Method render

src/activities/reader/EpubReaderActivity.cpp:792–979

TODO: Failure handling

// TODO: Failure handling
void EpubReaderActivity::render(RenderLock&& lock) {
  if (!epub) {
    return;
  }

  const auto showPendingSyncSaveError = [this]() {
    if (!pendingSyncSaveError) return;
    pendingSyncSaveError = false;
    GUI.drawPopup(renderer, tr(STR_SAVE_PROGRESS_FAILED));
  };

  // 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(UI_12_FONT_ID, 300, tr(STR_END_OF_BOOK), true, EpdFontFamily::BOLD);
    renderer.displayBuffer();
    automaticPageTurnActive = false;
    showPendingSyncSaveError();
    return;
  }

  // Apply screen viewable areas and additional padding
  int orientedMarginTop, orientedMarginRight, orientedMarginBottom, orientedMarginLeft;
  renderer.getOrientedViewableTRBL(&orientedMarginTop, &orientedMarginRight, &orientedMarginBottom,
                                   &orientedMarginLeft);
  orientedMarginTop += SETTINGS.screenMargin;
  orientedMarginLeft += SETTINGS.screenMargin;
  orientedMarginRight += SETTINGS.screenMargin;

  const uint8_t statusBarHeight = UITheme::getInstance().getStatusBarHeight();

  // reserves space for automatic page turn indicator when no status bar or progress bar only
  if (automaticPageTurnActive &&
      (statusBarHeight == 0 || statusBarHeight == UITheme::getInstance().getProgressBarHeight())) {
    orientedMarginBottom +=
        std::max(SETTINGS.screenMargin,
                 static_cast<uint8_t>(statusBarHeight + UITheme::getInstance().getMetrics().statusBarVerticalMargin));
  } else {
    orientedMarginBottom += std::max(SETTINGS.screenMargin, statusBarHeight);
  }

  const uint16_t viewportWidth = renderer.getScreenWidth() - orientedMarginLeft - orientedMarginRight;
  const uint16_t viewportHeight = renderer.getScreenHeight() - orientedMarginTop - orientedMarginBottom;

  if (!section) {
    const auto filepath = epub->getSpineItem(currentSpineIndex).href;
    LOG_DBG("ERS", "Loading file: %s, index: %d", filepath.c_str(), currentSpineIndex);
    section = std::unique_ptr<Section>(new Section(epub, currentSpineIndex, renderer));