, 0xFB, 0xFE, 0x38, 0xC3, 0x0C, 0x30, 0xC3, 0x0C, 0x00, 0x78, 0xFB, 0x1E, 0x3F, 0x8F, 0x81,
+    0x83, 0xC7, 0xFD, 0xF0, 0x61, 0x8F, 0xBF, 0x61, 0x86, 0x18, 0x61, 0x86, 0x1E, 0x7C, 0xC3, 0xC3, 0xC3, 0xC3, 0xC3,
+    0xC3, 0xC3, 0xC3, 0xC7, 0xFF, 0x7F, 0xC1, 0xE0, 0xF0, 0x7C, 0x76, 0x33, 0xB8, 0xD8, 0x6C, 0x3E, 0x0E, 0x07, 0x00,
+    0xC6, 0x3C, 0x63, 0xC6, 0x3F, 0xF7, 0x7F, 0x67, 0xF6, 0x7F, 0x67, 0xF6, 0x7B, 0xE3, 0x18, 0x31, 0x80, 0xC3, 0xC3,
+    0x66, 0x66, 0x7E, 0x3C, 0x3C, 0x7E, 0x66, 0xE7, 0xC3, 0xC1, 0xE0, 0xF0, 0x7C, 0x76, 0x33, 0xB8, 0xD8, 0x6C, 0x36,
+    0x1F, 0x07, 0x03, 0x81, 0xC3, 0xE1, 0xC0, 0xFF, 0xFF, 0x06, 0x1E, 0x1C, 0x1C, 0x30, 0x30, 0x70, 0xFF, 0xFF, 0x37,
+    0x66, 0x66, 0x6E, 0xCE, 0x66, 0x66, 0x67, 0x30, 0xFF, 0xFF, 0xFF, 0xC0, 0xCE, 0x66, 0x66, 0x67, 0x37, 0x66, 0x66,
+    0x6E, 0xC0, 0xC3, 0x9B, 0xFF, 0xF9, 0xB8, 0x30, 0xDB, 0x66, 0xC0, 0x6D, 0xBD, 0x80, 0x7F, 0xEF, 0x3C, 0xF3, 0xC0,
+    0x7D, 0xF7, 0xDF, 0xF3, 0xC0,
+};
+
+static const EpdGlyph pixelarial14Glyphs[] = {
+    {0, 0, 4, 0, 0, 0, 0},          //
+    {2, 13, 3, 0, 13, 4, 0},        // !
+    {4, 6, 5, 0, 13, 3, 4},         // "
+    {11, 13, 12, 0, 13, 18, 7},     // #
+    {7, 13, 8, 0, 13, 12, 25},      // $
+    {13, 13, 14, 0, 13, 22, 37},    // %
+    {11, 13, 12, 0, 13, 18, 59},    // &
+    {2, 6, 3, 0, 13, 2, 77},        // '
+    {4, 17, 5, 0, 13, 9, 79},       // (
+    {4, 17, 5, 0, 13, 9, 88},       // )
+    {4, 6, 5, 0, 13, 3, 97},        // *
+    {9, 10, 10, 0, 11, 12, 100},    // +
+    {2, 5, 3, 0, 2, 2, 112},        // ,
+    {6, 3, 6, 0, 6, 3, 114},        // -
+    {2, 2, 3, 0, 2, 1, 117},        // .
+    {6, 13, 6, 0, 13, 10, 118},     // /
+    {8, 13, 9, 0, 13, 13, 128},     // 0
+    {4, 13, 5, 0, 13, 7, 141},      // 1
+    {8, 13, 9, 0, 13, 13, 148},     // 2
+    {8, 13, 9, 0, 13, 13, 161},     // 3
+    {9, 13, 10, 0, 13, 15, 174},    // 4
+    {8, 13, 9, 0, 13, 13, 189},     // 5
+    {8, 13, 9, 0, 13, 13, 202},     // 6
+    {8, 13, 9, 0, 13, 13, 215},     // 7
+    {8, 13, 9, 0, 13, 13, 228},     // 8
+    {8, 13, 9, 0, 13, 13, 241},     // 9
+    {2, 11, 3, 0, 11, 3, 254},      // :
+    {2, 14, 3, 0, 11, 4, 257},      // ;
+    {8, 10, 9, 0, 11, 10, 261},     // <
+    {8, 6, 9, 0, 9, 6, 271},        // =
+    {8, 10, 9, 0, 11, 10, 277},     // >
+    {8, 13, 9, 0, 13, 13, 287},     // ?
+    {12, 12, 13, 0, 9, 18, 300},    // @
+    {12, 13, 13, 0, 13, 20, 318},   // A
+    {9, 13, 10, 0, 13, 15, 338},    // B
+    {11, 13, 12, 0, 13, 18, 353},   // C
+    {11, 13, 12, 0, 13, 18, 371},   // D
+    {9, 13, 10, 0, 13, 15, 389},    // E
+    {9, 13, 10, 0, 13, 15, 404},    // F
+    {12, 13, 13, 0, 13, 20, 419},   // G
+    {9, 13, 10, 0, 13, 15, 439},    // H
+    {2, 13, 3, 0, 13, 4, 454},      // I
+    {7, 13, 8, 0, 13, 12, 458},     // J
+    {11, 13, 12, 0, 13, 18, 470},   // K
+    {9, 13, 10, 0, 13, 15, 488},    // L
+    {12, 13, 13, 0, 13, 20, 503},   // M
+    {9, 13, 10, 0, 13, 15, 523},    // N
+    {12, 13, 13, 0, 13, 20, 538},   // O
+    {9, 13, 10, 0, 13, 15, 558},    // P
+    {12, 13, 13, 0, 13, 20, 573},   // Q
+    {11, 13, 12, 0, 13, 18, 593},   // R
+    {9, 13, 10, 0, 13, 15, 611},    // S
+    {9, 13, 10, 0, 13, 15, 626},    // T
+    {9, 13, 10, 0, 13, 15, 641},    // U
+    {12, 13, 13, 0, 13, 20, 656},   // V
+    {17, 13, 18, 0, 13, 28, 676},   // W
+    {11, 13, 12, 0, 13, 18, 704},   // X
+    {12, 13, 13, 0, 13, 20, 722},   // Y
+    {11, 13, 12, 0, 13, 18, 742},   // Z
+    {3, 17, 4, 0, 13, 7, 760},      // [
+    {6, 13, 6, 0, 13, 10, 767},     // <backslash>
+    {3, 17, 4, 0, 13, 7, 777},      // ]
+    {7, 7, 8, 0, 13, 7, 784},       // ^
+    {11, 2, 12, 0, 2, 3, 791},      // _
+    {4, 5, 5, 0, 13, 3, 794},       // `
+    {8, 11, 9, 0, 11, 11, 797},     // a
+    {8, 13, 9, 0, 13, 13, 808},     // b
+    {7, 11, 8, 0, 11, 10, 821},     // c
+    {8, 13, 9, 0, 13, 13, 831},     // d
+    {8, 11, 9, 0, 11, 11, 844},     // e
+    {6, 13, 6, 0, 13, 10, 855},     // f
+    {8, 15, 9, 0, 11, 15, 865},     // g
+    {8, 13, 9, 0, 13, 13, 880},     // h
+    {2, 13, 3, 0, 13, 4, 893},      // i
+    {4, 17, 5, 0, 13, 9, 897},      // j
+    {8, 13, 9, 0, 13, 13, 906},     // k
+    {2, 13, 3, 0, 13, 4, 919},      // l
+    {12, 11, 13, 0, 11, 17, 923},   // m
+    {8, 11, 9, 0, 11, 11, 940},     // n
+    {8, 11, 9, 0, 11, 11, 951},     // o
+    {8, 15, 9, 0, 11, 15, 962},     // p
+    {8, 15, 9, 0, 11, 15, 977},     // q
+    {6, 11, 6, 0, 11, 9, 992},      // r
+    {7, 11, 8, 0, 11, 10, 1001},    // s
+    {6, 13, 6, 0, 13, 10, 1011},    // t
+    {8, 11, 9, 0, 11, 11, 1021},    // u
+    {9, 11, 10, 0, 11, 13, 1032},   // v
+    {12, 11, 13, 0, 11, 17, 1045},  // w
+    {8, 11, 9, 0, 11, 11, 1062},    // x
+    {9, 15, 10, 0, 11, 17, 1073},   // y
+    {8, 11, 9, 0, 11, 11, 1090},    // z
+    {4, 17, 5, 0, 13, 9, 1101},     // {
+    {2, 13, 3, 0, 13, 4, 1110},     // |
+    {4, 17, 5, 0, 13, 9, 1114},     // }
+    {11, 4, 12, 0, 9, 6, 1123},     // ~
+    {3, 6, 4, 0, 13, 3, 1129},      // ‘
+    {3, 6, 4, 0, 13, 3, 1132},      // ’
+    {6, 6, 6, 0, 13, 5, 1135},      // “
+    {6, 6, 6, 0, 13, 5, 1140},      // ”
+};
+
+static const EpdUnicodeInterval pixelarial14Intervals[] = {
+    {0x20, 0x7E, 0x0},
+    {0x2018, 0x2019, 0x5F},
+    {0x201C, 0x201D, 0x61},
+};
+
+static const EpdFontData pixelarial14 = {
+    pixelarial14Bitmaps, pixelarial14Glyphs, pixelarial14Intervals, 3, 17, 13, -4, false,
+};

lib/Epub/Epub.cpp

@@ -6,250 +6,166 @@
 
 #include <map>
 
-bool Epub::findContentOpfFile(const ZipFile& zip, std::string& contentOpfFile) {
+#include "Epub/FsHelpers.h"
-  // open up the meta data to find where the content.opf file lives
+#include "Epub/parsers/ContainerParser.h"
-  size_t s;
+#include "Epub/parsers/ContentOpfParser.h"
-  const auto metaInfo = reinterpret_cast<char*>(zip.readFileToMemory("META-INF/container.xml", &s, true));
+#include "Epub/parsers/TocNcxParser.h"
-  if (!metaInfo) {
+
-    Serial.printf("[%lu] [EBP] Could not find META-INF/container.xml\n", millis());
+bool Epub::findContentOpfFile(std::string* contentOpfFile) const {
+  const auto containerPath = "META-INF/container.xml";
+  size_t containerSize;
+
+  // Get file size without loading it all into heap
+  if (!getItemSize(containerPath, &containerSize)) {
+    Serial.printf("[%lu] [EBP] Could not find or size META-INF/container.xml\n", millis());
     return false;
   }
 
-  // parse the meta data
+  ContainerParser containerParser(containerSize);
-  tinyxml2::XMLDocument metaDataDoc;
-  const auto result = metaDataDoc.Parse(metaInfo);
-  free(metaInfo);
 
-  if (result != tinyxml2::XML_SUCCESS) {
+  if (!containerParser.setup()) {
-    Serial.printf("[%lu] [EBP] Could not parse META-INF/container.xml. Error: %d\n", millis(), result);
     return false;
   }
 
-  const auto container = metaDataDoc.FirstChildElement("container");
+  // Stream read (reusing your existing stream logic)
-  if (!container) {
+  if (!readItemContentsToStream(containerPath, containerParser, 512)) {
-    Serial.printf("[%lu] [EBP] Could not find container element in META-INF/container.xml\n", millis());
+    Serial.printf("[%lu] [EBP] Could not read META-INF/container.xml\n", millis());
+    containerParser.teardown();
     return false;
   }
 
-  const auto rootfiles = container->FirstChildElement("rootfiles");
+  // Extract the result
-  if (!rootfiles) {
+  if (containerParser.fullPath.empty()) {
-    Serial.printf("[%lu] [EBP] Could not find rootfiles element in META-INF/container.xml\n", millis());
+    Serial.printf("[%lu] [EBP] Could not find valid rootfile in container.xml\n", millis());
+    containerParser.teardown();
     return false;
   }
 
-  // find the root file that has the media-type="application/oebps-package+xml"
+  *contentOpfFile = std::move(containerParser.fullPath);
-  auto rootfile = rootfiles->FirstChildElement("rootfile");
-  while (rootfile) {
-    const char* mediaType = rootfile->Attribute("media-type");
-    if (mediaType && strcmp(mediaType, "application/oebps-package+xml") == 0) {
-      const char* full_path = rootfile->Attribute("full-path");
-      if (full_path) {
-        contentOpfFile = full_path;
-        return true;
-      }
-    }
-    rootfile = rootfile->NextSiblingElement("rootfile");
-  }
 
-  Serial.printf("[%lu] [EBP] Could not get path to content.opf file\n", millis());
+  containerParser.teardown();
-  return false;
-}
-
-bool Epub::parseContentOpf(ZipFile& zip, std::string& content_opf_file) {
-  // read in the content.opf file and parse it
-  auto contents = reinterpret_cast<char*>(zip.readFileToMemory(content_opf_file.c_str(), nullptr, true));
-
-  // parse the contents
-  tinyxml2::XMLDocument doc;
-  auto result = doc.Parse(contents);
-  free(contents);
-
-  if (result != tinyxml2::XML_SUCCESS) {
-    Serial.printf("[%lu] [EBP] Error parsing content.opf - %s\n", millis(),
-                  tinyxml2::XMLDocument::ErrorIDToName(result));
-    return false;
-  }
-
-  auto package = doc.FirstChildElement("package");
-  if (!package) package = doc.FirstChildElement("opf:package");
-
-  if (!package) {
-    Serial.printf("[%lu] [EBP] Could not find package element in content.opf\n", millis());
-    return false;
-  }
-
-  // get the metadata - title and cover image
-  auto metadata = package->FirstChildElement("metadata");
-  if (!metadata) metadata = package->FirstChildElement("opf:metadata");
-  if (!metadata) {
-    Serial.printf("[%lu] [EBP] Missing metadata\n", millis());
-    return false;
-  }
-
-  auto titleEl = metadata->FirstChildElement("dc:title");
-  if (!titleEl) {
-    Serial.printf("[%lu] [EBP] Missing title\n", millis());
-    return false;
-  }
-  this->title = titleEl->GetText();
-
-  auto cover = metadata->FirstChildElement("meta");
-  if (!cover) cover = metadata->FirstChildElement("opf:meta");
-  while (cover && cover->Attribute("name") && strcmp(cover->Attribute("name"), "cover") != 0) {
-    cover = cover->NextSiblingElement("meta");
-  }
-  if (!cover) {
-    Serial.printf("[%lu] [EBP] Missing cover\n", millis());
-  }
-  auto coverItem = cover ? cover->Attribute("content") : nullptr;
-
-  // read the manifest and spine
-  // the manifest gives us the names of the files
-  // the spine gives us the order of the files
-  // we can then read the files in the order they are in the spine
-  auto manifest = package->FirstChildElement("manifest");
-  if (!manifest) manifest = package->FirstChildElement("opf:manifest");
-  if (!manifest) {
-    Serial.printf("[%lu] [EBP] Missing manifest\n", millis());
-    return false;
-  }
-
-  // create a mapping from id to file name
-  auto item = manifest->FirstChildElement("item");
-  if (!item) item = manifest->FirstChildElement("opf:item");
-  std::map<std::string, std::string> items;
-
-  while (item) {
-    std::string itemId = item->Attribute("id");
-    std::string href = contentBasePath + item->Attribute("href");
-
-    // grab the cover image
-    if (coverItem && itemId == coverItem) {
-      coverImageItem = href;
-    }
-
-    // grab the ncx file
-    if (itemId == "ncx" || itemId == "ncxtoc") {
-      tocNcxItem = href;
-    }
-
-    items[itemId] = href;
-    auto nextItem = item->NextSiblingElement("item");
-    if (!nextItem) nextItem = item->NextSiblingElement("opf:item");
-    item = nextItem;
-  }
-
-  // find the spine
-  auto spineEl = package->FirstChildElement("spine");
-  if (!spineEl) spineEl = package->FirstChildElement("opf:spine");
-  if (!spineEl) {
-    Serial.printf("[%lu] [EBP] Missing spine\n", millis());
-    return false;
-  }
-
-  // read the spine
-  auto itemref = spineEl->FirstChildElement("itemref");
-  if (!itemref) itemref = spineEl->FirstChildElement("opf:itemref");
-  while (itemref) {
-    auto id = itemref->Attribute("idref");
-    if (items.find(id) != items.end()) {
-      spine.emplace_back(id, items[id]);
-    }
-    auto nextItemRef = itemref->NextSiblingElement("itemref");
-    if (!nextItemRef) nextItemRef = itemref->NextSiblingElement("opf:itemref");
-    itemref = nextItemRef;
-  }
   return true;
 }
 
