Enable multiple select in ListBox

[idbirch]

I've got a listbox in my GUI and I want to allow multiple select, just like the $LBS_MULTIPLESEL style does but only when the CTRL key is held down. I've played with _IsPressed() but polling this contantly causes flicker. I've looked at HotKeySet but can't see a way of knowing when the Ctrl key has been released again. Is there an easy way to accomplish this which I'm missing?

At the moment, it's looking like I may have to add a checkbox to enable and disable muliple select but that just seems....lame.

[Zedna]

Post your code with _IsPressed() and I will remove flickering for you.

[Zedna]

Princip of antiflickering:

Global $ctrl = False
Global $ctrl_prev = False

While 1
 $ctrl = _IsPressed('11') = 1  ; Ctrl
 If $ctrl <> $ctrl_prev Then 
    $ctrl_prev = $ctrl
    If $ctrl Then
        ; enable
        ; ...
    Else
        ; disable
        ; ...
    EndIf
 EndIf

 $nMsg = GUIGetMsg()
    Switch $nMsg
        Case $GUI_EVENT_CLOSE
            Exit 
        Case ...
 EndSwitch
WEnd

Edited March 11, 2009 by Zedna

[idbirch]

Thanks for the help Zedna, your example script has solved the flickering issue. The only remaining problem is I can't get the toggle of multi-select to work. Here's an example script:

expandcollapse popup

#include <GUIConstantsEx.au3>
#include <GUIListBox.au3>
#include <StaticConstants.au3>
#include <WindowsConstants.au3>
#Include <Misc.au3>
#Include <GuiTab.au3>

Global $CTRLisPressed = False
Global $CTRLisPressed_prev = False

#Region ### START Koda GUI section ### Form=
$Form1 = GUICreate("Form1", 283, 289, 192, 124)
$List1 = GUICtrlCreateList("", 16, 40, 241, 214)
GUICtrlCreateLabel("List of stuff:", 16, 16, 58, 17)
GUISetState(@SW_SHOW)
#EndRegion ### END Koda GUI section ###

GUICtrlSetData ( $List1, "Item 1" )
GUICtrlSetData ( $List1, "Item 2" )
GUICtrlSetData ( $List1, "Item 3" )

While 1
    
     $CTRLisPressed = _IsPressed('11') = 1; Ctrl
     If $CTRLisPressed <> $CTRLisPressed_prev  Then 
        $CTRLisPressed_prev = $CTRLisPressed
        If $CTRLisPressed Then
           $Change = GUICtrlSetStyle ( $List1, $LBS_MULTIPLESEL )
           ConsoleWrite ( "Ctrl is held.  SetStyle result = " & $Change & @CRLF )
        Else
           $Change = GUICtrlSetStyle ( $List1, BitOr ($LBS_SORT, $WS_BORDER, $WS_VSCROLL))
           ConsoleWrite ( "Ctrl is released.  SetStyle result = " & $Change & @CRLF )
        EndIf
    EndIf
    
    $nMsgMainGUI = GUIGetMsg(1)
        
        Select
            Case $nMsgMainGUI[0] = $GUI_EVENT_CLOSE and $nMsgMainGUI[1] = $Form1
                Exit
                
        EndSelect
        
WEnd

Edited March 11, 2009 by idbirch

[Zedna]

From helpfile:

GUICtrlSetStyle()

Remarks

Some styles cannot be changed dynamically, check MSDN documentation. $CBS_UPPERCASE combo style is one example.

It seems you can't change LBS_MULTIPLESEL dynamically.

This works OK:

$List1 = GUICtrlCreateList("", 16, 40, 241, 214, BitOr($GUI_SS_DEFAULT_LIST, $LBS_MULTIPLESEL))

This doesn't work:

$List1 = GUICtrlCreateList("", 16, 40, 241, 214)
GUICtrlSetStyle ( $List1, BitOr($GUI_SS_DEFAULT_LIST, $LBS_MULTIPLESEL))

Edited March 11, 2009 by Zedna

[idbirch]

Hm, yes I did note that caveat in the help file but found nothing on MSDN to suggest that it couldn't be changed on the fly, damn. I'm not in the office with my code now but would destroying the listbox (backing up its contents first of course) and then recreating it with that style work? Or is that a stupid idea? Does anyone have any other suggestions as to how this could be achieved?

[Zedna]

I'm not sure about my theory. I just did some quick tests.

So try to search on the forum to see if somebody did something similar.

[Authenticity]

If you're satisfied with shift also, you can use $LBS_EXTENDEDSEL.

[idbirch]

Thanks Authenticity, another case of the 'GUI Control Styles' section of the help file not being updated with the newer styles available with the _GUICtrl* family. Anyway, yes, this seems like the best alternative for now. And thanks again Zedna, I'm sure I'll find another use for that IsPressed() trick.

[idbirch]

Hang on a sec! I've just tried out $LBS_EXTENDEDSEL and holding shift highlights everything in between the 2 items you click and CTRL lets you select multiple, non-adjacent items! Brilliant!

[Authenticity]

Are you using $LBS_MULTIPLESEL also? I didn't use it because it's not required in this case.

[idbirch]

No, just $LBS_EXTENDEDSEL which is doing exactly what I originally asked for - thanks.