Clean code.

esp/cpp/07_lcd-panel/main/display.cpp

@@ -26,29 +26,28 @@ Display::Display(const I2C &i2c) :
   }
 
   // Create a lvgl display.
-  // TODO: Use PanelDevice functions
+  // TODO: Use PanelDevice functions to get SSD1306 specs
   display_ = lv_display_create(LCD_H_RES, LCD_V_RES);
   // associate the i2c panel handle to the display
   lv_display_set_user_data(display_, panel_.get());
+
   // Create draw buffer.
   ESP_LOGI(TAG, "Allocate separate LVGL draw buffers");
-  // TODO: Use PanelDevice functions
+  // TODO: Use PanelDevice functions to get SSD1306 specs
-  size_t draw_buffer_sz = LCD_H_RES * LCD_V_RES / 8 + LVGL_PALETTE_SIZE;
+  buf_size_ = LCD_H_RES * LCD_V_RES / 8 + LVGL_PALETTE_SIZE;
-  buf_ = heap_caps_calloc(1, draw_buffer_sz,
+  buf_ = heap_caps_calloc(1, buf_size_, MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
-                          MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
   assert(buf_);
 
   // LVGL9 suooprt new monochromatic format.
   lv_display_set_color_format(display_, LV_COLOR_FORMAT_I1);
   // Initialize LVGL draw buffers.
-  lv_display_set_buffers(display_, buf_, nullptr, draw_buffer_sz,
+  lv_display_set_buffers(display_, buf_, nullptr, buf_size_,
                          LV_DISPLAY_RENDER_MODE_FULL);
   lv_display_set_rotation(display_, LV_DISPLAY_ROTATION_0);
   // Set callback which can copy the rendered image to an area of the display.
   lv_display_set_flush_cb(display_, Display::lvgl_flush_cb);
 
-  ESP_LOGI(TAG,
+  ESP_LOGI(TAG, "Register io panel callback for LVGL flush ready notification");
-           "Register io panel event callback for LVGL flush ready notification");
   const esp_lcd_panel_io_callbacks_t cbs = {
       .on_color_trans_done = Display::lvgl_flush_ready,
   };
@@ -189,19 +188,21 @@ I2C::I2C() :
 Panel::Panel(i2c_master_bus_handle_t i2c) :
     io_handle_(nullptr),
     panel_(nullptr),
+    // According to SSD1306 datasheet
     panel_config_(
         (esp_lcd_panel_dev_config_t) {
             .reset_gpio_num = PIN_RST,
             .bits_per_pixel = 1,
         }
     ),
+    // According to SSD1306 datasheet
     io_config_(
         (esp_lcd_panel_io_i2c_config_t) {
             .dev_addr = I2C_HW_ADDR,
-            .control_phase_bytes = 1,          // According to SSD1306 datasheet
+            .control_phase_bytes = 1,
-            .dc_bit_offset = 6,                // According to SSD1306 datasheet
+            .dc_bit_offset = 6,
-            .lcd_cmd_bits = LCD_CMD_BITS,      // According to SSD1306 datasheet
+            .lcd_cmd_bits = LCD_CMD_BITS,
-            .lcd_param_bits = LCD_CMD_BITS,    // According to SSD1306 datasheet
+            .lcd_param_bits = LCD_CMD_BITS,
             .scl_speed_hz = LCD_PIXEL_CLOCK_HZ,
         }
     )

esp/cpp/07_lcd-panel/main/display.h

@@ -106,8 +106,15 @@ private:
 
   lv_display_t *display_;
 
+  // Size of the draw buffer associated with the lv_display_t.
+  size_t buf_size_;
+
+  // Draw buffer associated with the lv_display_t.
   void *buf_;
 
+  // Objects stored in the screen associated with this display.
+  // @sa Display::set_text
+  // @sa lv_display_get_screen_active
   std::unordered_map<const char *, lv_obj_t *> objects_;
 };
 

esp/cpp/07_lcd-panel/main/panel_device.h

@@ -9,11 +9,11 @@
 #define LVGL_PALETTE_SIZE      8
 
 template<typename T>
-class PanelDevice {
+class PanelDeviceInterface {
 public:
-  PanelDevice(size_t width, size_t height) : width_(width), height_(height) { }
+  PanelDeviceInterface(size_t width, size_t height) : width_(width), height_(height) { }
 
-  ~PanelDevice() = default;
+  ~PanelDeviceInterface() = default;
 
   [[nodiscard]] size_t get_width() const { return width_; }
 
@@ -47,7 +47,7 @@ protected:
 };
 
 template<typename T>
-void PanelDevice<T>::create_panel(esp_lcd_panel_dev_config_t &config,
+void PanelDeviceInterface<T>::create_panel(esp_lcd_panel_dev_config_t &config,
                                            esp_lcd_panel_io_handle_t io,
                                            esp_lcd_panel_handle_t &panel)
 {

esp/cpp/07_lcd-panel/main/ssd1306.cpp

@@ -7,7 +7,7 @@ uint8_t SSD1306::oled_buffer_[LCD_H_RES * LCD_V_RES / 8];
 SSD1306::SSD1306(esp_lcd_panel_ssd1306_config_t ssd_config,
                  int width,
                  int height) :
-    PanelDevice<esp_lcd_panel_ssd1306_config_t>(width, height)
+    PanelDeviceInterface<esp_lcd_panel_ssd1306_config_t>(width, height)
 {
   vendor_config_ = ssd_config;
 }

esp/cpp/07_lcd-panel/main/ssd1306.h

@@ -22,7 +22,7 @@
 #define PIN_SCL                GPIO_NUM_22
 #define PIN_RST                -1
 
-class SSD1306 : public PanelDevice<esp_lcd_panel_ssd1306_config_t> {
+class SSD1306 : public PanelDeviceInterface<esp_lcd_panel_ssd1306_config_t> {
 public:
   explicit SSD1306(esp_lcd_panel_ssd1306_config_t ssd_config,
                    int width = SCREEN_WIDTH, int height = SCREEN_HEIGHT);