-bool Epub::parseTocNcxFile(const ZipFile& zip) {
+bool Epub::parseContentOpf(const std::string& contentOpfFilePath) {
+  size_t contentOpfSize;
+  if (!getItemSize(contentOpfFilePath, &contentOpfSize)) {
+    Serial.printf("[%lu] [EBP] Could not get size of content.opf\n", millis());
+    return false;
+  }
+
+  ContentOpfParser opfParser(getBasePath(), contentOpfSize);
+
+  if (!opfParser.setup()) {
+    Serial.printf("[%lu] [EBP] Could not setup content.opf parser\n", millis());
+    return false;
+  }
+
+  if (!readItemContentsToStream(contentOpfFilePath, opfParser, 1024)) {
+    Serial.printf("[%lu] [EBP] Could not read content.opf\n", millis());
+    opfParser.teardown();
+    return false;
+  }
+
+  // Grab data from opfParser into epub
+  title = opfParser.title;
+
+  if (opfParser.items.count("ncx")) {
+    tocNcxItem = opfParser.items.at("ncx");
+  } else if (opfParser.items.count("ncxtoc")) {
+    tocNcxItem = opfParser.items.at("ncxtoc");
+  }
+
+  for (auto& spineRef : opfParser.spineRefs) {
+    if (opfParser.items.count(spineRef)) {
+      spine.emplace_back(spineRef, opfParser.items.at(spineRef));
+    }
+  }
+
+  Serial.printf("[%lu] [EBP] Successfully parsed content.opf\n", millis());
+
+  opfParser.teardown();
+  return true;
+}
+
+bool Epub::parseTocNcxFile() {
   // the ncx file should have been specified in the content.opf file
   if (tocNcxItem.empty()) {
     Serial.printf("[%lu] [EBP] No ncx file specified\n", millis());
     return false;
   }
 
-  const auto ncxData = reinterpret_cast<char*>(zip.readFileToMemory(tocNcxItem.c_str(), nullptr, true));
+  size_t tocSize;
-  if (!ncxData) {
+  if (!getItemSize(tocNcxItem, &tocSize)) {
-    Serial.printf("[%lu] [EBP] Could not find %s\n", millis(), tocNcxItem.c_str());
+    Serial.printf("[%lu] [EBP] Could not get size of toc ncx\n", millis());
     return false;
   }
 
-  // Parse the Toc contents
+  TocNcxParser ncxParser(contentBasePath, tocSize);
-  tinyxml2::XMLDocument doc;
-  const auto result = doc.Parse(ncxData);
-  free(ncxData);
 
-  if (result != tinyxml2::XML_SUCCESS) {
+  if (!ncxParser.setup()) {
-    Serial.printf("[%lu] [EBP] Error parsing toc %s\n", millis(), tinyxml2::XMLDocument::ErrorIDToName(result));
+    Serial.printf("[%lu] [EBP] Could not setup toc ncx parser\n", millis());
     return false;
   }
 
-  const auto ncx = doc.FirstChildElement("ncx");
+  if (!readItemContentsToStream(tocNcxItem, ncxParser, 1024)) {
-  if (!ncx) {
+    Serial.printf("[%lu] [EBP] Could not read toc ncx stream\n", millis());
-    Serial.printf("[%lu] [EBP] Could not find first child ncx in toc\n", millis());
+    ncxParser.teardown();
     return false;
   }
 
-  const auto navMap = ncx->FirstChildElement("navMap");
+  this->toc = std::move(ncxParser.toc);
-  if (!navMap) {
-    Serial.printf("[%lu] [EBP] Could not find navMap child in ncx\n", millis());
-    return false;
-  }
 
-  recursivelyParseNavMap(navMap->FirstChildElement("navPoint"));
+  Serial.printf("[%lu] [EBP] Parsed %d TOC items\n", millis(), this->toc.size());
+
+  ncxParser.teardown();
   return true;
 }
 
-void Epub::recursivelyParseNavMap(tinyxml2::XMLElement* element) {
-  // Fills toc map
-  while (element) {
-    std::string navTitle = element->FirstChildElement("navLabel")->FirstChildElement("text")->FirstChild()->Value();
-    const auto content = element->FirstChildElement("content");
-    std::string href = contentBasePath + content->Attribute("src");
-    // split the href on the # to get the href and the anchor
-    const size_t pos = href.find('#');
-    std::string anchor;
-
-    if (pos != std::string::npos) {
-      anchor = href.substr(pos + 1);
-      href = href.substr(0, pos);
-    }
-
-    toc.emplace_back(navTitle, href, anchor, 0);
-
-    tinyxml2::XMLElement* nestedNavPoint = element->FirstChildElement("navPoint");
-    if (nestedNavPoint) {
-      recursivelyParseNavMap(nestedNavPoint);
-    }
-    element = element->NextSiblingElement("navPoint");
-  }
-}
-
 // load in the meta data for the epub file
 bool Epub::load() {
+  Serial.printf("[%lu] [EBP] Loading ePub: %s\n", millis(), filepath.c_str());
   ZipFile zip("/sd" + filepath);
 
-  std::string contentOpfFile;
+  std::string contentOpfFilePath;
-  if (!findContentOpfFile(zip, contentOpfFile)) {
+  if (!findContentOpfFile(&contentOpfFilePath)) {
-    Serial.printf("[%lu] [EBP] Could not open ePub\n", millis());
+    Serial.printf("[%lu] [EBP] Could not find content.opf in zip\n", millis());
     return false;
   }
 
-  contentBasePath = contentOpfFile.substr(0, contentOpfFile.find_last_of('/') + 1);
+  Serial.printf("[%lu] [EBP] Found content.opf at: %s\n", millis(), contentOpfFilePath.c_str());
 
-  if (!parseContentOpf(zip, contentOpfFile)) {
+  contentBasePath = contentOpfFilePath.substr(0, contentOpfFilePath.find_last_of('/') + 1);
+
+  if (!parseContentOpf(contentOpfFilePath)) {
+    Serial.printf("[%lu] [EBP] Could not parse content.opf\n", millis());
     return false;
   }
 
-  if (!parseTocNcxFile(zip)) {
+  if (!parseTocNcxFile()) {
+    Serial.printf("[%lu] [EBP] Could not parse toc\n", millis());
     return false;
   }
 
+  Serial.printf("[%lu] [EBP] Loaded ePub: %s\n", millis(), filepath.c_str());
+
   return true;
 }
 
-void Epub::clearCache() const { SD.rmdir(cachePath.c_str()); }
+bool Epub::clearCache() const {
+  if (!SD.exists(cachePath.c_str())) {
+    Serial.printf("[%lu] [EPB] Cache does not exist, no action needed\n", millis());
+    return true;
+  }
+
+  if (!FsHelpers::removeDir(cachePath.c_str())) {
+    Serial.printf("[%lu] [EPB] Failed to clear cache\n", millis());
+    return false;
+  }
+
+  Serial.printf("[%lu] [EPB] Cache cleared successfully\n", millis());
+  return true;
+}
 
 void Epub::setupCacheDir() const {
   if (SD.exists(cachePath.c_str())) {
@@ -329,6 +245,13 @@ bool Epub::readItemContentsToStream(const std::string& itemHref, Print& out, con
   return zip.readFileToStream(path.c_str(), out, chunkSize);
 }
 
+bool Epub::getItemSize(const std::string& itemHref, size_t* size) const {
+  const ZipFile zip("/sd" + filepath);
+  const std::string path = normalisePath(itemHref);
+
+  return zip.getInflatedFileSize(path.c_str(), size);
+}
+
 int Epub::getSpineItemsCount() const { return spine.size(); }
 
 std::string& Epub::getSpineItem(const int spineIndex) {
@@ -376,6 +299,5 @@ int Epub::getTocIndexForSpineIndex(const int spineIndex) const {
   }
 
   Serial.printf("[%lu] [EBP] TOC item not found\n", millis());
-  // not found - default to first item
+  return -1;
-  return 0;
 }

lib/Epub/Epub.h

@@ -1,22 +1,13 @@
 #pragma once
 #include <Print.h>
-#include <tinyxml2.h>
 
 #include <string>
 #include <unordered_map>
 #include <vector>
 
-class ZipFile;
+#include "Epub/EpubTocEntry.h"
 
-class EpubTocEntry {
+class ZipFile;
- public:
-  std::string title;
-  std::string href;
-  std::string anchor;
-  int level;
-  EpubTocEntry(std::string title, std::string href, std::string anchor, const int level)
-      : title(std::move(title)), href(std::move(href)), anchor(std::move(anchor)), level(level) {}
-};
 
 class Epub {
   // the title read from the EPUB meta data
@@ -36,11 +27,9 @@ class Epub {
   // Uniq cache key based on filepath
   std::string cachePath;
 
-  // find the path for the content.opf file
+  bool findContentOpfFile(std::string* contentOpfFile) const;
-  static bool findContentOpfFile(const ZipFile& zip, std::string& contentOpfFile);
+  bool parseContentOpf(const std::string& contentOpfFilePath);
-  bool parseContentOpf(ZipFile& zip, std::string& content_opf_file);
+  bool parseTocNcxFile();
-  bool parseTocNcxFile(const ZipFile& zip);
-  void recursivelyParseNavMap(tinyxml2::XMLElement* element);
 
  public:
   explicit Epub(std::string filepath, const std::string& cacheDir) : filepath(std::move(filepath)) {
@@ -50,7 +39,7 @@ class Epub {
   ~Epub() = default;
   std::string& getBasePath() { return contentBasePath; }
   bool load();
-  void clearCache() const;
+  bool clearCache() const;
   void setupCacheDir() const;
   const std::string& getCachePath() const;
   const std::string& getPath() const;
@@ -59,6 +48,7 @@ class Epub {
   uint8_t* readItemContentsToBytes(const std::string& itemHref, size_t* size = nullptr,
                                    bool trailingNullByte = false) const;
   bool readItemContentsToStream(const std::string& itemHref, Print& out, size_t chunkSize) const;
+  bool getItemSize(const std::string& itemHref, size_t* size) const;
   std::string& getSpineItem(int spineIndex);
   int getSpineItemsCount() const;
   EpubTocEntry& getTocItem(int tocTndex);

lib/Epub/Epub/EpubTocEntry.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <string>
+
+class EpubTocEntry {
+ public:
+  std::string title;
+  std::string href;
+  std::string anchor;
+  int level;
+  EpubTocEntry(std::string title, std::string href, std::string anchor, const int level)
+      : title(std::move(title)), href(std::move(href)), anchor(std::move(anchor)), level(level) {}
+};

lib/Epub/Epub/FsHelpers.cpp

@@ -0,0 +1,36 @@
+#include "FsHelpers.h"
+
+#include <SD.h>
+
+bool FsHelpers::removeDir(const char* path) {
+  // 1. Open the directory
+  File dir = SD.open(path);
+  if (!dir) {
+    return false;
+  }
+  if (!dir.isDirectory()) {
+    return false;
+  }
+
+  File file = dir.openNextFile();
+  while (file) {
+    String filePath = path;
+    if (!filePath.endsWith("/")) {
+      filePath += "/";
+    }
+    filePath += file.name();
+
+    if (file.isDirectory()) {
+      if (!removeDir(filePath.c_str())) {
+        return false;
+      }
+    } else {
+      if (!SD.remove(filePath.c_str())) {
+        return false;
+      }
+    }
+    file = dir.openNextFile();
+  }
+
+  return SD.rmdir(path);
+}

lib/Epub/Epub/FsHelpers.h

@@ -0,0 +1,6 @@
+#pragma once
+
+class FsHelpers {
+ public:
+  static bool removeDir(const char* path);
+};

lib/Epub/Epub/Page.cpp

@@ -3,7 +3,7 @@
 #include <HardwareSerial.h>
 #include <Serialization.h>
 
-constexpr uint8_t PAGE_FILE_VERSION = 1;
+constexpr uint8_t PAGE_FILE_VERSION = 3;
 
 void PageLine::render(GfxRenderer& renderer, const int fontId) { block->render(renderer, fontId, xPos, yPos); }
 
@@ -15,18 +15,18 @@ void PageLine::serialize(std::ostream& os) {
   block->serialize(os);
 }
 
-PageLine* PageLine::deserialize(std::istream& is) {
+std::unique_ptr<PageLine> PageLine::deserialize(std::istream& is) {
-  int32_t xPos;
+  int16_t xPos;
-  int32_t yPos;
+  int16_t yPos;
   serialization::readPod(is, xPos);
   serialization::readPod(is, yPos);
 
-  const auto tb = TextBlock::deserialize(is);
+  auto tb = TextBlock::deserialize(is);
-  return new PageLine(tb, xPos, yPos);
+  return std::unique_ptr<PageLine>(new PageLine(std::move(tb), xPos, yPos));
 }
 
 void Page::render(GfxRenderer& renderer, const int fontId) const {
-  for (const auto element : elements) {
+  for (auto& element : elements) {
     element->render(renderer, fontId);
   }
 }
@@ -37,14 +37,14 @@ void Page::serialize(std::ostream& os) const {
   const uint32_t count = elements.size();
   serialization::writePod(os, count);
 
-  for (auto* el : elements) {
+  for (const auto& el : elements) {
     // Only PageLine exists currently
     serialization::writePod(os, static_cast<uint8_t>(TAG_PageLine));
-    static_cast<PageLine*>(el)->serialize(os);
+    el->serialize(os);
   }
 }
 
-Page* Page::deserialize(std::istream& is) {
+std::unique_ptr<Page> Page::deserialize(std::istream& is) {
   uint8_t version;
   serialization::readPod(is, version);
   if (version != PAGE_FILE_VERSION) {
@@ -52,7 +52,7 @@ Page* Page::deserialize(std::istream& is) {
     return nullptr;
   }
 
