TCustomImage.Invalidate procedure
Causes the control to be repainted.
Declaration
procedure Invalidate; overrideDescription
Invalidate is an overridden procedure which causes the control to
be repainted. Invalidate is called when the content or dimensions for the
image have been changed.
Invalidate extends the ancestor method to include logic that reduces the
number of calls to the Paint method, and avoids flicker caused by
the redundant calls. It uses an internal flag in the class to determine if
the Paint method has already been called, but has not yet been completed. If
the flag has not been set, the inherited Invalidate method is called to
refresh the control using its visibility and control style settings.
No actions are performed in the method when Paint is already active.
See also
An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.