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diff --git a/tests/manual/qscreen/README b/tests/manual/qscreen/README new file mode 100644 index 0000000000..5f5da17293 --- /dev/null +++ b/tests/manual/qscreen/README @@ -0,0 +1,41 @@ +To test whether QScreen properties are updated properly when the screen +actually changes, you will need to run some kind of control panel to make +changes, and this test program at the same time. E.g. on Linux, you can use +xrandr with various parameters on the command line, but there is also a nice +GUI called arandr which will probably work on any distro. Real-world users +would probably use the Gnome or KDE control panels, so that's also a good way +to test. On OSX you can make changes in System Preferences | Displays, and you +can also configure it to put a "monitors" icon on the menubar with a drop-down +menu for convenience. On Windows you can right-click on the desktop to get +display settings. + +Note that on Linux, if you have one graphics card with two outputs, typically +the two monitors connected to the outputs are combined into a single virtual +"screen", but each screen has multiple outputs. In that case there will be a +unique QScreen for each output, and they will be virtual siblings. The virtual +geometry depends on how you arrange the monitors (second one is to the right, +or above the first one, for example). It should be about the same if you are +using two graphics cards but using Xinerama to combine them. This test app will +create two windows, and will center one each screen, by setting the geometry. + +Alternatively you can configure xorg.conf to create separate screens for each +graphics card; then the mouse cursor can move between the screens, but +application windows cannot: each app needs to be started up on the screen that +you want to run it on. In either case, ideally this test app ought to create +two windows, one on each screen; but in fact, it can do that only if the +screens are virtual siblings. If they are on different Displays, the second +Display is not accessible to the QXcbConnection instance which was createad on +the first Display. It can be considered a known bug that the API appears to +make this possible (you would think QWindow::setScreen might work) but it +isn't possible. + +The physical size of the screen is considered to be a constant. This can create +discrepancies in DPI when orientation is changed, or when the screen is +actually a VNC server and you change the resolution. So maybe +QScreen::physicalSize should also have a notifier, but that doesn't physically +make sense except when the screen is virtual. + +Another case is running two separate X servers on two graphics cards. In that +case they really do not know about each other, even at the xlib/xcb level, so +this test is irrelevant. You can run the test independently on each X server, +but you will just get one QScreen instance on each. |