[Development] Scalable UIs in QtQuick (take 2)

[Nikita Krupenko]

2016-02-18 12:50 GMT+02:00 Hausmann Simon <Simon.Hausmann at theqtcompany.com>:
> (1) In order to make it really easy to scale "logical" pixels without having to introduce your own context property or factor in a .qml file that you multiply everywhere, we could turn the regular "pixels" in QtQuick into truly logical pixels that scale with an application wide (or window wide) factor. So Image { width: 100 ... } will scale automatically from 100 logical pixels to maybe 200 physical pixels on a x2 display. This assumes the availability of API to change this mapping.
>
> (2) In the events where you still _want_ to use physical pixels, you could use "px" units.
>
> So at first nothing would change for app developers at all because we map logical pixels to physical pixels. But
> if you'd like to, you could opt into changing this mapping and having a relatively easy fallback to physical pixels using for example the "px" unit. We might as well offer the other physical units anyway, that probably causes little to no harm.

Isn't (1) already done with Qt::AA_EnableHighDpiScaling? Though
disabling this feature for some items would be useful, like for
Canvas, which is broken now with this scaling.