.github/workflows/ci.yml

@@ -12,6 +12,12 @@ jobs:
       - uses: actions/checkout@v6
         with:
           submodules: recursive
+      - uses: actions/cache@v5
+        with:
+          path: |
+            ~/.cache/pip
+            ~/.platformio/.cache
+          key: ${{ runner.os }}-pio
       - uses: actions/setup-python@v6
         with:
           python-version: '3.14'

lib/EpdFont/EpdFont.cpp

@@ -59,28 +59,14 @@ bool EpdFont::hasPrintableChars(const char* string) const {
 
 const EpdGlyph* EpdFont::getGlyph(const uint32_t cp) const {
   const EpdUnicodeInterval* intervals = data->intervals;
-  const int count = data->intervalCount;
-
-  if (count == 0) return nullptr;
-
-  // Binary search for O(log n) lookup instead of O(n)
-  // Critical for Korean fonts with many unicode intervals
-  int left = 0;
-  int right = count - 1;
-
-  while (left <= right) {
-    const int mid = left + (right - left) / 2;
-    const EpdUnicodeInterval* interval = &intervals[mid];
-
-    if (cp < interval->first) {
-      right = mid - 1;
-    } else if (cp > interval->last) {
-      left = mid + 1;
-    } else {
-      // Found: cp >= interval->first && cp <= interval->last
+  for (int i = 0; i < data->intervalCount; i++) {
+    const EpdUnicodeInterval* interval = &intervals[i];
+    if (cp >= interval->first && cp <= interval->last) {
       return &data->glyph[interval->offset + (cp - interval->first)];
     }
+    if (cp < interval->first) {
+      return nullptr;
+    }
   }
-
   return nullptr;
 }

lib/GfxRenderer/GfxRenderer.cpp

@@ -239,28 +239,6 @@ int GfxRenderer::getLineHeight(const int fontId) const {
   return fontMap.at(fontId).getData(REGULAR)->advanceY;
 }
 
-void GfxRenderer::drawButtonHints(const int fontId, const char* btn1, const char* btn2, const char* btn3,
-                                  const char* btn4) const {
-  const int pageHeight = getScreenHeight();
-  constexpr int buttonWidth = 106;
-  constexpr int buttonHeight = 40;
-  constexpr int buttonY = 40;     // Distance from bottom
-  constexpr int textYOffset = 5;  // Distance from top of button to text baseline
-  constexpr int buttonPositions[] = {25, 130, 245, 350};
-  const char* labels[] = {btn1, btn2, btn3, btn4};
-
-  for (int i = 0; i < 4; i++) {
-    // Only draw if the label is non-empty
-    if (labels[i] != nullptr && labels[i][0] != '\0') {
-      const int x = buttonPositions[i];
-      drawRect(x, pageHeight - buttonY, buttonWidth, buttonHeight);
-      const int textWidth = getTextWidth(fontId, labels[i]);
-      const int textX = x + (buttonWidth - 1 - textWidth) / 2;
-      drawText(fontId, textX, pageHeight - buttonY + textYOffset, labels[i]);
-    }
-  }
-}
-
 uint8_t* GfxRenderer::getFrameBuffer() const { return einkDisplay.getFrameBuffer(); }
 
 size_t GfxRenderer::getBufferSize() { return EInkDisplay::BUFFER_SIZE; }

lib/GfxRenderer/GfxRenderer.h

@@ -57,9 +57,6 @@ class GfxRenderer {
   int getSpaceWidth(int fontId) const;
   int getLineHeight(int fontId) const;
 
-  // UI Components
-  void drawButtonHints(int fontId, const char* btn1, const char* btn2, const char* btn3, const char* btn4) const;
-
   // Grayscale functions
   void setRenderMode(const RenderMode mode) { this->renderMode = mode; }
   void copyGrayscaleLsbBuffers() const;

src/activities/home/HomeActivity.cpp

@@ -4,24 +4,22 @@
 #include <InputManager.h>
 #include <SD.h>
 
-#include "CrossPointState.h"
 #include "config.h"
 