-  auto* page = new Page();
+  auto page = std::unique_ptr<Page>(new Page());
 
   uint32_t count;
   serialization::readPod(is, count);
@@ -62,10 +62,11 @@ Page* Page::deserialize(std::istream& is) {
     serialization::readPod(is, tag);
 
     if (tag == TAG_PageLine) {
-      auto* pl = PageLine::deserialize(is);
+      auto pl = PageLine::deserialize(is);
-      page->elements.push_back(pl);
+      page->elements.push_back(std::move(pl));
     } else {
-      throw std::runtime_error("Unknown PageElement tag");
+      Serial.printf("[%lu] [PGE] Deserialization failed: Unknown tag %u\n", millis(), tag);
+      return nullptr;
     }
   }
 

lib/Epub/Epub/Page.h

@@ -1,4 +1,7 @@
 #pragma once
+#include <utility>
+#include <vector>
+
 #include "blocks/TextBlock.h"
 
 enum PageElementTag : uint8_t {
@@ -8,9 +11,9 @@ enum PageElementTag : uint8_t {
 // represents something that has been added to a page
 class PageElement {
  public:
-  int xPos;
+  int16_t xPos;
-  int yPos;
+  int16_t yPos;
-  explicit PageElement(const int xPos, const int yPos) : xPos(xPos), yPos(yPos) {}
+  explicit PageElement(const int16_t xPos, const int16_t yPos) : xPos(xPos), yPos(yPos) {}
   virtual ~PageElement() = default;
   virtual void render(GfxRenderer& renderer, int fontId) = 0;
   virtual void serialize(std::ostream& os) = 0;
@@ -18,27 +21,21 @@ class PageElement {
 
 // a line from a block element
 class PageLine final : public PageElement {
-  const TextBlock* block;
+  std::shared_ptr<TextBlock> block;
 
  public:
-  PageLine(const TextBlock* block, const int xPos, const int yPos) : PageElement(xPos, yPos), block(block) {}
+  PageLine(std::shared_ptr<TextBlock> block, const int16_t xPos, const int16_t yPos)
-  ~PageLine() override { delete block; }
+      : PageElement(xPos, yPos), block(std::move(block)) {}
   void render(GfxRenderer& renderer, int fontId) override;
   void serialize(std::ostream& os) override;
-  static PageLine* deserialize(std::istream& is);
+  static std::unique_ptr<PageLine> deserialize(std::istream& is);
 };
 
 class Page {
  public:
-  ~Page() {
-    for (const auto element : elements) {
-      delete element;
-    }
-  }
-
   // the list of block index and line numbers on this page
-  std::vector<PageElement*> elements;
+  std::vector<std::shared_ptr<PageElement>> elements;
   void render(GfxRenderer& renderer, int fontId) const;
   void serialize(std::ostream& os) const;
-  static Page* deserialize(std::istream& is);
+  static std::unique_ptr<Page> deserialize(std::istream& is);
 };

lib/Epub/Epub/ParsedText.cpp

@@ -0,0 +1,164 @@
+#include "ParsedText.h"
+
+#include <GfxRenderer.h>
+
+#include <algorithm>
+#include <cmath>
+#include <functional>
+#include <limits>
+#include <vector>
+
+constexpr int MAX_COST = std::numeric_limits<int>::max();
+
+void ParsedText::addWord(std::string word, const EpdFontStyle fontStyle) {
+  if (word.empty()) return;
+
+  words.push_back(std::move(word));
+  wordStyles.push_back(fontStyle);
+}
+
+// Consumes data to minimize memory usage
+void ParsedText::layoutAndExtractLines(const GfxRenderer& renderer, const int fontId, const int horizontalMargin,
+                                       const std::function<void(std::shared_ptr<TextBlock>)>& processLine) {
+  if (words.empty()) {
+    return;
+  }
+
+  const size_t totalWordCount = words.size();
+  const int pageWidth = renderer.getScreenWidth() - horizontalMargin;
+  const int spaceWidth = renderer.getSpaceWidth(fontId);
+
+  std::vector<uint16_t> wordWidths;
+  wordWidths.reserve(totalWordCount);
+
+  auto wordsIt = words.begin();
+  auto wordStylesIt = wordStyles.begin();
+
+  while (wordsIt != words.end()) {
+    wordWidths.push_back(renderer.getTextWidth(fontId, wordsIt->c_str(), *wordStylesIt));
+
+    std::advance(wordsIt, 1);
+    std::advance(wordStylesIt, 1);
+  }
+
+  // DP table to store the minimum badness (cost) of lines starting at index i
+  std::vector<int> dp(totalWordCount);
+  // 'ans[i]' stores the index 'j' of the *last word* in the optimal line starting at 'i'
+  std::vector<size_t> ans(totalWordCount);
+
+  // Base Case
+  dp[totalWordCount - 1] = 0;
+  ans[totalWordCount - 1] = totalWordCount - 1;
+
+  for (int i = totalWordCount - 2; i >= 0; --i) {
+    int currlen = -spaceWidth;
+    dp[i] = MAX_COST;
+
+    for (size_t j = i; j < totalWordCount; ++j) {
+      // Current line length: previous width + space + current word width
+      currlen += wordWidths[j] + spaceWidth;
+
+      if (currlen > pageWidth) {
+        break;
+      }
+
+      int cost;
+      if (j == totalWordCount - 1) {
+        cost = 0;  // Last line
+      } else {
+        const int remainingSpace = pageWidth - currlen;
+        // Use long long for the square to prevent overflow
+        const long long cost_ll = static_cast<long long>(remainingSpace) * remainingSpace + dp[j + 1];
+
+        if (cost_ll > MAX_COST) {
+          cost = MAX_COST;
+        } else {
+          cost = static_cast<int>(cost_ll);
+        }
+      }
+
+      if (cost < dp[i]) {
+        dp[i] = cost;
+        ans[i] = j;  // j is the index of the last word in this optimal line
+      }
+    }
+  }
+
+  // Stores the index of the word that starts the next line (last_word_index + 1)
+  std::vector<size_t> lineBreakIndices;
+  size_t currentWordIndex = 0;
+  constexpr size_t MAX_LINES = 1000;
+
+  while (currentWordIndex < totalWordCount) {
+    if (lineBreakIndices.size() >= MAX_LINES) {
+      break;
+    }
+
+    size_t nextBreakIndex = ans[currentWordIndex] + 1;
+    lineBreakIndices.push_back(nextBreakIndex);
+
+    currentWordIndex = nextBreakIndex;
+  }
+
+  // Initialize iterators for consumption
+  auto wordStartIt = words.begin();
+  auto wordStyleStartIt = wordStyles.begin();
+  size_t wordWidthIndex = 0;
+
+  size_t lastBreakAt = 0;
+  for (const size_t lineBreak : lineBreakIndices) {
+    const size_t lineWordCount = lineBreak - lastBreakAt;
+
+    // Calculate end iterators for the range to splice
+    auto wordEndIt = wordStartIt;
+    auto wordStyleEndIt = wordStyleStartIt;
+    std::advance(wordEndIt, lineWordCount);
+    std::advance(wordStyleEndIt, lineWordCount);
+
+    // Calculate total word width for this line
+    int lineWordWidthSum = 0;
+    for (size_t i = 0; i < lineWordCount; ++i) {
+      lineWordWidthSum += wordWidths[wordWidthIndex + i];
+    }
+
+    // Calculate spacing
+    const int spareSpace = pageWidth - lineWordWidthSum;
+    int spacing = spaceWidth;
+    const bool isLastLine = lineBreak == totalWordCount;
+
+    if (style == TextBlock::JUSTIFIED && !isLastLine && lineWordCount >= 2) {
+      spacing = spareSpace / (lineWordCount - 1);
+    }
+
+    // Calculate initial x position
+    uint16_t xpos = 0;
+    if (style == TextBlock::RIGHT_ALIGN) {
+      xpos = spareSpace - (lineWordCount - 1) * spaceWidth;
+    } else if (style == TextBlock::CENTER_ALIGN) {
+      xpos = (spareSpace - (lineWordCount - 1) * spaceWidth) / 2;
+    }
+
+    // Pre-calculate X positions for words
+    std::list<uint16_t> lineXPos;
+    for (size_t i = 0; i < lineWordCount; ++i) {
+      const uint16_t currentWordWidth = wordWidths[wordWidthIndex + i];
+      lineXPos.push_back(xpos);
+      xpos += currentWordWidth + spacing;
+    }
+
+    // *** CRITICAL STEP: CONSUME DATA USING SPLICE ***
+    std::list<std::string> lineWords;
+    lineWords.splice(lineWords.begin(), words, wordStartIt, wordEndIt);
+    std::list<EpdFontStyle> lineWordStyles;
+    lineWordStyles.splice(lineWordStyles.begin(), wordStyles, wordStyleStartIt, wordStyleEndIt);
+
+    processLine(
+        std::make_shared<TextBlock>(std::move(lineWords), std::move(lineXPos), std::move(lineWordStyles), style));
+
+    // Update pointers/indices for the next line
+    wordStartIt = wordEndIt;
+    wordStyleStartIt = wordStyleEndIt;
+    wordWidthIndex += lineWordCount;
+    lastBreakAt = lineBreak;
+  }
+}

lib/Epub/Epub/ParsedText.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <EpdFontFamily.h>
+
+#include <cstdint>
+#include <functional>
+#include <list>
+#include <memory>
+#include <string>
+
+#include "blocks/TextBlock.h"
+
+class GfxRenderer;
+
+class ParsedText {
+  std::list<std::string> words;
+  std::list<EpdFontStyle> wordStyles;
+  TextBlock::BLOCK_STYLE style;
+
+ public:
+  explicit ParsedText(const TextBlock::BLOCK_STYLE style) : style(style) {}
+  ~ParsedText() = default;
+
+  void addWord(std::string word, EpdFontStyle fontStyle);
+  void setStyle(const TextBlock::BLOCK_STYLE style) { this->style = style; }
+  TextBlock::BLOCK_STYLE getStyle() const { return style; }
+  bool isEmpty() const { return words.empty(); }
+  void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, int horizontalMargin,
+                             const std::function<void(std::shared_ptr<TextBlock>)>& processLine);
+};

lib/Epub/Epub/Section.cpp

@@ -1,17 +1,17 @@
 #include "Section.h"
 
-#include <GfxRenderer.h>
 #include <SD.h>
+#include <Serialization.h>
 
 #include <fstream>
 
-#include "EpubHtmlParserSlim.h"
+#include "FsHelpers.h"
 #include "Page.h"
-#include "Serialization.h"
+#include "parsers/ChapterHtmlSlimParser.h"
 
-constexpr uint8_t SECTION_FILE_VERSION = 3;
+constexpr uint8_t SECTION_FILE_VERSION = 4;
 
-void Section::onPageComplete(const Page* page) {
+void Section::onPageComplete(std::unique_ptr<Page> page) {
   const auto filePath = cachePath + "/page_" + std::to_string(pageCount) + ".bin";
 
   std::ofstream outputFile("/sd" + filePath);
@@ -21,7 +21,6 @@ void Section::onPageComplete(const Page* page) {
   Serial.printf("[%lu] [SCT] Page %d processed\n", millis(), pageCount);
 
   pageCount++;
-  delete page;
 }
 
 void Section::writeCacheMetadata(const int fontId, const float lineCompression, const int marginTop,
@@ -57,8 +56,8 @@ bool Section::loadCacheMetadata(const int fontId, const float lineCompression, c
     serialization::readPod(inputFile, version);
     if (version != SECTION_FILE_VERSION) {
       inputFile.close();
-      clearCache();
       Serial.printf("[%lu] [SCT] Deserialization failed: Unknown version %u\n", millis(), version);
+      clearCache();
       return false;
     }
 
@@ -74,8 +73,8 @@ bool Section::loadCacheMetadata(const int fontId, const float lineCompression, c
     if (fontId != fileFontId || lineCompression != fileLineCompression || marginTop != fileMarginTop ||
         marginRight != fileMarginRight || marginBottom != fileMarginBottom || marginLeft != fileMarginLeft) {
       inputFile.close();
-      clearCache();
       Serial.printf("[%lu] [SCT] Deserialization failed: Parameters do not match\n", millis());
+      clearCache();
       return false;
     }
   }
@@ -91,7 +90,21 @@ void Section::setupCacheDir() const {
   SD.mkdir(cachePath.c_str());
 }
 
-void Section::clearCache() const { SD.rmdir(cachePath.c_str()); }
+// Your updated class method (assuming you are using the 'SD' object, which is a wrapper for a specific filesystem)
+bool Section::clearCache() const {
+  if (!SD.exists(cachePath.c_str())) {
+    Serial.printf("[%lu] [SCT] Cache does not exist, no action needed\n", millis());
+    return true;
+  }
+
+  if (!FsHelpers::removeDir(cachePath.c_str())) {
+    Serial.printf("[%lu] [SCT] Failed to clear cache\n", millis());
+    return false;
+  }
+
+  Serial.printf("[%lu] [SCT] Cache cleared successfully\n", millis());
+  return true;
+}
 
 bool Section::persistPageDataToSD(const int fontId, const float lineCompression, const int marginTop,
                                   const int marginRight, const int marginBottom, const int marginLeft) {
@@ -114,8 +127,9 @@ bool Section::persistPageDataToSD(const int fontId, const float lineCompression,
 
   const auto sdTmpHtmlPath = "/sd" + tmpHtmlPath;
 
-  auto visitor = EpubHtmlParserSlim(sdTmpHtmlPath.c_str(), renderer, fontId, lineCompression, marginTop, marginRight,
+  ChapterHtmlSlimParser visitor(sdTmpHtmlPath.c_str(), renderer, fontId, lineCompression, marginTop, marginRight,
-                                    marginBottom, marginLeft, [this](const Page* page) { this->onPageComplete(page); });
+                                marginBottom, marginLeft,
+                                [this](std::unique_ptr<Page> page) { this->onPageComplete(std::move(page)); });
   success = visitor.parseAndBuildPages();
 
   SD.remove(tmpHtmlPath.c_str());
@@ -129,7 +143,7 @@ bool Section::persistPageDataToSD(const int fontId, const float lineCompression,
   return true;
 }
 
-Page* Section::loadPageFromSD() const {
+std::unique_ptr<Page> Section::loadPageFromSD() const {
   const auto filePath = "/sd" + cachePath + "/page_" + std::to_string(currentPage) + ".bin";
   if (!SD.exists(filePath.c_str() + 3)) {
     Serial.printf("[%lu] [SCT] Page file does not exist: %s\n", millis(), filePath.c_str());
@@ -137,7 +151,7 @@ Page* Section::loadPageFromSD() const {
   }
 
   std::ifstream inputFile(filePath);
-  Page* p = Page::deserialize(inputFile);
+  auto page = Page::deserialize(inputFile);
   inputFile.close();
-  return p;
+  return page;
 }

lib/Epub/Epub/Section.h

@@ -1,24 +1,26 @@
 #pragma once
+#include <memory>
+
 #include "Epub.h"
 
 class Page;
 class GfxRenderer;
 
 class Section {
-  Epub* epub;
+  std::shared_ptr<Epub> epub;
   const int spineIndex;
   GfxRenderer& renderer;
   std::string cachePath;
 
   void writeCacheMetadata(int fontId, float lineCompression, int marginTop, int marginRight, int marginBottom,
                           int marginLeft) const;
-  void onPageComplete(const Page* page);
+  void onPageComplete(std::unique_ptr<Page> page);
 
  public:
   int pageCount = 0;
   int currentPage = 0;
 
