Enable non-integer device pixel ratio

Work around QPaintDevice::metric's int return type
by adding a new metric that returns a scaled devicePixelRatio.
Choose a scale factor that gives us more than enough
range.

The QPaintDevice::devicePixelRatio() convenience accessor
is public API and can unfortunately not be changed
to return a qreal. Add devicePixelRatioF() which
returns the (unscaled) devicePixelRatio.

Change all call sites of QPaintDevice::devicePixelRatio()
to use QPainDevice::devicePixelRatioF().

Task-number: QTBUG-46615
Change-Id: I97ec4000fe379b7ff5e1624a871ae2512790aad9
Reviewed-by: Paul Olav Tvete <paul.tvete@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/gui/text/qtextimagehandler.cpp b/src/gui/text/qtextimagehandler.cpp
index e85890baf2..1ba2cb31ca 100644
--- a/src/gui/text/qtextimagehandler.cpp
+++ b/src/gui/text/qtextimagehandler.cpp
@@ -256,10 +256,10 @@ void QTextImageHandler::drawObject(QPainter *p, const QRectF &rect, QTextDocumen
         const QTextImageFormat imageFormat = format.toImageFormat();
 
     if (QCoreApplication::instance()->thread() != QThread::currentThread()) {
-        const QImage image = getImage(doc, imageFormat, p->device()->devicePixelRatio());
+        const QImage image = getImage(doc, imageFormat, p->device()->devicePixelRatioF());
         p->drawImage(rect, image, image.rect());
     } else {
-        const QPixmap pixmap = getPixmap(doc, imageFormat, p->device()->devicePixelRatio());
+        const QPixmap pixmap = getPixmap(doc, imageFormat, p->device()->devicePixelRatioF());
         p->drawPixmap(rect, pixmap, pixmap.rect());
     }
 }