On Thu, 15 Jul 2021 15:48:18 GMT, Ambarish Rapte <ara...@openjdk.org> wrote:
>> On Windows, with two monitors with different DPI settings, if a JavaFX >> application changes screens (either by dragging or programmatically) there >> is a resize event to adjust the view to its new platform scale. >> >> Note that there is already a >> [call](https://github.com/openjdk/jfx/blob/master/modules/javafx.graphics/src/main/java/com/sun/glass/ui/win/WinWindow.java#L206) >> to `View::updateLocation` in WinWindow, right after >> `notifyMoveToAnotherScreen` and `notifyScaleChanged `. But this is done too >> soon, before the resize event. There are other MOVE events processed too (in >> a long complex chain of recursive calls to `WinWindow::setBounds`). >> >> As a consequence, as commented in the issue >> [JDK-8269374](https://bugs.openjdk.java.net/browse/JDK-8269374), the view >> x/y coordinates are wrongly set using the _old_ X,Y values (from the >> previous screen) with the _new_ platform scale (from the new screen). >> >> This PR adds an extra call to View::updateLocation` in WinWindow, forcing >> the view relocation on Windows after every resize event to fix the issue. >> With the correct location of the scene, the Menus are now perfectly aligned, >> and the mouse events are correctly processed. It doesn't have any side >> effect on other platforms. >> >> There's a very small penalty, as this new relocation will be called whenever >> there is a resize event on Windows, but it simplifies the overhead of >> detecting when the change of screens is effectively done (including the >> chain of move/resize) events. >> >> No tests are provided, since these would require a setup of two monitors >> with different DPI settings. However, the test case in the JBS issue can be >> used to validate the fix. > > I tested the fix with different scaling combinations, the issue reported in > JBS does not occur with fix. But noticed a similar issue that occurs only if > the primary screen is in landscape mode and external monitor is in portrait > mode. This behavior is observed both with and without this change. The > behavior may be unrelated to fix, in that it can be addressed separately. > @kevinrushforth request you to take look and call on this. > > Steps: > 1. Primary screen, 125%, Landscape mode > 2. Secondary screen, 100%, Portrait mode > 3. Run the program attached to JBS > 4. Move the Stage to secondary screen > 5. Maximize Stage > 6. Keep focus on the Stage and press Windows + Shift + Left key > 7. Stage will be moved to primary screen > 8. Click on menu, observe that location is not correct. Below is screenshot. > >  > > ---- > A slight different behavior can be observed with a change in step 6 > Follow same steps as above except at step 6: Click 'Change screen' button. > Below is the screenshot > >  I've filed [JDK-8270868](https://bugs.openjdk.java.net/browse/JDK-8270868), and also investigated the possible root cause of the issue. It turns out there is a reason for the issues @arapte notified, as those happened with a full screen. ------------- PR: https://git.openjdk.java.net/jfx/pull/572
