[Lazarus] ctrl mouse link in "compiler directives" or comments (which color)?

Martin Friebe lazarus at mfriebe.de
Tue Jul 15 10:05:05 CEST 2008

Luiz Americo Pereira Camara wrote:
> Mattias Gaertner wrote:
>> My question is:
>> What about the other widgetsets?


>> Can they easily distinguish between a popup selection change and
>> other changes?
>> If not, then we should redefine the LM_CHANGE, LM_SELCHANGE events for
>> the combobox. The TComboBox should be Delphi compatible, the
>> messages don't need to be. 
> One drawback, although unlikely, is if an descendant intercept LM_* 
> messages.
>> For example: It is quite simple to add a LM_CHANGE in the win32 intf. 
>> TComboBox could check before triggering an OnChange if something has
>> changed, which should be quite Delphi compatible.

It's the most doable solution . See below.

> It's an option. Another option (simpler) is see why the current code to 
> avoid the LM_CHANGED message  works for Gtk1  and not for gtk2. See if 
> is possible under detect under gtk2. I'll see.

Gtk2 is handled in an different callback function. Unlike gtk1 the 
LM_SELCHANGE message is sent inside the 'changed' event. At first look 
is not possible to determine if the changed event came from the 
selection list or not.

One issue is that in gtk2 and Qt the LM_CHANGED message is sent before 
LM_SELCHANGE unlike gtk1, but gtk1 could be reimplemented like gtk2.
Under Win32 is easy to sent an extra LM_CHANGED message in response to 
selection change


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