[Lazarus] TCustomNotebook

[Hans-Peter Diettrich]

Felipe Monteiro de Carvalho schrieb:

> General concepts:
> 1> Avoid changing the current TPageControl as much as possible,
> because it is extensively used and changes here might cause a pletora
> of problems
> 2> I think it is no problem to introduce heavy changes to TTabControl
> because it is rarely used
> 3> Use exactly the same class hierarchy as Delphi:
> 
> TCustomNotebook (in Delphi called TCustomTabControl)
> --> TPageControl
> --> TTabControl

That also was my design :-)

> However I would do one thing differently from your idea: Let
> TCustomTabControl still have a notion of pages so that it can fully
> implement TPageControl, but allow it to be able to display tabs
> without pages too. Hide page properties and let TPageControl increase
> their visibility.

TCustomTabControl inherits (abstract) Pages from TCustomNotebook.

> Just because this hard distinction of a control with pages and one
> without makes sense in Windows it doesn't mean at all that it makes
> sense in all widgetsets. Plus, just 1 implementation is better then 2
> spread across various classes for the widgetset interfaces.

ACK, but the use of TCustomPage for Pages sucks.

As already mentioned, the EasyDockManager allows to dock any controls 
into its notebook, and there it's overkill to wrap every docked control 
into another page control. Instead the unused Tabs.Objects[] can hold 
any kind of controls, which can be used like pages, on demand.

> And I would make smaller patches implementing the following actions:
> 
> 1> Make sure TCustomNotebook can implement TTabControl, add an option
> that it can work without tabs and test in all widgetsets (maybe it can
> already do that, you would need to check this)

I only can test with the available widgetsets (Win32, eventually gtk2)

> 2> Change TTabControl to inherit from TCustomNotebook
> 3> Fix all problems found in the new TTabControl

I'd leave the following steps for later, and for people which can test 
their changes to the widgetsets.

DoDi