Improve compact UI, improve DisplayApi, cleanup (#660)

Devices/m5stack-papers3/source/drivers/papers3_display.cpp

@@ -315,17 +315,6 @@ static uint16_t papers3_display_get_resolution_y(Device*) {
     return static_cast<uint16_t>(epd_rotated_display_height());
 }
 
-static void papers3_display_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    // Not exposed via the generic fb-direct path: EPDiy's framebuffer is its own 4bpp packed
-    // format, not the DISPLAY_COLOR_FORMAT_GRAYSCALE8 (1 byte/pixel) this driver reports.
-    // See get_frame_buffer_count() and draw_bitmap()'s conversion.
-    *out_buffer = nullptr;
-}
-
-static uint8_t papers3_display_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 // endregion
 
 static const DisplayApi papers3_display_api = {
@@ -352,8 +341,9 @@ static const DisplayApi papers3_display_api = {
     .get_color_format = papers3_display_get_color_format,
     .get_resolution_x = papers3_display_get_resolution_x,
     .get_resolution_y = papers3_display_get_resolution_y,
-    .get_frame_buffer = papers3_display_get_frame_buffer,
+    // EPDiy's frame buffer is 4bpp packed, not the GRAYSCALE8 format this driver reports, so it is not exposed
-    .get_frame_buffer_count = papers3_display_get_frame_buffer_count,
+    .get_frame_buffer = nullptr,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = nullptr,
     .has_capability = nullptr,
 };

Devices/simulator/Source/drivers/sdl_display.cpp

@@ -191,14 +191,6 @@ static uint16_t sdl_display_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void sdl_display_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t sdl_display_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 // endregion
 
 static const DisplayApi sdl_display_api = {
@@ -220,8 +212,8 @@ static const DisplayApi sdl_display_api = {
     .get_color_format = sdl_display_get_color_format,
     .get_resolution_x = sdl_display_get_resolution_x,
     .get_resolution_y = sdl_display_get_resolution_y,
-    .get_frame_buffer = sdl_display_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = sdl_display_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = nullptr,
     .has_capability = nullptr,
 };

Documentation/ideas.md

@@ -10,23 +10,13 @@
 ## Higher Priority
 
 - coreutils apps: Only emit colour escapes when stdout is the terminal (command_support.h color() function)
-- DisplayApi::get_frame_buffer should be nullable and have a default behaviour of assigning NULL to the output pointer. 
-  get_frame_buffer_count should be NULLable too, document it explicitly
-- Shell interpreter works recursive-descent algorithm, which requires a big stack size. Can we optimize this?
 - CrashDiagnostics shouldn't show a QR when there's no callstack
-- stopAppFromToolbar() in Tactility.cpp stops the top-most app. Change it so the toolbar knows for which app id it is created, so it can rely on that.
-- Warn if file operations are done from prohibited tasks (e.g. lvgl task)
 - Move USB host task stacks to SPIRAM when available: esp32_usbhost*.cpp
 - Get rid of WiFi service (Wifi.cpp/h) in Tactility.cpp
-- Make it more clear to end-users that an SD card is required to run Tactility
 - Add bold fonts for e-ink readability improvement
-- Improve Setup: Show "Step done" screen
 - Improve Setup: Add keyboard/keypad navigation explanation
-- Improve kernel_init.cpp (and other modules): create driver_ensure_added() and driver_ensure_destructed()
 - Drivers/audio-codec-module is not a module. Move it somewhere else. Or make it an actual module.
 - LilyGO T-Dongle S3: 1 button control, stop auto-launching web server
-- Core2: support power off via software
-- Create `#define` for empty module (for modules that fully rely on device.properties and don't define drivers or have start/stop logic)
 - Improve SPI kernel driver (implement read, write, transactions)
 - Add font design tokens such as "regular", "title" and "smaller". Perhaps via the LVGL kernel module.
 - TCA9534 keyboards should use interrupts
@@ -42,6 +32,13 @@
 