+namespace {
+constexpr int menuItemCount = 3;
+}
+
 void HomeActivity::taskTrampoline(void* param) {
   auto* self = static_cast<HomeActivity*>(param);
   self->displayTaskLoop();
 }
 
-int HomeActivity::getMenuItemCount() const { return hasContinueReading ? 4 : 3; }
-
 void HomeActivity::onEnter() {
   Activity::onEnter();
 
   renderingMutex = xSemaphoreCreateMutex();
 
-  // Check if we have a book to continue reading
-  hasContinueReading = !APP_STATE.openEpubPath.empty() && SD.exists(APP_STATE.openEpubPath.c_str());
-
   selectorIndex = 0;
 
   // Trigger first update
@@ -54,35 +52,19 @@ void HomeActivity::loop() {
   const bool nextPressed =
       inputManager.wasPressed(InputManager::BTN_DOWN) || inputManager.wasPressed(InputManager::BTN_RIGHT);
 
-  const int menuCount = getMenuItemCount();
-
   if (inputManager.wasPressed(InputManager::BTN_CONFIRM)) {
-    if (hasContinueReading) {
-      // Menu: Continue Reading, Browse, File transfer, Settings
-      if (selectorIndex == 0) {
-        onContinueReading();
-      } else if (selectorIndex == 1) {
-        onReaderOpen();
-      } else if (selectorIndex == 2) {
-        onFileTransferOpen();
-      } else if (selectorIndex == 3) {
-        onSettingsOpen();
-      }
-    } else {
-      // Menu: Browse, File transfer, Settings
-      if (selectorIndex == 0) {
-        onReaderOpen();
-      } else if (selectorIndex == 1) {
-        onFileTransferOpen();
-      } else if (selectorIndex == 2) {
-        onSettingsOpen();
-      }
+    if (selectorIndex == 0) {
+      onReaderOpen();
+    } else if (selectorIndex == 1) {
+      onFileTransferOpen();
+    } else if (selectorIndex == 2) {
+      onSettingsOpen();
     }
   } else if (prevPressed) {
-    selectorIndex = (selectorIndex + menuCount - 1) % menuCount;
+    selectorIndex = (selectorIndex + menuItemCount - 1) % menuItemCount;
     updateRequired = true;
   } else if (nextPressed) {
-    selectorIndex = (selectorIndex + 1) % menuCount;
+    selectorIndex = (selectorIndex + 1) % menuItemCount;
     updateRequired = true;
   }
 }
@@ -103,47 +85,27 @@ void HomeActivity::render() const {
   renderer.clearScreen();
 
   const auto pageWidth = renderer.getScreenWidth();
+  const auto pageHeight = renderer.getScreenHeight();
   renderer.drawCenteredText(READER_FONT_ID, 10, "CrossPoint Reader", true, BOLD);
 
   // Draw selection
   renderer.fillRect(0, 60 + selectorIndex * 30 + 2, pageWidth - 1, 30);
+  renderer.drawText(UI_FONT_ID, 20, 60, "Read", selectorIndex != 0);
+  renderer.drawText(UI_FONT_ID, 20, 90, "File transfer", selectorIndex != 1);
+  renderer.drawText(UI_FONT_ID, 20, 120, "Settings", selectorIndex != 2);
 
-  int menuY = 60;
-  int menuIndex = 0;
+  renderer.drawRect(25, pageHeight - 40, 106, 40);
+  renderer.drawText(UI_FONT_ID, 25 + (105 - renderer.getTextWidth(UI_FONT_ID, "Back")) / 2, pageHeight - 35, "Back");
 
-  if (hasContinueReading) {
-    // Extract filename from path for display
-    std::string bookName = APP_STATE.openEpubPath;
-    const size_t lastSlash = bookName.find_last_of('/');
-    if (lastSlash != std::string::npos) {
-      bookName = bookName.substr(lastSlash + 1);
-    }
-    // Remove .epub extension
-    if (bookName.length() > 5 && bookName.substr(bookName.length() - 5) == ".epub") {
-      bookName.resize(bookName.length() - 5);
-    }
-    // Truncate if too long
-    if (bookName.length() > 25) {
-      bookName.resize(22);
-      bookName += "...";
-    }
-    std::string continueLabel = "Continue: " + bookName;
-    renderer.drawText(UI_FONT_ID, 20, menuY, continueLabel.c_str(), selectorIndex != menuIndex);
-    menuY += 30;
-    menuIndex++;
-  }
+  renderer.drawRect(130, pageHeight - 40, 106, 40);
+  renderer.drawText(UI_FONT_ID, 130 + (105 - renderer.getTextWidth(UI_FONT_ID, "Confirm")) / 2, pageHeight - 35,
+                    "Confirm");
 
