Merge aa448fe470 into 78d6e5931c

## Summary

**What is the goal of this PR?**
- Minor correction to the `debugging_monitor.py` script instructions

**What changes are included?**
- `pyserial` should be installed, NOT `serial`, which is a [different
lib](https://pypi.org/project/serial/)
- Added macOS serial port

## Additional Context

- Just a minor docs update. I can confirm the debugging script is
working great on macOS

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? _**< NO >**_

README.md

@@ -102,13 +102,18 @@ After flashing the new features, it’s recommended to capture detailed logs fro
 First, make sure all required Python packages are installed:
 
 ```python
-python3 -m pip install serial colorama matplotlib
+python3 -m pip install pyserial colorama matplotlib
 ```
 after that run the script:
 ```sh
+# For Linux
+# This was tested on Debian and should work on most Linux systems.
 python3 scripts/debugging_monitor.py
+
+# For macOS
+python3 scripts/debugging_monitor.py /dev/cu.usbmodem2101
 ```
-This was tested on Debian and should work on most Linux systems. Minor adjustments may be required for Windows or macOS.
+Minor adjustments may be required for Windows.
 
 ## Internals
 

src/activities/network/WifiSelectionActivity.cpp

@@ -520,7 +520,7 @@ void WifiSelectionActivity::renderNetworkList() const {
     const auto height = renderer.getLineHeight(UI_10_FONT_ID);
     const auto top = (pageHeight - height) / 2;
     renderer.drawCenteredText(UI_10_FONT_ID, top, "No networks found");
-    renderer.drawCenteredText(SMALL_FONT_ID, top + height + 10, "Press OK to scan again");
+    renderer.drawCenteredText(SMALL_FONT_ID, top + height + 10, "Press Connect to scan again");
   } else {
     // Calculate how many networks we can display
     constexpr int startY = 60;

src/activities/reader/EpubReaderActivity.cpp

@@ -8,6 +8,8 @@
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "EpubReaderChapterSelectionActivity.h"
+#include "KOReaderCredentialStore.h"
+#include "KOReaderSyncActivity.h"
 #include "MappedInputManager.h"
 #include "RecentBooksStore.h"
 #include "ScreenComponents.h"
@@ -120,10 +122,49 @@ void EpubReaderActivity::loop() {
   // Pass input responsibility to sub activity if exists
   if (subActivity) {
     subActivity->loop();
+    // Deferred exit: process after subActivity->loop() returns to avoid use-after-free
+    if (pendingSubactivityExit) {
+      pendingSubactivityExit = false;
+      exitActivity();
+      updateRequired = true;
+      skipNextButtonCheck = true;  // Skip button processing to ignore stale events
+    }
+    // Deferred go home: process after subActivity->loop() returns to avoid race condition
+    if (pendingGoHome) {
+      pendingGoHome = false;
+      exitActivity();
+      if (onGoHome) {
+        onGoHome();
+      }
+      return;  // Don't access 'this' after callback
+    }
     return;
   }
 
-  // Enter chapter selection activity
+  // Handle pending go home when no subactivity (e.g., from long press back)
+  if (pendingGoHome) {
+    pendingGoHome = false;
+    if (onGoHome) {
+      onGoHome();
+    }
+    return;  // Don't access 'this' after callback
+  }
+
+  // Skip button processing after returning from subactivity
+  // This prevents stale button release events from triggering actions
+  // We wait until: (1) all relevant buttons are released, AND (2) wasReleased events have been cleared
+  if (skipNextButtonCheck) {
+    const bool confirmCleared = !mappedInput.isPressed(MappedInputManager::Button::Confirm) &&
+                                !mappedInput.wasReleased(MappedInputManager::Button::Confirm);
+    const bool backCleared = !mappedInput.isPressed(MappedInputManager::Button::Back) &&
+                             !mappedInput.wasReleased(MappedInputManager::Button::Back);
+    if (confirmCleared && backCleared) {
+      skipNextButtonCheck = false;
+    }
+    return;
+  }
+
+  // Confirm button opens menu
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
     // Don't start activity transition while rendering
     xSemaphoreTake(renderingMutex, portMAX_DELAY);
@@ -269,11 +310,8 @@ void EpubReaderActivity::onReaderMenuConfirm(EpubReaderMenuActivity::MenuAction
       break;
     }
     case EpubReaderMenuActivity::MenuAction::GO_HOME: {
-      // 2. Trigger the reader's "Go Home" callback
+      // Defer go home to avoid race condition with display task
-      if (onGoHome) {
+      pendingGoHome = true;
-        onGoHome();
-      }
-
       break;
     }
     case EpubReaderMenuActivity::MenuAction::DELETE_CACHE: {
@@ -294,10 +332,34 @@ void EpubReaderActivity::onReaderMenuConfirm(EpubReaderMenuActivity::MenuAction
 