 ## Medium Priority
 
+- Core2: support power off via software
+- Improve Setup: Show "Step done" screen
+- Make it more clear to end-users that an SD card is required to run Tactility
+- Warn if file operations are done from prohibited tasks (e.g. lvgl task)
+- Shell interpreter works recursive-descent algorithm, which requires a big stack size. Can we optimize this?
+- stopAppFromToolbar() in Tactility.cpp stops the top-most app. Change it so the toolbar knows for which app id it is created, so it can rely on that.
+- Consider not unpacking `.app` files and executing them directly. Might want to cache file offsets. Cache file must be pinned to app version.
 - lvgl-module's spinner relies on hard-coded spinner asset from Tactility main project.
 - esp_lvgl_port settings has a large stack size (~9kB) to fix stackoverflow when LVGL events (e.g. button click) do actions like file operations do actions like file operations. Can we reduce the callstack?
 - `struct Driver` has an `.owner`, but it's not always set. Either validate on Module construct that it matches, or otherwise set it during module start. The problem: NULL parent currently means that driver is not removable. This clashes with setting it dynamically. Consider some kind of flag to determine removability.

Drivers/esp-epaper-module/source/esp_epaper.cpp

@@ -251,14 +251,6 @@ static uint16_t esp_epaper_get_resolution_y(Device* device) {
     return esp_epaper_get_display_height(internal, GET_CONFIG(device)->rotation);
 }
 
-static void esp_epaper_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t esp_epaper_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static const DisplayApi esp_epaper_display_api = {
     .capabilities = DISPLAY_CAPABILITY_ON_OFF | DISPLAY_CAPABILITY_SLOW_REFRESH | DISPLAY_CAPABILITY_REQUIRES_FULL_FRAME,
     .reset = esp_epaper_reset,
@@ -280,8 +272,8 @@ static const DisplayApi esp_epaper_display_api = {
     .get_color_format = esp_epaper_get_color_format,
     .get_resolution_x = esp_epaper_get_resolution_x,
     .get_resolution_y = esp_epaper_get_resolution_y,
-    .get_frame_buffer = esp_epaper_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = esp_epaper_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = nullptr,
     .has_capability = nullptr,
 };

Drivers/gc9a01-module/source/gc9a01.cpp

@@ -305,14 +305,6 @@ static uint16_t gc9a01_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void gc9a01_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t gc9a01_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t gc9a01_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -347,8 +339,8 @@ static const DisplayApi gc9a01_display_api = {
     .get_color_format = gc9a01_get_color_format,
     .get_resolution_x = gc9a01_get_resolution_x,
     .get_resolution_y = gc9a01_get_resolution_y,
-    .get_frame_buffer = gc9a01_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = gc9a01_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = gc9a01_get_backlight,
     .has_capability = nullptr,
 };

Drivers/gdeq031t10-module/source/gdeq031t10.cpp

@@ -525,14 +525,6 @@ static uint16_t gdeq031t10_get_resolution_y(Device*) {
     return HEIGHT;
 }
 
-static void gdeq031t10_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t gdeq031t10_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 // endregion
 
 static error_t gdeq031t10_get_backlight(Device* device, Device** backlight) {
@@ -575,8 +567,8 @@ static const DisplayApi gdeq031t10_display_api = {
     .get_color_format = gdeq031t10_get_color_format,
     .get_resolution_x = gdeq031t10_get_resolution_x,
     .get_resolution_y = gdeq031t10_get_resolution_y,
-    .get_frame_buffer = gdeq031t10_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = gdeq031t10_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = gdeq031t10_get_backlight,
     .has_capability = gdeq031t10_has_capability,
 };

Drivers/hx8357-module/source/hx8357.cpp

@@ -417,14 +417,6 @@ static uint16_t hx8357_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void hx8357_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t hx8357_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t hx8357_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -462,8 +454,8 @@ static const DisplayApi hx8357_display_api = {
     .get_color_format = hx8357_get_color_format,
     .get_resolution_x = hx8357_get_resolution_x,
     .get_resolution_y = hx8357_get_resolution_y,
-    .get_frame_buffer = hx8357_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = hx8357_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = hx8357_get_backlight,
     .has_capability = nullptr,
 };

Drivers/ili9341-module/source/ili9341.cpp

@@ -410,14 +410,6 @@ static uint16_t ili9341_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void ili9341_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t ili9341_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t ili9341_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -452,8 +444,8 @@ static const DisplayApi ili9341_display_api = {
     .get_color_format = ili9341_get_color_format,
     .get_resolution_x = ili9341_get_resolution_x,
     .get_resolution_y = ili9341_get_resolution_y,
-    .get_frame_buffer = ili9341_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = ili9341_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = ili9341_get_backlight,
     .has_capability = nullptr,
 };

