diff options
| -rw-r--r-- | src/plugins/platforms/cocoa/qcocoawindow.mm | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm index a0e02501de..9259c2c772 100644 --- a/src/plugins/platforms/cocoa/qcocoawindow.mm +++ b/src/plugins/platforms/cocoa/qcocoawindow.mm @@ -1746,12 +1746,13 @@ qreal QCocoaWindow::devicePixelRatio() const { #if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7 if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_7) { - NSWindow* window = [m_contentView window]; - if (window) { - return qreal([window backingScaleFactor]); - } else { - return 1.0; - } + // The documented way to observe the relationship between device-independent + // and device pixels is to use one for the convertToBacking functions. Other + // methods such as [NSWindow backingScaleFacor] might not give the correct + // result, for example if setWantsBestResolutionOpenGLSurface is not set or + // or ignored by the OpenGL driver. + NSSize backingSize = [m_contentView convertSizeToBacking:NSMakeSize(1.0, 1.0)]; + return backingSize.height; } else #endif { |