On Tuesday 09 October 2012 03:01 PM, Sorvig Morten wrote: > On Oct 9, 2012, at 10:59 AM, Pritam <[email protected]> > wrote: >> Forgive my ignorance, but I didn't understand. AFAIK most of Qt API is >> in pixels. Do you mean after this patch, one should treat all API as points? > No problem, the concepts are new and I'm still figuring out how they apply to > Qt and how to best present them. > > If you don't care about supporting high-dpi you can continue as before, > behaviour changes are opt-in. You can even get some support for free, for > example text and mac style. If you work on Qt itself then I argue that you > _should_ care about high-dpi. > > If you do want to support high-dpi then you should aware of the points/pixels > distinction. And again the main message here is that very little changes, you > deal with widget and event geometry as before and can draw using QPainter > using the widget coordinate system. Behind the scenes QPainter will fill in > 4x as many pixels on high-dpi displays. Which means you should provide more > pixels when using raster images and pixmaps. thanks for the explanation, I am aware of distinction between point and pixels. But I was not aware that on mac all most of Qt API is point based as Eike pointed out. I dont develop for mac. But I like the idea.
We had to support different resolutions recently. We have most of our geometries supplied from stylesheet. I was thinking on similar lines. I was thinking that it will be great if Qt's stylesheet code determines a scale factor to be applied if dpi changes and pixmaps get picked up from the next higher resolution directory so that its always a scale down if at all scaling is required. In my case it will not be required because I have to support only a few already known screen sizes, I will provide raster images for those sizes. But I am not at liberty to change Qt, so I am doing all this from outside by changing pixmap directory and reapplying stylesheet with scaled factor applied to various sizes. Pixel based dimension suck when scalable UI has to be designed. I would love a seamlessly scalable generic solution within Qt. > So it's mostly a name change. On high-dpi displays the main coordinate system > units are not pixels any more, but we can pretend they are and get away with > it in most cases. > > Morten > > > _______________________________________________ > Development mailing list > [email protected] > http://lists.qt-project.org/mailman/listinfo/development > > -- Regards, Pritam **************** CAUTION - Disclaimer ***************** This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended solely for the use of the addressee(s). If you are not the intended recipient, please notify the sender by e-mail and delete the original message. Further, you are not to copy, disclose, or distribute this e-mail or its contents to any other person and any such actions are unlawful. This e-mail may contain viruses. Infosys has taken every reasonable precaution to minimize this risk, but is not liable for any damage you may sustain as a result of any virus in this e-mail. You should carry out your own virus checks before opening the e-mail or attachment. Infosys reserves the right to monitor and review the content of all messages sent to or from this e-mail address. Messages sent to or from this e-mail address may be stored on the Infosys e-mail system. ***INFOSYS******** End of Disclaimer ********INFOSYS*** _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
