lazarus

mirror of https://gitlab.com/freepascal.org/lazarus/lazarus.git synced 2025-04-10 15:08:28 +02:00

History

paul 78187ac487 - added WsWinControl.CanFocus that inform about ability of control to be focused with default widgetset value = True (overrided for gtk) - changed CanTab of TWinControl to use TWSWinControlClass.CanFocus - published TRadioGroup.TabStop git-svn-id: trunk@10829 -		2007-03-30 05:22:36 +00:00
..
README.txt
wsactnlist.pp
wsarrow.pp
wsbuttons.pp	* made ActiveDefaultButtonChanged naming more consistent with other routines	2007-03-10 02:48:32 +00:00
wscalendar.pp
wschecklst.pp
wsclistbox.pp
wscomctrls.pp	* Fixed bug #1854	2007-01-20 02:19:19 +00:00
wscontrols.pp	- added WsWinControl.CanFocus that inform about ability of control to be focused with default widgetset value = True (overrided for gtk)	2007-03-30 05:22:36 +00:00
wsdbctrls.pp
wsdbgrids.pp
wsdialogs.pp
wsdirsel.pp
wseditbtn.pp
wsextctrls.pp
wsextdlgs.pp
wsfilectrl.pp
wsforms.pp
wsgrids.pp
wsimglist.pp	gtk intf: added custom mouse cursor images from Marc	2007-02-09 17:42:52 +00:00
wslclclasses.pp	* Introduced a handlebased component baseclass	2007-02-07 23:36:22 +00:00
wsmaskedit.pp
wsmenus.pp
wspairsplitter.pp	* patch for tpairsplitter by Paul Ishenin	2007-03-06 00:08:35 +00:00
wsproc.pp
wsspin.pp
wsstdctrls.pp	- added WsWinControl.CanFocus that inform about ability of control to be focused with default widgetset value = True (overrided for gtk)	2007-03-30 05:22:36 +00:00
wstoolwin.pp

README.txt

This directory contains all skeleton widget set component 
classes. These classes will never get instantiated and may 
only contain class functions.
  
=========  
IMPORTANT
=========  

Derivation and inheritance of classes is different then one
might be used to. It will be explained by the following 
examples.

Suppose the following LCL class hierarchy:

 TLCLComponent
     |
  TControl
     |
 TWinControl
 
the corresponding WS skeleton would be

 TWSLCLComponent
      |
  TWSControl
      |
 TWSWinControl


When method X of TWSControl gets implemented by 
widgetset Q the hierarchy looks like

 TWSLCLComponent
      |
  TWSControl.X --> TQWSControl.X
      |
 TWSWinControl


Calling TWSWinControl.X doesn't call TQWSControl.X since
it's parent is TWSControl. This problem is solved by 
modifying the class hierarchy at runtime.
When a component class is registered by RegisterWSComponent,
the class is copied and the vmt entries are adjusted so 
that the hierarchy looks like:


 TWSLCLComponent
      |
  TWSControl.X --> TQWSControl.X
                        |
                   TWSWinControl

In this case, calling TWSWinControl.X will call the overridden 
TQWSControl.X. The only thing which doesn't get handled is the 
inherited statement. Suppose there is also a TQWSWinControl.X 
which implements a few extra steps. In a normal situation one 
would have called "inherited". The call to inherited is
resolved at compile time and would in this example to a call to
TWSControl.X. That is not what we want.
To get around this, call the parent yourself:
  TWSWinControlClass(ClassParent).X