Drivers/ili9488-module/source/ili9488.cpp

@@ -335,14 +335,6 @@ static uint16_t ili9488_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void ili9488_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t ili9488_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t ili9488_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -377,8 +369,8 @@ static const DisplayApi ili9488_display_api = {
     .get_color_format = ili9488_get_color_format,
     .get_resolution_x = ili9488_get_resolution_x,
     .get_resolution_y = ili9488_get_resolution_y,
-    .get_frame_buffer = ili9488_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = ili9488_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = ili9488_get_backlight,
     .has_capability = nullptr,
 };

Drivers/jd9853-module/source/jd9853.cpp

@@ -318,14 +318,6 @@ static uint16_t jd9853_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void jd9853_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t jd9853_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t jd9853_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -360,8 +352,8 @@ static const DisplayApi jd9853_display_api = {
     .get_color_format = jd9853_get_color_format,
     .get_resolution_x = jd9853_get_resolution_x,
     .get_resolution_y = jd9853_get_resolution_y,
-    .get_frame_buffer = jd9853_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = jd9853_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = jd9853_get_backlight,
     .has_capability = nullptr,
 };

Drivers/ssd1306-module/source/ssd1306.cpp

@@ -308,14 +308,6 @@ static uint16_t ssd1306_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void ssd1306_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t ssd1306_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 // get_backlight is not exposed: SSD1306 is a self-emitting OLED panel with no backlight.
 
 // endregion
@@ -341,8 +333,8 @@ static const DisplayApi ssd1306_display_api = {
     .get_color_format = ssd1306_get_color_format,
     .get_resolution_x = ssd1306_get_resolution_x,
     .get_resolution_y = ssd1306_get_resolution_y,
-    .get_frame_buffer = ssd1306_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = ssd1306_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = nullptr,
     .has_capability = nullptr,
 };

Drivers/st7735-module/source/st7735.cpp

@@ -337,14 +337,6 @@ static uint16_t st7735_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void st7735_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t st7735_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t st7735_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -379,8 +371,8 @@ static const DisplayApi st7735_display_api = {
     .get_color_format = st7735_get_color_format,
     .get_resolution_x = st7735_get_resolution_x,
     .get_resolution_y = st7735_get_resolution_y,
-    .get_frame_buffer = st7735_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = st7735_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = st7735_get_backlight,
     .has_capability = nullptr,
 };

Drivers/st7789-i8080-module/source/st7789_i8080.cpp

@@ -326,14 +326,6 @@ static uint16_t st7789_i8080_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void st7789_i8080_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t st7789_i8080_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t st7789_i8080_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -368,8 +360,8 @@ static const DisplayApi st7789_i8080_display_api = {
     .get_color_format = st7789_i8080_get_color_format,
     .get_resolution_x = st7789_i8080_get_resolution_x,
     .get_resolution_y = st7789_i8080_get_resolution_y,
-    .get_frame_buffer = st7789_i8080_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = st7789_i8080_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = st7789_i8080_get_backlight,
     .has_capability = nullptr,
 };

Drivers/st7789-module/source/st7789.cpp

@@ -337,14 +337,6 @@ static uint16_t st7789_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void st7789_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t st7789_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t st7789_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -379,8 +371,8 @@ static const DisplayApi st7789_display_api = {
     .get_color_format = st7789_get_color_format,
     .get_resolution_x = st7789_get_resolution_x,
     .get_resolution_y = st7789_get_resolution_y,
-    .get_frame_buffer = st7789_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = st7789_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = st7789_get_backlight,
     .has_capability = nullptr,
 };

Drivers/st7796-i8080-module/source/st7796_i8080.cpp

@@ -281,14 +281,6 @@ static uint16_t st7796_i8080_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void st7796_i8080_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t st7796_i8080_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t st7796_i8080_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -323,8 +315,8 @@ static const DisplayApi st7796_i8080_display_api = {
     .get_color_format = st7796_i8080_get_color_format,
     .get_resolution_x = st7796_i8080_get_resolution_x,
     .get_resolution_y = st7796_i8080_get_resolution_y,
-    .get_frame_buffer = st7796_i8080_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = st7796_i8080_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = st7796_i8080_get_backlight,
     .has_capability = nullptr,
 };

Drivers/st7796-module/source/st7796.cpp

@@ -337,14 +337,6 @@ static uint16_t st7796_get_resolution_y(Device* device) {
     return GET_CONFIG(device)->vertical_resolution;
 }
 