-  renderer.drawText(UI_FONT_ID, 20, menuY, "Browse", selectorIndex != menuIndex);
-  menuY += 30;
-  menuIndex++;
+  renderer.drawRect(245, pageHeight - 40, 106, 40);
+  renderer.drawText(UI_FONT_ID, 245 + (105 - renderer.getTextWidth(UI_FONT_ID, "Left")) / 2, pageHeight - 35, "Left");
 
-  renderer.drawText(UI_FONT_ID, 20, menuY, "File transfer", selectorIndex != menuIndex);
-  menuY += 30;
-  menuIndex++;
-
-  renderer.drawText(UI_FONT_ID, 20, menuY, "Settings", selectorIndex != menuIndex);
-
-  renderer.drawButtonHints(UI_FONT_ID, "Back", "Confirm", "Left", "Right");
+  renderer.drawRect(350, pageHeight - 40, 106, 40);
+  renderer.drawText(UI_FONT_ID, 350 + (105 - renderer.getTextWidth(UI_FONT_ID, "Right")) / 2, pageHeight - 35, "Right");
 
   renderer.displayBuffer();
 }

src/activities/home/HomeActivity.h

@@ -12,8 +12,6 @@ class HomeActivity final : public Activity {
   SemaphoreHandle_t renderingMutex = nullptr;
   int selectorIndex = 0;
   bool updateRequired = false;
-  bool hasContinueReading = false;
-  const std::function<void()> onContinueReading;
   const std::function<void()> onReaderOpen;
   const std::function<void()> onSettingsOpen;
   const std::function<void()> onFileTransferOpen;
@@ -21,14 +19,11 @@ class HomeActivity final : public Activity {
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
   void render() const;
-  int getMenuItemCount() const;
 
  public:
-  explicit HomeActivity(GfxRenderer& renderer, InputManager& inputManager,
-                        const std::function<void()>& onContinueReading, const std::function<void()>& onReaderOpen,
+  explicit HomeActivity(GfxRenderer& renderer, InputManager& inputManager, const std::function<void()>& onReaderOpen,
                         const std::function<void()>& onSettingsOpen, const std::function<void()>& onFileTransferOpen)
       : Activity("Home", renderer, inputManager),
-        onContinueReading(onContinueReading),
         onReaderOpen(onReaderOpen),
         onSettingsOpen(onSettingsOpen),
         onFileTransferOpen(onFileTransferOpen) {}

src/activities/network/CrossPointWebServerActivity.cpp

@@ -340,7 +340,7 @@ void CrossPointWebServerActivity::render() const {
   }
 }
 
-void drawQRCode(const GfxRenderer& renderer, const int x, const int y, const std::string& data) {
+void drawQRCode(GfxRenderer& renderer, const int x, const int y, const std::string& data) {
   // Implementation of QR code calculation
   // The structure to manage the QR code
   QRCode qrcode;
@@ -363,6 +363,8 @@ void drawQRCode(const GfxRenderer& renderer, const int x, const int y, const std
 }
 
 void CrossPointWebServerActivity::renderServerRunning() const {
+  const auto pageHeight = renderer.getScreenHeight();
+
   // Use consistent line spacing
   constexpr int LINE_SPACING = 28;  // Space between lines
 
@@ -429,5 +431,5 @@ void CrossPointWebServerActivity::renderServerRunning() const {
                               REGULAR);
   }
 
