From f08e57540d217e16d1d15e5638afafac17439c0d Mon Sep 17 00:00:00 2001
From: Liang Qi <liang.qi@qt.io>
Date: Tue, 8 Mar 2022 11:46:48 +0100
Subject: [PATCH] GUI: add ScreenWindowGrabbing capability
MIME-Version: 1.0
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On Wayland, there is no protocol to do it yet.

Task-number: QTBUG-100792
Task-number: QTBUG-101145
Change-Id: Id72625a8161359111a2d0f43f3215e787778ba6b
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
---
 src/gui/kernel/qplatformintegration.cpp       | 7 ++++++-
 src/gui/kernel/qplatformintegration.h         | 3 ++-
 tests/auto/gui/kernel/qscreen/tst_qscreen.cpp | 8 ++++++--
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index 1427db5c614..c6382243b91 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -260,6 +260,10 @@ QPlatformServices *QPlatformIntegration::services() const
     where there is an alternative, such as Qt Quick with its \c software backend, an
     automatic fallback to that alternative may occur, if applicable. The default
     implementation of hasCapability() returns \c true.
+
+    \value ScreenWindowGrabbing The platform supports grabbing window on screen.
+    On Wayland, this capability can be reported as \c false. The default implementation
+    of hasCapability() returns \c true.
  */
 
 /*!
@@ -284,7 +288,8 @@ QPlatformServices *QPlatformIntegration::services() const
 bool QPlatformIntegration::hasCapability(Capability cap) const
 {
     return cap == NonFullScreenWindows || cap == NativeWidgets || cap == WindowManagement
-        || cap == TopStackedNativeChildWindows || cap == WindowActivation || cap == RhiBasedRendering;
+        || cap == TopStackedNativeChildWindows || cap == WindowActivation
+        || cap == RhiBasedRendering || cap == ScreenWindowGrabbing;
 }
 
 QPlatformPixmap *QPlatformIntegration::createPlatformPixmap(QPlatformPixmap::PixelType type) const
diff --git a/src/gui/kernel/qplatformintegration.h b/src/gui/kernel/qplatformintegration.h
index 75b942f9988..d76aeee59e9 100644
--- a/src/gui/kernel/qplatformintegration.h
+++ b/src/gui/kernel/qplatformintegration.h
@@ -133,7 +133,8 @@ class Q_GUI_EXPORT QPlatformIntegration
         OpenGLOnRasterSurface,
         MaximizeUsingFullscreenGeometry,
         PaintEvents,
-        RhiBasedRendering
+        RhiBasedRendering,
+        ScreenWindowGrabbing // whether QScreen::grabWindow() is supported
     };
 
     virtual ~QPlatformIntegration() { }
diff --git a/tests/auto/gui/kernel/qscreen/tst_qscreen.cpp b/tests/auto/gui/kernel/qscreen/tst_qscreen.cpp
index c29162ee67a..ea644e2e2b1 100644
--- a/tests/auto/gui/kernel/qscreen/tst_qscreen.cpp
+++ b/tests/auto/gui/kernel/qscreen/tst_qscreen.cpp
@@ -30,6 +30,8 @@
 #include <qrasterwindow.h>
 #include <qscreen.h>
 #include <qpa/qwindowsysteminterface.h>
+#include <qpa/qplatformintegration.h>
+#include <private/qguiapplication_p.h>
 
 #include <QTest>
 #include <QSignalSpy>
@@ -205,6 +207,10 @@ void tst_QScreen::orientationChange()
 
 void tst_QScreen::grabWindow_data()
 {
+    if (!QGuiApplicationPrivate::platformIntegration()->hasCapability(
+                QPlatformIntegration::ScreenWindowGrabbing)) {
+        QSKIP("This platform does not support grabbing windows on screen.");
+    }
     QTest::addColumn<int>("screenIndex");
     QTest::addColumn<QByteArray>("screenName");
     QTest::addColumn<bool>("grabWindow");
@@ -302,8 +308,6 @@ void tst_QScreen::grabWindow()
 
     QImage grabbedImage = pixmap.toImage();
     const QSize grabbedSize = grabbedImage.size();
-    if (QGuiApplication::platformName().startsWith(QLatin1String("wayland"), Qt::CaseInsensitive))
-        QEXPECT_FAIL("", "Wayland: Screen grabbing not implemented, See QTBUG-100792.", Abort);
     QCOMPARE(grabbedSize, expectedGrabSize);
 
     QPoint pixelOffset = QPoint(0, 0);