Cocoa: Fix fonts on retina displays.

Hardcode logical dpi to 72 again. NSDeviceResolution
gives us the physical dpi (144) and results in double-
sized fonts in Qt. QPlatformScreen does not currently
have a physicalDpi virtual, perhaps this can be added
later on.

Unfortunately the usefulness of a per-screen correct
DPI metric seems questionable to me:
1) The value returned by the system is not correct,
   pixels per inch on the rMBP is around 220.
2) Qt always uses the dpi for the main screen, via
   qt_defaltDpiX/Y.

Change-Id: Ia35804be62ee7f1c623bad854f65d744dc9075d4
Reviewed-by: Jens Bache-Wiig <jens.bache-wiig@digia.com>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 481055a..f17e97c 100644 (file)
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -97,9 +97,8 @@ void QCocoaScreen::updateGeometry()
     CGDirectDisplayID dpy = [[devDesc objectForKey:@"NSScreenNumber"] unsignedIntValue];
     CGSize size = CGDisplayScreenSize(dpy);
     m_physicalSize = QSizeF(size.width, size.height);
-    NSSize resolution = [[devDesc valueForKey:NSDeviceResolution] sizeValue];
-    m_logicalDpi.first = resolution.width;
-    m_logicalDpi.second = resolution.height;
+    m_logicalDpi.first = 72;
+    m_logicalDpi.second = 72;
     m_refreshRate = CGDisplayModeGetRefreshRate(CGDisplayCopyDisplayMode(dpy));
 
     // Get m_name (brand/model of the monitor)
@@ -110,7 +109,7 @@ void QCocoaScreen::updateGeometry()
     [deviceInfo release];
 
     QWindowSystemInterface::handleScreenGeometryChange(screen(), geometry());
-    QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(screen(), resolution.width, resolution.height);
+    QWindowSystemInterface::handleScreenLogicalDotsPerInchChange(screen(), m_logicalDpi.first, m_logicalDpi.second);
     QWindowSystemInterface::handleScreenRefreshRateChange(screen(), m_refreshRate);
     QWindowSystemInterface::handleScreenAvailableGeometryChange(screen(), availableGeometry());
 }