-  renderer.drawButtonHints(UI_FONT_ID, "« Exit", "", "", "");
+  renderer.drawCenteredText(SMALL_FONT_ID, pageHeight - 30, "Press BACK to exit", true, REGULAR);
 }

src/activities/network/NetworkModeSelectionActivity.cpp

@@ -122,7 +122,7 @@ void NetworkModeSelectionActivity::render() const {
   }
 
   // Draw help text at bottom
-  renderer.drawButtonHints(UI_FONT_ID, "« Back", "Select", "", "");
+  renderer.drawCenteredText(SMALL_FONT_ID, pageHeight - 30, "Press OK to select, BACK to cancel", true, REGULAR);
 
   renderer.displayBuffer();
 }

src/activities/network/WifiSelectionActivity.cpp

@@ -553,12 +553,11 @@ void WifiSelectionActivity::renderNetworkList() const {
     // Show network count
     char countStr[32];
     snprintf(countStr, sizeof(countStr), "%zu networks found", networks.size());
-    renderer.drawText(SMALL_FONT_ID, 20, pageHeight - 90, countStr);
+    renderer.drawText(SMALL_FONT_ID, 20, pageHeight - 45, countStr);
   }
 
   // Draw help text
-  renderer.drawText(SMALL_FONT_ID, 20, pageHeight - 75, "* = Encrypted | + = Saved");
-  renderer.drawButtonHints(UI_FONT_ID, "« Back", "Connect", "", "");
+  renderer.drawText(SMALL_FONT_ID, 20, pageHeight - 30, "OK: Connect | * = Encrypted | + = Saved");
 }
 
 void WifiSelectionActivity::renderPasswordEntry() const {

src/activities/reader/EpubReaderActivity.cpp

@@ -14,7 +14,6 @@
 namespace {
 constexpr int pagesPerRefresh = 15;
 constexpr unsigned long skipChapterMs = 700;
-constexpr unsigned long goHomeMs = 1000;
 constexpr float lineCompression = 0.95f;
 constexpr int marginTop = 8;
 constexpr int marginRight = 10;
@@ -109,14 +108,7 @@ void EpubReaderActivity::loop() {
     xSemaphoreGive(renderingMutex);
   }
 
-  // Long press BACK (1s+) goes directly to home
-  if (inputManager.isPressed(InputManager::BTN_BACK) && inputManager.getHeldTime() >= goHomeMs) {
-    onGoHome();
-    return;
-  }
-
-  // Short press BACK goes to file selection
-  if (inputManager.wasReleased(InputManager::BTN_BACK) && inputManager.getHeldTime() < goHomeMs) {
+  if (inputManager.wasPressed(InputManager::BTN_BACK)) {
     onGoBack();
     return;
   }

src/activities/reader/EpubReaderActivity.h

@@ -17,7 +17,6 @@ class EpubReaderActivity final : public ActivityWithSubactivity {
   int pagesUntilFullRefresh = 0;
   bool updateRequired = false;
   const std::function<void()> onGoBack;
-  const std::function<void()> onGoHome;
 
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
@@ -27,11 +26,8 @@ class EpubReaderActivity final : public ActivityWithSubactivity {
 
  public:
   explicit EpubReaderActivity(GfxRenderer& renderer, InputManager& inputManager, std::unique_ptr<Epub> epub,
-                              const std::function<void()>& onGoBack, const std::function<void()>& onGoHome)
-      : ActivityWithSubactivity("EpubReader", renderer, inputManager),
-        epub(std::move(epub)),
-        onGoBack(onGoBack),
-        onGoHome(onGoHome) {}
+                              const std::function<void()>& onGoBack)
+      : ActivityWithSubactivity("EpubReader", renderer, inputManager), epub(std::move(epub)), onGoBack(onGoBack) {}
   void onEnter() override;
   void onExit() override;
   void loop() override;

src/activities/reader/FileSelectionActivity.cpp

@@ -9,7 +9,6 @@
 namespace {
 constexpr int PAGE_ITEMS = 23;
 constexpr int SKIP_PAGE_MS = 700;
-constexpr unsigned long GO_HOME_MS = 1000;
 }  // namespace
 
 void sortFileList(std::vector<std::string>& strs) {
@@ -54,7 +53,7 @@ void FileSelectionActivity::onEnter() {
 
   renderingMutex = xSemaphoreCreateMutex();
 
