> >My knowledge of available "HiDPI" APIs is currently based on your > >(excellent) blog post, which does not seem to mention that use case: > > > >http://blog.qt.io/blog/2013/04/25/retina-display-support-for-mac-os-ios-and-x11/ > > <http://blog.qt.io/blog/2013/04/25/retina-display-support-for-mac-os-ios-and-x11/> Thanks for posting the excellent link. It may help me find a work-around for a Qt3D windows scaling issue that affects OS X and iOS as well.
Qt3D has issues with displaying the openGl rendering at 1/4 window size on the retina display. If Window is moved to external display it displays normally taking up the full window space.. -Ed > On Mar 24, 2015, at 8:26 AM, Till Oliver Knoll <till.oliver.kn...@gmail.com> > wrote: > > > Am 19.03.2015 um 14:17 schrieb Sorvig Morten <morten.sor...@theqtcompany.com > <mailto:morten.sor...@theqtcompany.com>>: > >> Hi, >> >> ... >> >> In case there issues that I’ve missed I would be interested in hearing about >> it. I can’t promise that everything will be fixed, but it will be at least >> put on the radar. > > Hi Morten, > > Not a bug by itself and hence a bit off-topic, but is there a way to detect > "screen resolution changes" in some way? The use case is of course when an > application window is moved from a Retina (HiDPI) screen to a non-Retina > screen (or vice versa) (in a multi-monitor setup). > > My knowledge of available "HiDPI" APIs is currently based on your (excellent) > blog post, which does not seem to mention that use case: > > > http://blog.qt.io/blog/2013/04/25/retina-display-support-for-mac-os-ios-and-x11/ > > <http://blog.qt.io/blog/2013/04/25/retina-display-support-for-mac-os-ios-and-x11/> > > I could imagine that getting informed e.g. by the QDesktopWidget (or some > other related "screen/resolution" class) whenever the application is > "switched" (dragged) to another screen, and then querying the resolution of > the new screen, could be a solution. However I currently do not see any > corresponding signal in QDesktopWidget's API, nor anywhere else... > > In the end I am not even sure whether I need to get informed about this > event, since most drawing - and also the switch between Retina/non-Retina > worlds - is handled for me already by Qt/underlying Core Graphics APIs. Even > the Apple Developer docs mention that "Listening for > NSWindowDidChangeBackingPropertiesNotification is something only a few apps > [...] will need to do." > > However my app probably /is/ one of those that "specialize in video or > graphics work". I draw on a QGraphicsView(-scene) and have > QGraphicsPixmapItems with a QPixmap behind them. I imagine that I have to be > able to dynamically switch between the normal and the "@2x" version of those > pixmaps, and have the QGraphicsView paint itself whenever such a "resolution > change" is detected. Or so I imagine... > > So I am basically looking for a "cross-platform" way to get notified in > analogy to the Cocoa notification > > NSWindowDidChangeBackingPropertiesNotification > > See chapter "Handle Dynamic Changes in Window Resolution Only When You Must" > > https://developer.apple.com/library/mac/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/CapturingScreenContents/CapturingScreenContents.html#//apple_ref/doc/uid/TP40012302-CH10-SW1 > > <https://developer.apple.com/library/mac/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/CapturingScreenContents/CapturingScreenContents.html#//apple_ref/doc/uid/TP40012302-CH10-SW1> > > > Or would I have access to this event (+ platform-specific code) in e.g. > QWidget::nativeEvent (in the top-level QMainWindow)? The Apple docs talk > about a "window delegate" (Cocoa code), to which I probably don't have (easy) > access, at least not without modifying Qt's code itself - right? (I am not a > Cocoa expert). > > > Is something like "detecting resolution changes" (otherwise) already > possible, or is this on the "HiDPI Roadmap"? > > Thanks, Oliver > > _______________________________________________ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest
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