Android: rework app state tracking

Cleanup 'isStarted' and state management logic and move it
to QtNative. Currently, it's spread between QtActivityDelegate and
QtNative where multiple variables are used for overlapping use
cases.

Task-number: QTBUG-118077
Change-Id: I2c98b48be78809c30636bfdf6d6640317470cec6
Reviewed-by: Tinja Paavoseppä <tinja.paavoseppa@qt.io>

6 files changed, 49 insertions, 56 deletions

diff --git a/src/android/jar/CMakeLists.txt b/src/android/jar/CMakeLists.txt
index 7bef9679c2..729ea07013 100644
--- a/src/android/jar/CMakeLists.txt
+++ b/src/android/jar/CMakeLists.txt
@@ -26,7 +26,6 @@ set(java_sources
     src/org/qtproject/qt/android/extras/QtAndroidBinder.java
     src/org/qtproject/qt/android/extras/QtAndroidServiceConnection.java
     src/org/qtproject/qt/android/extras/QtNative.java
-    src/org/qtproject/qt/android/QtConstants.java
     src/org/qtproject/qt/android/QtClipboardManager.java
     src/org/qtproject/qt/android/QtDisplayManager.java
     src/org/qtproject/qt/android/UsedFromNativeCode.java
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtActivityBase.java b/src/android/jar/src/org/qtproject/qt/android/QtActivityBase.java
index 415c8f3a1a..159f31be9d 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtActivityBase.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtActivityBase.java
@@ -59,7 +59,7 @@ public class QtActivityBase extends Activity
     }
 
     private void handleActivityRestart() {
-        if (QtNative.isStarted()) {
+        if (QtNative.getStateDetails().isStarted) {
             boolean updated = m_delegate.updateActivityAfterRestart(this);
             if (!updated) {
                 // could not update the activity so restart the application
@@ -119,15 +119,15 @@ public class QtActivityBase extends Activity
     {
         super.onPause();
         if (Build.VERSION.SDK_INT < 24 || !isInMultiWindowMode())
-            QtNative.setApplicationState(QtConstants.ApplicationState.ApplicationInactive);
+            QtNative.setApplicationState(QtNative.ApplicationState.ApplicationInactive);
     }
 
     @Override
     protected void onResume()
     {
         super.onResume();
-        QtNative.setApplicationState(QtConstants.ApplicationState.ApplicationActive);
-        if (m_delegate.isStarted()) {
+        QtNative.setApplicationState(QtNative.ApplicationState.ApplicationActive);
+        if (QtNative.getStateDetails().isStarted) {
             QtNative.updateWindow();
             // Suspending the app clears the immersive mode, so we need to set it again.
             m_delegate.displayManager().updateFullScreen(this);
@@ -138,7 +138,7 @@ public class QtActivityBase extends Activity
     protected void onStop()
     {
         super.onStop();
-        QtNative.setApplicationState(QtConstants.ApplicationState.ApplicationSuspended);
+        QtNative.setApplicationState(QtNative.ApplicationState.ApplicationSuspended);
     }
 
     @Override
@@ -187,7 +187,8 @@ public class QtActivityBase extends Activity
     @Override
     public boolean dispatchKeyEvent(KeyEvent event)
     {
-        if (m_delegate.isStarted() && m_delegate.getInputDelegate().handleDispatchKeyEvent(event))
+        boolean handleResult = m_delegate.getInputDelegate().handleDispatchKeyEvent(event);
+        if (QtNative.getStateDetails().isStarted && handleResult)
             return true;
 
         return super.dispatchKeyEvent(event);
@@ -197,7 +198,7 @@ public class QtActivityBase extends Activity
     public boolean dispatchGenericMotionEvent(MotionEvent event)
     {
         boolean handled = m_delegate.getInputDelegate().handleDispatchGenericMotionEvent(event);
-        if (m_delegate.isStarted() && handled)
+        if (QtNative.getStateDetails().isStarted && handled)
             return true;
 
