[Lazarus] TPageControl OnChange calling issue

Ondrej Pokorny lazarus at kluug.net
Wed Oct 5 12:40:16 CEST 2016

On 05.10.2016 11:37, Michael W. Vogel via Lazarus wrote:
> But I'm not sure, would such a property be accepted by the Lazarus 
> developer?

I am against. LCL is designed to be Delphi-compatible so the default 
events are what they are and they behave how they behave.

Furthermore it would be quite hard to make it work on all WS because in 
a lot of cases you don't get the information from the WS what caused the 
change. A good example for a problematic component is TComboBox under 
Win32 (btw. TComboBox.OnClick isn't Delphi compatible either).

If you need an "event" when something changed programatically, call a 
method directly after the change.

(Well my opinion may change if you supply good arguments and supply a 
patch that makes the new "OnChangeEx(Sender: TObject; Reason: 
TChangeReason)" event work on all major WS for basic controls.) IMO the 
effort and maintenance don't pay off.


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