feat: add AppRegistry, RootLayout, UIHandler, and UIApp classes for improved UI management

main/ui/root_layout.h

@@ -0,0 +1,138 @@
+#pragma once
+
+#include "lvgl.h"
+#include "esp_err.h"
+#include <string>
+
+// Forward declaration
+class UIHandler;
+
+/**
+ * @brief Root Layout Manager - manages the main screen layout
+ *
+ * The RootLayout class is responsible for:
+ * - Creating and managing the main screen structure (header, app container, nav bar)
+ * - Rendering app icons from the AppRegistry
+ * - Managing the back button
+ * - Updating header content
+ */
+class RootLayout {
+public:
+  /**
+   * @brief Construct a new RootLayout object
+   *
+   * @param ui_handler Pointer to the UIHandler (for callbacks)
+   */
+  RootLayout(UIHandler* ui_handler);
+
+  /**
+   * @brief Initialize the layout
+   *
+   * Creates the main screen with header, app container, and navigation bar.
+   *
+   * @param parent Parent LVGL object to attach layout to
+   * @return ESP_OK on success, error code otherwise
+   */
+  esp_err_t init(lv_obj_t* parent);
+
+  /**
+   * @brief Deinitialize the layout
+   *
+   * Cleans up all layout widgets.
+   *
+   * @return ESP_OK on success, error code otherwise
+   */
+  esp_err_t deinit(void);
+
+  /**
+   * @brief Render app icons in the navigation bar
+   *
+   * Queries the AppRegistry for all registered apps and
+   * renders their icons in the navigation bar. Also creates
+   * the back button.
+   *
+   * @return ESP_OK on success, error code otherwise
+   */
+  esp_err_t render_app_icons(void);
+
+  /**
+   * @brief Update header with app name
+   *
+   * @param app_name Name to display in header (nullptr for default)
+   */
+  void update_header(std::string app_name);
+
+  /**
+   * @brief Show the back button
+   */
+  void show_back_button(void);
+
+  /**
+   * @brief Hide the back button
+   */
+  void hide_back_button(void);
+
+  /**
+   * @brief Get the header object
+   *
+   * @return lv_obj_t* pointer to the header container
+   */
+  lv_obj_t* get_header(void) const {
+    return _header;
+  }
+
+  /**
+   * @brief Get the app container (where apps render)
+   *
+   * @return lv_obj_t* pointer to the app container
+   */
+  lv_obj_t* get_app_container(void) const {
+    return _app_container;
+  }
+
+  /**
+   * @brief Get the navigation bar object
+   *
+   * @return lv_obj_t* pointer to the navigation bar container
+   */
+  lv_obj_t* get_nav_bar(void) const {
+    return _nav_bar;
+  }
+
+private:
+  UIHandler* _ui_handler = nullptr;      ///< Reference to UIHandler for callbacks
+  lv_obj_t* _header = nullptr;           ///< Header area (top)
+  lv_obj_t* _header_label = nullptr;     ///< Header text label
+  lv_obj_t* _app_container = nullptr;    ///< Container for app widgets (middle)
+  lv_obj_t* _nav_bar = nullptr;          ///< Navigation bar (bottom)
+  lv_obj_t* _back_button = nullptr;      ///< Back button in navigation bar
+
+  /**
+   * @brief Create the layout structure
+   *
+   * Sets up header, app container, and navigation bar with
+   * appropriate dimensions and positioning.
+   *
+   * @param parent Parent object to attach layout to
+   * @return ESP_OK on success, error code otherwise
+   */
+  esp_err_t create_layout(lv_obj_t* parent);
+
+  /**
+   * @brief Handle app icon click event
+   *
+   * Static callback for LVGL event handling.
+   *
+   * @param event LVGL event object
+   */
+  static void on_app_icon_clicked(lv_event_t* event);
+
+  /**
+   * @brief Handle back button click event
+   *
+   * Static callback for LVGL event handling.
+   *
+   * @param event LVGL event object
+   */
+  static void on_back_button_clicked(lv_event_t* event);
+};