-  // basepath is set via constructor parameter (defaults to "/" if not specified)
+  basepath = "/";
   loadFiles();
   selectorIndex = 0;
 
@@ -84,16 +83,6 @@ void FileSelectionActivity::onExit() {
 }
 
 void FileSelectionActivity::loop() {
-  // Long press BACK (1s+) goes to root folder
-  if (inputManager.isPressed(InputManager::BTN_BACK) && inputManager.getHeldTime() >= GO_HOME_MS) {
-    if (basepath != "/") {
-      basepath = "/";
-      loadFiles();
-      updateRequired = true;
-    }
-    return;
-  }
-
   const bool prevReleased =
       inputManager.wasReleased(InputManager::BTN_UP) || inputManager.wasReleased(InputManager::BTN_LEFT);
   const bool nextReleased =
@@ -114,17 +103,15 @@ void FileSelectionActivity::loop() {
     } else {
       onSelect(basepath + files[selectorIndex]);
     }
-  } else if (inputManager.wasReleased(InputManager::BTN_BACK)) {
-    // Short press: go up one directory, or go home if at root
-    if (inputManager.getHeldTime() < GO_HOME_MS) {
-      if (basepath != "/") {
-        basepath.replace(basepath.find_last_of('/'), std::string::npos, "");
-        if (basepath.empty()) basepath = "/";
-        loadFiles();
-        updateRequired = true;
-      } else {
-        onGoHome();
-      }
+  } else if (inputManager.wasPressed(InputManager::BTN_BACK)) {
+    if (basepath != "/") {
+      basepath.replace(basepath.find_last_of('/'), std::string::npos, "");
+      if (basepath.empty()) basepath = "/";
+      loadFiles();
+      updateRequired = true;
+    } else {
+      // At root level, go back home
+      onGoHome();
     }
   } else if (prevReleased) {
     if (skipPage) {
@@ -162,7 +149,7 @@ void FileSelectionActivity::render() const {
   renderer.drawCenteredText(READER_FONT_ID, 10, "Books", true, BOLD);
 
   // Help text
-  renderer.drawButtonHints(UI_FONT_ID, "« Home", "", "", "");
+  renderer.drawText(SMALL_FONT_ID, 20, GfxRenderer::getScreenHeight() - 30, "Press BACK for Home");
 
   if (files.empty()) {
     renderer.drawText(UI_FONT_ID, 20, 60, "No EPUBs found");

src/activities/reader/FileSelectionActivity.h

@@ -27,11 +27,8 @@ class FileSelectionActivity final : public Activity {
  public:
   explicit FileSelectionActivity(GfxRenderer& renderer, InputManager& inputManager,
                                  const std::function<void(const std::string&)>& onSelect,
-                                 const std::function<void()>& onGoHome, std::string initialPath = "/")
-      : Activity("FileSelection", renderer, inputManager),
-        basepath(initialPath.empty() ? "/" : std::move(initialPath)),
-        onSelect(onSelect),
-        onGoHome(onGoHome) {}
+                                 const std::function<void()>& onGoHome)
+      : Activity("FileSelection", renderer, inputManager), onSelect(onSelect), onGoHome(onGoHome) {}
   void onEnter() override;
   void onExit() override;
   void loop() override;

src/activities/reader/ReaderActivity.cpp

@@ -7,14 +7,6 @@
 #include "FileSelectionActivity.h"
 #include "activities/util/FullScreenMessageActivity.h"
 
-std::string ReaderActivity::extractFolderPath(const std::string& filePath) {
-  const auto lastSlash = filePath.find_last_of('/');
-  if (lastSlash == std::string::npos || lastSlash == 0) {
-    return "/";
-  }
-  return filePath.substr(0, lastSlash);
-}
-
 std::unique_ptr<Epub> ReaderActivity::loadEpub(const std::string& path) {
   if (!SD.exists(path.c_str())) {
     Serial.printf("[%lu] [   ] File does not exist: %s\n", millis(), path.c_str());
@@ -31,7 +23,6 @@ std::unique_ptr<Epub> ReaderActivity::loadEpub(const std::string& path) {
 }
 
 void ReaderActivity::onSelectEpubFile(const std::string& path) {
-  currentEpubPath = path;  // Track current book path
   exitActivity();
   enterNewActivity(new FullScreenMessageActivity(renderer, inputManager, "Loading..."));
 
