1448199 - Open window in maximized state triggers extra reflow in window open path

Status: NEW

(Core :: Widget: Win32, enhancement)

Description

[Xidorn Quan [:xidorn] UTC+11]

See the analysis in bug 1446264 comment 34.

I had two patches in that bug to remove these extra reflows, but those end up causing other non-trivial issues e.g. bug 1447864, so we should probably have it fixed separately.

Comment 1

[Xidorn Quan [:xidorn] UTC+11]

Attachment: Bug 1448199 part 1 - Allow window to show earlier when sizemode is changed before window turned visible.

This would show a blank window at an earlier time before other stuff are
ready. It saves us from an extra resize reflow which otherwise would
happen because the window is resized only when it's shown.

Review commit: https://reviewboard.mozilla.org/r/231172/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/231172/

Comment 2

[Xidorn Quan [:xidorn] UTC+11]

Attachment: Bug 1448199 part 2 - Delay handling of WM_SETFOCUS after we explicit show the window.

With the previous patch, we now may activate a window which we still
consider invisible, that brings the focus to the new window. This leads
to extra reflow in window open path because focus manager now dispatches
event which it didn't when the window doesn't have focus.

This patch delays WM_SETFOCUS until nsWindow::Show is invoked, so that
focus would not be set on an "invisible" window.

Review commit: https://reviewboard.mozilla.org/r/231174/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/231174/

Comment 3

[Xidorn Quan [:xidorn] UTC+11]

These are the patches previously reviewed in bug 1446264 comment 83 and bug 1446264 comment 84. They are not landable at the moment until we can fix bug 1447864.

Comment 4

[Jim Mathies [:jimm]]

Comment on attachment 8962292 [details]
Bug 1448199 part 1 - Allow window to show earlier when sizemode is changed before window turned visible.

https://reviewboard.mozilla.org/r/231172/#review236768

Comment 5

[Jim Mathies [:jimm]]

Comment on attachment 8962293 [details]
Bug 1448199 part 2 - Delay handling of WM_SETFOCUS after we explicit show the window.

https://reviewboard.mozilla.org/r/231174/#review236770

Comment 6

[Xidorn Quan [:xidorn] UTC+11]

I think there is an alternate approach for avoiding the resize reflow here that, we can size the window as if it's maximized from the very beginning, but change its normal size via SetWindowPlacement. That way we can update the normal size whatever we want even when the window is maximized.

Exactly how that should work is a question, though.

Comment 7

[Kobiljon Singh]

Attachment: same problem

Thanks from hanponsthetu1984.