Do Slider limits have maximum values?

[weirddave]

I'm using a slider to access data packets in a file. The number of packets is variable, I've had over 1M.

I'm using:

GUICtrlSetLimit ($idSliderReplay, $FilePackets-1, 0)

to set the slider limits. However, when I return the current slider position using:

$FilePos = GUICtrlRead($idSliderReplay)

msgbox(0,$FilePackets-1,$FilePos)

 

I get 30599 returned (the msgbox shows 12575784 in the title) when I slide all the way to the right.

 

The optimum would probably be to set the slider limit to the number of pixels it can slide along, but I don't see a way to find that out. Then I would just multiply the slider position by $FilePackets/$SliderPixels to get my position.

 

Any thoughts?

 

 

 

[Bert]

why use a slider? why not use a picklist?

[weirddave]

Not entirely sure what a pick list is? Will it scale well from small numbers to millions?

[Melba23]

weirddave,

Native sliders, and the GUICtrlSetLimit function, are limited to a maximum of 32767 - this is a Windows limitation and nothing to do with AutoIt. Try increasing the value here as see what happens:

#include <GUIConstantsEx.au3>
#include <MsgBoxConstants.au3>


$hGUI = GUICreate("Test", 500, 500)

$cSlider = GUICtrlCreateSlider(10, 10, 300, 20)
GUICtrlSetLimit($cSlider, 32767, 0) ; <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

$cButton = GUICtrlCreateButton("Read", 10, 100, 80, 30)

GUISetState()

While 1
    Switch GUIGetMsg()
        Case $GUI_EVENT_CLOSE
            Exit
        Case $cButton
            $iValue = GUICtrlRead($cSlider)
            MsgBox($MB_SYSTEMMODAL, "Slider", $iValue)
    EndSwitch
WEnd

But all is not lost - we can send a message to the slider to increase the maximum - but this comes with some disadvantages as we will see when we try:

#include <GUIConstantsEx.au3>
#include <MsgBoxConstants.au3>
#include <SliderConstants.au3>

$hGUI = GUICreate("Test", 500, 500)

$cSlider = GUICtrlCreateSlider(10, 10, 300, 20)
GUICtrlSendMsg($cSlider, $TBM_SETRANGEMAX, True, 12575784) ; <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

$cButton = GUICtrlCreateButton("Read", 10, 100, 80, 30)

GUISetState()

While 1
    Switch GUIGetMsg()
        Case $GUI_EVENT_CLOSE
            Exit
        Case $cButton
            $iValue = GUICtrlRead($cSlider)
            MsgBox($MB_SYSTEMMODAL, "Slider", $iValue)
    EndSwitch
WEnd

I certainly get the correct maximum value returned, but the slider is very sluggish - no doubt because it has to do a fair bit of behind the scenes work to calculate the correct value as the thumb is moved. >

I would strongly suggest sticking to a more sensible maximum value and doing the maths yourself to get the position:

#include <GUIConstantsEx.au3>
#include <MsgBoxConstants.au3>

; Determine the value increment for each slider unit - the default is 100
$iFactor = 12575784 / 100

$hGUI = GUICreate("Test", 500, 500)

$cSlider = GUICtrlCreateSlider(10, 10, 300, 20)


$cButton = GUICtrlCreateButton("Read", 10, 100, 80, 30)

GUISetState()

While 1
    Switch GUIGetMsg()
        Case $GUI_EVENT_CLOSE
            Exit
        Case $cButton
            ; Calculate the value to return
            $iValue = int(GUICtrlRead($cSlider) * $iFactor)
            MsgBox($MB_SYSTEMMODAL, "Slider", $iValue)
    EndSwitch
WEnd

Will that do?

M23

[weirddave]

Ah, so that's the limit, I think doing the maths myself will have to do, ta

I will probably use 0 to 9999 so that no matter the slider size (within reason ), the result will stay relatively smooth and linear and not go granular.