[Lazarus] Docking and Layout managers

[Hans-Peter Diettrich]

Mattias Gaertner schrieb:

>> I'd suggest a layout layer, between TControl and TWinControl, dealing 
>> with child controls (e.g. TContainerControl). As Paul pointed out, a 
>> TWinControl uses system resources (handles), which are not required
>> for layout (and docking) managers.
> 
> TWinControl has childs, TControl has not. This is usually tested with 
> if AControl is TWinControl then 
> 
> If a TContainerControl that is not a TWinControl has childs this
> test will break.

It only won't work if the old checks are used together with the new 
controls.

DoDi