The current version of Mac OS X does not support controls over a
complex background such as a picture. Future versions of OS X
probably will, and we will then be able to build that capability into
RB.
Hurry up Apple !
I'm confused by this. It certainly is possible to draw controls over
any background you like. When you call to draw a theme button or
control, one of the settings you send is a callback to a function
that fills in the background, whatever it may be or whatever you want
to draw.
You dont have to pass anything at all, in which case no clearing is
done on the rect before the control is drawn.
If you want to have things show through the controls, then you can't
do that, but OSX happily draws the shadows over anything you have
underneath it without erasing the background. I did a quick little
demo with a single call to
DrawThemeButton(btnRect, proc, newInfo, oldInfo, 0, 0, 0)
online at:
http://www.sentman.com/picts/button_over_picture.jpg
The picture is in the backdrop of a canvas underneath the canvas onto
which I'm drawing the button via the above command.
I dont see why RB has to always call the methods to clear the
underlying graphics to the window background? There could certainly
be options here.
Now, drawing these controls yourself has some very big aggrivations,
so it's not that easy to overtake RB's plumbing and do this. First,
you can't pass it a graphics object, it just draws into the current
graphics object, or the window and it seems hard to get it to always
end up where you want it. You'll have to monitor for mouse clicks and
re-draw as necessary to display the correct state of the control. And
it only seems to work properly when drawing from the pain event. Any
other attempted drawing to the graphics object results in nothing at
all. At least that is the result of my 15 minutes of messing around
here. I'm sure that most if not all of those things could be overcome
and made into a canvas based control that behaved very much like a
regular RB control, but didn't erase the background...
Anybody have any more experience with drawing the theme controls like that?
Thanks,
James
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_____________________________________________________________________________
James Sentman <james at sentman dot com>
http://www.sentman.com
Enterprise server monitoring for Mac OS X: http://whistleblower.sentman.com
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