ComboBoxGadget limit?

[PB]

Is there any practical limit to the number of items shown in
the drop-down list of a ComboBoxGadget? One of my apps
keeps a history of text in it, but I'm worried that a heavy
user might put around 1000 or more items in it.

[citystate]

not too sure of the upper maximum, but I tested it out with 100000 items and it didn't flinch

Code: Select all

OpenWindow(0,0,0,120,80,"ComboBox Test",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
ComboBoxGadget(0,5,5,110,20)
For i=1 To 100000
  AddGadgetItem(0,i-1,Str(i))
Next

Repeat
Until WaitWindowEvent(20)=#PB_Event_CloseWindow

[Neil]

not too sure of the upper maximum, but I tested it out with 100000 items and it didn't flinch

Code: Select all

OpenWindow(0,0,0,120,80,"ComboBox Test",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
ComboBoxGadget(0,5,5,110,20)
For i=1 To 100000
  AddGadgetItem(0,i-1,Str(i))
Next

Repeat
Until WaitWindowEvent(20)=#PB_Event_CloseWindow

I flinched on 1000000 !! but got there in the end.

[PB]

Thanks for testing! Didn't even cross my mind to do that,
because I was thinking that even if it populates, it might
crash later on or something (due to memory limits).

[charvista]

The standard limit is 65'565 elements.
Because, if you use one more, 65'566 (or more), and when you scroll to the end while holding the scroll block directly to the end, you will see that the last ones are not into the 65'500 but back to the begin (see example below, where I put 65566). This is asking for trouble.
However, if you scroll with the mouse wheel, or by clicking on the free space of the scroller under the scoll block, or on the arrow-down button of the scrollbar, it will work.

Code: Select all

    Win=OpenWindow(#PB_Any,0,0,520,580,"ComboBox Test",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
    Sgad=ComboBoxGadget(#PB_Any,5,5,510,520)
    For i=1 To 65566; that's too much, the ultimate max here should be 65'565.
      AddGadgetItem(Sgad,i-1,Str(i-1))
    Next

    Repeat
        Event=WaitWindowEvent()
        Select Event
        Case #PB_Event_CloseWindow
            ExitEventLoop=#True
        Case #PB_Event_Gadget
            Gadget=EventGadget()
            Select Gadget
            Case Sgad
                Debug GetGadgetState(Sgad)
            EndSelect
        EndSelect
    Until ExitEventLoop

Note that this limit is on Windows. I don't know what happens on Mac or Linux.

[PB]

Thanks for testing and confirming the limits. I doubt my users would
have that many; but it's always good to know the limitations.

[blueznl]

I messed with different Windows controls as I was doing the same thing: storing everything in a control / gadget. Behaviour got unpredictable when going over 65533 (not 65536, strangely enough). Must be somewhere a hardcoded 16 bits limit. I'd suggest to keep the controls a little smaller

[electrochrisso]

I messed with different Windows controls as I was doing the same thing: storing everything in a control / gadget. Behaviour got unpredictable when going over 65533 (not 65536, strangely enough). Must be somewhere a hardcoded 16 bits limit. I'd suggest to keep the controls a little smaller

I think the 16 bit limit is 65535, as 0 need to be counted to make 65536.