-static void st7796_get_frame_buffer(Device*, uint8_t, void** out_buffer) {
-    *out_buffer = nullptr;
-}
-
-static uint8_t st7796_get_frame_buffer_count(Device*) {
-    return 0;
-}
-
 static error_t st7796_get_backlight(Device* device, Device** backlight) {
     auto* configured_backlight = GET_CONFIG(device)->backlight;
     if (configured_backlight == nullptr) {
@@ -379,8 +371,8 @@ static const DisplayApi st7796_display_api = {
     .get_color_format = st7796_get_color_format,
     .get_resolution_x = st7796_get_resolution_x,
     .get_resolution_y = st7796_get_resolution_y,
-    .get_frame_buffer = st7796_get_frame_buffer,
+    .get_frame_buffer = nullptr,
-    .get_frame_buffer_count = st7796_get_frame_buffer_count,
+    .get_frame_buffer_count = nullptr,
     .get_backlight = st7796_get_backlight,
     .has_capability = nullptr,
 };

Modules/app-module/source/package_manifest_parsing_v3.cpp

@@ -108,6 +108,8 @@ error_t parse_app_manifest(const std::map<std::string, std::string>& properties,
         out_manifest.stack.depth = static_cast<uint16_t>(stack_size);
     }
 
+    out_manifest.flags = 0;
+
     // <index>.hidden (optional; defaults to false)
     auto hidden_iterator = properties.find(prefix + "hidden");
     if (hidden_iterator != properties.end()) {
@@ -115,7 +117,21 @@ error_t parse_app_manifest(const std::map<std::string, std::string>& properties,
             LOG_E(TAG, "Invalid %shidden", prefix.c_str());
             return ERROR_INVALID_ARGUMENT;
         }
-        out_manifest.flags = hidden_iterator->second == "true" ? APP_MANIFEST_FLAG_HIDDEN : 0;
+        if (hidden_iterator->second == "true") {
+            out_manifest.flags |= APP_MANIFEST_FLAG_HIDDEN;
+        }
+    }
+
+    // <index>.headless (optional; defaults to false)
+    auto headless_iterator = properties.find(prefix + "headless");
+    if (headless_iterator != properties.end()) {
+        if (!app_package_manifest_is_valid_bool(headless_iterator->second)) {
+            LOG_E(TAG, "Invalid %sheadless", prefix.c_str());
+            return ERROR_INVALID_ARGUMENT;
+        }
+        if (headless_iterator->second == "true") {
+            out_manifest.flags |= APP_MANIFEST_FLAG_HEADLESS;
+        }
     }
 
     out_manifest.category = APP_CATEGORY_USER;

Modules/lvgl-module/source/widgets/toolbar.cpp

@@ -12,7 +12,7 @@
 
 static uint32_t getToolbarHeight(UiDensity uiDensity) {
     if (uiDensity == LVGL_UI_DENSITY_COMPACT) {
-        return lvgl_get_text_font_height(FONT_SIZE_DEFAULT) * 1.4f;
+        return lvgl_get_text_font_height(FONT_SIZE_DEFAULT) * 1.6f;
     } else {
         return lvgl_get_text_font_height(FONT_SIZE_LARGE) * 2.2f;
     }
@@ -29,7 +29,7 @@ static const _lv_font_t* getToolbarFont(UiDensity uiDensity) {
 static uint32_t getActionIconPadding(UiDensity uiDensity) {
     auto toolbar_height = getToolbarHeight(uiDensity);
     // Minimal 8 pixels total padding for selection/animation (4+4 pixels)
-    return (uiDensity != LVGL_UI_DENSITY_COMPACT) ? (uint32_t)(toolbar_height * 0.2f) : 8;
+    return (uiDensity != LVGL_UI_DENSITY_COMPACT) ? (uint32_t)(toolbar_height * 0.2f) : 10;
 }
 
 /**

Tactility/Include/Tactility/lvgl/Toolbar.h

@@ -1,7 +0,0 @@
-#pragma once
-
-#include <lvgl/widgets/toolbar.h>
-
-namespace tt::lvgl {
-
-} // namespace

