UI: Improved Default GetWindowUnderCursor Behavior #111489

Harley Acheson · 2023-08-24T21:34:31+02:00

Harley Acheson commented

2023-08-24 21:34:31 +02:00

For default GetWindowUnderCursor (when there is not a platform-specific
version), search windows in reverse order. This is because in most
cases with overlapping windows the one that is on top was created after
those that are below it.

Note that this fixes #111295, although potentially imperfectly. A perfect fix on the Windows platform is #111359.

So what is this for? Ghost provides a base implementation of getWindowUnderCursor in GHOST_System::getWindowUnderCursor. This function tries to guess which blender window is at the supplied cursor location. Unfortunately we don't track the Z-order or activation order of our windows. This means that when two windows are overlapping we just return the first one that has bounds that include the location.

Unfortunately we iterate through our window list in forward order. This means that a window that is created first will be returned when windows overlap. But in the vast majority of cases a window that is on top of another is created after those below it. #111295 is an example of this function failing in simple cases. This PR just reverses this search to give better results in most cases.

Note that this is the base implementation. For better results that work correctly with z-depth and activation order it is best to ask the operating system, which requires having a platform-specific version of this function. The MacOS platform currently has such. And my #111359 does so for Windows. Once that is merged it will be just Linux that will use the version referenced in this PR.

For default GetWindowUnderCursor (when there is not a platform-specific version), search windows in reverse order. This is because in most cases with overlapping windows the one that is on top was created after those that are below it. --- Note that this fixes #111295, although potentially imperfectly. A perfect fix on the Windows platform is #111359. So what is this for? Ghost provides a **base** implementation of `getWindowUnderCursor` in `GHOST_System::getWindowUnderCursor`. This function tries to _guess_ which blender window is at the supplied cursor location. Unfortunately we don't track the Z-order or activation order of our windows. This means that when two windows are overlapping we just return the first one that has bounds that include the location. Unfortunately we iterate through our window list in forward order. This means that a window that is created first will be returned when windows overlap. But in the vast majority of cases a window that is on top of another is created after those below it. #111295 is an example of this function failing in simple cases. This PR just reverses this search to give better results in most cases. Note that this is the base implementation. For better results that work correctly with z-depth and activation order it is best to ask the operating system, which requires having a platform-specific version of this function. The MacOS platform currently has such. And my #111359 does so for Windows. Once that is merged it will be just Linux that will use the version referenced in this PR.

👍 1

Harley Acheson added 1 commit 2023-08-24 21:34:42 +02:00

8fe899eb5f UI: Improved Default GetWindowUnderCursor Behavior

For default GetWindowUnderCursor (when there is not a platform-specific
version), search windows in reverse order. This is because in most
cases with overlapping windows the one that is on top was created after
those that are below it.

Harley Acheson added this to the User Interface project 2023-08-24 21:35:01 +02:00

Harley Acheson requested review from Campbell Barton 2023-08-24 21:35:12 +02:00

Harley Acheson commented

2023-08-24 21:37:43 +02:00

@ChengduLittleA - This should fix #111295 for you on LInux.

Campbell Barton approved these changes 2024-01-15 03:22:28 +01:00

intern/ghost/intern/GHOST_System.cc Outdated

						
				@ -217,0 +220,4 @@

				  /* Search through the windows in reverse order because in most cases

				   * the window that is on top was created after those that are below it. */

				  for (iwindow = windows.rbegin(); iwindow != windows.rend(); ++iwindow) {