Android: make sure that orientationChange is reported after resize

On Android orientation changes are reported from the
DisplayListener.onDisplayChanged() method, while the screen size
changes are reported from QtLayout.onSizeChanged().
In practice these callbacks come in random order, so rotating the
screen multiple times might result in inconsistent order of signals
and events.

This patch makes sure that size change events always happen before
orientation changes. This is done by caching the new orientation
values and reporting them only when needed. At this point we also
need to use QMetaObject::invokeMethod() for orientation change,
like it is done for geometry change. Otherwise the orientation
update can still be processed earlier than the geometry change.

Also note that at some point we might get an orientation change
without a size change (for example Qt::LandscapeOrientation ->
Qt::InvertedLandscapeOrientation). That is the reason for
isSimilarRotation() helper function.

As a drive-by: ignore size changes with inconsistent values when window
size is reported to have old orientation, while the screen has already
been rotated. In such cases a new size change will be triggered shortly
with normal value.

Task-number: QTBUG-94459
Pick-to: 6.3 6.2 5.15
Change-Id: I5c98e526d0370d380344b2297169d5e0c0ee8ea7
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

3 files changed, 17 insertions, 4 deletions

diff --git a/src/plugins/platforms/android/androidjnimain.cpp b/src/plugins/platforms/android/androidjnimain.cpp
index ac1b29ba5b..6cb9d8fe7e 100644
--- a/src/plugins/platforms/android/androidjnimain.cpp
+++ b/src/plugins/platforms/android/androidjnimain.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2014 BogDan Vatra <bogdan@kde.org>
-** Copyright (C) 2021 The Qt Company Ltd.
+** Copyright (C) 2022 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the plugins of the Qt Toolkit.
@@ -541,6 +541,9 @@ static void startQtApplication(JNIEnv */*env*/, jclass /*clazz*/)
             vm->AttachCurrentThread(&env, &args);
     }
 
+    // Register type for invokeMethod() calls.
+    qRegisterMetaType<Qt::ScreenOrientation>("Qt::ScreenOrientation");
+
     // Register resources if they are available
     if (QFile{QStringLiteral("assets:/android_rcc_bundle.rcc")}.exists())
         QResource::registerResource(QStringLiteral("assets:/android_rcc_bundle.rcc"));
@@ -759,9 +762,13 @@ static void handleOrientationChanged(JNIEnv */*env*/, jobject /*thiz*/, jint new
     QAndroidPlatformIntegration::setScreenOrientation(screenOrientation, native);
     QMutexLocker lock(&m_platformMutex);
     if (m_androidPlatformIntegration) {
-        QPlatformScreen *screen = m_androidPlatformIntegration->screen();
-        QWindowSystemInterface::handleScreenOrientationChange(screen->screen(),
-                                                              screenOrientation);
+        QAndroidPlatformScreen *screen = m_androidPlatformIntegration->screen();
+        // Use invokeMethod to keep the certain order of the "geometry change"
+        // and "orientation change" event handling.
+        if (screen) {
+            QMetaObject::invokeMethod(screen, "setOrientation", Qt::AutoConnection,
+                                      Q_ARG(Qt::ScreenOrientation, screenOrientation));
+        }
     }
 }
 
diff --git a/src/plugins/platforms/android/qandroidplatformscreen.cpp b/src/plugins/platforms/android/qandroidplatformscreen.cpp
index 75967f5678..fdb027b9de 100644
--- a/src/plugins/platforms/android/qandroidplatformscreen.cpp
+++ b/src/plugins/platforms/android/qandroidplatformscreen.cpp
@@ -309,6 +309,11 @@ void QAndroidPlatformScreen::setRefreshRate(qreal refreshRate)
     QWindowSystemInterface::handleScreenRefreshRateChange(QPlatformScreen::screen(), refreshRate);
 }
 
+void QAndroidPlatformScreen::setOrientation(Qt::ScreenOrientation orientation)
+{
+    QWindowSystemInterface::handleScreenOrientationChange(QPlatformScreen::screen(), orientation);
+}
+
 void QAndroidPlatformScreen::setAvailableGeometry(const QRect &rect)
 {
     QMutexLocker lock(&m_surfaceMutex);
diff --git a/src/plugins/platforms/android/qandroidplatformscreen.h b/src/plugins/platforms/android/qandroidplatformscreen.h
index 4a06bb20bd..24494de2da 100644
--- a/src/plugins/platforms/android/qandroidplatformscreen.h
+++ b/src/plugins/platforms/android/qandroidplatformscreen.h
@@ -96,6 +96,7 @@ public slots:
     void setSizeParameters(const QSize &physicalSize, const QSize &size,
                            const QRect &availableGeometry);
     void setRefreshRate(qreal refreshRate);
+    void setOrientation(Qt::ScreenOrientation orientation);
 
 protected:
     bool event(QEvent *event) override;