Bug 573782

Summary: [BigSur] GLCanvas does not update after PaintListener.paintControl
Product: [Eclipse Project] Platform Reporter: Mario Marinato <mariomarinato>
Component: SWTAssignee: Platform-SWT-Inbox <platform-swt-inbox>
Status: NEW --- QA Contact:
Severity: normal    
Priority: P3 CC: lshanmug, mariomarinato
Version: 4.14   
Target Milestone: ---   
Hardware: Macintosh   
OS: Mac OS X   
Whiteboard:
Bug Depends on:    
Bug Blocks: 575659, 569361    
Attachments:
Description Flags
Snippet that reproduces the bug none

Description Mario Marinato CLA 2021-05-26 08:07:50 EDT 
If I add a PaintListener on a GLCanvas, the canvas is not updated to reflect the drawings made on the paintControl method.

Before BigSur, I could avoid this bad behavior by adding a child component on the canvas.  I added a new Label as a child of the GLCanvas and sized it to 1px x 1px.  Doing this made the drawings made on paintControl appear.

But now even this workaround is useless.
Comment 1 Lakshmi P Shanmugam CLA 2021-05-28 04:02:19 EDT 
Can you please provide a snippet to reproduce the problem?
Comment 2 Mario Marinato CLA 2021-05-28 07:17:45 EDT 
Created attachment 286469 [details]
Snippet that reproduces the bug

There you go, a snippet.

Comment / uncomment lines 33 and 36 to see the difference in behavior.

This same snippet can be used to reproduce Bug 570649.