         saveProgress(backupSpine, backupPage, backupPageCount);
       }
-      exitActivity();
-      updateRequired = true;
       xSemaphoreGive(renderingMutex);
-      if (onGoHome) onGoHome();
+      // Defer go home to avoid race condition with display task
+      pendingGoHome = true;
+      break;
+    }
+    case EpubReaderMenuActivity::MenuAction::SYNC: {
+      if (KOREADER_STORE.hasCredentials()) {
+        xSemaphoreTake(renderingMutex, portMAX_DELAY);
+        const int currentPage = section ? section->currentPage : 0;
+        const int totalPages = section ? section->pageCount : 0;
+        exitActivity();
+        enterNewActivity(new KOReaderSyncActivity(
+            renderer, mappedInput, epub, epub->getPath(), currentSpineIndex, currentPage, totalPages,
+            [this]() {
+              // On cancel - defer exit to avoid use-after-free
+              pendingSubactivityExit = true;
+            },
+            [this](int newSpineIndex, int newPage) {
+              // On sync complete - update position and defer exit
+              if (currentSpineIndex != newSpineIndex || (section && section->currentPage != newPage)) {
+                currentSpineIndex = newSpineIndex;
+                nextPageNumber = newPage;
+                section.reset();
+              }
+              pendingSubactivityExit = true;
+            }));
+        xSemaphoreGive(renderingMutex);
+      }
       break;
     }
   }

src/activities/reader/EpubReaderActivity.h

@@ -19,6 +19,9 @@ class EpubReaderActivity final : public ActivityWithSubactivity {
   int cachedSpineIndex = 0;
   int cachedChapterTotalPageCount = 0;
   bool updateRequired = false;
+  bool pendingSubactivityExit = false;  // Defer subactivity exit to avoid use-after-free
+  bool pendingGoHome = false;           // Defer go home to avoid race condition with display task
+  bool skipNextButtonCheck = false;     // Skip button processing for one frame after subactivity exit
   const std::function<void()> onGoBack;
   const std::function<void()> onGoHome;
 

src/activities/reader/EpubReaderChapterSelectionActivity.cpp

@@ -2,8 +2,6 @@
 
 #include <GfxRenderer.h>
 
-#include "KOReaderCredentialStore.h"
-#include "KOReaderSyncActivity.h"
 #include "MappedInputManager.h"
 #include "fontIds.h"
 
@@ -12,25 +10,7 @@ namespace {
 constexpr int SKIP_PAGE_MS = 700;
 }  // namespace
 
-bool EpubReaderChapterSelectionActivity::hasSyncOption() const { return KOREADER_STORE.hasCredentials(); }
+int EpubReaderChapterSelectionActivity::getTotalItems() const { return epub->getTocItemsCount(); }
-
-int EpubReaderChapterSelectionActivity::getTotalItems() const {
-  // Add 2 for sync options (top and bottom) if credentials are configured
-  const int syncCount = hasSyncOption() ? 2 : 0;
-  return epub->getTocItemsCount() + syncCount;
-}
-
-bool EpubReaderChapterSelectionActivity::isSyncItem(int index) const {
-  if (!hasSyncOption()) return false;
-  // First item and last item are sync options
-  return index == 0 || index == getTotalItems() - 1;
-}
-
-int EpubReaderChapterSelectionActivity::tocIndexFromItemIndex(int itemIndex) const {
-  // Account for the sync option at the top
-  const int offset = hasSyncOption() ? 1 : 0;
-  return itemIndex - offset;
-}
 
 int EpubReaderChapterSelectionActivity::getPageItems() const {
   // Layout constants used in renderScreen
@@ -64,13 +44,10 @@ void EpubReaderChapterSelectionActivity::onEnter() {
 
   renderingMutex = xSemaphoreCreateMutex();
 
-  // Account for sync option offset when finding current TOC index
-  const int syncOffset = hasSyncOption() ? 1 : 0;
   selectorIndex = epub->getTocIndexForSpineIndex(currentSpineIndex);
   if (selectorIndex == -1) {
     selectorIndex = 0;
   }
-  selectorIndex += syncOffset;  // Offset for top sync option
 
   // Trigger first update
   updateRequired = true;
@@ -95,24 +72,6 @@ void EpubReaderChapterSelectionActivity::onExit() {
   renderingMutex = nullptr;
 }
 
