On Nov 18, 2007 8:00 PM, James Chandler Jr <[EMAIL PROTECTED]> wrote:
> Hi Tom
>
> You do great work!
>
> Here is a symptom which might be related (or not). Am only mentioning it
> because
> this also had an invisible font issue. Am busy in Win32 right now, and will
> trace the issue further (if it still exists) when I can get back to carbon in
> a
> few weeks.
>
> I had four TPaintBoxes in a TPanel, which are graphic views for an audio wave
> display, a location timestrip, a chord strip, and a piano-roll note strip.
>
> Not all paintboxes are erased to the same background color at the start of
> their
> OnPaint procs. The drawing in all paintboxes is a mixture of lines,
> rectangles,
> and text, of various colors. Some Text drawing used transparent mode, and some
> did not.
>
> This multiple TPaintBox in a TPanel would draw correctly in Win32.
>
> On Carbon, it appeared that PaintBox canvas properties were somehow 'leaking'
> into the parent TPanel canvas, and affecting other TPaintBox OnPaints. The
> symptom was that some text would draw with the canvas background color (of
> some
> other paintbox) rather than the current paintbox Font color. This happened
> even
> if I would explicitly set TFont properties before each and every TextOut, in
> each OnPaint proc.
>
> If the background of all the TPaintBoxes had been the same, it would have been
> completely invisible text. But since the background of the most problematic
> paintbox was clButtonFace, and some other TPaintBoxes had a clWhite
> background,
> I was getting white-on-gray text, rather than the desired black-on-gray text.
>
> It may have had something to do with the transparent property leaking between
> canvases. Dunno.
>
> I 'fixed' it on the carbon target, by calling Application.processmessages
> between each of the TCanvas OnPaint procedures. I think this was flushing the
> screen after each OnPaint and avoiding transparency or some other property
> from
> 'leaking' between canvases. But the gratuitous calling of ProcessMessages
> slows
> donw the screen update, so it is just a temporary hack.
>
> When I can get back to carbon, will send a bug report with example, if the
> issue
> remains.
>
> Tobias' reported issue seemed similar, I just thought this example might be
> related.
>
> ====
>
> Here is another 'invisible text' issue--
>
> The default size of Win32 TLabel seems vertically smaller by a pixel or two,
> than the text rectangle which Carbon likes to draw into. If the TLabel has a
> default background color and font color, it draws the TLabel correctly in
> spite
> of the size discrepancy. In that mode, apparently a TLabel is able to
> 'overdraw'
> the control bounds and successfully put un-clipped text onscreen.
>
> But for instance if the TLabel Color is black, and the TLabel Font color is
> green (any non-default color combination would probably show the same bug),
> then
> all you get is a black square with no text, if the TLabel is not tall enough
> to
> fully contain the text.
>
> The fix for that issue was to make the TLabel a few pixels taller than the
> default size for Win32, and then it draws green on black just fine.
>
> That is a minor issue. It may be that carbon refuses to draw any text at all
> in
> certain modes, if the destination rectangle isn't tall enough.
>
> So there may not be a realistic fix. Perhaps if a fix was attempted, it would
> involve automatically growing the TLabel (or shrinking the TFont) if the Label
> is too small to contain the text.
>
> It is just that such minor issues take time to diagnose/fix, and makes the
> thing
> a little less 'cross platform'. But since carbon likes to draw controls more
> 'spread out' than Win32, it might be that manual form re-spacing is
> unavoidable
> labor when moving code from Win32 to carbon. The minor labor of re-spacing a
> form is so much less than 'writing from scratch' when moving between
> platforms.
>
> jcjr
>
Hi,
sorry that I have found some time for this issue so late.
I have tested it with latest SVN and I was unable to reproduce those
problems you have reported.
Please retest them and if they persist report them into bug tracker,
optimally upload sample application and screenshots. Don't forget to
add OS version.
Thanks,
Tom
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