@@ -47,32 +38,25 @@ void ReaderActivity::onSelectEpubFile(const std::string& path) {
   }
 }
 
-void ReaderActivity::onGoToFileSelection(const std::string& fromEpubPath) {
+void ReaderActivity::onGoToFileSelection() {
   exitActivity();
-  // If coming from a book, start in that book's folder; otherwise start from root
-  const auto initialPath = fromEpubPath.empty() ? "/" : extractFolderPath(fromEpubPath);
   enterNewActivity(new FileSelectionActivity(
-      renderer, inputManager, [this](const std::string& path) { onSelectEpubFile(path); }, onGoBack, initialPath));
+      renderer, inputManager, [this](const std::string& path) { onSelectEpubFile(path); }, onGoBack));
 }
 
 void ReaderActivity::onGoToEpubReader(std::unique_ptr<Epub> epub) {
-  const auto epubPath = epub->getPath();
-  currentEpubPath = epubPath;
   exitActivity();
-  enterNewActivity(new EpubReaderActivity(
-      renderer, inputManager, std::move(epub), [this, epubPath] { onGoToFileSelection(epubPath); },
-      [this] { onGoBack(); }));
+  enterNewActivity(new EpubReaderActivity(renderer, inputManager, std::move(epub), [this] { onGoToFileSelection(); }));
 }
 
 void ReaderActivity::onEnter() {
   ActivityWithSubactivity::onEnter();
 
   if (initialEpubPath.empty()) {
-    onGoToFileSelection();  // Start from root when entering via Browse
+    onGoToFileSelection();
     return;
   }
 
-  currentEpubPath = initialEpubPath;
   auto epub = loadEpub(initialEpubPath);
   if (!epub) {
     onGoBack();

src/activities/reader/ReaderActivity.h

@@ -7,13 +7,11 @@ class Epub;
 
 class ReaderActivity final : public ActivityWithSubactivity {
   std::string initialEpubPath;
-  std::string currentEpubPath;  // Track current book path for navigation
   const std::function<void()> onGoBack;
   static std::unique_ptr<Epub> loadEpub(const std::string& path);
 
-  static std::string extractFolderPath(const std::string& filePath);
   void onSelectEpubFile(const std::string& path);
-  void onGoToFileSelection(const std::string& fromEpubPath = "");
+  void onGoToFileSelection();
   void onGoToEpubReader(std::unique_ptr<Epub> epub);
 
  public:

src/activities/settings/SettingsActivity.cpp

@@ -169,7 +169,7 @@ void SettingsActivity::render() const {
   }
 
   // Draw help text
-  renderer.drawButtonHints(UI_FONT_ID, "« Save", "Toggle", "", "");
+  renderer.drawText(SMALL_FONT_ID, 20, pageHeight - 30, "Press OK to toggle, BACK to save & exit");
   renderer.drawText(SMALL_FONT_ID, pageWidth - 20 - renderer.getTextWidth(SMALL_FONT_ID, CROSSPOINT_VERSION),
                     pageHeight - 30, CROSSPOINT_VERSION);
 

src/main.cpp

@@ -142,7 +142,6 @@ void onGoToReader(const std::string& initialEpubPath) {
   enterNewActivity(new ReaderActivity(renderer, inputManager, initialEpubPath, onGoHome));
 }
 void onGoToReaderHome() { onGoToReader(std::string()); }
-void onContinueReading() { onGoToReader(APP_STATE.openEpubPath); }
 
 void onGoToFileTransfer() {
   exitActivity();
@@ -156,8 +155,7 @@ void onGoToSettings() {
 
 void onGoHome() {
   exitActivity();
-  enterNewActivity(new HomeActivity(renderer, inputManager, onContinueReading, onGoToReaderHome, onGoToSettings,
-                                    onGoToFileTransfer));
+  enterNewActivity(new HomeActivity(renderer, inputManager, onGoToReaderHome, onGoToSettings, onGoToFileTransfer));
 }
 
 void setupDisplayAndFonts() {