-void EpubReaderChapterSelectionActivity::launchSyncActivity() {
-  xSemaphoreTake(renderingMutex, portMAX_DELAY);
-  exitActivity();
-  enterNewActivity(new KOReaderSyncActivity(
-      renderer, mappedInput, epub, epubPath, currentSpineIndex, currentPage, totalPagesInSpine,
-      [this]() {
-        // On cancel
-        exitActivity();
-        updateRequired = true;
-      },
-      [this](int newSpineIndex, int newPage) {
-        // On sync complete
-        exitActivity();
-        onSyncPosition(newSpineIndex, newPage);
-      }));
-  xSemaphoreGive(renderingMutex);
-}
-
 void EpubReaderChapterSelectionActivity::loop() {
   if (subActivity) {
     subActivity->loop();
@@ -129,15 +88,7 @@ void EpubReaderChapterSelectionActivity::loop() {
   const int totalItems = getTotalItems();
 
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
-    // Check if sync option is selected (first or last item)
+    const auto newSpineIndex = epub->getSpineIndexForTocIndex(selectorIndex);
-    if (isSyncItem(selectorIndex)) {
-      launchSyncActivity();
-      return;
-    }
-
-    // Get TOC index (account for top sync offset)
-    const int tocIndex = tocIndexFromItemIndex(selectorIndex);
-    const auto newSpineIndex = epub->getSpineIndexForTocIndex(tocIndex);
     if (newSpineIndex == -1) {
       onGoBack();
     } else {
@@ -192,11 +143,7 @@ void EpubReaderChapterSelectionActivity::renderScreen() {
     const int displayY = 60 + i * 30;
     const bool isSelected = (itemIndex == selectorIndex);
 
-    if (isSyncItem(itemIndex)) {
+    auto item = epub->getTocItem(itemIndex);
-      renderer.drawText(UI_10_FONT_ID, 20, displayY, ">> Sync Progress", !isSelected);
-    } else {
-      const int tocIndex = tocIndexFromItemIndex(itemIndex);
-      auto item = epub->getTocItem(tocIndex);
 
     const int indentSize = 20 + (item.level - 1) * 15;
     const std::string chapterName =
@@ -204,7 +151,6 @@ void EpubReaderChapterSelectionActivity::renderScreen() {
 
     renderer.drawText(UI_10_FONT_ID, indentSize, displayY, chapterName.c_str(), !isSelected);
   }
-  }
 
   // Skip button hints in landscape CW mode (they overlap content)
   if (renderer.getOrientation() != GfxRenderer::LandscapeClockwise) {

src/activities/reader/EpubReaderChapterSelectionActivity.h

@@ -26,22 +26,12 @@ class EpubReaderChapterSelectionActivity final : public ActivityWithSubactivity
   // This adapts automatically when switching between portrait and landscape.
   int getPageItems() const;
 
-  // Total items including sync options (top and bottom)
+  // Total TOC items count
   int getTotalItems() const;
 
-  // Check if sync option is available (credentials configured)
-  bool hasSyncOption() const;
-
-  // Check if given item index is a sync option (first or last)
-  bool isSyncItem(int index) const;
-
-  // Convert item index to TOC index (accounting for top sync option offset)
-  int tocIndexFromItemIndex(int itemIndex) const;
-
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
   void renderScreen();
-  void launchSyncActivity();
 
  public:
   explicit EpubReaderChapterSelectionActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,

src/activities/reader/EpubReaderMenuActivity.h

@@ -13,7 +13,7 @@
 
 class EpubReaderMenuActivity final : public ActivityWithSubactivity {
  public:
-  enum class MenuAction { SELECT_CHAPTER, GO_HOME, DELETE_CACHE };
+  enum class MenuAction { SELECT_CHAPTER, GO_HOME, SYNC, DELETE_CACHE };
 
   explicit EpubReaderMenuActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, const std::string& title,
                                   const std::function<void()>& onBack, const std::function<void(MenuAction)>& onAction)
@@ -34,6 +34,7 @@ class EpubReaderMenuActivity final : public ActivityWithSubactivity {
 
   const std::vector<MenuItem> menuItems = {{MenuAction::SELECT_CHAPTER, "Go to Chapter"},
                                            {MenuAction::GO_HOME, "Go Home"},
+                                           {MenuAction::SYNC, "Sync Progress"},
                                            {MenuAction::DELETE_CACHE, "Delete Book Cache"}};
 
   int selectedIndex = 0;