Canvas not updated on macos

[krystophny]

After drawing objects on macos, the canvas is not updated. The next update happens at a paint event triggered by resizing the window or accessing the menu. The issue seems to be related to TViewport.CopyBackBufferRectOnCanvas and that fOnPaint is not assigned there.

tpx/ViewPort.pas

Line 1007 in acba881

if Assigned(fOnPaint) and GenEvent and (not fDisablePaintEvent)

[krystophny]

The problem seems to be more general and appears also when redrawing the cursor crosshair. https://forum.lazarus.freepascal.org/index.php?topic=38041.0 and http://wiki.lazarus.freepascal.org/Custom_Drawn_Interface could be related.

• The issue appears on both, Carbon and Cocoa UI.
• fOnBeginRedraw is not assigned in TViewport.UpdateViewport

[krystophny]

Live redrawing while painting still doesn't work on macos, but now the system is usable.