Delphi 10.3.2 FMX
In prior versions of Delphi, drawing on the canvas of a control would work in a TPanel’s OnResize() procedure.
Now it appears to be unsafe to draw in this procedure. My app draws random artifacts for the custom control while the user is resizing the TPanel (on both Windows and Macintosh).
I tried setting a TTimer for drawing it later, but anything drawn in the OnTimer() procedure is also messed up.
How can I safely draw a control in a TPanel’s OnResize() procedure?