Tactility/Source/app/alertdialog/AlertDialog.cpp

@@ -84,10 +84,13 @@ void createWidgets(lv_obj_t* parent, void* userData) {
     lv_obj_t* button_wrapper = lv_obj_create(parent);
     lv_obj_set_flex_flow(button_wrapper, LV_FLEX_FLOW_ROW);
     lv_obj_set_size(button_wrapper, LV_PCT(100), LV_SIZE_CONTENT);
-    lv_obj_set_style_pad_all(button_wrapper, 0, 0);
     lv_obj_set_flex_align(button_wrapper, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
     lv_obj_set_style_border_width(button_wrapper, 0, 0);
     lv_obj_align(button_wrapper, LV_ALIGN_BOTTOM_MID, 0, -4);
+    // Ensures showing selection state for keyboard/encoder devices
+    lv_obj_set_style_pad_all(button_wrapper, 0, LV_ALIGN_DEFAULT);
+    lv_obj_set_style_pad_column(button_wrapper, 12, LV_STATE_DEFAULT);
+    lv_obj_set_style_pad_ver(button_wrapper, 4, LV_STATE_DEFAULT);
 
     for (int32_t index = 0; index < argc - 2; index++) {
         createButton(ctx, button_wrapper, argv[2 + index], index);

Tactility/Source/app/btmanage/View.cpp

@@ -6,8 +6,6 @@
 #include <Tactility/app/btmanage/View.h>
 #include <Tactility/app/btmanage/BtManagePrivate.h>
 #include <Tactility/app/btpeersettings/BtPeerSettings.h>
-#include <Tactility/lvgl/Style.h>
-#include <Tactility/lvgl/Toolbar.h>
 #include <Tactility/bluetooth/Bluetooth.h>
 #include <Tactility/bluetooth/BluetoothSettings.h>
 #include <Tactility/bluetooth/BluetoothPairedDevice.h>

Tactility/Source/app/i2cscanner/I2cScanner.cpp

@@ -325,8 +325,9 @@ void createWidgets(lv_obj_t* parent, void* userData) {
     auto* wrapper = lv_obj_create(main_wrapper);
     lv_obj_set_width(wrapper, LV_PCT(100));
     lv_obj_set_height(wrapper, LV_SIZE_CONTENT);
-    lv_obj_set_style_pad_all(wrapper, 0, 0);
     lv_obj_set_style_border_width(wrapper, 0, 0);
+    // Ensures showing selection state for keyboard/encoder devices
+    lv_obj_set_style_pad_all(wrapper, 6, LV_ALIGN_DEFAULT);
 
     auto* scan_button = lv_button_create(wrapper);
     lv_obj_set_width(scan_button, LV_PCT(48));

Tactility/Source/app/inputdialog/InputDialog.cpp

@@ -10,7 +10,9 @@
 #include <lvgl_window_manager/window_manager.h>
 
 #include <lvgl/widgets/toolbar.h>
+
 #include <tactility/check.h>
+#include <tactility/error.h>
 #include <tactility/log.h>
 
 #include <lvgl.h>
@@ -86,6 +88,9 @@ void createWidgets(lv_obj_t* parent, void* userData) {
     lv_label_set_long_mode(message_label, LV_LABEL_LONG_WRAP);
 
     auto* textarea = lv_textarea_create(parent);
+    // Ensures showing selection state for keyboard/encoder devices
+    lv_obj_set_style_margin_hor(textarea, 4, LV_STATE_DEFAULT);
+    lv_obj_set_width(textarea, LV_PCT(80));
     lv_obj_align_to(textarea, message_label, LV_ALIGN_OUT_BOTTOM_MID, 0, 4);
     lv_textarea_set_one_line(textarea, true);
     if (argv[2][0] != '\0') {
@@ -99,6 +104,9 @@ void createWidgets(lv_obj_t* parent, void* userData) {
     lv_obj_set_flex_align(button_wrapper, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
     lv_obj_set_style_border_width(button_wrapper, 0, 0);
     lv_obj_align(button_wrapper, LV_ALIGN_BOTTOM_MID, 0, -4);
+    // Ensures showing selection state for keyboard/encoder devices
+    lv_obj_set_style_pad_column(button_wrapper, 12, LV_STATE_DEFAULT);
+    lv_obj_set_style_pad_ver(button_wrapper, 6, LV_STATE_DEFAULT);
 
     createButton(ctx, button_wrapper, "OK", textarea);
     createButton(ctx, button_wrapper, "Cancel", nullptr);
@@ -106,7 +114,7 @@ void createWidgets(lv_obj_t* parent, void* userData) {
 
 int32_t appMain(int argc, char* argv[]) {
     uint32_t appInstanceId = app_scheduler_current_app_id();
-    Context ctx { appInstanceId };
+    Context ctx { .appInstanceId = appInstanceId };
     ctx.argc = argc;
     ctx.argv = argv;
 

