Drag item inside or out of listbox?

BlitzMax Forums/MaxGUI Module/Drag item inside or out of listbox?

Grisu

(Posted 2014) [#1]

Hello everyone!

Is there a way to drag & drop listbox items inside a listbox, from one listbox to another or on a canvas via mouse? (Windows only)

I've put up a basic setup example below...

Icon strip (use as "icons.png"):

Code:

' Drag Grisu around!

SuperStrict

Import MaxGui.Drivers

AppTitle = "How to drag & drop Grisu around?"

Global window:TGadget = CreateWindow( AppTitle, 100, 100, 800, 600, Null, WINDOW_TITLEBAR|WINDOW_STATUS|WINDOW_RESIZABLE )
	
Global listbox1:TGadget = CreateListBox( 0, 0, 200, ClientHeight(window), window )
SetGadgetLayout listbox1, EDGE_ALIGNED, 0, EDGE_ALIGNED, EDGE_ALIGNED
	
SetGadgetIconStrip listbox1, LoadIconStrip("icons.png")
	
AddGadgetItem listbox1, "Unknown User", False, 1, "Unkown User"
AddGadgetItem listbox1, "Grisu, the Dummy", False, 0, "Grisu, the Dummy"
AddGadgetItem listbox1, "Unknown User", False, 1, "Unkown User"
AddGadgetItem listbox1, "Unknown User", False, 1, "Unkown User"
	
SelectGadgetItem listbox1, 1 ' select Grisu

Global listbox2:TGadget = CreateListBox( ClientWidth(window)-200, 0, 200, ClientHeight(window), window )
SetGadgetLayout listbox2, 0, EDGE_ALIGNED, EDGE_ALIGNED, EDGE_ALIGNED
	
SetGadgetIconStrip listbox2, LoadIconStrip("icons.png")
	
AddGadgetItem listbox2, "Unknown User", False, 1, "Unkown User"
AddGadgetItem listbox2, "Unknown User", False, 1, "Unkown User"
AddGadgetItem listbox2, "Unknown User", False, 1, "Unkown User"
AddGadgetItem listbox2, "Unknown User", False, 1, "Unkown User"

Global canvas:TGadget=CreateCanvas(200,ClientHeight(window)/2,ClientWidth(window)-400,400,window)

Global timer:TTimer=CreateTimer(60)

While WaitEvent()
	'Print CurrentEvent.ToString()
	Select EventID()
		Case EVENT_TIMERTICK
		    'Print "tick"
			RedrawGadget canvas
			
		Case EVENT_GADGETPAINT
			SetGraphics CanvasGraphics(canvas)
  		    Cls
			Flip

		Case EVENT_WINDOWCLOSE, EVENT_APPTERMINATE;End
		'ListBox Event(s)
		'EventData() holds the index of the corresponding listbox item.
		Case EVENT_GADGETSELECT
            Select EventSource()
             Case Listbox1
   				SetStatusText window, "Listbox 1 - Selected Item Index: " + EventData()
             Case Listbox2
   				SetStatusText window, "Listbox 2 - Selected Item Index: " + EventData()
            End Select  
		Case EVENT_GADGETACTION
            Select EventSource()
             Case Listbox1
				SetStatusText window, "Listbox 1 - Double-Clicked Item Index: " + EventData()
             Case Listbox2
				SetStatusText window, "Listbox 2 - Double-Clicked Item Index: " + EventData()
            End Select  
		Case EVENT_GADGETMENU
            Select EventSource()
             Case Listbox1
				SetStatusText window, "Listbox 1 - Right-Clicked Item Index: " + EventData()
	         Case Listbox2
				SetStatusText window, "Listbox 2 - Right-Clicked Item Index: " + EventData()
            End Select  
	End Select
Wend

I'd like to visually move an item between listbox 1 <-> 2, inside each listbox or drag it onto a canvas.

Thanks
Grisu

Derron

(Posted 2014) [#2]

I do not know if "maxgui" handles drag n drop somewhere (cannot remember to have seen that).

So I assume you will have to "code" it on your own:

- onmousedown on a list entry you store that entry
- if the mouse moves out of the gadgets area without "mouse release" you start a "drag"-action (or if the mouse moves > X distance)
-> create a temporary widget "attached" to the mouse position (move it with the mouse), also add the needed data (text, linked data block ...)
- if the mouse enters the other list, you ask the gadget if it accepts "drops", if yes, you might eg. recolor it or add a border or ...
- if the mouse gets released over that gadget, you start the "drop"-action
-> add the wanted data (text, data block) to the list entry and remove the temporary widget/gadget

Above just simulates DragNDrop, it could get extended to allow multiple widgets, to send out specific events (onDrag, onDrop, ...) but yay, this should be all you need.

bye
Ron