Make QIcon generate high-dpi pixmaps.

QIcon::pixmap() can now return pixmaps that are larger
than the requested size, This is a behavior change
that may require updating existing application code,
and is enabled by setting Qt::AA_UseHighDPIIamges.

Add new pixmap() and actualSize() overloads that take
a window pointer. For 100% correctness you want to
target pixmap generation to a specific window, in
case the system has a mix of normal and high-dpi
displays. (The non-window versions uses QGuiApplication::
devicePixelRatio(), which returns the ratio for the
"best" display on the system.)

actualSize now returns the size in device-independent
pixels - not the pixmap pixel size. This matches
its intended use case which is layout calculations.

Change-Id: I2eefc4ed4aa48b036a7019446694e56213070efa
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/gui/image/qicon.h b/src/gui/image/qicon.h
index cda2360bed..e81bea69d6 100644
--- a/src/gui/image/qicon.h
+++ b/src/gui/image/qicon.h
@@ -79,8 +79,10 @@ public:
         { return pixmap(QSize(w, h), mode, state); }
     inline QPixmap pixmap(int extent, Mode mode = Normal, State state = Off) const
         { return pixmap(QSize(extent, extent), mode, state); }
+    QPixmap pixmap(QWindow *window, const QSize &size, Mode mode = Normal, State state = Off) const;
 
     QSize actualSize(const QSize &size, Mode mode = Normal, State state = Off) const;
+    QSize actualSize(QWindow *window, const QSize &size, Mode mode = Normal, State state = Off) const;
 
     QString name() const;