-  explicit Section(Epub* epub, const int spineIndex, GfxRenderer& renderer)
+  explicit Section(const std::shared_ptr<Epub>& epub, const int spineIndex, GfxRenderer& renderer)
       : epub(epub), spineIndex(spineIndex), renderer(renderer) {
     cachePath = epub->getCachePath() + "/" + std::to_string(spineIndex);
   }
@@ -26,8 +28,8 @@ class Section {
   bool loadCacheMetadata(int fontId, float lineCompression, int marginTop, int marginRight, int marginBottom,
                          int marginLeft);
   void setupCacheDir() const;
-  void clearCache() const;
+  bool clearCache() const;
   bool persistPageDataToSD(int fontId, float lineCompression, int marginTop, int marginRight, int marginBottom,
                            int marginLeft);
-  Page* loadPageFromSD() const;
+  std::unique_ptr<Page> loadPageFromSD() const;
 };

lib/Epub/Epub/blocks/TextBlock.cpp

@@ -3,170 +3,17 @@
 #include <GfxRenderer.h>
 #include <Serialization.h>
 
-void TextBlock::addWord(const std::string& word, const bool is_bold, const bool is_italic) {
-  if (word.length() == 0) return;
-
-  words.push_back(word);
-  wordStyles.push_back((is_bold ? BOLD_SPAN : 0) | (is_italic ? ITALIC_SPAN : 0));
-}
-
-std::list<TextBlock*> TextBlock::splitIntoLines(const GfxRenderer& renderer, const int fontId,
-                                                const int horizontalMargin) {
-  const int totalWordCount = words.size();
-  const int pageWidth = GfxRenderer::getScreenWidth() - horizontalMargin;
-  const int spaceWidth = renderer.getSpaceWidth(fontId);
-
-  words.shrink_to_fit();
-  wordStyles.shrink_to_fit();
-  wordXpos.reserve(totalWordCount);
-
-  // measure each word
-  uint16_t wordWidths[totalWordCount];
-  for (int i = 0; i < totalWordCount; i++) {
-    // measure the word
-    EpdFontStyle fontStyle = REGULAR;
-    if (wordStyles[i] & BOLD_SPAN) {
-      if (wordStyles[i] & ITALIC_SPAN) {
-        fontStyle = BOLD_ITALIC;
-      } else {
-        fontStyle = BOLD;
-      }
-    } else if (wordStyles[i] & ITALIC_SPAN) {
-      fontStyle = ITALIC;
-    }
-    const int width = renderer.getTextWidth(fontId, words[i].c_str(), fontStyle);
-    wordWidths[i] = width;
-  }
-
-  // now apply the dynamic programming algorithm to find the best line breaks
-  // DP table in which dp[i] represents cost of line starting with word words[i]
-  int dp[totalWordCount];
-
-  // Array in which ans[i] store index of last word in line starting with word
-  // word[i]
-  size_t ans[totalWordCount];
-
-  // If only one word is present then only one line is required. Cost of last
-  // line is zero. Hence cost of this line is zero. Ending point is also n-1 as
-  // single word is present
-  dp[totalWordCount - 1] = 0;
-  ans[totalWordCount - 1] = totalWordCount - 1;
-
-  // Make each word first word of line by iterating over each index in arr.
-  for (int i = totalWordCount - 2; i >= 0; i--) {
-    int currlen = -1;
-    dp[i] = INT_MAX;
-
-    // Variable to store possible minimum cost of line.
-    int cost;
-
-    // Keep on adding words in current line by iterating from starting word upto
-    // last word in arr.
-    for (int j = i; j < totalWordCount; j++) {
-      // Update the width of the words in current line + the space between two
-      // words.
-      currlen += wordWidths[j] + spaceWidth;
-
-      // If we're bigger than the current pagewidth then we can't add more words
-      if (currlen > pageWidth) break;
-
-      // if we've run out of words then this is last line and the cost should be
-      // 0 Otherwise the cost is the sqaure of the left over space + the costs
-      // of all the previous lines
-      if (j == totalWordCount - 1)
-        cost = 0;
-      else
-        cost = (pageWidth - currlen) * (pageWidth - currlen) + dp[j + 1];
-
-      // Check if this arrangement gives minimum cost for line starting with
-      // word words[i].
-      if (cost < dp[i]) {
-        dp[i] = cost;
-        ans[i] = j;
-      }
-    }
-  }
-
-  // We can now iterate through the answer to find the line break positions
-  std::list<uint16_t> lineBreaks;
-  for (size_t i = 0; i < totalWordCount;) {
-    i = ans[i] + 1;
-    if (i > totalWordCount) {
-      break;
-    }
-    lineBreaks.push_back(i);
-    // Text too big, just exit
-    if (lineBreaks.size() > 1000) {
-      break;
-    }
-  }
-
-  std::list<TextBlock*> lines;
-
-  // With the line breaks calculated we can now position the words along the
-  // line
-  int startWord = 0;
-  for (const auto lineBreak : lineBreaks) {
-    const int lineWordCount = lineBreak - startWord;
-
-    int lineWordWidthSum = 0;
-    for (int i = startWord; i < lineBreak; i++) {
-      lineWordWidthSum += wordWidths[i];
-    }
-
-    // Calculate spacing between words
-    const uint16_t spareSpace = pageWidth - lineWordWidthSum;
-    uint16_t spacing = spaceWidth;
-    // evenly space words if using justified style, not the last line, and at
-    // least 2 words
-    if (style == JUSTIFIED && lineBreak != lineBreaks.back() && lineWordCount >= 2) {
-      spacing = spareSpace / (lineWordCount - 1);
-    }
-
-    uint16_t xpos = 0;
-    if (style == RIGHT_ALIGN) {
-      xpos = spareSpace - (lineWordCount - 1) * spaceWidth;
-    } else if (style == CENTER_ALIGN) {
-      xpos = (spareSpace - (lineWordCount - 1) * spaceWidth) / 2;
-    }
-
-    for (int i = startWord; i < lineBreak; i++) {
-      wordXpos[i] = xpos;
-      xpos += wordWidths[i] + spacing;
-    }
-
-    std::vector<std::string> lineWords;
-    std::vector<uint16_t> lineXPos;
-    std::vector<uint8_t> lineWordStyles;
-    lineWords.reserve(lineWordCount);
-    lineXPos.reserve(lineWordCount);
-    lineWordStyles.reserve(lineWordCount);
-
-    for (int i = startWord; i < lineBreak; i++) {
-      lineWords.push_back(words[i]);
-      lineXPos.push_back(wordXpos[i]);
-      lineWordStyles.push_back(wordStyles[i]);
-    }
-    const auto textLine = new TextBlock(lineWords, lineXPos, lineWordStyles, style);
-    lines.push_back(textLine);
-    startWord = lineBreak;
-  }
-
-  return lines;
-}
-
 void TextBlock::render(const GfxRenderer& renderer, const int fontId, const int x, const int y) const {
+  auto wordIt = words.begin();
+  auto wordStylesIt = wordStyles.begin();
+  auto wordXposIt = wordXpos.begin();
+
   for (int i = 0; i < words.size(); i++) {
-    // render the word
+    renderer.drawText(fontId, *wordXposIt + x, y, wordIt->c_str(), true, *wordStylesIt);
-    EpdFontStyle fontStyle = REGULAR;
+
-    if (wordStyles[i] & BOLD_SPAN && wordStyles[i] & ITALIC_SPAN) {
+    std::advance(wordIt, 1);
-      fontStyle = BOLD_ITALIC;
+    std::advance(wordStylesIt, 1);
-    } else if (wordStyles[i] & BOLD_SPAN) {
+    std::advance(wordXposIt, 1);
-      fontStyle = BOLD;
-    } else if (wordStyles[i] & ITALIC_SPAN) {
-      fontStyle = ITALIC;
-    }
-    renderer.drawText(fontId, x + wordXpos[i], y, words[i].c_str(), true, fontStyle);
   }
 }
 
@@ -190,11 +37,11 @@ void TextBlock::serialize(std::ostream& os) const {
   serialization::writePod(os, style);
 }
 
-TextBlock* TextBlock::deserialize(std::istream& is) {
+std::unique_ptr<TextBlock> TextBlock::deserialize(std::istream& is) {
   uint32_t wc, xc, sc;
-  std::vector<std::string> words;
+  std::list<std::string> words;
-  std::vector<uint16_t> wordXpos;
+  std::list<uint16_t> wordXpos;
-  std::vector<uint8_t> wordStyles;
+  std::list<EpdFontStyle> wordStyles;
   BLOCK_STYLE style;
 
   // words
@@ -215,5 +62,5 @@ TextBlock* TextBlock::deserialize(std::istream& is) {
   // style
   serialization::readPod(is, style);
 
-  return new TextBlock(words, wordXpos, wordStyles, style);
+  return std::unique_ptr<TextBlock>(new TextBlock(std::move(words), std::move(wordXpos), std::move(wordStyles), style));
 }

lib/Epub/Epub/blocks/TextBlock.h

@@ -1,50 +1,40 @@
 #pragma once
+#include <EpdFontFamily.h>
+
 #include <list>
+#include <memory>
 #include <string>
-#include <vector>
 
 #include "Block.h"
 
-enum SPAN_STYLE : uint8_t {
-  BOLD_SPAN = 1,
-  ITALIC_SPAN = 2,
-};
-
-enum BLOCK_STYLE : uint8_t {
-  JUSTIFIED = 0,
-  LEFT_ALIGN = 1,
-  CENTER_ALIGN = 2,
-  RIGHT_ALIGN = 3,
-};
-
 // represents a block of words in the html document
 class TextBlock final : public Block {
-  // pointer to each word
+ public:
-  std::vector<std::string> words;
+  enum BLOCK_STYLE : uint8_t {
-  // x position of each word
+    JUSTIFIED = 0,
-  std::vector<uint16_t> wordXpos;
+    LEFT_ALIGN = 1,
-  // the styles of each word
+    CENTER_ALIGN = 2,
-  std::vector<uint8_t> wordStyles;
+    RIGHT_ALIGN = 3,
+  };
 
-  // the style of the block - left, center, right aligned
+ private:
+  std::list<std::string> words;
+  std::list<uint16_t> wordXpos;
+  std::list<EpdFontStyle> wordStyles;
   BLOCK_STYLE style;
 
  public:
-  explicit TextBlock(const BLOCK_STYLE style) : style(style) {}
+  explicit TextBlock(std::list<std::string> words, std::list<uint16_t> word_xpos, std::list<EpdFontStyle> word_styles,
-  explicit TextBlock(const std::vector<std::string>& words, const std::vector<uint16_t>& word_xpos,
+                     const BLOCK_STYLE style)
-                     // the styles of each word
+      : words(std::move(words)), wordXpos(std::move(word_xpos)), wordStyles(std::move(word_styles)), style(style) {}
-                     const std::vector<uint8_t>& word_styles, const BLOCK_STYLE style)
-      : words(words), wordXpos(word_xpos), wordStyles(word_styles), style(style) {}
   ~TextBlock() override = default;
-  void addWord(const std::string& word, bool is_bold, bool is_italic);
   void setStyle(const BLOCK_STYLE style) { this->style = style; }
   BLOCK_STYLE getStyle() const { return style; }
   bool isEmpty() override { return words.empty(); }
   void layout(GfxRenderer& renderer) override {};
   // given a renderer works out where to break the words into lines
-  std::list<TextBlock*> splitIntoLines(const GfxRenderer& renderer, int fontId, int horizontalMargin);
   void render(const GfxRenderer& renderer, int fontId, int x, int y) const;
   BlockType getType() override { return TEXT_BLOCK; }
   void serialize(std::ostream& os) const;
-  static TextBlock* deserialize(std::istream& is);
+  static std::unique_ptr<TextBlock> deserialize(std::istream& is);
 };

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp

@@ -1,11 +1,11 @@
-#include "EpubHtmlParserSlim.h"
+#include "ChapterHtmlSlimParser.h"
 
 #include <GfxRenderer.h>
 #include <HardwareSerial.h>
 #include <expat.h>
 
-#include "Page.h"
+#include "../Page.h"
-#include "htmlEntities.h"
+#include "../htmlEntities.h"
 
 const char* HEADER_TAGS[] = {"h1", "h2", "h3", "h4", "h5", "h6"};
 constexpr int NUM_HEADER_TAGS = sizeof(HEADER_TAGS) / sizeof(HEADER_TAGS[0]);
@@ -38,7 +38,7 @@ bool matches(const char* tag_name, const char* possible_tags[], const int possib
 }
 
 // start a new text block if needed
-void EpubHtmlParserSlim::startNewTextBlock(const BLOCK_STYLE style) {
+void ChapterHtmlSlimParser::startNewTextBlock(const TextBlock::BLOCK_STYLE style) {
   if (currentTextBlock) {
     // already have a text block running and it is empty - just reuse it
     if (currentTextBlock->isEmpty()) {
@@ -46,15 +46,13 @@ void EpubHtmlParserSlim::startNewTextBlock(const BLOCK_STYLE style) {
       return;
     }
 
-    currentTextBlock->finish();
     makePages();
-    delete currentTextBlock;
   }
-  currentTextBlock = new TextBlock(style);
+  currentTextBlock.reset(new ParsedText(style));
 }
 
-void XMLCALL EpubHtmlParserSlim::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
+void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
-  auto* self = static_cast<EpubHtmlParserSlim*>(userData);
+  auto* self = static_cast<ChapterHtmlSlimParser*>(userData);
   (void)atts;
 
