Implement a return app stack

Each opened app (screen) is pushed on a stack, which is then popped from
when returning instead of hard coded "previous apps". Return swipe and
refresh directions are automatically determined from the app transition.

src/StaticStack.h

@@ -0,0 +1,38 @@
+#include <array>
+#include <cstddef>
+
+template <typename T, size_t N> class StaticStack {
+public:
+  T Pop();
+  void Push(T element);
+  void Reset();
+  T Top();
+
+private:
+  std::array<T, N> elementArray;
+  // Number of elements in stack, points to the next empty slot
+  size_t stackPointer = 0;
+};
+
+// Returns random data when popping from empty array.
+template <typename T, size_t N> T StaticStack<T, N>::Pop() {
+  if (stackPointer > 0) {
+    stackPointer--;
+  }
+  return elementArray[stackPointer];
+}
+
+template <typename T, size_t N> void StaticStack<T, N>::Push(T element) {
+  if (stackPointer < elementArray.size()) {
+    elementArray[stackPointer] = element;
+    stackPointer++;
+  }
+}
+
+template <typename T, size_t N> void StaticStack<T, N>::Reset() {
+  stackPointer = 0;
+}
+
+template <typename T, size_t N> T StaticStack<T, N>::Top() {
+  return elementArray[stackPointer - 1];
+}

src/displayapp/DisplayApp.cpp

@@ -102,9 +102,9 @@ void DisplayApp::Start(System::BootErrors error) {
   bootError = error;
 
   if (error == System::BootErrors::TouchController) {
-    LoadApp(Apps::Error, DisplayApp::FullRefreshDirections::None);
+    LoadNewScreen(Apps::Error, DisplayApp::FullRefreshDirections::None);
   } else {
-    LoadApp(Apps::Clock, DisplayApp::FullRefreshDirections::None);
+    LoadNewScreen(Apps::Clock, DisplayApp::FullRefreshDirections::None);
   }
 
   if (pdPASS != xTaskCreate(DisplayApp::Process, "displayapp", 800, this, 0, &taskHandle)) {
@@ -132,7 +132,25 @@ void DisplayApp::InitHw() {
 
 void DisplayApp::Refresh() {
   auto LoadPreviousScreen = [this]() {
-    LoadApp(returnToApp, returnDirection);
+    FullRefreshDirections returnDirection;
+    switch (appStackDirections.Pop()) {
+      case FullRefreshDirections::Up:
+        returnDirection = FullRefreshDirections::Down;
+        break;
+      case FullRefreshDirections::Down:
+        returnDirection = FullRefreshDirections::Up;
+        break;
+      case FullRefreshDirections::LeftAnim:
+        returnDirection = FullRefreshDirections::RightAnim;
+        break;
+      case FullRefreshDirections::RightAnim:
+        returnDirection = FullRefreshDirections::LeftAnim;
+        break;
+      default:
+        returnDirection = FullRefreshDirections::None;
+        break;
+    }
+    LoadScreen(returnAppStack.Pop(), returnDirection);
   };
 
