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Author Topic: TScrollWindow  (Read 3688 times)

JimKueneman

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TScrollWindow
« on: May 01, 2017, 10:18:50 pm »
Is there anyone who is good at Carbon graphics who can help me finally fix the TScrollWindow?  The way the mouse position is calculated works correctly if the window is not scrolled but as you scroll the window the offsets that appear in the Mouse events get more incorrect the further you scroll.  This make using TScrollWindow for anything that involves the mouse useless.  This problem has been around for years.  I put ticked and demo in the tracker a long, long time ago but it is still broken and I am not smart enough with Carbon to fully understand where it is going wrong.  I have single stepped through the code and can see it is not getting the right offset but the way it gets and calculates these points is convoluted and I am not sure which step is failing.  It works correctly in Linux and Windows builds.

I think it may have something to do with the scrollbar code itself (which is used in one of the steps to calculate the client area for the mouse events).  There is no way to set the scrollbar parameter to get the window to scroll completely, you always have to add some non-consistent padding on the scroll max to compensate, again Linux and Windows work correctly. If I make a rectangle larger than the visible screen and set the scrollbar bounds to the size of the rectangle OSX will not scroll the rectangle completely and will always cut off some of the far edge.


https://bugs.freepascal.org/view.php?id=24279

thanks,
Jim
« Last Edit: May 01, 2017, 10:29:16 pm by JimKueneman »

Alextp

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Re: TScrollWindow
« Reply #1 on: May 08, 2017, 12:19:19 pm »
Hi
If you try own control, based on Paintbox+Scrollbars, its good.
Consider also own control based on ATScrollbar+Panel. not themed scrollbars, but stable.