   // Middle of skip
@@ -64,23 +62,7 @@ void XMLCALL EpubHtmlParserSlim::startElement(void* userData, const XML_Char* na
   }
 
   if (matches(name, IMAGE_TAGS, NUM_IMAGE_TAGS)) {
-    // const char* src = element.Attribute("src");
+    // TODO: Start processing image tags
-    // if (src) {
-    //   // don't leave an empty text block in the list
-    //   // const BLOCK_STYLE style = currentTextBlock->get_style();
-    //   if (currentTextBlock->isEmpty()) {
-    //     delete currentTextBlock;
-    //     currentTextBlock = nullptr;
-    //   }
-    //   // TODO: Fix this
-    //   // blocks.push_back(new ImageBlock(m_base_path + src));
-    //   // start a new text block - with the same style as before
-    //   // startNewTextBlock(style);
-    // } else {
-    //   // ESP_LOGE(TAG, "Could not find src attribute");
-    // }
-
-    // start skip
     self->skipUntilDepth = self->depth;
     self->depth += 1;
     return;
@@ -94,13 +76,13 @@ void XMLCALL EpubHtmlParserSlim::startElement(void* userData, const XML_Char* na
   }
 
   if (matches(name, HEADER_TAGS, NUM_HEADER_TAGS)) {
-    self->startNewTextBlock(CENTER_ALIGN);
+    self->startNewTextBlock(TextBlock::CENTER_ALIGN);
     self->boldUntilDepth = min(self->boldUntilDepth, self->depth);
   } else if (matches(name, BLOCK_TAGS, NUM_BLOCK_TAGS)) {
     if (strcmp(name, "br") == 0) {
       self->startNewTextBlock(self->currentTextBlock->getStyle());
     } else {
-      self->startNewTextBlock(JUSTIFIED);
+      self->startNewTextBlock(TextBlock::JUSTIFIED);
     }
   } else if (matches(name, BOLD_TAGS, NUM_BOLD_TAGS)) {
     self->boldUntilDepth = min(self->boldUntilDepth, self->depth);
@@ -111,21 +93,29 @@ void XMLCALL EpubHtmlParserSlim::startElement(void* userData, const XML_Char* na
   self->depth += 1;
 }
 
-void XMLCALL EpubHtmlParserSlim::characterData(void* userData, const XML_Char* s, const int len) {
+void XMLCALL ChapterHtmlSlimParser::characterData(void* userData, const XML_Char* s, const int len) {
-  auto* self = static_cast<EpubHtmlParserSlim*>(userData);
+  auto* self = static_cast<ChapterHtmlSlimParser*>(userData);
 
   // Middle of skip
   if (self->skipUntilDepth < self->depth) {
     return;
   }
 
+  EpdFontStyle fontStyle = REGULAR;
+  if (self->boldUntilDepth < self->depth && self->italicUntilDepth < self->depth) {
+    fontStyle = BOLD_ITALIC;
+  } else if (self->boldUntilDepth < self->depth) {
+    fontStyle = BOLD;
+  } else if (self->italicUntilDepth < self->depth) {
+    fontStyle = ITALIC;
+  }
+
   for (int i = 0; i < len; i++) {
     if (isWhitespace(s[i])) {
       // Currently looking at whitespace, if there's anything in the partWordBuffer, flush it
       if (self->partWordBufferIndex > 0) {
         self->partWordBuffer[self->partWordBufferIndex] = '\0';
-        self->currentTextBlock->addWord(replaceHtmlEntities(self->partWordBuffer), self->boldUntilDepth < self->depth,
+        self->currentTextBlock->addWord(std::move(replaceHtmlEntities(self->partWordBuffer)), fontStyle);
-                                        self->italicUntilDepth < self->depth);
         self->partWordBufferIndex = 0;
       }
       // Skip the whitespace char
@@ -135,8 +125,7 @@ void XMLCALL EpubHtmlParserSlim::characterData(void* userData, const XML_Char* s
     // If we're about to run out of space, then cut the word off and start a new one
     if (self->partWordBufferIndex >= MAX_WORD_SIZE) {
       self->partWordBuffer[self->partWordBufferIndex] = '\0';
-      self->currentTextBlock->addWord(replaceHtmlEntities(self->partWordBuffer), self->boldUntilDepth < self->depth,
+      self->currentTextBlock->addWord(std::move(replaceHtmlEntities(self->partWordBuffer)), fontStyle);
-                                      self->italicUntilDepth < self->depth);
       self->partWordBufferIndex = 0;
     }
 
@@ -144,8 +133,8 @@ void XMLCALL EpubHtmlParserSlim::characterData(void* userData, const XML_Char* s
   }
 }
 
-void XMLCALL EpubHtmlParserSlim::endElement(void* userData, const XML_Char* name) {
+void XMLCALL ChapterHtmlSlimParser::endElement(void* userData, const XML_Char* name) {
-  auto* self = static_cast<EpubHtmlParserSlim*>(userData);
+  auto* self = static_cast<ChapterHtmlSlimParser*>(userData);
   (void)name;
 
   if (self->partWordBufferIndex > 0) {
@@ -158,9 +147,17 @@ void XMLCALL EpubHtmlParserSlim::endElement(void* userData, const XML_Char* name
         matches(name, BOLD_TAGS, NUM_BOLD_TAGS) || matches(name, ITALIC_TAGS, NUM_ITALIC_TAGS) || self->depth == 1;
 
     if (shouldBreakText) {
+      EpdFontStyle fontStyle = REGULAR;
+      if (self->boldUntilDepth < self->depth && self->italicUntilDepth < self->depth) {
+        fontStyle = BOLD_ITALIC;
+      } else if (self->boldUntilDepth < self->depth) {
+        fontStyle = BOLD;
+      } else if (self->italicUntilDepth < self->depth) {
+        fontStyle = ITALIC;
+      }
+
       self->partWordBuffer[self->partWordBufferIndex] = '\0';
-      self->currentTextBlock->addWord(replaceHtmlEntities(self->partWordBuffer), self->boldUntilDepth < self->depth,
+      self->currentTextBlock->addWord(std::move(replaceHtmlEntities(self->partWordBuffer)), fontStyle);
-                                      self->italicUntilDepth < self->depth);
       self->partWordBufferIndex = 0;
     }
   }
@@ -183,8 +180,8 @@ void XMLCALL EpubHtmlParserSlim::endElement(void* userData, const XML_Char* name
   }
 }
 
-bool EpubHtmlParserSlim::parseAndBuildPages() {
+bool ChapterHtmlSlimParser::parseAndBuildPages() {
-  startNewTextBlock(JUSTIFIED);
+  startNewTextBlock(TextBlock::JUSTIFIED);
 
   const XML_Parser parser = XML_ParserCreate(nullptr);
   int done;
@@ -240,56 +237,43 @@ bool EpubHtmlParserSlim::parseAndBuildPages() {
   // Process last page if there is still text
   if (currentTextBlock) {
     makePages();
-    completePageFn(currentPage);
+    completePageFn(std::move(currentPage));
-    currentPage = nullptr;
+    currentPage.reset();
-    delete currentTextBlock;
+    currentTextBlock.reset();
-    currentTextBlock = nullptr;
   }
 
   return true;
 }
 
-void EpubHtmlParserSlim::makePages() {
+void ChapterHtmlSlimParser::addLineToPage(std::shared_ptr<TextBlock> line) {
+  const int lineHeight = renderer.getLineHeight(fontId) * lineCompression;
+  const int pageHeight = GfxRenderer::getScreenHeight() - marginTop - marginBottom;
+
+  if (currentPageNextY + lineHeight > pageHeight) {
+    completePageFn(std::move(currentPage));
+    currentPage.reset(new Page());
+    currentPageNextY = marginTop;
+  }
+
+  currentPage->elements.push_back(std::make_shared<PageLine>(line, marginLeft, currentPageNextY));
+  currentPageNextY += lineHeight;
+}
+
+void ChapterHtmlSlimParser::makePages() {
   if (!currentTextBlock) {
     Serial.printf("[%lu] [EHP] !! No text block to make pages for !!\n", millis());
     return;
   }
 
   if (!currentPage) {
-    currentPage = new Page();
+    currentPage.reset(new Page());
     currentPageNextY = marginTop;
   }
 
   const int lineHeight = renderer.getLineHeight(fontId) * lineCompression;
-  const int pageHeight = GfxRenderer::getScreenHeight() - marginTop - marginBottom;
+  currentTextBlock->layoutAndExtractLines(
-
+      renderer, fontId, marginLeft + marginRight,
-  // Long running task, make sure to let other things happen
+      [this](const std::shared_ptr<TextBlock>& textBlock) { addLineToPage(textBlock); });
-  vTaskDelay(1);
+  // Extra paragrpah spacing
-
+  currentPageNextY += lineHeight / 2;
-  if (currentTextBlock->getType() == TEXT_BLOCK) {
-    const auto lines = currentTextBlock->splitIntoLines(renderer, fontId, marginLeft + marginRight);
-
-    for (const auto line : lines) {
-      if (currentPageNextY + lineHeight > pageHeight) {
-        completePageFn(currentPage);
-        currentPage = new Page();
-        currentPageNextY = marginTop;
-      }
-
-      currentPage->elements.push_back(new PageLine(line, marginLeft, currentPageNextY));
-      currentPageNextY += lineHeight;
-    }
-    // add some extra line between blocks
-    currentPageNextY += lineHeight / 2;
-  }
-  // TODO: Image block support
-  // if (block->getType() == BlockType::IMAGE_BLOCK) {
-  //   ImageBlock *imageBlock = (ImageBlock *)block;
-  //   if (y + imageBlock->height > page_height) {
-  //     pages.push_back(new Page());
-  //     y = 0;
-  //   }
-  //   pages.back()->elements.push_back(new PageImage(imageBlock, y));
-  //   y += imageBlock->height;
-  // }
 }

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h

@@ -4,18 +4,20 @@
 
 #include <climits>
 #include <functional>
+#include <memory>
 
-#include "blocks/TextBlock.h"
+#include "../ParsedText.h"
+#include "../blocks/TextBlock.h"
 
 class Page;
 class GfxRenderer;
 
 #define MAX_WORD_SIZE 200
 
-class EpubHtmlParserSlim {
+class ChapterHtmlSlimParser {
   const char* filepath;
   GfxRenderer& renderer;
-  std::function<void(Page*)> completePageFn;
+  std::function<void(std::unique_ptr<Page>)> completePageFn;
   int depth = 0;
   int skipUntilDepth = INT_MAX;
   int boldUntilDepth = INT_MAX;
@@ -24,9 +26,9 @@ class EpubHtmlParserSlim {
   // leave one char at end for null pointer
   char partWordBuffer[MAX_WORD_SIZE + 1] = {};
   int partWordBufferIndex = 0;
-  TextBlock* currentTextBlock = nullptr;
+  std::unique_ptr<ParsedText> currentTextBlock = nullptr;
-  Page* currentPage = nullptr;
+  std::unique_ptr<Page> currentPage = nullptr;
-  int currentPageNextY = 0;
+  int16_t currentPageNextY = 0;
   int fontId;
   float lineCompression;
   int marginTop;
@@ -34,7 +36,7 @@ class EpubHtmlParserSlim {
   int marginBottom;
   int marginLeft;
 
-  void startNewTextBlock(BLOCK_STYLE style);
+  void startNewTextBlock(TextBlock::BLOCK_STYLE style);
   void makePages();
   // XML callbacks
   static void XMLCALL startElement(void* userData, const XML_Char* name, const XML_Char** atts);
@@ -42,10 +44,10 @@ class EpubHtmlParserSlim {
   static void XMLCALL endElement(void* userData, const XML_Char* name);
 
  public:
-  explicit EpubHtmlParserSlim(const char* filepath, GfxRenderer& renderer, const int fontId,
+  explicit ChapterHtmlSlimParser(const char* filepath, GfxRenderer& renderer, const int fontId,
-                              const float lineCompression, const int marginTop, const int marginRight,
+                                 const float lineCompression, const int marginTop, const int marginRight,
-                              const int marginBottom, const int marginLeft,
+                                 const int marginBottom, const int marginLeft,
-                              const std::function<void(Page*)>& completePageFn)
+                                 const std::function<void(std::unique_ptr<Page>)>& completePageFn)
       : filepath(filepath),
         renderer(renderer),
         fontId(fontId),
@@ -55,6 +57,7 @@ class EpubHtmlParserSlim {
         marginBottom(marginBottom),
         marginLeft(marginLeft),
         completePageFn(completePageFn) {}
-  ~EpubHtmlParserSlim() = default;
+  ~ChapterHtmlSlimParser() = default;
   bool parseAndBuildPages();
+  void addLineToPage(std::shared_ptr<TextBlock> line);
 };

lib/Epub/Epub/parsers/ContainerParser.cpp

@@ -0,0 +1,96 @@
+#include "ContainerParser.h"
+
+#include <HardwareSerial.h>
+
+bool ContainerParser::setup() {
+  parser = XML_ParserCreate(nullptr);
+  if (!parser) {
+    Serial.printf("[%lu] [CTR] Couldn't allocate memory for parser\n", millis());
+    return false;
+  }
+
+  XML_SetUserData(parser, this);
+  XML_SetElementHandler(parser, startElement, endElement);
+  return true;
+}
+
+bool ContainerParser::teardown() {
+  if (parser) {
+    XML_ParserFree(parser);
+    parser = nullptr;
+  }
+  return true;
+}
+
+size_t ContainerParser::write(const uint8_t data) { return write(&data, 1); }
+
+size_t ContainerParser::write(const uint8_t* buffer, const size_t size) {
+  if (!parser) return 0;
+
+  const uint8_t* currentBufferPos = buffer;
+  auto remainingInBuffer = size;
+
+  while (remainingInBuffer > 0) {
+    void* const buf = XML_GetBuffer(parser, 1024);
+    if (!buf) {
+      Serial.printf("[%lu] [CTR] Couldn't allocate buffer\n", millis());
+      return 0;
+    }
+
+    const auto toRead = remainingInBuffer < 1024 ? remainingInBuffer : 1024;
+    memcpy(buf, currentBufferPos, toRead);
+
+    if (XML_ParseBuffer(parser, static_cast<int>(toRead), remainingSize == toRead) == XML_STATUS_ERROR) {
+      Serial.printf("[%lu] [CTR] Parse error: %s\n", millis(), XML_ErrorString(XML_GetErrorCode(parser)));
+      return 0;
+    }
+
+    currentBufferPos += toRead;
+    remainingInBuffer -= toRead;
+    remainingSize -= toRead;
+  }
+  return size;
+}
+
+void XMLCALL ContainerParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
+  auto* self = static_cast<ContainerParser*>(userData);
+
+  // Simple state tracking to ensure we are looking at the valid schema structure
+  if (self->state == START && strcmp(name, "container") == 0) {
+    self->state = IN_CONTAINER;
+    return;
+  }
+
+  if (self->state == IN_CONTAINER && strcmp(name, "rootfiles") == 0) {
+    self->state = IN_ROOTFILES;
+    return;
+  }
+
+  if (self->state == IN_ROOTFILES && strcmp(name, "rootfile") == 0) {
+    const char* mediaType = nullptr;
+    const char* path = nullptr;
+
+    for (int i = 0; atts[i]; i += 2) {
+      if (strcmp(atts[i], "media-type") == 0) {
+        mediaType = atts[i + 1];
+      } else if (strcmp(atts[i], "full-path") == 0) {
+        path = atts[i + 1];
+      }
+    }
+
+    // Check if this is the standard OEBPS package
+    if (mediaType && path && strcmp(mediaType, "application/oebps-package+xml") == 0) {
+      self->fullPath = path;
+    }
+  }
+}
+
+void XMLCALL ContainerParser::endElement(void* userData, const XML_Char* name) {
+  auto* self = static_cast<ContainerParser*>(userData);
+
+  if (self->state == IN_ROOTFILES && strcmp(name, "rootfiles") == 0) {
+    self->state = IN_CONTAINER;
+  } else if (self->state == IN_CONTAINER && strcmp(name, "container") == 0) {
+    self->state = START;
+  }
+}

