Who can tell me more about SfxToolBoxControls and registerControl()?

Hello all,

I am struggling a bit to get various colour buttons (e.g. font/background/border colour) working as 
split buttons, so that the last used colour can be applied again right away. See fdo45671 for more 
details on the specific buttons/wishes.

For a lot of buttons I have succeeded to convert them to split buttons, for some other buttons I 
encounter problems. The button on the toolbar is of type split button (two buttons in one), but the 
left part of the button (use last used colour) does not work An example, that is present since 
before my interferences is the font color in reportdesign (base).

The 'split button' is a derived SfxToolBoxControl which triggers an Execute function when the 
colour is chosen from the colour palette and triggers a virtual Select function when the left half 
of the button (last used colour) is clicked. According to a comment in /core/sfx2/inx/sfx2/tbxc.hxx 
(line 179-185)<http://opengrok.libreoffice.org/xref/core/sfx2/inc/sfx2/tbxctrl.hxx#179> 
RegisterControl must be used for extra functionality (such as the split button uses).
The absence of RegisterControl may well be the cause of the problems I encounter (the 
afore-mentioned font color in reportdesign does not call registerControl), but I don't understand 
how and where to apply RegisterControl correctly.
(the font color button in reportdesign is in 
/core/reportdesign/source/ui/misc/toolboxcontroller.cxx<http://opengrok.libreoffice.org/xref/core/reportdesign/source/ui/misc/toolboxcontroller.cxx>
 )

Who can give me advise and or hints?



Winfried