Here is some code I've been playing around with to make drag and drop worth within a Treeview control. The code is based off of the msdn documentation of drag&drop in TV controls
here:
I've documented the script pretty thoroughly, so a lot of the information is in there, but some things of note:
- No drag image - I point out in the comments where the code for the dragimage stuff should go, but decided not to include it because it was being buggy and because I frankly prefer the method I ended up going with (drop target highlighting and insertion marks)
- Drop handling - my focus was on the getting the dragging stuff to work, which I did. What to do when the dragging ends is something I contended with only in a very simple way (just added the dragged node as a child of the drop target). There are other things one could do - vary the drop action depending on what kind of drop target / drag item you were contending with, etc.
Anyway, here's the code:
Code:
#NoEnv
Gui, +lastfound
hgui := WinExist()
; Set the message handlers
OnMessage( 0x4E, "Treeview_BeginDrag" ) ; WM_NOTIFY
OnMessage( 0x200, "Treeview_Dragging" ) ; WM_MOUSEMOVE
OnMessage( 0x202, "Treeview_EndDrag" ) ; WM_LBUTTONUP
; Add the Treeview
Gui, Add, TreeView, x0 y0 w200 h300 HWNDhTreeview
P1 := TV_Add("Apple", 0, "Expand" )
P1C1 := TV_Add("Apple juice", P1, "Expand" )
P2 := TV_Add("Orange", 0, "Expand" )
P2C1 := TV_Add("Orange juice", P2, "Expand" )
P2C2 := TV_Add("Orange soda", P2, "Expand" )
P2C2C1 := TV_Add("Tang", P2C2, "Expand" )
otherfruits = pear,kiwi,lime,grape,peach
Loop, parse, otherfruits, `,
TV_ADD( A_LoopField, 0 )
; Show the GUI
Gui, Show, w200 h300
return
; ----- End Auto-Execute section -----
guiclose:
exitapp
Treeview_BeginDrag( wParam, lParam )
{
global TV_is_dragging, hTreeview, hDragitem
static TVM_SELECTITEM := 0x110B, TVGN_CARET := 0x9
nmhdr_code := NumGet( lParam + 0, 8, "uint" )
; TVN_BEGINDRAGA = 0xFFFFFE69, TVN_BEGINDRAGW = 0xFFFFFE38
If ( nmhdr_code = 0xFFFFFE69 ) or ( nmhdr_code = 0xFFFFFE38 )
{
; Get the drag item out of the NMTREEVIEW structure
hDragitem := NumGet( lParam + 0, 60, "uint" )
; Select the item before dragging so it's clear what you're dragging
SendMessage( hTreeview, TVM_SELECTITEM, TVGN_CARET, hDragitem )
; If you were so inclined, you could initialize drag image stuff here:
; 1. get a drag image (either by using TVM_SETIMAGE, which requires
; that the Treeview control have been created with an associated
; imagelist) OR just use TVM_GETITEMRECT and fancy gdi-style stuff
; and make one yourself
; 2. add the image to an imagelist and use the imagelist drag functions
; (read up on it at msdn)
; 3. add the appropriate imagelist dragging code in the Treeview_Dragging()
; and Treeview_EndDrag() functions
;
; I initially had some code here that was mostly working but (a) it was
; creating some strange visual artifacts and (b) I kind of prefer just using
; insertion marks and highlighting the drop target.
; Set the dragging flag
TV_is_dragging := 1
}
}
Treeview_Dragging( wParam, lParam )
{
global TV_is_dragging, hTreeview, height
static TVM_HITTEST := 0x1111, TVM_SETINSERTMARK := 0x111A, TVM_GETITEMRECT := 0x1104
static TVM_SELECTITEM := 0x110B, TVGN_DROPHILITE := 0x8, TVM_GETITEMHEIGHT := 0x111C
If TV_is_dragging
{
if not height
height := SendMessage( hTreeview, TVM_GETITEMHEIGHT, 0, 0 )
; Get the mouse location out of lParam
x := lParam & 0xFFFF
y := lParam >> 16
; Create the TVHITTESTINFO struct...
VarSetCapacity( tvht, 16, 0 )
NumPut( x, tvht, 0, "int" ), NumPut( y, tvht, 4, "int" )
; ... to determine whether the pointer is over an item. If it is...
If hitTarget := SendMessage( hTreeview, TVM_HITTEST, 0, &tvht )
{
; ... highlight the item as a drop target, and / or ...
SendMessage( hTreeview, TVM_SELECTITEM, TVGN_DROPHILITE, hitTarget )
; ... if the pointer is in the top or bottom quarter of the item,
; show an insertion mark before or after, respectively.
