On Tue, 16 Dec 2025 07:44:53 GMT, John Hendrikx <[email protected]> wrote:
>> When a Window is created with a certain X/Y coordinate to place it on a >> specific screen, and is subsequently shown for the first time, one of the >> first things it does is size the window according to the size of the Scene. >> It does this based on the render scale of the *primary* screen as it has not >> moved the peer yet to the correct screen. After the scene has been sized, >> it is moved to the correct screen, triggering a change of render scale, but >> not a resizing of the Window (as this is only done once). >> >> The result of this is that due to slight difference in render scale, the >> size calculated for the scene may be a few pixels off. As the scene's >> preferred size is used for this calculation, even a few pixels too small can >> result in Labels being shown with ellipsis on the intended target screen >> with a different render scale. >> >> When observing the render scale X or Y property, one can observe a change >> from 1.0 (the default value) to 2.0 (the primary screen's render scale) to >> another value (depending on the target screen). However, the Window >> involved (being positioned by the user using setX()/setY() before it is >> shown) was never shown on the primary screen, yet the size calculation >> assumed it was. >> >> To solve this problem, the peer should be moved to the correct screen >> **before** asking the Scene for its preferred size to use as the initial >> Window size. Doing so (by adding an additional `applyBounds` call) also >> results in the render scale properties to only change once (or not at all) >> from their default value to the target screen's value (or not at all if the >> target screen is 1.0 scale). > > John Hendrikx has updated the pull request incrementally with one additional > commit since the last revision: > > Add more debug output Judging from how square the MT screen looks (700 x 700 orso), it seems that after the window is shown, it is not resizing it to fit the window. It is actually keeping the `sizeToScene` information (which it is supposed to ignore as you're setting sizes from preferences stored), or it is not triggering a resize even though the window is a totally different size than the scene. I think I can work with that to have a deeper look. It's certainly odd, since I'm only moving the `applyBounds` call to be slightly earlier, so it uses the correct render scale. Later it does it again anyway. In my tests the calculated `sizeToScene` was usually larger than the Window settings, so perhaps shrinking the window works correctly, but not expanding it when it doesn't fit the scene. ------------- PR Comment: https://git.openjdk.org/jfx/pull/2007#issuecomment-3662224281
