How to extend/subclass a gadget or window (cross platform)?

[hmasr]

I’ve seen some topics for that but for windows only using API calls. I want to add properties and methods to a gadget or window but should be valid for all supported platforms.

[idle]

there isn't any cross platform PB function available to do it.
You would need to resort to API's.

For windows you have the native PB function to subclass the window SetWindowCallBack
and you can use this to do the same on Linux (except its global)
In the your call back you need to cast the event to the event type.

Code: Select all

ProcedureC WinManCallBack(*event.gdkEvent,window)
 Protected *bevent.GdkEventButton   
 If *event\gdktype = #GDK_BUTTON_PRESS
     ;cast event to button event 
      *bevent.GdkEventButton = *event
      If *bevent\button = 1 
         ;left 
      elseif *bevent\button = 3 
         ;right
      endif 
   endif 
   ;Pass control back to pb so it can get events
  ProcessPureBasicEvents(*event)
    

Code: Select all

CompilerIf #PB_Compiler_OS = #PB_OS_Linux
Enumeration -1  
  ;GdkEventTypes
#GDK_NOTHING ;     = -1
#GDK_DELETE   ;   = 0
#GDK_DESTROY;      = 1
#GDK_EXPOSE  ;    = 2
#GDK_MOTION_NOTIFY ;= 3
#GDK_BUTTON_PRESS ;= 4
#GDK_2BUTTON_PRESS; = 5
#GDK_3BUTTON_PRESS ;= 6
#GDK_BUTTON_RELEASE; = 7
#GDK_KEY_PRESS      ;= 8
#GDK_KEY_RELEASE ;= 9
#GDK_ENTER_NOTIFY; = 10
#GDK_LEAVE_NOTIFY; = 11
#GDK_FOCUS_CHANGE; = 12
#GDK_CONFIGURE     ; = 13
#GDK_MAP      ;= 14
#GDK_UNMAP  ;    = 15
#GDK_PROPERTY_NOTIFY ;= 16
#GDK_SELECTION_CLEAR ;= 17
#GDK_SELECTION_REQUEST ;= 18
#GDK_SELECTION_NOTIFY ;= 19
#GDK_PROXIMITY_IN ;= 20
#GDK_PROXIMITY_OUT ;= 21
#GDK_DRAG_ENTER      ;  = 22
#GDK_DRAG_LEAVE       ; = 23
#GDK_DRAG_MOTION    ;   = 24
#GDK_DRAG_STATUS     ;  = 25
#GDK_DROP_START       ; = 26
#GDK_DROP_FINISHED   ;  = 27
#GDK_CLIENT_EVENT ;= 28
#GDK_VISIBILITY_NOTIFY ;= 29
#GDK_NO_EXPOSE      ;= 30
#GDK_SCROLL           ; = 31
#GDK_WINDOW_STATE;      = 32
#GDK_SETTING           ;= 33
#GDK_OWNER_CHANGE;      = 34
#GDK_GRAB_BROKEN    ;   = 35
#GDK_DAMAGE           ; = 36
EndEnumeration
 CompilerIf Defined(GdkEvent,#PB_Structure)=#False
      Structure GdkEvent
        gdktype.l
        StructureUnion
          any.GdkEventAny
          expose.GdkEventExpose   
          no_expose.GdkEventNoExpose   
          visibility.GdkEventVisibility   
          motion.GdkEventMotion
          button.GdkEventButton
          scroll.GdkEventScroll
          key.GdkEventKey
          crossing.GdkEventCrossing
          focus_change.GdkEventFocus           
          configure.GdkEventConfigure       
          property.GdkEventProperty   
          selection.GdkEventSelection   
          proximity.GdkEventProximity
          client.GdkEventClient       
          dnd.GdkEventDND               
          window_state.GdkEventWindowState       
          setting.GdkEventSetting           
        EndStructureUnion
      EndStructure
CompilerEndIf

ImportC  "-gdk"
   gtk_main_do_event( *event.gdkEvent)
   gdk_event_handler_set (*func,*mdata,*notify);
EndImport

Macro SetWindowCallback(EventHandler)
      gdk_event_handler_set (EventHandler,0,0);
EndMacro 

Macro ProcessPureBasicEvents(event)
   gtk_main_do_event(event);
 EndMacro   
 
 
CompilerEndIf