Introducing OnMouseEnter/OnMouseLeave events on TControl in VCL for Delphi 2006

In Delphi 2006 we’ve added
OnMouseEnter and OnMouseLeave events to TControl so if you’re a component writer
be sure to publish these new events on your controls. One of the criteria for
adding these events at the TControl level was to ensure that they were fired
correctly all the time. In previous versions of the VCL mouse enter/leave events
were handled in a somewhat lazy fashion where they were fired as part of idle
processing and as a result the mouse enter/leave logic was somewhat error prone.
In some cases the events were not fired correctly which resulted in less than
desirable behavior particularly for controls like speedbuttons. We’ve now
implemented support for the Windows API _TrackMouseEvent
which allows us to accurately process these messages without dropping events as
a result of quick mouse movements.

Tag: borland delphi