   TickType_t queueTimeout;
@@ -180,14 +198,14 @@ void DisplayApp::Refresh() {
         //        Screens::Clock::BleConnectionStates::NotConnected);
         break;
       case Messages::NewNotification:
-        LoadApp(Apps::NotificationsPreview, DisplayApp::FullRefreshDirections::Down);
+        LoadNewScreen(Apps::NotificationsPreview, DisplayApp::FullRefreshDirections::Down);
         break;
       case Messages::TimerDone:
         if (currentApp == Apps::Timer) {
           auto* timer = static_cast<Screens::Timer*>(currentScreen.get());
           timer->Reset();
         } else {
-          LoadApp(Apps::Timer, DisplayApp::FullRefreshDirections::Down);
+          LoadNewScreen(Apps::Timer, DisplayApp::FullRefreshDirections::Up);
         }
         break;
       case Messages::AlarmTriggered:
@@ -195,11 +213,11 @@ void DisplayApp::Refresh() {
           auto* alarm = static_cast<Screens::Alarm*>(currentScreen.get());
           alarm->SetAlerting();
         } else {
-          LoadApp(Apps::Alarm, DisplayApp::FullRefreshDirections::None);
+          LoadNewScreen(Apps::Alarm, DisplayApp::FullRefreshDirections::None);
         }
         break;
       case Messages::ShowPairingKey:
-        LoadApp(Apps::PassKey, DisplayApp::FullRefreshDirections::Up);
+        LoadNewScreen(Apps::PassKey, DisplayApp::FullRefreshDirections::Up);
         break;
       case Messages::TouchEvent: {
         if (state != States::Running) {
@@ -209,17 +227,30 @@ void DisplayApp::Refresh() {
         if (gesture == TouchEvents::None) {
           break;
         }
+        auto LoadDirToReturnSwipe = [](DisplayApp::FullRefreshDirections refreshDirection) {
+          switch (refreshDirection) {
+            default:
+            case DisplayApp::FullRefreshDirections::Up:
+              return TouchEvents::SwipeDown;
+            case DisplayApp::FullRefreshDirections::Down:
+              return TouchEvents::SwipeUp;
+            case DisplayApp::FullRefreshDirections::LeftAnim:
+              return TouchEvents::SwipeRight;
+            case DisplayApp::FullRefreshDirections::RightAnim:
+              return TouchEvents::SwipeLeft;
+          }
+        };
         if (!currentScreen->OnTouchEvent(gesture)) {
           if (currentApp == Apps::Clock) {
             switch (gesture) {
               case TouchEvents::SwipeUp:
-                LoadApp(Apps::Launcher, DisplayApp::FullRefreshDirections::Up);
+                LoadNewScreen(Apps::Launcher, DisplayApp::FullRefreshDirections::Up);
                 break;
               case TouchEvents::SwipeDown:
-                LoadApp(Apps::Notifications, DisplayApp::FullRefreshDirections::Down);
+                LoadNewScreen(Apps::Notifications, DisplayApp::FullRefreshDirections::Down);
                 break;
               case TouchEvents::SwipeRight:
-                LoadApp(Apps::QuickSettings, DisplayApp::FullRefreshDirections::RightAnim);
+                LoadNewScreen(Apps::QuickSettings, DisplayApp::FullRefreshDirections::RightAnim);
                 break;
               case TouchEvents::DoubleTap:
                 PushMessageToSystemTask(System::Messages::GoToSleep);
@@ -227,7 +258,7 @@ void DisplayApp::Refresh() {
               default:
                 break;
             }
-          } else if (returnTouchEvent == gesture) {
+          } else if (gesture == LoadDirToReturnSwipe(appStackDirections.Top())) {
             LoadPreviousScreen();
           }
         } else {
@@ -246,26 +277,28 @@ void DisplayApp::Refresh() {
       case Messages::ButtonLongPressed:
         if (currentApp != Apps::Clock) {
           if (currentApp == Apps::Notifications) {
-            LoadApp(Apps::Clock, DisplayApp::FullRefreshDirections::Up);
+            LoadNewScreen(Apps::Clock, DisplayApp::FullRefreshDirections::Up);
           } else if (currentApp == Apps::QuickSettings) {
-            LoadApp(Apps::Clock, DisplayApp::FullRefreshDirections::LeftAnim);
+            LoadNewScreen(Apps::Clock, DisplayApp::FullRefreshDirections::LeftAnim);
           } else {
-            LoadApp(Apps::Clock, DisplayApp::FullRefreshDirections::Down);
+            LoadNewScreen(Apps::Clock, DisplayApp::FullRefreshDirections::Down);
           }
+          appStackDirections.Reset();
+          returnAppStack.Reset();
         }
         break;
       case Messages::ButtonLongerPressed:
         // Create reboot app and open it instead
-        LoadApp(Apps::SysInfo, DisplayApp::FullRefreshDirections::Up);
+        LoadNewScreen(Apps::SysInfo, DisplayApp::FullRefreshDirections::Up);
         break;
       case Messages::ButtonDoubleClicked:
         if (currentApp != Apps::Notifications && currentApp != Apps::NotificationsPreview) {
-          LoadApp(Apps::Notifications, DisplayApp::FullRefreshDirections::Down);
+          LoadNewScreen(Apps::Notifications, DisplayApp::FullRefreshDirections::Down);
         }
         break;
 
