; German forum:
; Author: Freak (updated for PB4.00 by blbltheworm)
; Date: 17. December 2002
; OS: Windows
; Demo: No


; --------------------------------------------------------------------------
; Drag'n' Drop mit TreeGadgets
; by Timo Harter
;
; Syntax:
; EnableDragDrop( #Gadget, DragMode, @DropProcedure() )
;
;  #Gadget : Die Gadgetnummer vom TreeGadget
;
; DragMode : #Drag_LeftMouse  = Drag'n'Drop mit linker Maustaste
;            #Drag_RightMouse = Drag'n'Drop mit rechter Maustaste
;            (kann man mit '|' kombinieren)
;
; @DropProcedure()
;            Adresse einer Procedure, die aufgerufen wird, wenn ein Item losgelassen wurde.
;            Sie muss folgenden Syntax haben:
;
;            Procedure DropProcedure(X.l, Y.l, Button.l, Item.l)
;
;            EndProcedure
;
;            X, Y    enthält die Position, wo es losgelassen wurde
;
;            Button  enthält #Drag_LeftMouse, wenn die linke Taste benutzt wurde, oder
;                    #Drag_RightMouse, wenn es die rechte war.
;
;            Item    enthält die Nummer des Items im TreeGadget, das losgelassen wurde
;                    (gleicher Index wie bei GetGadgetState() )
;
;
; Anmerkung:
; Wenn das TreeView keine Icons enthält, so werden leere Icons hnzugefügt, weil das Ganze
; ohne nicht funktioniert.
;
; Für mehr Infos bitte das Beispiel ansehen.
;
; -------------------------------------------------------------------------

#TVN_BEGINDRAG       = -407
#TVN_BEGINRDRAG      = -408
#TVS_DISABLEDRAGDROP = $10
#Drag_LeftMouse  = 1
#Drag_RightMouse = 2

#winMain=1

Global hWndTV.l, DropProc.l, DragDropMode.l, hDragIml.l, DragItem.l

Procedure.l DragDropCallback(Window.l, Message.l, wParam.l, lParam.l)
  Protected DoDrag.l, DropX.l, DropY.l, hItem.l, hItem2.l, dItem.l
  result = #PB_ProcessPureBasicEvents
  Select Message
    Case #WM_NOTIFY
      *lp.NMHDR = lParam
      If *lp\code = #TVN_BEGINDRAG And (DragDropMode & #Drag_LeftMouse): DoDrag = #True: EndIf
      If *lp\code = #TVN_BEGINRDRAG And (DragDropMode & #Drag_RightMouse): DoDrag = #True: EndIf
      If DoDrag
        *pnmtv.NMTREEVIEW = lParam
        DragItem = *pnmtv\itemNew\hItem
        hDragIml = SendMessage_(hWndTV, #TVM_CREATEDRAGIMAGE, 0, DragItem)
        SendMessage_(hWndTV, #TVM_SELECTITEM, #TVGN_CARET, #Null)
        ImageList_BeginDrag_(hDragIml, 0, 0, 0)
        ImageList_DragEnter_(GetParent_(hWndTV), 0, 0)
        ImageList_DragShowNolock_(#True)
        ImageList_DragLeave_(hWndTV)
        ShowCursor_(#False)
        SetCapture_(GetParent_(hWndTV))
        SendMessage_(hWndTV, #TVM_SELECTITEM, #TVGN_CARET, DragItem)
      EndIf
    Case #WM_MOUSEMOVE
        If hDragIml
          DropX = PeekW(@lParam)
          DropY = PeekW(@lParam+2)
          ImageList_DragMove_(DropX, DropY+20)
          ImageList_DragShowNolock_(#False)
          ImageList_DragShowNolock_(#True)
        EndIf
    Case #WM_LBUTTONUP
        If hDragIml And (DragDropMode & #Drag_LeftMouse)
          ImageList_EndDrag_()
          ReleaseCapture_()
          ShowCursor_(#True)
          ImageList_Destroy_(hDragIml)
          hDragIml = #False
          dItem = 0
          hItem = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_ROOT, 0)
          While hItem <> DragItem
            hItem2 = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_CHILD, hItem)
            Repeat
              If hItem2 = #Null: hItem2 = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_NEXT, hItem): EndIf
              If hItem2 = #Null: hItem = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_PARENT, hItem): EndIf
            Until hItem2 <> #Null
            hItem = hItem2
            dItem + 1
          Wend
          CallFunctionFast(DropProc, WindowMouseX(#winMain), WindowMouseY(#winMain), #Drag_LeftMouse, dItem)
        EndIf
    Case #WM_RBUTTONUP
        If hDragIml And (DragDropMode & #Drag_RightMouse)
          ImageList_EndDrag_()
          ReleaseCapture_()
          ShowCursor_(#True)
          ImageList_Destroy_(hDragIml)
          hDragIml = #False
          dItem = 0
          hItem = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_ROOT, 0)
          While hItem <> DragItem
            hItem2 = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_CHILD, hItem)
            Repeat
              If hItem2 = #Null: hItem2 = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_NEXT, hItem): EndIf
              If hItem2 = #Null: hItem = SendMessage_(hWndTV, #TVM_GETNEXTITEM, #TVGN_PARENT, hItem): EndIf
            Until hItem2 <> #Null
            hItem = hItem2
            dItem + 1
          Wend
          CallFunctionFast(DropProc, WindowMouseX(#winMain), WindowMouseY(#winMain), #Drag_RightMouse, DragItem)         
        EndIf
  EndSelect
  ProcedureReturn result
EndProcedure

