Proper geometry conversion for devicePixelRatio > 1

Rounding the bottom right corner position means that the size
can change when the window moves. For windows we need
to round the size up in order to have a stable geometry.

Task-number: QTBUG-45076
Change-Id: I9a85a5915bfec55b0a7295be137b6fbfd7b53095
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 78ccf8a3e9..45245a1454 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -155,6 +155,11 @@ static inline QPoint dpr_ceil(const QPoint &p, int dpr)
     return QPoint((p.x() + dpr - 1) / dpr, (p.y() + dpr - 1) / dpr);
 }
 
+static inline QSize dpr_ceil(const QSize &s, int dpr)
+{
+    return QSize((s.width() + dpr - 1) / dpr, (s.height() + dpr - 1) / dpr);
+}
+
 static inline QRect mapExposeFromNative(const QRect &xRect, int dpr)
 {
     return QRect(dpr_floor(xRect.topLeft(), dpr), dpr_ceil(xRect.bottomRight(), dpr));
@@ -162,7 +167,7 @@ static inline QRect mapExposeFromNative(const QRect &xRect, int dpr)
 
 static inline QRect mapGeometryFromNative(const QRect &xRect, int dpr)
 {
-    return QRect(xRect.topLeft() / dpr, xRect.bottomRight() / dpr);
+    return QRect(xRect.topLeft() / dpr, dpr_ceil(xRect.size(), dpr));
 }
 
 // Returns \c true if we should set WM_TRANSIENT_FOR on \a w