; This way you can decide whether to make the dragged item
; a child or sibling of the drop target item.
;
; If you really wanted, you could check here to see what kind of
; item hitTarget was and display the insertion mark accordingly.
VarSetCapacity( rcitem, 16, 0 ), NumPut( hitTarget, rcitem )
SendMessage( hTreeview, TVM_GETITEMRECT, 1, &rcitem )
rcitem_top := NumGet( rcitem, 4, "int" )
rcitem_bottom := NumGet( rcitem, 12, "int" )
fAfter := 99 ; just a default that's not 0 or 1
fAfter := ( y - rcitem_top ) < ( height/4 ) ? 0 : ( rcitem_bottom - y) < ( height/4 ) ? 1 : fAfter
If ( fAfter = 99 )
SendMessage( hTreeview, TVM_SETINSERTMARK, 0, 0 ) ; hide insertionmark
Else
SendMessage( hTreeview, TVM_SETINSERTMARK, fAfter, hitTarget ) ; show insertion mark
}
}
}
Treeview_EndDrag( wParam, lParam )
{
global TV_is_dragging, hTreeview, hDragitem
static TVM_SETINSERTMARK := 0x111A, TVM_SELECTITEM := 0x110B, TVGN_DROPHILITE := 0x8
static TVM_HITTEST := 0x1111
If TV_is_dragging
{
; Remove the drop-target highlighting and insertion mark
SendMessage( hTreeview, TVM_SELECTITEM, TVGN_DROPHILITE, 0 )
SendMessage( hTreeview, TVM_SETINSERTMARK, 1, 0 )
; Add code here to handle the moving of the dragged node
; - hDragitem is the handle to the item currently being dragged
; - you can use the code from the WM_MOUSEMOVE to determine
; where the pointer is and where/how the item should be inserted
;
; For the sake of simplicity, this script will always move the
; dragitem to be a child of the drop target
; Get the mouse location out of lParam
x := lParam & 0xFFFF
y := lParam >> 16
; Create the TVHITTESTINFO struct...
VarSetCapacity( tvht, 16, 0 )
NumPut( x, tvht, 0, "int" ), NumPut( y, tvht, 4, "int" )
; ... to determine whether the pointer is over an item.
If hDroptarget := SendMessage( hTreeview, TVM_HITTEST, 0, &tvht )
{
; Only do stuff if the droptarget is different from the drag item
If ( hDragitem != hDroptarget )
{
; To prevent infinite loops, first make sure "parent" isn't actually a
; descendant of node (it's like going back in time and becoming your own
; great-grandfather: no good can come of it)
If not IsParentADescendant( hDragitem, hDroptarget )
{
AddNodeToParent( hDragitem, hDroptarget )
TV_Modify( hDropTarget, "Expand" )
TV_Delete( hDragitem )
}
}
}
; Set the dragging flag and dragitem handle to false
TV_is_dragging := 0, hDragitem := 0
}
}
IsParentADescendant( node, parent )
{
dlist := GetDescendantsList( node )
Loop, parse, dlist, `,
If ( A_LoopField = parent )
return 1
return 0
}
; Wheeeee! Recursion is fun!
GetDescendantsList( node )
{
If ( kid := TV_GetChild( node ) )
{
kids .= kid . "," . GetDescendantsList( kid )
While ( kid := TV_GetNext( kid ) )
kids .= kid . "," . GetDescendantsList( kid )
}
return kids
}
; I recurse! You recurse! We all recurse for Ira Curs! (or something )
AddNodeToParent( node, parent )
{
TV_GetText( t, node)
node_id := TV_Add( t, parent, "Expand" )
If ( kid := TV_GetChild( node ) )
{
AddNodeToParent( kid, node_id )
While ( kid := TV_GetNext( kid ) )
AddNodeToParent( kid, node_id )
}
return node_id
}
SendMessage( hWnd, Msg, wParam, lParam )
{
static SendMessageA
If not SendMessageA
SendMessageA := LoadDllFunction( "user32.dll", "SendMessageA" )
return DllCall( SendMessageA, uint, hWnd, uint, Msg, uint , wParam, uint, lParam )
}
LoadDllFunction( file, function ) {
if !hModule := DllCall( "GetModuleHandle", uint, &file, uint )
hModule := DllCall( "LoadLibrary", uint, &file, uint )
return DllCall("GetProcAddress", uint, hModule, uint, &function, uint)
}
I welcome comments/questions/criticisms.
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