lib/Epub/Epub/parsers/ContainerParser.h

@@ -0,0 +1,32 @@
+#pragma once
+#include <Print.h>
+
+#include <string>
+
+#include "expat.h"
+
+class ContainerParser final : public Print {
+  enum ParserState {
+    START,
+    IN_CONTAINER,
+    IN_ROOTFILES,
+  };
+
+  size_t remainingSize;
+  XML_Parser parser = nullptr;
+  ParserState state = START;
+
+  static void startElement(void* userData, const XML_Char* name, const XML_Char** atts);
+  static void endElement(void* userData, const XML_Char* name);
+
+ public:
+  std::string fullPath;
+
+  explicit ContainerParser(const size_t xmlSize) : remainingSize(xmlSize) {}
+
+  bool setup();
+  bool teardown();
+
+  size_t write(uint8_t) override;
+  size_t write(const uint8_t* buffer, size_t size) override;
+};

lib/Epub/Epub/parsers/ContentOpfParser.cpp

@@ -0,0 +1,161 @@
+#include "ContentOpfParser.h"
+
+#include <HardwareSerial.h>
+#include <ZipFile.h>
+
+bool ContentOpfParser::setup() {
+  parser = XML_ParserCreate(nullptr);
+  if (!parser) {
+    Serial.printf("[%lu] [COF] Couldn't allocate memory for parser\n", millis());
+    return false;
+  }
+
+  XML_SetUserData(parser, this);
+  XML_SetElementHandler(parser, startElement, endElement);
+  XML_SetCharacterDataHandler(parser, characterData);
+  return true;
+}
+
+bool ContentOpfParser::teardown() {
+  if (parser) {
+    XML_ParserFree(parser);
+    parser = nullptr;
+  }
+  return true;
+}
+
+size_t ContentOpfParser::write(const uint8_t data) { return write(&data, 1); }
+
+size_t ContentOpfParser::write(const uint8_t* buffer, const size_t size) {
+  if (!parser) return 0;
+
+  const uint8_t* currentBufferPos = buffer;
+  auto remainingInBuffer = size;
+
+  while (remainingInBuffer > 0) {
+    void* const buf = XML_GetBuffer(parser, 1024);
+
+    if (!buf) {
+      Serial.printf("[%lu] [COF] Couldn't allocate memory for buffer\n", millis());
+      XML_ParserFree(parser);
+      parser = nullptr;
+      return 0;
+    }
+
+    const auto toRead = remainingInBuffer < 1024 ? remainingInBuffer : 1024;
+    memcpy(buf, currentBufferPos, toRead);
+
+    if (XML_ParseBuffer(parser, static_cast<int>(toRead), remainingSize == toRead) == XML_STATUS_ERROR) {
+      Serial.printf("[%lu] [COF] Parse error at line %lu: %s\n", millis(), XML_GetCurrentLineNumber(parser),
+                    XML_ErrorString(XML_GetErrorCode(parser)));
+      XML_ParserFree(parser);
+      parser = nullptr;
+      return 0;
+    }
+
+    currentBufferPos += toRead;
+    remainingInBuffer -= toRead;
+    remainingSize -= toRead;
+  }
+
+  return size;
+}
+
+void XMLCALL ContentOpfParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
+  auto* self = static_cast<ContentOpfParser*>(userData);
+  (void)atts;
+
+  if (self->state == START && (strcmp(name, "package") == 0 || strcmp(name, "opf:package") == 0)) {
+    self->state = IN_PACKAGE;
+    return;
+  }
+
+  if (self->state == IN_PACKAGE && (strcmp(name, "metadata") == 0 || strcmp(name, "opf:metadata") == 0)) {
+    self->state = IN_METADATA;
+    return;
+  }
+
+  if (self->state == IN_METADATA && strcmp(name, "dc:title") == 0) {
+    self->state = IN_BOOK_TITLE;
+    return;
+  }
+
+  if (self->state == IN_PACKAGE && (strcmp(name, "manifest") == 0 || strcmp(name, "opf:manifest") == 0)) {
+    self->state = IN_MANIFEST;
+    return;
+  }
+
+  if (self->state == IN_PACKAGE && (strcmp(name, "spine") == 0 || strcmp(name, "opf:spine") == 0)) {
+    self->state = IN_SPINE;
+    return;
+  }
+
+  // TODO: Support book cover
+  // if (self->state == IN_METADATA && (strcmp(name, "meta") == 0 || strcmp(name, "opf:meta") == 0)) {
+  // }
+
+  if (self->state == IN_MANIFEST && (strcmp(name, "item") == 0 || strcmp(name, "opf:item") == 0)) {
+    std::string itemId;
+    std::string href;
+
+    for (int i = 0; atts[i]; i += 2) {
+      if (strcmp(atts[i], "id") == 0) {
+        itemId = atts[i + 1];
+      } else if (strcmp(atts[i], "href") == 0) {
+        href = self->baseContentPath + atts[i + 1];
+      }
+    }
+
+    self->items[itemId] = href;
+    return;
+  }
+
+  if (self->state == IN_SPINE && (strcmp(name, "itemref") == 0 || strcmp(name, "opf:itemref") == 0)) {
+    for (int i = 0; atts[i]; i += 2) {
+      if (strcmp(atts[i], "idref") == 0) {
+        self->spineRefs.emplace_back(atts[i + 1]);
+        break;
+      }
+    }
+    return;
+  }
+}
+
+void XMLCALL ContentOpfParser::characterData(void* userData, const XML_Char* s, const int len) {
+  auto* self = static_cast<ContentOpfParser*>(userData);
+
+  if (self->state == IN_BOOK_TITLE) {
+    self->title.append(s, len);
+    return;
+  }
+}
+
+void XMLCALL ContentOpfParser::endElement(void* userData, const XML_Char* name) {
+  auto* self = static_cast<ContentOpfParser*>(userData);
+  (void)name;
+
+  if (self->state == IN_SPINE && (strcmp(name, "spine") == 0 || strcmp(name, "opf:spine") == 0)) {
+    self->state = IN_PACKAGE;
+    return;
+  }
+
+  if (self->state == IN_MANIFEST && (strcmp(name, "manifest") == 0 || strcmp(name, "opf:manifest") == 0)) {
+    self->state = IN_PACKAGE;
+    return;
+  }
+
+  if (self->state == IN_BOOK_TITLE && strcmp(name, "dc:title") == 0) {
+    self->state = IN_METADATA;
+    return;
+  }
+
+  if (self->state == IN_METADATA && (strcmp(name, "metadata") == 0 || strcmp(name, "opf:metadata") == 0)) {
+    self->state = IN_PACKAGE;
+    return;
+  }
+
+  if (self->state == IN_PACKAGE && (strcmp(name, "package") == 0 || strcmp(name, "opf:package") == 0)) {
+    self->state = START;
+    return;
+  }
+}

lib/Epub/Epub/parsers/ContentOpfParser.h

@@ -0,0 +1,42 @@
+#pragma once
+#include <Print.h>
+
+#include <map>
+
+#include "Epub.h"
+#include "expat.h"
+
+class ContentOpfParser final : public Print {
+  enum ParserState {
+    START,
+    IN_PACKAGE,
+    IN_METADATA,
+    IN_BOOK_TITLE,
+    IN_MANIFEST,
+    IN_SPINE,
+  };
+
+  const std::string& baseContentPath;
+  size_t remainingSize;
+  XML_Parser parser = nullptr;
+  ParserState state = START;
+
+  static void startElement(void* userData, const XML_Char* name, const XML_Char** atts);
+  static void characterData(void* userData, const XML_Char* s, int len);
+  static void endElement(void* userData, const XML_Char* name);
+
+ public:
+  std::string title;
+  std::string tocNcxPath;
+  std::map<std::string, std::string> items;
+  std::vector<std::string> spineRefs;
+
+  explicit ContentOpfParser(const std::string& baseContentPath, const size_t xmlSize)
+      : baseContentPath(baseContentPath), remainingSize(xmlSize) {}
+
+  bool setup();
+  bool teardown();
+
+  size_t write(uint8_t) override;
+  size_t write(const uint8_t* buffer, size_t size) override;
+};

lib/Epub/Epub/parsers/TocNcxParser.cpp

@@ -0,0 +1,165 @@
+#include "TocNcxParser.h"
+
+#include <HardwareSerial.h>
+
+bool TocNcxParser::setup() {
+  parser = XML_ParserCreate(nullptr);
+  if (!parser) {
+    Serial.printf("[%lu] [TOC] Couldn't allocate memory for parser\n", millis());
+    return false;
+  }
+
+  XML_SetUserData(parser, this);
+  XML_SetElementHandler(parser, startElement, endElement);
+  XML_SetCharacterDataHandler(parser, characterData);
+  return true;
+}
+
+bool TocNcxParser::teardown() {
+  if (parser) {
+    XML_ParserFree(parser);
+    parser = nullptr;
+  }
+  return true;
+}
+
+size_t TocNcxParser::write(const uint8_t data) { return write(&data, 1); }
+
+size_t TocNcxParser::write(const uint8_t* buffer, const size_t size) {
+  if (!parser) return 0;
+
+  const uint8_t* currentBufferPos = buffer;
+  auto remainingInBuffer = size;
+
+  while (remainingInBuffer > 0) {
+    void* const buf = XML_GetBuffer(parser, 1024);
+    if (!buf) {
+      Serial.printf("[%lu] [TOC] Couldn't allocate memory for buffer\n", millis());
+      return 0;
+    }
+
+    const auto toRead = remainingInBuffer < 1024 ? remainingInBuffer : 1024;
+    memcpy(buf, currentBufferPos, toRead);
+
+    if (XML_ParseBuffer(parser, static_cast<int>(toRead), remainingSize == toRead) == XML_STATUS_ERROR) {
+      Serial.printf("[%lu] [TOC] Parse error at line %lu: %s\n", millis(), XML_GetCurrentLineNumber(parser),
+                    XML_ErrorString(XML_GetErrorCode(parser)));
+      return 0;
+    }
+
+    currentBufferPos += toRead;
+    remainingInBuffer -= toRead;
+    remainingSize -= toRead;
+  }
+  return size;
+}
+
+void XMLCALL TocNcxParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
+  // NOTE: We rely on navPoint label and content coming before any nested navPoints, this will be fine:
+  // <navPoint>
+  //   <navLabel><text>Chapter 1</text></navLabel>
+  //   <content src="ch1.html"/>
+  //   <navPoint> ...nested... </navPoint>
+  // </navPoint>
+  //
+  // This will NOT:
+  // <navPoint>
+  //   <navPoint> ...nested... </navPoint>
+  //   <navLabel><text>Chapter 1</text></navLabel>
+  //   <content src="ch1.html"/>
+  // </navPoint>
+
+  auto* self = static_cast<TocNcxParser*>(userData);
+
+  if (self->state == START && strcmp(name, "ncx") == 0) {
+    self->state = IN_NCX;
+    return;
+  }
+
+  if (self->state == IN_NCX && strcmp(name, "navMap") == 0) {
+    self->state = IN_NAV_MAP;
+    return;
+  }
+
+  // Handles both top-level and nested navPoints
+  if ((self->state == IN_NAV_MAP || self->state == IN_NAV_POINT) && strcmp(name, "navPoint") == 0) {
+    self->state = IN_NAV_POINT;
+    self->currentDepth++;
+
+    self->currentLabel.clear();
+    self->currentSrc.clear();
+    return;
+  }
+
+  if (self->state == IN_NAV_POINT && strcmp(name, "navLabel") == 0) {
+    self->state = IN_NAV_LABEL;
+    return;
+  }
+
+  if (self->state == IN_NAV_LABEL && strcmp(name, "text") == 0) {
+    self->state = IN_NAV_LABEL_TEXT;
+    return;
+  }
+
+  if (self->state == IN_NAV_POINT && strcmp(name, "content") == 0) {
+    for (int i = 0; atts[i]; i += 2) {
+      if (strcmp(atts[i], "src") == 0) {
+        self->currentSrc = atts[i + 1];
+        break;
+      }
+    }
+    return;
+  }
+}
+
+void XMLCALL TocNcxParser::characterData(void* userData, const XML_Char* s, const int len) {
+  auto* self = static_cast<TocNcxParser*>(userData);
+  if (self->state == IN_NAV_LABEL_TEXT) {
+    self->currentLabel.append(s, len);
+  }
+}
+
+void XMLCALL TocNcxParser::endElement(void* userData, const XML_Char* name) {
+  auto* self = static_cast<TocNcxParser*>(userData);
+
+  if (self->state == IN_NAV_LABEL_TEXT && strcmp(name, "text") == 0) {
+    self->state = IN_NAV_LABEL;
+    return;
+  }
+
+  if (self->state == IN_NAV_LABEL && strcmp(name, "navLabel") == 0) {
+    self->state = IN_NAV_POINT;
+    return;
+  }
+
+  if (self->state == IN_NAV_POINT && strcmp(name, "navPoint") == 0) {
+    self->currentDepth--;
+    if (self->currentDepth == 0) {
+      self->state = IN_NAV_MAP;
+    }
+    return;
+  }
+
+  if (self->state == IN_NAV_POINT && strcmp(name, "content") == 0) {
+    // At this point (end of content tag), we likely have both Label (from previous tags) and Src.
+    // This is the safest place to push the data, assuming <navLabel> always comes before <content>.
+    // NCX spec says navLabel comes before content.
+    if (!self->currentLabel.empty() && !self->currentSrc.empty()) {
+      std::string href = self->baseContentPath + self->currentSrc;
+      std::string anchor;
+
+      const size_t pos = href.find('#');
+      if (pos != std::string::npos) {
+        anchor = href.substr(pos + 1);
+        href = href.substr(0, pos);
+      }
+
+      // Push to vector
+      self->toc.emplace_back(self->currentLabel, href, anchor, self->currentDepth);
+
+      // Clear them so we don't re-add them if there are weird XML structures
+      self->currentLabel.clear();
+      self->currentSrc.clear();
+    }
+  }
+}

lib/Epub/Epub/parsers/TocNcxParser.h

@@ -0,0 +1,37 @@
+#pragma once
+#include <Print.h>
+
+#include <string>
+#include <vector>
+
+#include "Epub/EpubTocEntry.h"
+#include "expat.h"
+
+class TocNcxParser final : public Print {
+  enum ParserState { START, IN_NCX, IN_NAV_MAP, IN_NAV_POINT, IN_NAV_LABEL, IN_NAV_LABEL_TEXT, IN_CONTENT };
+
+  const std::string& baseContentPath;
+  size_t remainingSize;
+  XML_Parser parser = nullptr;
+  ParserState state = START;
+
+  std::string currentLabel;
+  std::string currentSrc;
+  size_t currentDepth = 0;
+
+  static void startElement(void* userData, const XML_Char* name, const XML_Char** atts);
+  static void characterData(void* userData, const XML_Char* s, int len);
+  static void endElement(void* userData, const XML_Char* name);
+
+ public:
+  std::vector<EpubTocEntry> toc;
+
+  explicit TocNcxParser(const std::string& baseContentPath, const size_t xmlSize)
+      : baseContentPath(baseContentPath), remainingSize(xmlSize) {}
+
+  bool setup();
+  bool teardown();
+
+  size_t write(uint8_t) override;
+  size_t write(const uint8_t* buffer, size_t size) override;
+};

lib/GfxRenderer/GfxRenderer.cpp

@@ -162,8 +162,12 @@ int GfxRenderer::getLineHeight(const int fontId) const {
   return fontMap.at(fontId).getData(REGULAR)->advanceY;
 }
 