       case Messages::BleFirmwareUpdateStarted:
-        LoadApp(Apps::FirmwareUpdate, DisplayApp::FullRefreshDirections::Down);
+        LoadNewScreen(Apps::FirmwareUpdate, DisplayApp::FullRefreshDirections::Down);
         break;
       case Messages::BleRadioEnableToggle:
         PushMessageToSystemTask(System::Messages::BleRadioEnableToggle);
@@ -275,7 +308,7 @@ void DisplayApp::Refresh() {
         // What should happen here?
         break;
       case Messages::Clock:
-        LoadApp(Apps::Clock, DisplayApp::FullRefreshDirections::None);
+        LoadNewScreen(Apps::Clock, DisplayApp::FullRefreshDirections::None);
         break;
     }
   }
@@ -285,7 +318,7 @@ void DisplayApp::Refresh() {
   }
 
   if (nextApp != Apps::None) {
-    LoadApp(nextApp, nextDirection);
+    LoadNewScreen(nextApp, nextDirection);
     nextApp = Apps::None;
   }
 }
@@ -295,27 +328,23 @@ void DisplayApp::StartApp(Apps app, DisplayApp::FullRefreshDirections direction)
   nextDirection = direction;
 }
 
-void DisplayApp::ReturnApp(Apps app, DisplayApp::FullRefreshDirections direction, TouchEvents touchEvent) {
+void DisplayApp::LoadNewScreen(Apps app, DisplayApp::FullRefreshDirections direction) {
-  returnToApp = app;
+  returnAppStack.Push(currentApp);
-  returnDirection = direction;
+  appStackDirections.Push(direction);
-  returnTouchEvent = touchEvent;
+  LoadScreen(app, direction);
 }
 
-void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction) {
+void DisplayApp::LoadScreen(Apps app, DisplayApp::FullRefreshDirections direction) {
   touchHandler.CancelTap();
   ApplyBrightness();
 
   currentScreen.reset(nullptr);
   SetFullRefresh(direction);
 
-  // default return to launcher
-  ReturnApp(Apps::Launcher, FullRefreshDirections::Down, TouchEvents::SwipeDown);
-
   switch (app) {
     case Apps::Launcher:
       currentScreen =
         std::make_unique<Screens::ApplicationList>(this, settingsController, batteryController, bleController, dateTimeController);
-      ReturnApp(Apps::Clock, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::None:
     case Apps::Clock:
@@ -332,21 +361,17 @@ void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction)
 
     case Apps::Error:
       currentScreen = std::make_unique<Screens::Error>(this, bootError);
-      ReturnApp(Apps::Clock, FullRefreshDirections::Down, TouchEvents::None);
       break;
 
     case Apps::FirmwareValidation:
       currentScreen = std::make_unique<Screens::FirmwareValidation>(this, validator);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::FirmwareUpdate:
       currentScreen = std::make_unique<Screens::FirmwareUpdate>(this, bleController);
-      ReturnApp(Apps::Clock, FullRefreshDirections::Down, TouchEvents::None);
       break;
 
     case Apps::PassKey:
       currentScreen = std::make_unique<Screens::PassKey>(this, bleController.GetPairingKey());
-      ReturnApp(Apps::Clock, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
 
