[Lazarus] Dark themed lazarus

[Anthony Walter]

About the patch, I am still making some changes, but what I've done is the
this. Currently the object inspector draws every row even if it doesn't
need redrawing. I modified the SetItemIndex method to InvalidateRect the
OldIndex and NewIndex, then only redraw those two rows in DoPaint. I added
a public Fast property for testing so that you can toggle between the old
behavior and new behavior at runtime, allowing users to measure the
difference both in responsiveness and CPU usage.

So far with this change if you click, hold down the mouse, and drag up/down
quickly in the inspector the lag seems greatly reduced, as well as less CPU
usage. I have not testing how this effects Windows/Qt/Mac yet, but as I
said in my OP those platforms/widget sets did not suffer from the same
laggy like behavior. Either way, shortly I'll submit it with a patch, a
stand alone example testing program, and let others try it for themselves.

Next I might tackle the lagginess in drag moving controls on the form
designer. Does that seem like a laggy problem to anyone else?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lazarus-ide.org/pipermail/lazarus/attachments/20180405/6d28b393/attachment.html>