fix: Validate settings on read. (#492)

## Summary

Fixes #487 

---

### 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? _** YES **_

Co-authored-by: Dave Allie <dave@daveallie.com>

src/CrossPointSettings.cpp

@@ -11,6 +11,14 @@
 // Initialize the static instance
 CrossPointSettings CrossPointSettings::instance;
 
+void readAndValidate(FsFile& file, uint8_t& member, const uint8_t maxValue) {
+  uint8_t tempValue;
+  serialization::readPod(file, tempValue);
+  if (tempValue < maxValue) {
+    member = tempValue;
+  }
+}
+
 namespace {
 constexpr uint8_t SETTINGS_FILE_VERSION = 1;
 // Increment this when adding new persisted settings fields
@@ -78,35 +86,35 @@ bool CrossPointSettings::loadFromFile() {
   // load settings that exist (support older files with fewer fields)
   uint8_t settingsRead = 0;
   do {
-    serialization::readPod(inputFile, sleepScreen);
+    readAndValidate(inputFile, sleepScreen, SLEEP_SCREEN_MODE_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
     serialization::readPod(inputFile, extraParagraphSpacing);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, shortPwrBtn);
+    readAndValidate(inputFile, shortPwrBtn, SHORT_PWRBTN_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, statusBar);
+    readAndValidate(inputFile, statusBar, STATUS_BAR_MODE_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, orientation);
+    readAndValidate(inputFile, orientation, ORIENTATION_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, frontButtonLayout);
+    readAndValidate(inputFile, frontButtonLayout, FRONT_BUTTON_LAYOUT_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, sideButtonLayout);
+    readAndValidate(inputFile, sideButtonLayout, SIDE_BUTTON_LAYOUT_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, fontFamily);
+    readAndValidate(inputFile, fontFamily, FONT_FAMILY_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, fontSize);
+    readAndValidate(inputFile, fontSize, FONT_SIZE_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, lineSpacing);
+    readAndValidate(inputFile, lineSpacing, LINE_COMPRESSION_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, paragraphAlignment);
+    readAndValidate(inputFile, paragraphAlignment, PARAGRAPH_ALIGNMENT_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, sleepTimeout);
+    readAndValidate(inputFile, sleepTimeout, SLEEP_TIMEOUT_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, refreshFrequency);
+    readAndValidate(inputFile, refreshFrequency, REFRESH_FREQUENCY_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
     serialization::readPod(inputFile, screenMargin);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, sleepScreenCoverMode);
+    readAndValidate(inputFile, sleepScreenCoverMode, SLEEP_SCREEN_COVER_MODE_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
     {
       std::string urlStr;
@@ -117,7 +125,7 @@ bool CrossPointSettings::loadFromFile() {
     if (++settingsRead >= fileSettingsCount) break;
     serialization::readPod(inputFile, textAntiAliasing);
     if (++settingsRead >= fileSettingsCount) break;
-    serialization::readPod(inputFile, hideBatteryPercentage);
+    readAndValidate(inputFile, hideBatteryPercentage, HIDE_BATTERY_PERCENTAGE_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
     serialization::readPod(inputFile, longPressChapterSkip);
     if (++settingsRead >= fileSettingsCount) break;

src/CrossPointSettings.h

@@ -15,18 +15,18 @@ class CrossPointSettings {
   CrossPointSettings(const CrossPointSettings&) = delete;
   CrossPointSettings& operator=(const CrossPointSettings&) = delete;
 
-  // Should match with SettingsActivity text
+  enum SLEEP_SCREEN_MODE { DARK = 0, LIGHT = 1, CUSTOM = 2, COVER = 3, BLANK = 4, SLEEP_SCREEN_MODE_COUNT };
-  enum SLEEP_SCREEN_MODE { DARK = 0, LIGHT = 1, CUSTOM = 2, COVER = 3, BLANK = 4 };
+  enum SLEEP_SCREEN_COVER_MODE { FIT = 0, CROP = 1, SLEEP_SCREEN_COVER_MODE_COUNT };
-  enum SLEEP_SCREEN_COVER_MODE { FIT = 0, CROP = 1 };
 
   // Status bar display type enum
-  enum STATUS_BAR_MODE { NONE = 0, NO_PROGRESS = 1, FULL = 2 };
+  enum STATUS_BAR_MODE { NONE = 0, NO_PROGRESS = 1, FULL = 2, STATUS_BAR_MODE_COUNT };
 
   enum ORIENTATION {
-    PORTRAIT = 0,      // 480x800 logical coordinates (current default)
+    PORTRAIT = 0,       // 480x800 logical coordinates (current default)
-    LANDSCAPE_CW = 1,  // 800x480 logical coordinates, rotated 180° (swap top/bottom)
+    LANDSCAPE_CW = 1,   // 800x480 logical coordinates, rotated 180° (swap top/bottom)
-    INVERTED = 2,      // 480x800 logical coordinates, inverted
+    INVERTED = 2,       // 480x800 logical coordinates, inverted
-    LANDSCAPE_CCW = 3  // 800x480 logical coordinates, native panel orientation
+    LANDSCAPE_CCW = 3,  // 800x480 logical coordinates, native panel orientation
+    ORIENTATION_COUNT
   };
 