     case Apps::Notifications:
@@ -356,7 +381,6 @@ void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction)
                                                                motorController,
                                                                *systemTask,
                                                                Screens::Notifications::Modes::Normal);
-      ReturnApp(Apps::Clock, FullRefreshDirections::Up, TouchEvents::SwipeUp);
       break;
     case Apps::NotificationsPreview:
       currentScreen = std::make_unique<Screens::Notifications>(this,
@@ -365,7 +389,6 @@ void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction)
                                                                motorController,
                                                                *systemTask,
                                                                Screens::Notifications::Modes::Preview);
-      ReturnApp(Apps::Clock, FullRefreshDirections::Up, TouchEvents::SwipeUp);
       break;
     case Apps::Timer:
       currentScreen = std::make_unique<Screens::Timer>(this, timerController);
@@ -383,55 +406,42 @@ void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction)
                                                                motorController,
                                                                settingsController,
                                                                bleController);
-      ReturnApp(Apps::Clock, FullRefreshDirections::LeftAnim, TouchEvents::SwipeLeft);
       break;
     case Apps::Settings:
       currentScreen = std::make_unique<Screens::Settings>(this, settingsController);
-      ReturnApp(Apps::QuickSettings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingWatchFace:
       currentScreen = std::make_unique<Screens::SettingWatchFace>(this, settingsController, filesystem);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingTimeFormat:
       currentScreen = std::make_unique<Screens::SettingTimeFormat>(this, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingWakeUp:
       currentScreen = std::make_unique<Screens::SettingWakeUp>(this, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingDisplay:
       currentScreen = std::make_unique<Screens::SettingDisplay>(this, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingSteps:
       currentScreen = std::make_unique<Screens::SettingSteps>(this, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingSetDate:
       currentScreen = std::make_unique<Screens::SettingSetDate>(this, dateTimeController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingSetTime:
       currentScreen = std::make_unique<Screens::SettingSetTime>(this, dateTimeController, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingChimes:
       currentScreen = std::make_unique<Screens::SettingChimes>(this, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingShakeThreshold:
       currentScreen = std::make_unique<Screens::SettingShakeThreshold>(this, settingsController, motionController, *systemTask);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SettingBluetooth:
       currentScreen = std::make_unique<Screens::SettingBluetooth>(this, settingsController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::BatteryInfo:
       currentScreen = std::make_unique<Screens::BatteryInfo>(this, batteryController);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::SysInfo:
       currentScreen = std::make_unique<Screens::SystemInfo>(this,
@@ -442,11 +452,9 @@ void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction)
                                                             watchdog,
                                                             motionController,
                                                             touchPanel);
-      ReturnApp(Apps::Settings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::FlashLight:
       currentScreen = std::make_unique<Screens::FlashLight>(this, *systemTask, brightnessController);
-      ReturnApp(Apps::QuickSettings, FullRefreshDirections::Down, TouchEvents::SwipeDown);
       break;
     case Apps::StopWatch:
       currentScreen = std::make_unique<Screens::StopWatch>(this, *systemTask);
@@ -471,7 +479,6 @@ void DisplayApp::LoadApp(Apps app, DisplayApp::FullRefreshDirections direction)
       break;
     case Apps::Metronome:
       currentScreen = std::make_unique<Screens::Metronome>(this, motorController, *systemTask);
-      ReturnApp(Apps::Launcher, FullRefreshDirections::Down, TouchEvents::None);
       break;
     case Apps::Motion:
       currentScreen = std::make_unique<Screens::Motion>(this, motionController);

src/displayapp/DisplayApp.h

@@ -20,6 +20,8 @@
 #include "displayapp/Messages.h"
 #include "BootErrors.h"
 
+#include "StaticStack.h"
+
 namespace Pinetime {
 
   namespace Drivers {
@@ -114,14 +116,18 @@ namespace Pinetime {
       static void Process(void* instance);
       void InitHw();
       void Refresh();
-      void ReturnApp(Apps app, DisplayApp::FullRefreshDirections direction, TouchEvents touchEvent);
+      void LoadNewScreen(Apps app, DisplayApp::FullRefreshDirections direction);
-      void LoadApp(Apps app, DisplayApp::FullRefreshDirections direction);
+      void LoadScreen(Apps app, DisplayApp::FullRefreshDirections direction);
       void PushMessageToSystemTask(Pinetime::System::Messages message);
 
       Apps nextApp = Apps::None;
       DisplayApp::FullRefreshDirections nextDirection;
       System::BootErrors bootError;
       void ApplyBrightness();
+
+      static constexpr size_t returnAppStackSize = 10;
+      StaticStack<Apps, returnAppStackSize> returnAppStack;
+      StaticStack<FullRefreshDirections, returnAppStackSize> appStackDirections;
     };
   }
 }

src/displayapp/screens/Metronome.cpp

@@ -146,7 +146,6 @@ void Metronome::OnEvent(lv_obj_t* obj, lv_event_t event) {
 bool Metronome::OnTouchEvent(TouchEvents event) {
   if (event == TouchEvents::SwipeDown && allowExit) {
     running = false;
-    return true;
   }
-  return false;
+  return true;
 }