Automatic handling of ThreeState checkboxes

[Michael Vogel]

Maybe there's a simple approach to handle checkboxes using the #PB_CheckBox_ThreeState flag, but I don't think so.
Wouldn't it be fine, if PB would be able to handle also three state boxes automatically?

Code: Select all

Procedure SetGadgetThreeState(Gadget,Value,*State.Integer=0)
	If Value=2
		Value=-1
	EndIf
	SetGadgetState(Gadget,Value)
	If *State
		*State\i=Value
	EndIf
	ProcedureReturn value
EndProcedure

*** Initialization ***
OptFatLineState=0
SetGadgetState(#OptFatLine,OptFatLineState)

*** Event-Handling ***
  Case #PB_Event_Gadget,#PB_Event_Menu
     Select EventGadget()
        :
	Case #OptFatLine
		OptFatLineState=(OptFatLineState+1)%3
		SetGadgetThreeState(#OptFatLine,OptFatLineState)

[Danilo]

Wouldn't it be fine, if PB would be able to handle also three state boxes automatically?

Like the following on Windows?

Code: Select all

If OpenWindow(0, 0, 0, 270, 160, "CheckBoxGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
    ButtonGadget(1, 10,  10, 250, 20, "CheckBox three state", #BS_AUTO3STATE)
    Repeat
        Select WaitWindowEvent()
            Case #PB_Event_CloseWindow : End
            Case #PB_Event_Gadget      : Debug SendMessage_(GadgetID(1),#BM_GETSTATE,0,0)&3
        EndSelect
    ForEver
EndIf

Makes sense for cross-platform #PB_CheckBox_ThreeState.

Creates a button that is the same as a three-state check box, except that the box changes its state when the user selects it.
The state cycles through checked, indeterminate, and cleared.

[Shardik]

By clicking on the checkbox, the user can bring it back to either the "on" or "off" state to apply this to all the items. Therefore the "inbetween" state can only be set by the program via SetGadgetState() and not by the user by clicking on the checkbox.

As a workaround for cycling through all 3 states when clicking onto the
CheckBoxGadget it's not necessary to use API functions. The following
example works cross-platform (tested on Windows 7 x86, Kubuntu 9.04,
Xubuntu 10.04 and MacOS X 10.6.8 ):

Code: Select all

OpenWindow(0, 270, 100, 270, 40, "Cycle through CheckBox states")
CheckBoxGadget(0, 10, 10, 250, 20, "3-state CheckBox", #PB_CheckBox_ThreeState)
CheckBoxState = 1

Repeat
  Select WaitWindowEvent()
    Case #PB_Event_CloseWindow
      Break
    Case #PB_Event_Gadget
      If EventGadget() = 0
        CheckBoxState = (CheckBoxState + 1) % 3

        If CheckBoxState = 2
          SetGadgetState(0, #PB_Checkbox_Inbetween)
        EndIf
      EndIf
  EndSelect
ForEver

[Michael Vogel]

Wouldn't it be fine, if PB would be able to handle also three state boxes automatically?

Like the following on Windows?

Code: Select all

If OpenWindow(0, 0, 0, 270, 160, "CheckBoxGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
    ButtonGadget(1, 10,  10, 250, 20, "CheckBox three state", #BS_AUTO3STATE)
    Repeat
        Select WaitWindowEvent()
            Case #PB_Event_CloseWindow : End
            Case #PB_Event_Gadget      : Debug SendMessage_(GadgetID(1),#BM_GETSTATE,0,0)&3
        EndSelect
    ForEver
EndIf

Makes sense for cross-platform #PB_CheckBox_ThreeState.

Creates a button that is the same as a three-state check box, except that the box changes its state when the user selects it.
The state cycles through checked, indeterminate, and cleared.

Exactly, thanks

PS: I believe, BM_GETCHECK and BM_SETCHECK should be used for windows