Fix display corruption when the timer is triggered

src/displayapp/DisplayApp.cpp

@@ -207,7 +207,7 @@ void DisplayApp::Refresh() {
       case Messages::TimerDone:
         if (currentApp == Apps::Timer) {
           auto* timer = static_cast<Screens::Timer*>(currentScreen.get());
-          timer->setDone();
+          timer->SetDone();
         } else {
           LoadApp(Apps::Timer, DisplayApp::FullRefreshDirections::Down);
         }

src/displayapp/screens/Timer.cpp

@@ -1,17 +1,16 @@
 #include "displayapp/screens/Timer.h"
-
 #include "displayapp/screens/Screen.h"
 #include "displayapp/screens/Symbols.h"
 #include <lvgl/lvgl.h>
 
 using namespace Pinetime::Applications::Screens;
 
 static void btnEventHandler(lv_obj_t* obj, lv_event_t event) {
-  Timer* screen = static_cast<Timer*>(obj->user_data);
+  auto* screen = static_cast<Timer*>(obj->user_data);
   screen->OnButtonEvent(obj, event);
 }
 
-void Timer::createButtons() {
+void Timer::CreateButtons() {
   btnMinutesUp = lv_btn_create(lv_scr_act(), nullptr);
   btnMinutesUp->user_data = this;
   lv_obj_set_event_cb(btnMinutesUp, btnEventHandler);
@@ -51,6 +50,12 @@ void Timer::createButtons() {
 
 Timer::Timer(DisplayApp* app, Controllers::TimerController& timerController)
   : Screen(app), running {true}, timerController {timerController} {
+  backgroundLabel = lv_label_create(lv_scr_act(), nullptr);
+  lv_obj_set_click(backgroundLabel, true);
+  lv_label_set_long_mode(backgroundLabel, LV_LABEL_LONG_CROP);
+  lv_obj_set_size(backgroundLabel, 240, 240);
+  lv_obj_set_pos(backgroundLabel, 0, 0);
+  lv_label_set_text(backgroundLabel, "");
 
   time = lv_label_create(lv_scr_act(), nullptr);
   lv_obj_set_style_local_text_font(time, LV_LABEL_PART_MAIN, LV_STATE_DEFAULT, &jetbrains_mono_76);
@@ -71,7 +76,7 @@ Timer::Timer(DisplayApp* app, Controllers::TimerController& timerController)
     lv_label_set_text(txtPlayPause, Symbols::pause);
   } else {
     lv_label_set_text(txtPlayPause, Symbols::play);
-    createButtons();
+    CreateButtons();
   }
 
   taskRefresh = lv_task_create(RefreshTaskCallback, LV_DISP_DEF_REFR_PERIOD, LV_TASK_PRIO_MID, this);
@@ -98,7 +103,7 @@ void Timer::OnButtonEvent(lv_obj_t* obj, lv_event_t event) {
         minutesToSet = seconds / 60;
         secondsToSet = seconds % 60;
         timerController.StopTimer();
-        createButtons();
+        CreateButtons();
 
       } else if (secondsToSet + minutesToSet > 0) {
         lv_label_set_text(txtPlayPause, Symbols::pause);
@@ -152,10 +157,10 @@ void Timer::OnButtonEvent(lv_obj_t* obj, lv_event_t event) {
   }
 }
 
-void Timer::setDone() {
+void Timer::SetDone() {
   lv_label_set_text(time, "00:00");
   lv_label_set_text(txtPlayPause, Symbols::play);
   secondsToSet = 0;
   minutesToSet = 0;
-  createButtons();
+  CreateButtons();
 }

src/displayapp/screens/Timer.h

@@ -8,32 +8,35 @@
 #include "components/timer/TimerController.h"
 
 namespace Pinetime::Applications::Screens {
-
   class Timer : public Screen {
   public:
     enum class Modes { Normal, Done };
 
     Timer(DisplayApp* app, Controllers::TimerController& timerController);
-
     ~Timer() override;
-
     void Refresh() override;
-
-    void setDone();
-
+    void SetDone();
     void OnButtonEvent(lv_obj_t* obj, lv_event_t event);
 
   private:
+    void CreateButtons();
     bool running;
     uint8_t secondsToSet = 0;
     uint8_t minutesToSet = 0;
     Controllers::TimerController& timerController;
-
-    void createButtons();
-
-    lv_obj_t *time, *msecTime, *btnPlayPause, *txtPlayPause, *btnMinutesUp, *btnMinutesDown, *btnSecondsUp, *btnSecondsDown, *txtMUp,
-      *txtMDown, *txtSUp, *txtSDown;
-
+    lv_obj_t* backgroundLabel;
+    lv_obj_t* time;
+    lv_obj_t* msecTime;
+    lv_obj_t* btnPlayPause;
+    lv_obj_t* txtPlayPause;
+    lv_obj_t* btnMinutesUp;
+    lv_obj_t* btnMinutesDown;
+    lv_obj_t* btnSecondsUp;
+    lv_obj_t* btnSecondsDown;
+    lv_obj_t* txtMUp;
+    lv_obj_t* txtMDown;
+    lv_obj_t* txtSUp;
+    lv_obj_t* txtSDown;
     lv_task_t* taskRefresh;
   };
 }