QMacStyle: Ensure proper focus ring clipping

By rendering the focus ring directly on the backing NSView, we
would ignore the painter's clipping information. It would also
require creating a custom CGContext and attached NSGraphicsContext
every time.

The first step is to render the focus ring on a pixmap and then
use the painter to render that pixamp. This ensures the clipping
is done properly. The second step is to cache said pixmap and
render it as a nine-patch image.

Change-Id: I1df1baf7dc490023319f025a16306d4f04e5264c
Task-number: QTBUG-50645
Reviewed-by: Morten Johan Sørvig <morten.sorvig@theqtcompany.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/widgets/styles/qmacstyle_mac_p_p.h b/src/widgets/styles/qmacstyle_mac_p_p.h
index 33818568ec..b2c76c2d76 100644
--- a/src/widgets/styles/qmacstyle_mac_p_p.h
+++ b/src/widgets/styles/qmacstyle_mac_p_p.h
@@ -209,6 +209,8 @@ public:
     void drawNSViewInRect(QCocoaWidget widget, NSView *view, const QRect &rect, QPainter *p, bool isQWidget = true, QCocoaDrawRectBlock drawRectBlock = nil) const;
     void resolveCurrentNSView(QWindow *window);
 
+    void drawFocusRing(QPainter *p, const QRect &targetRect, int hMargin, int vMargin, qreal radius = 0) const;
+
 public:
     mutable QPointer<QObject> pressedButton;
     mutable QPointer<QObject> defaultButton;