QmlDesigner: Fix for high dpi and Qt 6

When grabbing the window  we have to clip the window using
the root item size.
Depending on the window manager the window is resized.

Another issue is that when grabbing the window offscreen
the pixel ratio is always 1.

Before we assumed that the pixel ratio of all images
is the same for the host process as for the puppet.
This is not necessarily anymore and we have to set
and forward the correct pixel ratio.

Change-Id: I36b467291ab120f825119adea4ed7db10d34266d
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

2 files changed, 19 insertions, 10 deletions

diff --git a/share/qtcreator/qml/qmlpuppet/container/imagecontainer.cpp b/share/qtcreator/qml/qmlpuppet/container/imagecontainer.cpp
index 8348cbecb0..8fbbbc48cf 100644
--- a/share/qtcreator/qml/qmlpuppet/container/imagecontainer.cpp
+++ b/share/qtcreator/qml/qmlpuppet/container/imagecontainer.cpp
@@ -128,15 +128,16 @@ static void writeSharedMemory(SharedMemory *sharedMemory, const QImage &image)
 {
     sharedMemory->lock();
 
-    qint32 headerData[5];
+    qint32 headerData[6];
     headerData[0] = qint32(image.sizeInBytes());
     headerData[1] = image.bytesPerLine();
     headerData[2] = image.size().width();
     headerData[3] = image.size().height();
     headerData[4] = image.format();
+    headerData[5] = image.devicePixelRatio() * 100;
 
-    std::memcpy(sharedMemory->data(), headerData, 20);
-    std::memcpy(reinterpret_cast<char*>(sharedMemory->data()) + 20, image.constBits(), image.sizeInBytes());
+    std::memcpy(sharedMemory->data(), headerData, 24);
+    std::memcpy(reinterpret_cast<char*>(sharedMemory->data()) + 24, image.constBits(), image.sizeInBytes());
     sharedMemory->unlock();
 }
 
@@ -146,12 +147,13 @@ static void writeStream(QDataStream &out, const QImage &image)
     out << image.size();
     out << qint32(image.format());
     out << qint32(image.sizeInBytes());
+    out << qint32(image.devicePixelRatio() * 100);
     out.writeRawData(reinterpret_cast<const char*>(image.constBits()), image.sizeInBytes());
 }
 
 QDataStream &operator<<(QDataStream &out, const ImageContainer &container)
 {
-    const int extraDataSize =  20;
+    const int extraDataSize =  24;
     static const bool dontUseSharedMemory = qEnvironmentVariableIsSet("DESIGNER_DONT_USE_SHARED_MEMORY");
 
     out << container.instanceId();
@@ -183,24 +185,26 @@ static void readSharedMemory(qint32 key, ImageContainer &container)
 
     bool canAttach = sharedMemory.attach(QSharedMemory::ReadOnly);
 
-    if (canAttach && sharedMemory.size() >= 20)
+    if (canAttach && sharedMemory.size() >= 24)
     {
         sharedMemory.lock();
-        qint32 headerData[5];
-        std::memcpy(headerData, sharedMemory.constData(), 20);
+        qint32 headerData[6];
+        std::memcpy(headerData, sharedMemory.constData(), 24);
 
         qint32 byteCount = headerData[0];
 //        qint32 bytesPerLine = headerData[1];
         qint32 imageWidth = headerData[2];
         qint32 imageHeight = headerData[3];
         qint32 imageFormat = headerData[4];
+        qreal pixelRatio = headerData[5] / 100.0;
 
         QImage image = QImage(imageWidth, imageHeight, QImage::Format(imageFormat));
+        image.setDevicePixelRatio(pixelRatio);
 
         if (image.isNull())
             qDebug() << Q_FUNC_INFO << "Not able to create image:" << imageWidth << imageHeight << imageFormat;
         else
-            std::memcpy(image.bits(), reinterpret_cast<const qint32*>(sharedMemory.constData()) + 5, byteCount);
+            std::memcpy(image.bits(), reinterpret_cast<const qint32*>(sharedMemory.constData()) + 6, byteCount);
 
         container.setImage(image);
 
@@ -215,6 +219,7 @@ static void readStream(QDataStream &in, ImageContainer &container)
     qint32 bytesPerLine;
     QSize imageSize;
     qint32 imageFormat;
+    qint32 pixelRatio;
 
     in >> bytesPerLine;
     in >> imageSize;
@@ -224,6 +229,7 @@ static void readStream(QDataStream &in, ImageContainer &container)
     QImage image = QImage(imageSize, QImage::Format(imageFormat));
 
     in.readRawData(reinterpret_cast<char*>(image.bits()), byteCount);
+    image.setDevicePixelRatio(pixelRatio / 100.0);
 
     container.setImage(image);
 }
diff --git a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.cpp b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.cpp
index bc91a47505..b400d8c2d2 100644
--- a/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.cpp
+++ b/share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.cpp
@@ -428,12 +428,14 @@ QImage QuickItemNodeInstance::renderImage() const
 
         nodeInstanceServer()->quickView()->afterRendering();
     }
+    renderImage.setDevicePixelRatio(devicePixelRatio);
 #else
     renderImage = nodeInstanceServer()->quickView()->grabWindow();
+    renderImage = renderImage.copy(renderBoundingRect.toRect());
+    /* When grabbing an offscren window the device pixel ratio is 1 */
+    renderImage.setDevicePixelRatio(1);
 #endif
 
-    renderImage.setDevicePixelRatio(devicePixelRatio);
-
     return renderImage;
 }
 
@@ -462,6 +464,7 @@ QImage QuickItemNodeInstance::renderPreviewImage(const QSize &previewImageSize)
             }
 #else
             image = nodeInstanceServer()->quickView()->grabWindow();
+            image = image.copy(previewItemBoundingRect.toRect());
 #endif
 
             image = image.scaledToWidth(size.width());