Android: Add preliminary support for child windows

Update the manual test case for embedded windows to have
native window on Android.

There are still some sharp corners, for example:

* The windows are implemented with SurfaceViews, which makes
  z-ordering with multiple of them a bit tricky. The Surfaces
  they instantiate are basically z-ordered to either be below
  everything, with a hole punched in the window, or on top of
  everything, with the Surfaces created later on top of the
  ones created earlier. Also, with the foreign views it looks
  like the native view is on top of the Surface, because it
  is created later. And since the child windows create their
  Surfaces before the parent, they would be behind the parent
  window, currently circumventing this with letting the
  parent be z-ordered behind everything, and the children
  on top of everything. A follow up commit addresses this by
  changing the native view class to TextureView when multiple
  windows are present.
* Parent window always gets the touch events - fixed in
  a follow up commit
* If a child window has a text edit, it does not receive
  focus when clicking on it

Task-number: QTBUG-116187
Change-Id: I32188ec5e3d3fce9fd8e3a931e317d1e081f691c
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 53 insertions, 18 deletions

diff --git a/src/plugins/platforms/android/qandroidplatformwindow.cpp b/src/plugins/platforms/android/qandroidplatformwindow.cpp
index 1e30799ae4..9a633e97af 100644
--- a/src/plugins/platforms/android/qandroidplatformwindow.cpp
+++ b/src/plugins/platforms/android/qandroidplatformwindow.cpp
@@ -19,10 +19,9 @@ Q_LOGGING_CATEGORY(lcQpaWindow, "qt.qpa.window")
 Q_CONSTINIT static QBasicAtomicInt winIdGenerator = Q_BASIC_ATOMIC_INITIALIZER(0);
 
 QAndroidPlatformWindow::QAndroidPlatformWindow(QWindow *window)
-    : QPlatformWindow(window), m_nativeQtWindow(QNativeInterface::QAndroidApplication::context()),
+    : QPlatformWindow(window), m_nativeQtWindow(nullptr), m_nativeParentQtWindow(nullptr),
       m_androidSurfaceObject(nullptr)
 {
-    m_nativeViewId = m_nativeQtWindow.callMethod<jint>("getId");
     m_windowFlags = Qt::Widget;
     m_windowState = Qt::WindowNoState;
     // the surfaceType is overwritten in QAndroidPlatformOpenGLWindow ctor so let's save
@@ -48,22 +47,44 @@ QAndroidPlatformWindow::QAndroidPlatformWindow(QWindow *window)
         if (requestedNativeGeometry != finalNativeGeometry)
             setGeometry(finalNativeGeometry);
     }
-    platformScreen()->addWindow(this);
+
+    if (parent())
+        m_nativeParentQtWindow = static_cast<QAndroidPlatformWindow*>(parent())->nativeWindow();
+
+    QNativeInterface::QAndroidApplication::runOnAndroidMainThread([this]() {
+        m_nativeQtWindow = QJniObject::construct<QtJniTypes::QtWindow>(
+            QNativeInterface::QAndroidApplication::context(),
+            m_nativeParentQtWindow);
+        m_nativeViewId = m_nativeQtWindow.callMethod<jint>("getId");
+    }).waitForFinished();
+
+    if (window->isTopLevel())
+        platformScreen()->addWindow(this);
 }
 
 QAndroidPlatformWindow::~QAndroidPlatformWindow()
 {
-    platformScreen()->removeWindow(this);
+    if (window()->isTopLevel())
+        platformScreen()->removeWindow(this);
 }
 
 
 void QAndroidPlatformWindow::lower()
 {
+    if (m_nativeParentQtWindow.isValid()) {
+        m_nativeParentQtWindow.callMethod<void>("bringChildToBack", nativeViewId());
+        return;
+    }
     platformScreen()->lower(this);
 }
 
