Android: QtActivityDelegateBase listens to focus events from child views

In order to detect gaining/losing and moving focus between windows,
implement GlobalFocusChangeListener for the root View.

Add a surfaceFocusChanged native function in QAndroidPlatformWindow in
order to follow these focus changes.

Task-number: QTBUG-118139
Pick-to: 6.7
Change-Id: Ia9bf6249c28a420f42793a9829aef31b12757630
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

4 files changed, 24 insertions, 0 deletions

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 1fee857a58..25ac59ec32 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
@@ -138,6 +138,7 @@ class QtActivityDelegate extends QtActivityDelegateBase
                                              r.width(), kbHeight);
             return true;
         });
+        registerGlobalFocusChangeListener(m_layout);
         m_inputDelegate.setEditPopupMenu(new EditPopupMenu(m_activity, m_layout));
     }
 
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegateBase.java b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegateBase.java
index 5c36c5fd05..8625c1f601 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegateBase.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegateBase.java
@@ -133,6 +133,26 @@ abstract class QtActivityDelegateBase
         setUpLayout();
     }
 
+    protected void registerGlobalFocusChangeListener(final View view) {
+        view.getViewTreeObserver().addOnGlobalFocusChangeListener(this::onGlobalFocusChanged);
+    }
+
+    private void onGlobalFocusChanged(View oldFocus, View newFocus) {
+        if (newFocus instanceof QtEditText) {
+            final QtWindow newWindow = (QtWindow) newFocus.getParent();
+            QtWindow.windowFocusChanged(true, newWindow.getId());
+            m_inputDelegate.setFocusedView((QtEditText) newFocus);
+        } else {
+            int id = -1;
+            if (oldFocus instanceof QtEditText) {
+                final QtWindow oldWindow = (QtWindow) oldFocus.getParent();
+                id = oldWindow.getId();
+            }
+            QtWindow.windowFocusChanged(false, id);
+            m_inputDelegate.setFocusedView(null);
+        }
+    }
+
     public void hideSplashScreen()
     {
         hideSplashScreen(0);
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtEmbeddedDelegate.java b/src/android/jar/src/org/qtproject/qt/android/QtEmbeddedDelegate.java
index cab542622b..66a3f6c949 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtEmbeddedDelegate.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtEmbeddedDelegate.java
@@ -135,6 +135,7 @@ class QtEmbeddedDelegate extends QtActivityDelegateBase implements QtNative.AppS
 
     void setView(QtView view) {
         m_view = view;
+        registerGlobalFocusChangeListener(m_view);
     }
 
     public void setRootWindowRef(long ref) {
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtWindow.java b/src/android/jar/src/org/qtproject/qt/android/QtWindow.java
index d126ba3dc1..2f8f9cfbdc 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtWindow.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtWindow.java
@@ -24,6 +24,7 @@ class QtWindow extends QtLayout implements QtSurfaceInterface {
     private final QtEditText m_editText;
 
     private static native void setSurface(int windowId, Surface surface);
+    static native void windowFocusChanged(boolean hasFocus, int id);
 
     public QtWindow(Context context, QtWindow parentWindow)
     {
@@ -31,6 +32,7 @@ class QtWindow extends QtLayout implements QtSurfaceInterface {
         setId(View.generateViewId());
         m_editText = new QtEditText(context);
         setParent(parentWindow);
+        setFocusableInTouchMode(true);
 
         QtNative.runAction(() -> {
             m_gestureDetector =