Tactility/Source/app/usbsettings/UsbSettings.cpp

@@ -53,6 +53,8 @@ void createWidgets(lv_obj_t* parent, void* userData) {
     lv_obj_set_flex_align(wrapper, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER, LV_FLEX_ALIGN_CENTER);
     lv_obj_set_size(wrapper, lv_pct(100), LV_SIZE_CONTENT);
     lv_obj_align(wrapper, LV_ALIGN_CENTER, 0, 0);
+    // Ensures showing selection state for keyboard/encoder devices
+    lv_obj_set_style_pad_all(wrapper, 6, LV_ALIGN_DEFAULT);
 
     bool hasSd = hal::usb::canRebootIntoMassStorageSdmmc();
     bool hasFlash = hal::usb::canRebootIntoMassStorageFlash();

Tactility/Source/lvgl/Toolbar.cpp

@@ -1 +0,0 @@
-#include <Tactility/lvgl/Toolbar.h>

Tactility/Source/lvgl/wrappers/button.cpp

@@ -12,7 +12,7 @@ lv_obj_t* __wrap_lv_button_create(lv_obj_t* parent) {
     auto button = __real_lv_button_create(parent);
 
     if (lvgl_get_ui_density() == LVGL_UI_DENSITY_COMPACT) {
-        lv_obj_set_style_pad_all(button, 2, LV_STATE_DEFAULT);
+        lv_obj_set_style_pad_all(button, 3, LV_STATE_DEFAULT);
         lv_obj_set_style_radius(button, 3, LV_STATE_DEFAULT);
     }
 

TactilityKernel/include/tactility/drivers/display.h

@@ -218,6 +218,7 @@ struct DisplayApi {
 
     /**
      * @brief Gets a pointer to one of the panel's frame buffers, for panels that expose direct frame buffer access.
+     * @warning Nullable. When null, display_get_frame_buffer() sets *out_buffer to NULL.
      * @param[in] device the display device
      * @param[in] index the frame buffer index (see get_frame_buffer_count())
      * @param[out] out_buffer the buffer pointer
@@ -226,6 +227,7 @@ struct DisplayApi {
 
     /**
      * @brief Gets the number of frame buffers exposed by the panel via get_frame_buffer(). 0 when unsupported.
+     * @warning Nullable. When null, display_get_frame_buffer_count() returns 0.
      * @param[in] device the display device
      * @return the frame buffer count
      */
@@ -366,11 +368,13 @@ uint16_t display_get_resolution_y(struct Device* device);
 
 /**
  * @brief Gets a pointer to one of the panel's frame buffers using the specified display.
+ * @param[out] out_buffer set to NULL when the display doesn't expose frame buffers
  */
 void display_get_frame_buffer(struct Device* device, uint8_t index, void** out_buffer);
 
 /**
  * @brief Gets the number of frame buffers exposed by the panel using the specified display.
+ * @return the frame buffer count, or 0 when the display doesn't expose frame buffers
  */
 uint8_t display_get_frame_buffer_count(struct Device* device);
 

TactilityKernel/source/drivers/display.cpp

@@ -122,12 +122,21 @@ uint16_t display_get_resolution_y(Device* device) {
 
 void display_get_frame_buffer(Device* device, uint8_t index, void** out_buffer) {
     const auto* driver = device_get_driver(device);
-    DISPLAY_DRIVER_API(driver)->get_frame_buffer(device, index, out_buffer);
+    const auto* api = DISPLAY_DRIVER_API(driver);
+    if (api->get_frame_buffer == nullptr) {
+        *out_buffer = nullptr;
+        return;
+    }
+    api->get_frame_buffer(device, index, out_buffer);
 }
 
 uint8_t display_get_frame_buffer_count(Device* device) {
     const auto* driver = device_get_driver(device);
-    return DISPLAY_DRIVER_API(driver)->get_frame_buffer_count(device);
+    const auto* api = DISPLAY_DRIVER_API(driver);
+    if (api->get_frame_buffer_count == nullptr) {
+        return 0;
+    }
+    return api->get_frame_buffer_count(device);
 }
 
 error_t display_get_backlight(Device* device, Device** backlight) {