Comment 1 Jeeeyul Lee 2020-11-30 02:12:43 EST

Created attachment 284921 [details]
file to reproduce problem

Comment 2 Jeeeyul Lee 2020-11-30 02:16:51 EST

Control#update(): 1324
context.setPatternPhase(phase);

seems not work properly for specific case.

I found these:
* This problem occurs when there are some SWT.BORDER flagged controls in the same shell.
* This problem also occurs when there are some NSScrollable controls in the same shell

Comment 3 Sravan Kumar Lakkimsetti 2020-11-30 03:17:06 EST

Another related bug 569168. Looks like root cause same for both.

Comment 4 Jeeeyul Lee 2020-11-30 03:33:52 EST

(In reply to Sravan Kumar Lakkimsetti from comment #3)
> Another related bug 569168. Looks like root cause same for both.

I agree. 

I have a theory about this, I will mention about it after more digging tomorrow.

Comment 5 Jeeeyul Lee 2020-12-01 00:54:04 EST

Sorry, I have failed to find useful clues. The office will be closed for the time being due to covid 19, I can't pursuit this problem for while. Please somebody else pull this excalibur out instead.

Comment 6 Jeeeyul Lee 2020-12-07 20:21:05 EST

I found these things:

Consider that situation:

Shell
 +- A
 +- B
 +- C (has an NSSCrollView due to SWT.X_SCROLL or SWT.BORDER)
 +- D
 +- E

1. Background patterns of D, E are rendered properly. (after scrollview)
2. Background patterns of A, B, C are rendered incorrectly. 
3. Painting A, B, C seems to use a not flipped coordinate system.

when I add below code on Control#fillBackground():1324

  phase.x -= tx;
  phase.y += ty;
  phase.y = controlView.bounds().height; // <- I've added this line
  context.setPatternPhase(phase);

These small change just ignore the coordinate system of the window content view. And it assumes that those view has it's own buffers and own drawing context.
Then interestingly A, B C are rendered properly. 

However NSView.isFlipped() always returns true.


And it is not just control's background problem. Painting image patterns using GC facing same problem. See GC.setPatternPhase()

Comment 7 Jeeeyul Lee 2020-12-07 20:22:15 EST

Created attachment 284987 [details]
Example code about the above comment (ABCDE thing)

Comment 8 Jeeeyul Lee 2020-12-07 20:29:09 EST

(In reply to Jeeeyul Lee from comment #6)
>   phase.y = controlView.bounds().height; // <- I've added this line

There was a typo, It was actually likes that:
 controlView.frame().height - imgHeight;

Comment 9 Sravan Kumar Lakkimsetti 2020-12-15 01:26:48 EST

I will investigate this tomorrow after 4.18 release is almost complete

Comment 10 Sravan Kumar Lakkimsetti 2020-12-18 02:48:28 EST

(In reply to Jeeeyul Lee from comment #8)
> (In reply to Jeeeyul Lee from comment #6)
> >   phase.y = controlView.bounds().height; // <- I've added this line
> 
> There was a typo, It was actually likes that:
>  controlView.frame().height - imgHeight;

When I tried this the problem moved from top three to bottom two.
Adding this line fixes A,B and C images but breaks D and E