+uint8_t* GfxRenderer::getFrameBuffer() const { return einkDisplay.getFrameBuffer(); }
+
 void GfxRenderer::swapBuffers() const { einkDisplay.swapBuffers(); }
 
+void GfxRenderer::grayscaleRevert() const { einkDisplay.grayscaleRevert(); }
+
 void GfxRenderer::copyGrayscaleLsbBuffers() const { einkDisplay.copyGrayscaleLsbBuffers(einkDisplay.getFrameBuffer()); }
 
 void GfxRenderer::copyGrayscaleMsbBuffers() const { einkDisplay.copyGrayscaleMsbBuffers(einkDisplay.getFrameBuffer()); }

lib/GfxRenderer/GfxRenderer.h

@@ -1,11 +1,10 @@
 #pragma once
 
 #include <EInkDisplay.h>
+#include <EpdFontFamily.h>
 
 #include <map>
 
-#include "EpdFontFamily.h"
-
 class GfxRenderer {
  public:
   enum FontRenderMode { BW, GRAYSCALE_LSB, GRAYSCALE_MSB };
@@ -47,7 +46,9 @@ class GfxRenderer {
   int getLineHeight(int fontId) const;
 
   // Low level functions
+  uint8_t* getFrameBuffer() const;
   void swapBuffers() const;
+  void grayscaleRevert() const;
   void copyGrayscaleLsbBuffers() const;
   void copyGrayscaleMsbBuffers() const;
   void displayGrayBuffer() const;

lib/ZipFile/ZipFile.cpp

@@ -40,7 +40,7 @@ bool ZipFile::loadFileStat(const char* filename, mz_zip_archive_file_stat* fileS
   // find the file
   mz_uint32 fileIndex = 0;
   if (!mz_zip_reader_locate_file_v2(&zipArchive, filename, nullptr, 0, &fileIndex)) {
-    Serial.printf("[%lu] [ZIP] Could not find file %s\n", millis, filename);
+    Serial.printf("[%lu] [ZIP] Could not find file %s\n", millis(), filename);
     mz_zip_reader_end(&zipArchive);
     return false;
   }
@@ -82,6 +82,16 @@ long ZipFile::getDataOffset(const mz_zip_archive_file_stat& fileStat) const {
   return fileOffset + localHeaderSize + filenameLength + extraOffset;
 }
 
+bool ZipFile::getInflatedFileSize(const char* filename, size_t* size) const {
+  mz_zip_archive_file_stat fileStat;
+  if (!loadFileStat(filename, &fileStat)) {
+    return false;
+  }
+
+  *size = static_cast<size_t>(fileStat.m_uncomp_size);
+  return true;
+}
+
 uint8_t* ZipFile::readFileToMemory(const char* filename, size_t* size, const bool trailingNullByte) const {
   mz_zip_archive_file_stat fileStat;
   if (!loadFileStat(filename, &fileStat)) {
@@ -268,7 +278,14 @@ bool ZipFile::readFileToStream(const char* filename, Print& out, const size_t ch
       // Write output chunk
       if (outBytes > 0) {
         processedOutputBytes += outBytes;
-        out.write(outputBuffer + outputCursor, outBytes);
+        if (out.write(outputBuffer + outputCursor, outBytes) != outBytes) {
+          Serial.printf("[%lu] [ZIP] Failed to write all output bytes to stream\n", millis());
+          fclose(file);
+          free(outputBuffer);
+          free(fileReadBuffer);
+          free(inflator);
+          return false;
+        }
         // Update output position in buffer (with wraparound)
         outputCursor = (outputCursor + outBytes) & (TINFL_LZ_DICT_SIZE - 1);
       }

lib/ZipFile/ZipFile.h

@@ -14,6 +14,7 @@ class ZipFile {
  public:
   explicit ZipFile(std::string filePath) : filePath(std::move(filePath)) {}
   ~ZipFile() = default;
+  bool getInflatedFileSize(const char* filename, size_t* size) const;
   uint8_t* readFileToMemory(const char* filename, size_t* size = nullptr, bool trailingNullByte = false) const;
   bool readFileToStream(const char* filename, Print& out, size_t chunkSize) const;
 };

platformio.ini

@@ -1,5 +1,5 @@
 [platformio]
-crosspoint_version = 0.3.0
+crosspoint_version = 0.5.1
 default_envs = default
 
 [base]
@@ -20,6 +20,7 @@ build_flags =
 # https://libexpat.github.io/doc/api/latest/#XML_GE
   -DXML_GE=0
   -DXML_CONTEXT_BYTES=1024
+  -std=c++2a
 
 ; Board configuration
 board_build.flash_mode = dio
@@ -28,7 +29,6 @@ board_build.partitions = partitions.csv
 
 ; Libraries
 lib_deps =
-  https://github.com/leethomason/tinyxml2.git#11.0.0
   BatteryMonitor=symlink://open-x4-sdk/libs/hardware/BatteryMonitor
   InputManager=symlink://open-x4-sdk/libs/hardware/InputManager
   EInkDisplay=symlink://open-x4-sdk/libs/display/EInkDisplay

src/config.h

@@ -23,7 +23,7 @@
 /**
  * Generated with:
  *  ruby -rdigest -e 'puts [
- *    "./lib/EpdFont/builtinFonts/babyblue.h",
+ *    "./lib/EpdFont/builtinFonts/pixelarial14.h",
  *  ].map{|f| Digest::SHA256.hexdigest(File.read(f)).to_i(16) }.sum % (2 ** 32) - (2 ** 31)'
  */
-#define SMALL_FONT_ID 141891058
+#define SMALL_FONT_ID 2037928017

src/main.cpp

@@ -5,16 +5,16 @@
 #include <InputManager.h>
 #include <SD.h>
 #include <SPI.h>
+#include <builtinFonts/bookerly_2b.h>
+#include <builtinFonts/bookerly_bold_2b.h>
+#include <builtinFonts/bookerly_bold_italic_2b.h>
+#include <builtinFonts/bookerly_italic_2b.h>
+#include <builtinFonts/pixelarial14.h>
+#include <builtinFonts/ubuntu_10.h>
+#include <builtinFonts/ubuntu_bold_10.h>
 
 #include "Battery.h"
 #include "CrossPointState.h"
-#include "builtinFonts/babyblue.h"
-#include "builtinFonts/bookerly_2b.h"
-#include "builtinFonts/bookerly_bold_2b.h"
-#include "builtinFonts/bookerly_bold_italic_2b.h"
-#include "builtinFonts/bookerly_italic_2b.h"
-#include "builtinFonts/ubuntu_10.h"
-#include "builtinFonts/ubuntu_bold_10.h"
 #include "config.h"
 #include "screens/BootLogoScreen.h"
 #include "screens/EpubReaderScreen.h"
@@ -49,7 +49,7 @@ EpdFont bookerlyItalicFont(&bookerly_italic_2b);
 EpdFont bookerlyBoldItalicFont(&bookerly_bold_italic_2b);
 EpdFontFamily bookerlyFontFamily(&bookerlyFont, &bookerlyBoldFont, &bookerlyItalicFont, &bookerlyBoldItalicFont);
 
-EpdFont smallFont(&babyblue);
+EpdFont smallFont(&pixelarial14);
 EpdFontFamily smallFontFamily(&smallFont);
 
 EpdFont ubuntu10Font(&ubuntu_10);
@@ -62,19 +62,18 @@ constexpr unsigned long POWER_BUTTON_WAKEUP_MS = 1000;
 // Time required to enter sleep mode
 constexpr unsigned long POWER_BUTTON_SLEEP_MS = 1000;
 
-Epub* loadEpub(const std::string& path) {
+std::unique_ptr<Epub> loadEpub(const std::string& path) {
   if (!SD.exists(path.c_str())) {
     Serial.printf("[%lu] [   ] File does not exist: %s\n", millis(), path.c_str());
     return nullptr;
   }
 
-  const auto epub = new Epub(path, "/.crosspoint");
+  auto epub = std::unique_ptr<Epub>(new Epub(path, "/.crosspoint"));
   if (epub->load()) {
     return epub;
   }
 
   Serial.printf("[%lu] [   ] Failed to load epub\n", millis());
-  delete epub;
   return nullptr;
 }
 
@@ -151,12 +150,12 @@ void onSelectEpubFile(const std::string& path) {
   exitScreen();
   enterNewScreen(new FullScreenMessageScreen(renderer, inputManager, "Loading..."));
 
-  Epub* epub = loadEpub(path);
+  auto epub = loadEpub(path);
   if (epub) {
     appState.openEpubPath = path;
     appState.saveToFile();
     exitScreen();
-    enterNewScreen(new EpubReaderScreen(renderer, inputManager, epub, onGoHome));
+    enterNewScreen(new EpubReaderScreen(renderer, inputManager, std::move(epub), onGoHome));
   } else {
     exitScreen();
     enterNewScreen(
@@ -172,11 +171,7 @@ void onGoHome() {
 }
 
 void setup() {
-  // Begin serial only if USB connected
+  Serial.begin(115200);
-  pinMode(UART0_RXD, INPUT);
-  if (digitalRead(UART0_RXD) == HIGH) {
-    Serial.begin(115200);
-  }
 
   Serial.printf("[%lu] [   ] Starting CrossPoint version " CROSSPOINT_VERSION "\n", millis());
 
@@ -206,10 +201,10 @@ void setup() {
 
   appState.loadFromFile();
   if (!appState.openEpubPath.empty()) {
-    Epub* epub = loadEpub(appState.openEpubPath);
+    auto epub = loadEpub(appState.openEpubPath);
     if (epub) {
       exitScreen();
-      enterNewScreen(new EpubReaderScreen(renderer, inputManager, epub, onGoHome));
+      enterNewScreen(new EpubReaderScreen(renderer, inputManager, std::move(epub), onGoHome));
       // Ensure we're not still holding the power button before leaving setup
       waitForPowerRelease();
       return;

src/screens/EpubReaderChapterSelectionScreen.cpp

@@ -0,0 +1,107 @@
+#include "EpubReaderChapterSelectionScreen.h"
+
+#include <GfxRenderer.h>
+#include <SD.h>
+
+#include "config.h"
+
+constexpr int PAGE_ITEMS = 24;
+constexpr int SKIP_PAGE_MS = 700;
+
+void EpubReaderChapterSelectionScreen::taskTrampoline(void* param) {
+  auto* self = static_cast<EpubReaderChapterSelectionScreen*>(param);
+  self->displayTaskLoop();
+}
+
+void EpubReaderChapterSelectionScreen::onEnter() {
+  if (!epub) {
+    return;
+  }
+
+  renderingMutex = xSemaphoreCreateMutex();
+  selectorIndex = currentSpineIndex;
+
+  // Trigger first update
+  updateRequired = true;
+  xTaskCreate(&EpubReaderChapterSelectionScreen::taskTrampoline, "EpubReaderChapterSelectionScreenTask",
+              2048,               // Stack size
+              this,               // Parameters
+              1,                  // Priority
+              &displayTaskHandle  // Task handle
+  );
+}
+
+void EpubReaderChapterSelectionScreen::onExit() {
+  // Wait until not rendering to delete task to avoid killing mid-instruction to EPD
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+  if (displayTaskHandle) {
+    vTaskDelete(displayTaskHandle);
+    displayTaskHandle = nullptr;
+  }
+  vSemaphoreDelete(renderingMutex);
+  renderingMutex = nullptr;
+}
+
+void EpubReaderChapterSelectionScreen::handleInput() {
+  const bool prevReleased =
+      inputManager.wasReleased(InputManager::BTN_UP) || inputManager.wasReleased(InputManager::BTN_LEFT);
+  const bool nextReleased =
+      inputManager.wasReleased(InputManager::BTN_DOWN) || inputManager.wasReleased(InputManager::BTN_RIGHT);
+
+  const bool skipPage = inputManager.getHeldTime() > SKIP_PAGE_MS;
+
+  if (inputManager.wasPressed(InputManager::BTN_CONFIRM)) {
+    onSelectSpineIndex(selectorIndex);
+  } else if (inputManager.wasPressed(InputManager::BTN_BACK)) {
+    onGoBack();
+  } else if (prevReleased) {
+    if (skipPage) {
+      selectorIndex =
+          ((selectorIndex / PAGE_ITEMS - 1) * PAGE_ITEMS + epub->getSpineItemsCount()) % epub->getSpineItemsCount();
+    } else {
+      selectorIndex = (selectorIndex + epub->getSpineItemsCount() - 1) % epub->getSpineItemsCount();
+    }
+    updateRequired = true;
+  } else if (nextReleased) {
+    if (skipPage) {
+      selectorIndex = ((selectorIndex / PAGE_ITEMS + 1) * PAGE_ITEMS) % epub->getSpineItemsCount();
+    } else {
+      selectorIndex = (selectorIndex + 1) % epub->getSpineItemsCount();
+    }
+    updateRequired = true;
+  }
+}
+
+void EpubReaderChapterSelectionScreen::displayTaskLoop() {
+  while (true) {
+    if (updateRequired) {
+      updateRequired = false;
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      renderScreen();
+      xSemaphoreGive(renderingMutex);
+    }
+    vTaskDelay(10 / portTICK_PERIOD_MS);
+  }
+}
+
+void EpubReaderChapterSelectionScreen::renderScreen() {
+  renderer.clearScreen();
+
+  const auto pageWidth = renderer.getScreenWidth();
+  renderer.drawCenteredText(READER_FONT_ID, 10, "Select Chapter", true, BOLD);
+
+  const auto pageStartIndex = selectorIndex / PAGE_ITEMS * PAGE_ITEMS;
+  renderer.fillRect(0, 60 + (selectorIndex % PAGE_ITEMS) * 30 + 2, pageWidth - 1, 30);
+  for (int i = pageStartIndex; i < epub->getSpineItemsCount() && i < pageStartIndex + PAGE_ITEMS; i++) {
+    const int tocIndex = epub->getTocIndexForSpineIndex(i);
+    if (tocIndex == -1) {
+      renderer.drawText(UI_FONT_ID, 20, 60 + (i % PAGE_ITEMS) * 30, "Unnamed", i != selectorIndex);
+    } else {
+      auto item = epub->getTocItem(tocIndex);
+      renderer.drawText(UI_FONT_ID, 20 + (item.level - 1) * 15, 60 + (i % PAGE_ITEMS) * 30, item.title.c_str(),
+                        i != selectorIndex);
+    }
+  }
+
+  renderer.displayBuffer();
+}

