Integrated: 8270874: JFrame paint artifacts when dragged from standard monitor to HiDPI monitor

[Sergey Bylokhov]

On Wed, 10 Nov 2021 18:45:12 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

> The bug occurs more often if initially the window is moved partly outside of the first screen(let's name this part as the invisible part), and then slowly moved to the second screen where that invisible part became visible on the second screen.
> 
> The problem is how we try to repaint the frame. The Windows send us coordinates to repaint in the device space, if the width/height values are less than a unit in the user's space, we round it to the empty rectangle and skip it.
> 
> Solution: request to repaint the smallest non-empty bounding box in the user's space around the region of pixels.
> 
> Workaround: repaint the whole window on the component resize/move event or at the end of the drag.
> 
> Notes:
>  * It is not reproducible(at least much less often) when d3d is enabled because the d3d pipeline sends repaint events more often (example https://github.com/openjdk/jdk/pull/6064). That hides the current issue.
>  * It started to be reproducible during the drag from one screen to another after JDK-8211999 because before JDK-8211999 we make a resize at the end of the drag, which caused the full repaint of the window.

This pull request has now been integrated.

Changeset: 03473b4c
Author:    Sergey Bylokhov <serb at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/03473b4c271b2ec7f0ebdb0edabadf7f36816b9d
Stats:     19 lines in 2 files changed: 10 ins; 0 del; 9 mod

8270874: JFrame paint artifacts when dragged from standard monitor to HiDPI monitor

Reviewed-by: jdv

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PR: https://git.openjdk.java.net/jdk/pull/6339