 void QAndroidPlatformWindow::raise()
 {
+    if (m_nativeParentQtWindow.isValid()) {
+        m_nativeParentQtWindow.callMethod<void>("bringChildToFront", nativeViewId());
+        QWindowSystemInterface::handleFocusWindowChanged(window(), Qt::ActiveWindowFocusReason);
+        return;
+    }
     updateSystemUiVisibility();
     platformScreen()->raise(this);
 }
@@ -87,16 +108,20 @@ void QAndroidPlatformWindow::setGeometry(const QRect &rect)
 
 void QAndroidPlatformWindow::setVisible(bool visible)
 {
+    m_nativeQtWindow.callMethod<void>("setVisible", visible);
+
     if (visible) {
-        updateSystemUiVisibility();
-        if ((m_windowState & Qt::WindowFullScreen)
-                || ((m_windowState & Qt::WindowMaximized) && (window()->flags() & Qt::MaximizeUsingFullscreenGeometryHint))) {
-            setGeometry(platformScreen()->geometry());
-        } else if (m_windowState & Qt::WindowMaximized) {
-            setGeometry(platformScreen()->availableGeometry());
+        if (window()->isTopLevel()) {
+            updateSystemUiVisibility();
+            if ((m_windowState & Qt::WindowFullScreen)
+                    || ((m_windowState & Qt::WindowMaximized) && (window()->flags() & Qt::MaximizeUsingFullscreenGeometryHint))) {
+                setGeometry(platformScreen()->geometry());
+            } else if (m_windowState & Qt::WindowMaximized) {
+                setGeometry(platformScreen()->availableGeometry());
+            }
+            requestActivateWindow();
         }
-        requestActivateWindow();
-    } else if (window() == qGuiApp->focusWindow()) {
+    } else if (window()->isTopLevel() && window() == qGuiApp->focusWindow()) {
         platformScreen()->topVisibleWindowChanged();
     }
 
@@ -132,13 +157,22 @@ Qt::WindowFlags QAndroidPlatformWindow::windowFlags() const
 
 void QAndroidPlatformWindow::setParent(const QPlatformWindow *window)
 {
-    // even though we do not yet support child windows properly, any windows getting a parent
-    // should be removed from screen's window stack which is only for top level windows,
-    // and respectively any window becoming top level should go in there
+    using namespace QtJniTypes;
     if (window) {
-        platformScreen()->removeWindow(this);
+        // If we were a top level window, remove from screen
+        if (!m_nativeParentQtWindow.isValid())
+            platformScreen()->removeWindow(this);
+
+        const QAndroidPlatformWindow *androidWindow =
+                                                static_cast<const QAndroidPlatformWindow*>(window);
+        const QtWindow parentWindow = androidWindow->nativeWindow();
+        // If this was a child window of another window, the java method takes care of that
+        m_nativeQtWindow.callMethod<void, QtWindow>("setParent", parentWindow.object());
+        m_nativeParentQtWindow = parentWindow;
     } else {
+        m_nativeQtWindow.callMethod<void, QtWindow>("setParent", nullptr);
         platformScreen()->addWindow(this);
+        m_nativeParentQtWindow = QJniObject();
     }
 }
 
@@ -154,6 +188,7 @@ void QAndroidPlatformWindow::propagateSizeHints()
 
 void QAndroidPlatformWindow::requestActivateWindow()
 {
+    // raise() will handle differences between top level and child windows, and requesting focus
     if (!blockedByModal())
         raise();
 }
@@ -214,7 +249,7 @@ void QAndroidPlatformWindow::destroySurface()
     }
 }
 
-void QAndroidPlatformWindow::setSurfaceGeometry(const QRect &geometry)
+void QAndroidPlatformWindow::setNativeGeometry(const QRect &geometry)
 {
     if (!m_surfaceCreated)
         return;
@@ -229,7 +264,7 @@ void QAndroidPlatformWindow::setSurfaceGeometry(const QRect &geometry)
         w = geometry.width();
         h = geometry.height();
     }
-    m_nativeQtWindow.callMethod<void>("setSurfaceGeometry", x, y, w, h);
+    m_nativeQtWindow.callMethod<void>("setGeometry", x, y, w, h);
 }
 
 void QAndroidPlatformWindow::onSurfaceChanged(QtJniTypes::Surface surface)