         return super.dispatchGenericMotionEvent(event);
@@ -206,7 +207,8 @@ public class QtActivityBase extends Activity
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event)
     {
-        if (!m_delegate.isStarted() || !m_delegate.isPluginRunning())
+        QtNative.ApplicationStateDetails stateDetails = QtNative.getStateDetails();
+        if (!stateDetails.isStarted || !m_delegate.isPluginRunning())
             return false;
 
         return m_delegate.getInputDelegate().onKeyDown(keyCode, event);
@@ -215,7 +217,8 @@ public class QtActivityBase extends Activity
     @Override
     public boolean onKeyUp(int keyCode, KeyEvent event)
     {
-        if (!m_delegate.isStarted() || !m_delegate.isPluginRunning())
+        QtNative.ApplicationStateDetails stateDetails = QtNative.getStateDetails();
+        if (!stateDetails.isStarted || !m_delegate.isPluginRunning())
             return false;
 
         return m_delegate.getInputDelegate().onKeyUp(keyCode, event);
@@ -252,7 +255,7 @@ public class QtActivityBase extends Activity
     protected void onRestoreInstanceState(Bundle savedInstanceState)
     {
         super.onRestoreInstanceState(savedInstanceState);
-        m_delegate.setStarted(savedInstanceState.getBoolean("Started"));
+        QtNative.setStarted(savedInstanceState.getBoolean("Started"));
         // FIXME restore all surfaces
     }
 
@@ -269,7 +272,7 @@ public class QtActivityBase extends Activity
     {
         super.onSaveInstanceState(outState);
         outState.putInt("SystemUiVisibility", m_delegate.displayManager().systemUiVisibility());
-        outState.putBoolean("Started", m_delegate.isStarted());
+        outState.putBoolean("Started", QtNative.getStateDetails().isStarted);
     }
 
     @Override
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
index 79d00fac15..c154399911 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
@@ -37,7 +37,6 @@ public class QtActivityDelegate
 {
     private Activity m_activity;
 
-    private boolean m_started = false;
     private boolean m_isPluginRunning = false;
 
     private HashMap<Integer, QtSurface> m_surfaces = null;
@@ -98,16 +97,6 @@ public class QtActivityDelegate
         });
     }
 
-    void setStarted(boolean started)
-    {
-        m_started = started;
-    }
-
-    boolean isStarted()
-    {
-        return m_started;
-    }
-
     boolean isPluginRunning()
     {
         return m_isPluginRunning;
@@ -153,13 +142,11 @@ public class QtActivityDelegate
         Runnable startApplication = () -> {
             try {
                 QtNative.startApplication(appParams, mainLib);
-                m_started = true;
             } catch (Exception e) {
                 e.printStackTrace();
                 m_activity.finish();
             }
         };
-
         initMembers(startApplication);
     }
 
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtConstants.java b/src/android/jar/src/org/qtproject/qt/android/QtConstants.java
deleted file mode 100644
index c3dfc3d9f9..0000000000
--- a/src/android/jar/src/org/qtproject/qt/android/QtConstants.java
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright (C) 2023 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
-
-package org.qtproject.qt.android;
-
-public class QtConstants {
-    // Application states
-    public static class ApplicationState {
-        public static final int ApplicationSuspended = 0x0;
-        public static final int ApplicationHidden = 0x1;
-        public static final int ApplicationInactive = 0x2;
-        public static final int ApplicationActive = 0x4;
-    }
-}
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtNative.java b/src/android/jar/src/org/qtproject/qt/android/QtNative.java
index 7d48a4ea0f..8d39398837 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtNative.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtNative.java
@@ -33,26 +33,21 @@ import javax.net.ssl.X509TrustManager;
 public class QtNative
 {
     private static WeakReference<Activity> m_activity = null;
-    private static boolean m_activityPaused = false;
     private static WeakReference<Service> m_service = null;
     public static final Object m_mainActivityMutex = new Object(); // mutex used to synchronize runnable operations
 
+    private static final ApplicationStateDetails m_stateDetails = new ApplicationStateDetails();
+
     public static final String QtTAG = "Qt JAVA";
 