   // Front button layout options
@@ -36,32 +36,53 @@ class CrossPointSettings {
     BACK_CONFIRM_LEFT_RIGHT = 0,
     LEFT_RIGHT_BACK_CONFIRM = 1,
     LEFT_BACK_CONFIRM_RIGHT = 2,
-    BACK_CONFIRM_RIGHT_LEFT = 3
+    BACK_CONFIRM_RIGHT_LEFT = 3,
+    FRONT_BUTTON_LAYOUT_COUNT
   };
 
   // Side button layout options
   // Default: Previous, Next
   // Swapped: Next, Previous
-  enum SIDE_BUTTON_LAYOUT { PREV_NEXT = 0, NEXT_PREV = 1 };
+  enum SIDE_BUTTON_LAYOUT { PREV_NEXT = 0, NEXT_PREV = 1, SIDE_BUTTON_LAYOUT_COUNT };
 
   // Font family options
-  enum FONT_FAMILY { BOOKERLY = 0, NOTOSANS = 1, OPENDYSLEXIC = 2 };
+  enum FONT_FAMILY { BOOKERLY = 0, NOTOSANS = 1, OPENDYSLEXIC = 2, FONT_FAMILY_COUNT };
   // Font size options
-  enum FONT_SIZE { SMALL = 0, MEDIUM = 1, LARGE = 2, EXTRA_LARGE = 3 };
+  enum FONT_SIZE { SMALL = 0, MEDIUM = 1, LARGE = 2, EXTRA_LARGE = 3, FONT_SIZE_COUNT };
-  enum LINE_COMPRESSION { TIGHT = 0, NORMAL = 1, WIDE = 2 };
+  enum LINE_COMPRESSION { TIGHT = 0, NORMAL = 1, WIDE = 2, LINE_COMPRESSION_COUNT };
-  enum PARAGRAPH_ALIGNMENT { JUSTIFIED = 0, LEFT_ALIGN = 1, CENTER_ALIGN = 2, RIGHT_ALIGN = 3 };
+  enum PARAGRAPH_ALIGNMENT {
+    JUSTIFIED = 0,
+    LEFT_ALIGN = 1,
+    CENTER_ALIGN = 2,
+    RIGHT_ALIGN = 3,
+    PARAGRAPH_ALIGNMENT_COUNT
+  };
 
   // Auto-sleep timeout options (in minutes)
-  enum SLEEP_TIMEOUT { SLEEP_1_MIN = 0, SLEEP_5_MIN = 1, SLEEP_10_MIN = 2, SLEEP_15_MIN = 3, SLEEP_30_MIN = 4 };
+  enum SLEEP_TIMEOUT {
+    SLEEP_1_MIN = 0,
+    SLEEP_5_MIN = 1,
+    SLEEP_10_MIN = 2,
+    SLEEP_15_MIN = 3,
+    SLEEP_30_MIN = 4,
+    SLEEP_TIMEOUT_COUNT
+  };
 
   // E-ink refresh frequency (pages between full refreshes)
-  enum REFRESH_FREQUENCY { REFRESH_1 = 0, REFRESH_5 = 1, REFRESH_10 = 2, REFRESH_15 = 3, REFRESH_30 = 4 };
+  enum REFRESH_FREQUENCY {
+    REFRESH_1 = 0,
+    REFRESH_5 = 1,
+    REFRESH_10 = 2,
+    REFRESH_15 = 3,
+    REFRESH_30 = 4,
+    REFRESH_FREQUENCY_COUNT
+  };
 
   // Short power button press actions
-  enum SHORT_PWRBTN { IGNORE = 0, SLEEP = 1, PAGE_TURN = 2 };
+  enum SHORT_PWRBTN { IGNORE = 0, SLEEP = 1, PAGE_TURN = 2, SHORT_PWRBTN_COUNT };
 
   // Hide battery percentage
-  enum HIDE_BATTERY_PERCENTAGE { HIDE_NEVER = 0, HIDE_READER = 1, HIDE_ALWAYS = 2 };
+  enum HIDE_BATTERY_PERCENTAGE { HIDE_NEVER = 0, HIDE_READER = 1, HIDE_ALWAYS = 2, HIDE_BATTERY_PERCENTAGE_COUNT };
 
   // Sleep screen settings
   uint8_t sleepScreen = DARK;