[news.eclipse.platform.swt] Re: Screen patches, still occuring?

["Robert B" <oh1226@xxxxxxxxxxx>]

Actaully this problem is much serious than I have thought.
You can easily reproduce by dragging a window in front of
SWT programs. It normally does not happen if the widgets
in screen are simple. But with complexity it happen frequently.
It happens evertwhere, scrollbars, canvas, ....

I suspect this could be a consequence of single-threaded nature
of SWT. Why not farm drawing operations using multiple threads.
It could be that since a single thread handles everything and
unable to receive next signals on time for heavy drawing,
some signals may be lost, resulting in unpatched screens?

That's my guess. I have to say this could be a core reason that
killed SWT developed community. I hardly see developers
and companies using SWT these days. With 3.3, I can see
XP-look has been fixed. I can write wonderful systems that I never
imagined possible with AWT/Swing. However, This has killed off
my ambition.

I don't think developers will come back to SWT until this problem
is fixed. If it's a wdiget related problem, I can avoid it with different
designs. But no ways for this! You gotta fix this ASAP and make
wonderful SWT.

R.





"Mark Melvin" <mark_melvin@xxxxxxxx> wrote in message 
news:op.t8oqvgc6y7f1g1@xxxxxxxxxxxxxxxxxxxxxxxx
On Thu, 27 Mar 2008 11:07:30 -0400, Dave Wegener <wegener@xxxxxxxxxxxxxx>
wrote:

>
> "Robert B" <oh1226@xxxxxxxxxxx> wrote in message
> news:fsed4g$nk6$1@xxxxxxxxxxxxxxxxxxxx
>> Unpatched means that not-repainted clipping rectangles.
>> I had lots of them in the past. Most common ones are
>> small fellows, say, 20x10 pixels, or vertical or horizontal
>> lines, or areas not repainted, retaining previous images.
>>
>> On Eclipse SDK, open lots of elements for "Package explore"
>> make both scrollbars appear. Then pull down the SDK
>> so the right-bottom rectangle area (where two scrollbars
>> meet) goes below Windows task bar. Try up and down. You will
>> see the area get unpatched images!
>>
> Following your steps, I don't see any "unpatched images".  The windows
> repaint corectly.  I'm running Eclipse 3.3.2 on Windows 2000 Pentium 4 
> 3ghz
> with 1GB of RAM.
>

I know exactly what he means and I have not found a reason for it yet.  I
filed a bug here:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=219187

It was suggested it could be due to "A custom draw Tree with lots of
visible items" not being able to redraw itself quickly enough, but I saw
it with no tree view at all - just dragging a notepad window over an
Eclipse showing empty views in fact (see the screenshot in the bug).


>> This could be a related problem. The problem I seen normally
>> happens in the spacing area where no components are
>> drawn. For example, margin areas in formlayout, etc.
>>
>> R.
>>
>>
>>
>>
>>
>>
>> "Eric Rizzo" <eclipse-news@xxxxxxxxxxxx> wrote in message
>> news:fsdk70$3bh$4@xxxxxxxxxxxxxxxxxxxx
>> > Robert B wrote:
>> >> Hi,
>> >>
>> >> When I tested SWT-written programs about 15 months ago
>> >> on single CPU 1.6GHz Windows machine with SWT 3.2 installed,
>> >> I had lots of unpatched screen patches. This was happening especially
>> >> when I use several windows and shuttle around them.
>> >>
>> >> Now I use dual process of the same speed with SWT 3.3.
>> >> The interface is now Windows XP. In addition, most unpatched
>> >> screen patches are gone. Now it happens very seldom!
>> >> But does happen.
>> >
>> > I don't know about anyone else, but I don't know what you mean by
>> > "unpatched screen patches." Can you explain in more detail, maybe even
>> > provide a screen-shot?
>> >
>> > Eric
>>