     // a list containing all actions which could not be performed (e.g. the main activity is destroyed, etc.)
     private static final ArrayList<Runnable> m_lostActions = new ArrayList<>();
-    private static boolean m_started = false;
 
     private static final QtThread m_qtThread = new QtThread();
     private static ClassLoader m_classLoader = null;
 
     private static final Runnable runPendingCppRunnablesRunnable = QtNative::runPendingCppRunnables;
 
-    public static boolean isStarted()
-    {
-        return m_started && (isActivityValid() || isServiceValid());
-    }
-
     @UsedFromNativeCode
     public static ClassLoader classLoader()
     {
@@ -198,16 +193,37 @@ public class QtNative
         return m_qtThread;
     }
 
+    // Keep in sync with src/corelib/global/qnamespace.h
+    public static class ApplicationState {
+        static final int ApplicationSuspended = 0x0;
+        static final int ApplicationHidden = 0x1;
+        static final int ApplicationInactive = 0x2;
+        static final int ApplicationActive = 0x4;
+    }
+
+    public static class ApplicationStateDetails {
+        int state = ApplicationState.ApplicationSuspended;
+        boolean isStarted = false;
+    }
+
+    public static ApplicationStateDetails getStateDetails()
+    {
+        return m_stateDetails;
+    }
+
+    public static void setStarted(boolean started)
+    {
+        m_stateDetails.isStarted = started;
+    }
+
     public static void setApplicationState(int state)
     {
         synchronized (m_mainActivityMutex) {
-            if (state == QtConstants.ApplicationState.ApplicationActive) {
-                m_activityPaused = false;
+            m_stateDetails.state = state;
+            if (state == ApplicationState.ApplicationActive) {
                 for (Runnable mLostAction : m_lostActions)
                     runAction(mLostAction);
                 m_lostActions.clear();
-            } else {
-                m_activityPaused = true;
             }
         }
         updateApplicationState(state);
@@ -220,7 +236,8 @@ public class QtNative
         synchronized (m_mainActivityMutex) {
             final Looper mainLooper = Looper.getMainLooper();
             final Handler handler = new Handler(mainLooper);
-            final boolean active = (isActivityValid() && !m_activityPaused) || isServiceValid();
+            final boolean isStateActive = m_stateDetails.state == ApplicationState.ApplicationActive;
+            final boolean active = (isActivityValid() && isStateActive) || isServiceValid();
             if (!active || !handler.post(action))
                 m_lostActions.add(action);
         }
@@ -231,7 +248,7 @@ public class QtNative
     {
         synchronized (m_mainActivityMutex) {
             if (isActivityValid()) {
-                if (!m_activityPaused)
+                if (m_stateDetails.state == ApplicationState.ApplicationActive)
                     m_activity.get().runOnUiThread(runPendingCppRunnablesRunnable);
                 else
                     runAction(runPendingCppRunnablesRunnable);
@@ -264,7 +281,7 @@ public class QtNative
             });
             m_qtThread.post(QtNative::startQtApplication);
             waitForServiceSetup();
-            m_started = true;
+            m_stateDetails.isStarted = true;
         }
     }
 
@@ -276,8 +293,7 @@ public class QtNative
                 m_activity.get().finish();
             if (isServiceValid())
                 m_service.get().stopSelf();
-
-             m_started = false;
+            m_stateDetails.isStarted = false;
         });
     }
 
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtServiceBase.java b/src/android/jar/src/org/qtproject/qt/android/QtServiceBase.java
index 3f2a82fd5e..8ecd8d5643 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtServiceBase.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtServiceBase.java
@@ -14,8 +14,10 @@ public class QtServiceBase extends Service {
     {
         super.onCreate();
 
+        QtNative.setApplicationState(QtNative.ApplicationState.ApplicationHidden);
+
         // the application has already started, do not reload everything again
-        if (QtNative.isStarted()) {
+        if (QtNative.getStateDetails().isStarted) {
             Log.w(QtNative.QtTAG,
                     "A QtService tried to start in the same process as an initiated " +
                             "QtActivity. That is not supported. This results in the service " +