macOS: Make screen property changes more verbose and granular

We only update the properties that have actually changed.

Change-Id: If711530c6118d2550d5a0e968ee02c903b44fd04
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@qt.io>

src/plugins/platforms/cocoa/qcocoahelpers.h

@@ -65,6 +65,7 @@ QT_BEGIN_NAMESPACE
 Q_DECLARE_LOGGING_CATEGORY(lcQpaWindow)
 Q_DECLARE_LOGGING_CATEGORY(lcQpaDrawing)
 Q_DECLARE_LOGGING_CATEGORY(lcQpaMouse)
+Q_DECLARE_LOGGING_CATEGORY(lcQpaScreen)
 
 class QPixmap;
 class QString;

src/plugins/platforms/cocoa/qcocoahelpers.mm

@@ -60,6 +60,7 @@ QT_BEGIN_NAMESPACE
 Q_LOGGING_CATEGORY(lcQpaWindow, "qt.qpa.window");
 Q_LOGGING_CATEGORY(lcQpaDrawing, "qt.qpa.drawing");
 Q_LOGGING_CATEGORY(lcQpaMouse, "qt.qpa.input.mouse");
+Q_LOGGING_CATEGORY(lcQpaScreen, "qt.qpa.screen");
 
 //
 // Conversion Functions

src/plugins/platforms/cocoa/qcocoaintegration.mm

@@ -225,8 +225,6 @@ QCocoaIntegration::Options QCocoaIntegration::options() const
     return mOptions;
 }
 
-Q_LOGGING_CATEGORY(lcQpaScreen, "qt.qpa.screen");
-
 /*!
     \brief Synchronizes the screen list, adds new screens, removes deleted ones
 */
@@ -265,8 +263,7 @@ void QCocoaIntegration::updateScreens()
             }
         if (screen) {
             remainingScreens.remove(screen);
-            screen->updateGeometry();
-            qCDebug(lcQpaScreen) << "Updated properties of" << screen;
+            screen->updateProperties();
         } else {
             screen = new QCocoaScreen(i);
             mScreens.append(screen);

src/plugins/platforms/cocoa/qcocoascreen.h

@@ -75,7 +75,7 @@ public:
     // Additional methods
     void setVirtualSiblings(const QList<QPlatformScreen *> &siblings) { m_siblings = siblings; }
     NSScreen *nativeScreen() const;
-    void updateGeometry();
+    void updateProperties();
 
     void requestUpdate();
     void deliverUpdateRequests();

src/plugins/platforms/cocoa/qcocoascreen.mm

@@ -59,7 +59,7 @@ class QFontEngineFT;
 QCocoaScreen::QCocoaScreen(int screenIndex)
     : QPlatformScreen(), m_screenIndex(screenIndex), m_refreshRate(60.0)
 {
-    updateGeometry();
+    updateProperties();
     m_cursor = new QCocoaCursor;
 }
 
@@ -115,12 +115,17 @@ static QString displayName(CGDirectDisplayID displayID)
     return QString();
 }
 
-void QCocoaScreen::updateGeometry()
+void QCocoaScreen::updateProperties()
 {
     NSScreen *nsScreen = nativeScreen();
     if (!nsScreen)
         return;
 
+    const QRect previousGeometry = m_geometry;
+    const QRect previousAvailableGeometry = m_availableGeometry;
+    const QDpi previousLogicalDpi = m_logicalDpi;
+    const qreal previousRefreshRate = m_refreshRate;
+
     // The reference screen for the geometry is always the primary screen
     QRectF primaryScreenGeometry = QRectF::fromCGRect([[NSScreen screens] firstObject].frame);
     m_geometry = qt_mac_flip(QRectF::fromCGRect(nsScreen.frame), primaryScreenGeometry).toRect();
@@ -142,9 +147,14 @@ void QCocoaScreen::updateGeometry()
 
     m_name = displayName(dpy);
 
-    QWindowSystemInterface::handleScreenGeometryChange(screen(), geometry(), availableGeometry());
-    QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(screen(), m_logicalDpi.first, m_logicalDpi.second);
-    QWindowSystemInterface::handleScreenRefreshRateChange(screen(), m_refreshRate);
+    if (m_geometry != previousGeometry || m_availableGeometry != previousAvailableGeometry)
+        QWindowSystemInterface::handleScreenGeometryChange(screen(), geometry(), availableGeometry());
+    if (m_logicalDpi != previousLogicalDpi)
+        QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(screen(), m_logicalDpi.first, m_logicalDpi.second);
+    if (m_refreshRate != previousRefreshRate)
+        QWindowSystemInterface::handleScreenRefreshRateChange(screen(), m_refreshRate);
+
+    qCDebug(lcQpaScreen) << "Updated properties for" << this;
 }
 
 // ----------------------- Display link -----------------------

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -1218,11 +1218,21 @@ void QCocoaWindow::windowDidChangeScreen()
 
     const bool wasRunningDisplayLink = static_cast<QCocoaScreen *>(screen())->isRunningDisplayLink();
 
-    if (QCocoaScreen *cocoaScreen = QCocoaIntegration::instance()->screenForNSScreen(m_view.window.screen)) {
-        QWindowSystemInterface::handleWindowScreenChanged<QWindowSystemInterface::SynchronousDelivery>(window(), cocoaScreen->screen());
+    if (QCocoaScreen *newScreen = QCocoaIntegration::instance()->screenForNSScreen(m_view.window.screen)) {
+        if (newScreen == screen()) {
+            // Screen properties have changed. Will be handled by
+            // NSApplicationDidChangeScreenParametersNotification
+            // in QCocoaIntegration::updateScreens().
+            return;
+        }
+
+        qCDebug(lcQpaWindow) << window() << "moved to" << newScreen;
+        QWindowSystemInterface::handleWindowScreenChanged<QWindowSystemInterface::SynchronousDelivery>(window(), newScreen->screen());
 
         if (hasPendingUpdateRequest() && wasRunningDisplayLink)
             requestUpdate(); // Restart display-link on new screen
+    } else {
+        qCWarning(lcQpaWindow) << "Failed to get QCocoaScreen for" << m_view.window.screen;
     }
 }