[Lazarus] Message dialogs in Lazarus

Hans-Peter Diettrich DrDiettrich1 at aol.com
Wed Dec 22 16:41:08 CET 2010

michael.vancanneyt at wisa.be schrieb:

>> There is nothing magic with layout managers, they have to do nothing 
>> but arrange their child controls, and to report the minimal and 
>> desired sizes to their parent (with AutoSize). Every docking manager 
>> already is a layout manager for its site, and its interface only lacks 
>> beforementioned AutoSize capabilities.
> I also thought this. In theory, a layout manager only needs to manipulate
> some rectangles. Independent of a GUI, you could do it in the FCL. So I set
> about implementing one.
> Mattias Gaertner quickly convinced me that this view is too simplistic.

Right :-(

The calculation of the positions and extents is quite easy, no special 
FCL support is needed. Problem is the conversation with the widgetsets.

> Under windows this may work; Under X, you have the window manager to take
> into account, the underlying widget set which doesn't listen, 'AutoSize'
> kicks in etc.
> So I suggest you contact him about this prior to advocating your views.

Since the layouts work already, all problems with the widgetsets seem to 
be solved (as far as possible). At least remaining problems do not 
affect layout managers in a special way.

It's known that the placement of widgets frequently is delayed, with 
according features (intended position...) implemented in the LCL. A 
layout manager only has to use and update the intended position and size 
of the controls, and everything else will happen as usual.


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