Procedure.l EnableDragDrop(TVGadget.l, DragMode.l, DropProcedure.l)
  Protected Style.l, hIml.l
  hWndTV = GadgetID(TVGadget)
  DropProc = DropProcedure
  DragDropMode = DragMode
  Style = GetWindowLong_(hWndTV, #GWL_STYLE)
  Style = Style & (~#TVS_DISABLEDRAGDROP)
  SetWindowLong_(hWndTV, #GWL_STYLE, Style)
  If SendMessage_(hWndTV, #TVM_GETIMAGELIST, #TVSIL_NORMAL, 0) = #Null
    hIml = ImageList_Create_(16,16,#ILC_COLOR8,0,999)
    SendMessage_(hWndTV, #TVM_SETIMAGELIST, #TVSIL_NORMAL, hIml)
  EndIf
  SetWindowCallback(@DragDropCallback())
  ProcedureReturn #True
EndProcedure

; -------------------------------------------------------------------------
; Beispiel Code:
; -------------------------------------------------------------------------


; diese Procedure wird aufgerufen nach dem Drag'n'drop Vorgang:
Procedure DropProcedure(X.l, Y.l, Button.l, Item.l)
  If Button = #Drag_LeftMouse
    MessageRequester("Drag'n Drop","Item Number "+Str(Item)+" has been dropped at X:"+Str(X)+" Y:"+Str(Y)+" using left Button.",#MB_ICONINFORMATION)
  Else
    MessageRequester("Drag'n Drop","Item Number "+Str(Item)+" has been dropped at X:"+Str(X)+" Y:"+Str(Y)+" using right Button.",#MB_ICONINFORMATION)
  EndIf
EndProcedure

#Tree = 1

; Window und Gadget...
OpenWindow(#winMain, 0, 0, 640, 480, "Drag'n Drop", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
CreateGadgetList(WindowID(#winMain))

TreeGadget(#Tree, 5, 5, 150, 250)
hImg = LoadIcon_(0,#IDI_APPLICATION)
AddGadgetItem(#Tree, -1, "Item1", hImg)
AddGadgetItem(#Tree, -1, "Item2", hImg)
  AddGadgetItem(#Tree, -1, "Item3",0,1)
  AddGadgetItem(#Tree, -1, "Item4",0,1)

; mehr als das muß man nicht tun:
EnableDragDrop(#Tree, #Drag_LeftMouse|#Drag_RightMouse, @DropProcedure())

; warten auf Ende...
While WaitWindowEvent() <> #PB_Event_CloseWindow: Wend
End

; -------------------------------------------------------------------------

; IDE Options = PureBasic v4.00 (Windows - x86)
; Folding = -
; EnableXP