mirror of
https://gitlab.com/freepascal.org/lazarus/lazarus.git
synced 2025-04-10 15:08:28 +02:00
|
|
||
|---|---|---|
| .. | ||
| README | ||
| wsactnlist.pp | ||
| wsarrow.pp | ||
| wsbuttons.pp | ||
| wscalendar.pp | ||
| wschecklst.pp | ||
| wsclistbox.pp | ||
| wscomctrls.pp | ||
| wscontrols.pp | ||
| wsdbctrls.pp | ||
| wsdbgrids.pp | ||
| wsdialogs.pp | ||
| wsdirsel.pp | ||
| wseditbtn.pp | ||
| wsextctrls.pp | ||
| wsextdlgs.pp | ||
| wsfilectrl.pp | ||
| wsforms.pp | ||
| wsgrids.pp | ||
| wsimglist.pp | ||
| wslclclasses.pp | ||
| wsmaskedit.pp | ||
| wsmenus.pp | ||
| wspairsplitter.pp | ||
| wsproc.pp | ||
| wsspin.pp | ||
| wsstdctrls.pp | ||
| wstoolwin.pp | ||
This directory contains all sceleton widgetset 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 wil 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 ComponentClass 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 overriden
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 compiletime 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