src/screens/EpubReaderChapterSelectionScreen.h

@@ -0,0 +1,38 @@
+#pragma once
+#include <Epub.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <memory>
+
+#include "Screen.h"
+
+class EpubReaderChapterSelectionScreen final : public Screen {
+  std::shared_ptr<Epub> epub;
+  TaskHandle_t displayTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+  int currentSpineIndex = 0;
+  int selectorIndex = 0;
+  bool updateRequired = false;
+  const std::function<void()> onGoBack;
+  const std::function<void(int newSpineIndex)> onSelectSpineIndex;
+
+  static void taskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+  void renderScreen();
+
+ public:
+  explicit EpubReaderChapterSelectionScreen(GfxRenderer& renderer, InputManager& inputManager,
+                                            const std::shared_ptr<Epub>& epub, const int currentSpineIndex,
+                                            const std::function<void()>& onGoBack,
+                                            const std::function<void(int newSpineIndex)>& onSelectSpineIndex)
+      : Screen(renderer, inputManager),
+        epub(epub),
+        currentSpineIndex(currentSpineIndex),
+        onGoBack(onGoBack),
+        onSelectSpineIndex(onSelectSpineIndex) {}
+  void onEnter() override;
+  void onExit() override;
+  void handleInput() override;
+};

src/screens/EpubReaderScreen.cpp

@@ -5,14 +5,15 @@
 #include <SD.h>
 
 #include "Battery.h"
+#include "EpubReaderChapterSelectionScreen.h"
 #include "config.h"
 
 constexpr int PAGES_PER_REFRESH = 15;
 constexpr unsigned long SKIP_CHAPTER_MS = 700;
 constexpr float lineCompression = 0.95f;
-constexpr int marginTop = 11;
+constexpr int marginTop = 8;
 constexpr int marginRight = 10;
-constexpr int marginBottom = 30;
+constexpr int marginBottom = 22;
 constexpr int marginLeft = 10;
 
 void EpubReaderScreen::taskTrampoline(void* param) {
@@ -60,13 +61,42 @@ void EpubReaderScreen::onExit() {
   }
   vSemaphoreDelete(renderingMutex);
   renderingMutex = nullptr;
-  delete section;
+  section.reset();
-  section = nullptr;
+  epub.reset();
-  delete epub;
-  epub = nullptr;
 }
 
 void EpubReaderScreen::handleInput() {
+  // Pass input responsibility to sub screen if exists
+  if (subScreen) {
+    subScreen->handleInput();
+    return;
+  }
+
+  // Enter chapter selection screen
+  if (inputManager.wasPressed(InputManager::BTN_CONFIRM)) {
+    // Don't start screen transition while rendering
+    xSemaphoreTake(renderingMutex, portMAX_DELAY);
+    subScreen.reset(new EpubReaderChapterSelectionScreen(
+        this->renderer, this->inputManager, epub, currentSpineIndex,
+        [this] {
+          subScreen->onExit();
+          subScreen.reset();
+          updateRequired = true;
+        },
+        [this](const int newSpineIndex) {
+          if (currentSpineIndex != newSpineIndex) {
+            currentSpineIndex = newSpineIndex;
+            nextPageNumber = 0;
+            section.reset();
+          }
+          subScreen->onExit();
+          subScreen.reset();
+          updateRequired = true;
+        }));
+    subScreen->onEnter();
+    xSemaphoreGive(renderingMutex);
+  }
+
   if (inputManager.wasPressed(InputManager::BTN_BACK)) {
     onGoHome();
     return;
@@ -81,6 +111,14 @@ void EpubReaderScreen::handleInput() {
     return;
   }
 
+  // any botton press when at end of the book goes back to the last page
+  if (currentSpineIndex > 0 && currentSpineIndex >= epub->getSpineItemsCount()) {
+    currentSpineIndex = epub->getSpineItemsCount() - 1;
+    nextPageNumber = UINT16_MAX;
+    updateRequired = true;
+    return;
+  }
+
   const bool skipChapter = inputManager.getHeldTime() > SKIP_CHAPTER_MS;
 
   if (skipChapter) {
@@ -88,8 +126,7 @@ void EpubReaderScreen::handleInput() {
     xSemaphoreTake(renderingMutex, portMAX_DELAY);
     nextPageNumber = 0;
     currentSpineIndex = nextReleased ? currentSpineIndex + 1 : currentSpineIndex - 1;
-    delete section;
+    section.reset();
-    section = nullptr;
     xSemaphoreGive(renderingMutex);
     updateRequired = true;
     return;
@@ -109,8 +146,7 @@ void EpubReaderScreen::handleInput() {
       xSemaphoreTake(renderingMutex, portMAX_DELAY);
       nextPageNumber = UINT16_MAX;
       currentSpineIndex--;
-      delete section;
+      section.reset();
-      section = nullptr;
       xSemaphoreGive(renderingMutex);
     }
     updateRequired = true;
@@ -122,8 +158,7 @@ void EpubReaderScreen::handleInput() {
       xSemaphoreTake(renderingMutex, portMAX_DELAY);
       nextPageNumber = 0;
       currentSpineIndex++;
-      delete section;
+      section.reset();
-      section = nullptr;
       xSemaphoreGive(renderingMutex);
     }
     updateRequired = true;
@@ -148,14 +183,27 @@ void EpubReaderScreen::renderScreen() {
     return;
   }
 
-  if (currentSpineIndex >= epub->getSpineItemsCount() || currentSpineIndex < 0) {
+  // edge case handling for sub-zero spine index
+  if (currentSpineIndex < 0) {
     currentSpineIndex = 0;
   }
+  // based bounds of book, show end of book screen
+  if (currentSpineIndex > epub->getSpineItemsCount()) {
+    currentSpineIndex = epub->getSpineItemsCount();
+  }
+
+  // Show end of book screen
+  if (currentSpineIndex == epub->getSpineItemsCount()) {
+    renderer.clearScreen();
+    renderer.drawCenteredText(READER_FONT_ID, 300, "End of book", true, BOLD);
+    renderer.displayBuffer();
+    return;
+  }
 
   if (!section) {
     const auto filepath = epub->getSpineItem(currentSpineIndex);
     Serial.printf("[%lu] [ERS] Loading file: %s, index: %d\n", millis(), filepath.c_str(), currentSpineIndex);
-    section = new Section(epub, currentSpineIndex, renderer);
+    section = std::unique_ptr<Section>(new Section(epub, currentSpineIndex, renderer));
     if (!section->loadCacheMetadata(READER_FONT_ID, lineCompression, marginTop, marginRight, marginBottom,
                                     marginLeft)) {
       Serial.printf("[%lu] [ERS] Cache not found, building...\n", millis());
@@ -167,7 +215,10 @@ void EpubReaderScreen::renderScreen() {
         constexpr int y = 50;
         const int w = textWidth + margin * 2;
         const int h = renderer.getLineHeight(READER_FONT_ID) + margin * 2;
+        renderer.grayscaleRevert();
+        uint8_t* fb1 = renderer.getFrameBuffer();
         renderer.swapBuffers();
+        memcpy(fb1, renderer.getFrameBuffer(), EInkDisplay::BUFFER_SIZE);
         renderer.fillRect(x, y, w, h, 0);
         renderer.drawText(READER_FONT_ID, x + margin, y + margin, "Indexing...");
         renderer.drawRect(x + 5, y + 5, w - 10, h - 10);
@@ -179,8 +230,7 @@ void EpubReaderScreen::renderScreen() {
       if (!section->persistPageDataToSD(READER_FONT_ID, lineCompression, marginTop, marginRight, marginBottom,
                                         marginLeft)) {
         Serial.printf("[%lu] [ERS] Failed to persist page data to SD\n", millis());
-        delete section;
+        section.reset();
-        section = nullptr;
         return;
       }
     } else {
@@ -212,11 +262,18 @@ void EpubReaderScreen::renderScreen() {
     return;
   }
 
-  const Page* p = section->loadPageFromSD();
+  {
-  const auto start = millis();
+    auto p = section->loadPageFromSD();
-  renderContents(p);
+    if (!p) {
-  Serial.printf("[%lu] [ERS] Rendered page in %dms\n", millis(), millis() - start);
+      Serial.printf("[%lu] [ERS] Failed to load page from SD - clearing section cache\n", millis());
-  delete p;
+      section->clearCache();
+      section.reset();
+      return renderScreen();
+    }
+    const auto start = millis();
+    renderContents(std::move(p));
+    Serial.printf("[%lu] [ERS] Rendered page in %dms\n", millis(), millis() - start);
+  }
 
   File f = SD.open((epub->getCachePath() + "/progress.bin").c_str(), FILE_WRITE);
   uint8_t data[4];
@@ -228,8 +285,8 @@ void EpubReaderScreen::renderScreen() {
   f.close();
 }
 
-void EpubReaderScreen::renderContents(const Page* p) {
+void EpubReaderScreen::renderContents(std::unique_ptr<Page> page) {
-  p->render(renderer, READER_FONT_ID);
+  page->render(renderer, READER_FONT_ID);
   renderStatusBar();
   if (pagesUntilFullRefresh <= 1) {
     renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
@@ -244,13 +301,13 @@ void EpubReaderScreen::renderContents(const Page* p) {
   {
     renderer.clearScreen(0x00);
     renderer.setFontRenderMode(GfxRenderer::GRAYSCALE_LSB);
-    p->render(renderer, READER_FONT_ID);
+    page->render(renderer, READER_FONT_ID);
     renderer.copyGrayscaleLsbBuffers();
 
     // Render and copy to MSB buffer
     renderer.clearScreen(0x00);
     renderer.setFontRenderMode(GfxRenderer::GRAYSCALE_MSB);
-    p->render(renderer, READER_FONT_ID);
+    page->render(renderer, READER_FONT_ID);
     renderer.copyGrayscaleMsbBuffers();
 
     // display grayscale part
@@ -260,17 +317,18 @@ void EpubReaderScreen::renderContents(const Page* p) {
 }
 
 void EpubReaderScreen::renderStatusBar() const {
+  constexpr auto textY = 776;
   // Right aligned text for progress counter
   const std::string progress = std::to_string(section->currentPage + 1) + " / " + std::to_string(section->pageCount);
   const auto progressTextWidth = renderer.getTextWidth(SMALL_FONT_ID, progress.c_str());
-  renderer.drawText(SMALL_FONT_ID, GfxRenderer::getScreenWidth() - marginRight - progressTextWidth, 776,
+  renderer.drawText(SMALL_FONT_ID, GfxRenderer::getScreenWidth() - marginRight - progressTextWidth, textY,
                     progress.c_str());
 
   // Left aligned battery icon and percentage
   const uint16_t percentage = battery.readPercentage();
   const auto percentageText = std::to_string(percentage) + "%";
   const auto percentageTextWidth = renderer.getTextWidth(SMALL_FONT_ID, percentageText.c_str());
-  renderer.drawText(SMALL_FONT_ID, 20 + marginLeft, 776, percentageText.c_str());
+  renderer.drawText(SMALL_FONT_ID, 20 + marginLeft, textY, percentageText.c_str());
 
   // 1 column on left, 2 columns on right, 5 columns of battery body
   constexpr int batteryWidth = 15;
@@ -286,8 +344,8 @@ void EpubReaderScreen::renderStatusBar() const {
   renderer.drawLine(x, y, x, y + batteryHeight - 1);
   // Battery end
   renderer.drawLine(x + batteryWidth - 4, y, x + batteryWidth - 4, y + batteryHeight - 1);
-  renderer.drawLine(x + batteryWidth - 3, y + 2, x + batteryWidth - 3, y + batteryHeight - 3);
+  renderer.drawLine(x + batteryWidth - 3, y + 2, x + batteryWidth - 1, y + 2);
-  renderer.drawLine(x + batteryWidth - 2, y + 2, x + batteryWidth - 2, y + batteryHeight - 3);
+  renderer.drawLine(x + batteryWidth - 3, y + batteryHeight - 3, x + batteryWidth - 1, y + batteryHeight - 3);
   renderer.drawLine(x + batteryWidth - 1, y + 2, x + batteryWidth - 1, y + batteryHeight - 3);
 
   // The +1 is to round up, so that we always fill at least one pixel
@@ -302,13 +360,22 @@ void EpubReaderScreen::renderStatusBar() const {
   const int titleMarginLeft = 20 + percentageTextWidth + 30 + marginLeft;
   const int titleMarginRight = progressTextWidth + 30 + marginRight;
   const int availableTextWidth = GfxRenderer::getScreenWidth() - titleMarginLeft - titleMarginRight;
-  const auto tocItem = epub->getTocItem(epub->getTocIndexForSpineIndex(currentSpineIndex));
+  const int tocIndex = epub->getTocIndexForSpineIndex(currentSpineIndex);
-  auto title = tocItem.title;
+
-  int titleWidth = renderer.getTextWidth(SMALL_FONT_ID, title.c_str());
+  std::string title;
-  while (titleWidth > availableTextWidth) {
+  int titleWidth;
-    title = title.substr(0, title.length() - 8) + "...";
+  if (tocIndex == -1) {
+    title = "Unnamed";
+    titleWidth = renderer.getTextWidth(SMALL_FONT_ID, "Unnamed");
+  } else {
+    const auto tocItem = epub->getTocItem(tocIndex);
+    title = tocItem.title;
     titleWidth = renderer.getTextWidth(SMALL_FONT_ID, title.c_str());
+    while (titleWidth > availableTextWidth) {
+      title = title.substr(0, title.length() - 8) + "...";
+      titleWidth = renderer.getTextWidth(SMALL_FONT_ID, title.c_str());
+    }
   }
 
-  renderer.drawText(SMALL_FONT_ID, titleMarginLeft + (availableTextWidth - titleWidth) / 2, 777, title.c_str());
+  renderer.drawText(SMALL_FONT_ID, titleMarginLeft + (availableTextWidth - titleWidth) / 2, textY, title.c_str());
 }

src/screens/EpubReaderScreen.h

@@ -8,10 +8,11 @@
 #include "Screen.h"
 
 class EpubReaderScreen final : public Screen {
-  Epub* epub;
+  std::shared_ptr<Epub> epub;
-  Section* section = nullptr;
+  std::unique_ptr<Section> section = nullptr;
   TaskHandle_t displayTaskHandle = nullptr;
   SemaphoreHandle_t renderingMutex = nullptr;
+  std::unique_ptr<Screen> subScreen = nullptr;
   int currentSpineIndex = 0;
   int nextPageNumber = 0;
   int pagesUntilFullRefresh = 0;
@@ -21,13 +22,13 @@ class EpubReaderScreen final : public Screen {
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
   void renderScreen();
-  void renderContents(const Page* p);
+  void renderContents(std::unique_ptr<Page> p);
   void renderStatusBar() const;
 
  public:
-  explicit EpubReaderScreen(GfxRenderer& renderer, InputManager& inputManager, Epub* epub,
+  explicit EpubReaderScreen(GfxRenderer& renderer, InputManager& inputManager, std::unique_ptr<Epub> epub,
                             const std::function<void()>& onGoHome)
-      : Screen(renderer, inputManager), epub(epub), onGoHome(onGoHome) {}
+      : Screen(renderer, inputManager), epub(std::move(epub)), onGoHome(onGoHome) {}
   void onEnter() override;
   void onExit() override;
   void handleInput() override;