Fix USB-UART bridge exit screen stopping the bridge prematurely (#3892)

* fix: exit screen stopping bridge prematurely
* refactor: merge exit confirmation scene into main usb uart scene

applications/main/gpio/scenes/gpio_scene_config.h

@@ -3,4 +3,3 @@ ADD_SCENE(gpio, test, Test)
 ADD_SCENE(gpio, usb_uart, UsbUart)
 ADD_SCENE(gpio, usb_uart_cfg, UsbUartCfg)
 ADD_SCENE(gpio, usb_uart_close_rpc, UsbUartCloseRpc)
-ADD_SCENE(gpio, exit_confirm, ExitConfirm)

applications/main/gpio/scenes/gpio_scene_usb_uart.c

@@ -6,18 +6,29 @@ typedef struct {
     UsbUartState state;
 } SceneUsbUartBridge;
 
-static SceneUsbUartBridge* scene_usb_uart;
+static SceneUsbUartBridge* scene_usb_uart = NULL;
 
 void gpio_scene_usb_uart_callback(GpioCustomEvent event, void* context) {
     furi_assert(context);
     GpioApp* app = context;
     view_dispatcher_send_custom_event(app->view_dispatcher, event);
 }
 
+void gpio_scene_usb_uart_dialog_callback(DialogExResult result, void* context) {
+    GpioApp* app = context;
+    if(result == DialogExResultLeft) {
+        usb_uart_disable(app->usb_uart_bridge);
+        free(scene_usb_uart);
+        scene_usb_uart = NULL;
+        scene_manager_search_and_switch_to_previous_scene(app->scene_manager, GpioSceneStart);
+    } else {
+        view_dispatcher_switch_to_view(app->view_dispatcher, GpioAppViewUsbUart);
+    }
+}
+
 void gpio_scene_usb_uart_on_enter(void* context) {
     GpioApp* app = context;
-    uint32_t prev_state = scene_manager_get_scene_state(app->scene_manager, GpioAppViewUsbUart);
-    if(prev_state == 0) {
+    if(!scene_usb_uart) {
         scene_usb_uart = malloc(sizeof(SceneUsbUartBridge));
         scene_usb_uart->cfg.vcp_ch = 0;
         scene_usb_uart->cfg.uart_ch = 0;
@@ -31,19 +42,23 @@ void gpio_scene_usb_uart_on_enter(void* context) {
     usb_uart_get_state(app->usb_uart_bridge, &scene_usb_uart->state);
 
     gpio_usb_uart_set_callback(app->gpio_usb_uart, gpio_scene_usb_uart_callback, app);
-    scene_manager_set_scene_state(app->scene_manager, GpioSceneUsbUart, 0);
     view_dispatcher_switch_to_view(app->view_dispatcher, GpioAppViewUsbUart);
     notification_message(app->notifications, &sequence_display_backlight_enforce_on);
 }
 
 bool gpio_scene_usb_uart_on_event(void* context, SceneManagerEvent event) {
     GpioApp* app = context;
     if(event.type == SceneManagerEventTypeCustom) {
-        scene_manager_set_scene_state(app->scene_manager, GpioSceneUsbUart, 1);
         scene_manager_next_scene(app->scene_manager, GpioSceneUsbUartCfg);
         return true;
     } else if(event.type == SceneManagerEventTypeBack) {
-        scene_manager_next_scene(app->scene_manager, GpioSceneExitConfirm);
+        DialogEx* dialog = app->dialog;
+        dialog_ex_set_context(dialog, app);
+        dialog_ex_set_left_button_text(dialog, "Exit");
+        dialog_ex_set_right_button_text(dialog, "Stay");
+        dialog_ex_set_header(dialog, "Exit USB-UART?", 22, 12, AlignLeft, AlignTop);
+        dialog_ex_set_result_callback(dialog, gpio_scene_usb_uart_dialog_callback);
+        view_dispatcher_switch_to_view(app->view_dispatcher, GpioAppViewExitConfirm);
         return true;
     } else if(event.type == SceneManagerEventTypeTick) {
         uint32_t tx_cnt_last = scene_usb_uart->state.tx_cnt;
@@ -61,10 +76,5 @@ bool gpio_scene_usb_uart_on_event(void* context, SceneManagerEvent event) {
 
 void gpio_scene_usb_uart_on_exit(void* context) {
     GpioApp* app = context;
-    uint32_t prev_state = scene_manager_get_scene_state(app->scene_manager, GpioSceneUsbUart);
-    if(prev_state == 0) {
-        usb_uart_disable(app->usb_uart_bridge);
-        free(scene_usb_uart);
-    }
     notification_message(app->notifications, &sequence_display_backlight_enforce_auto);
 }