Scrollable area and resizing

[mpower]

Hi guys, I have a GUI which requires scrolling, however resizing is a bit of a problem because any time you scroll down/up and then resize, the controls move down/up and blank space is created within the scrollable area. 

Any help with maintaining scrollable area size to be fixed would be great.

Here is a reproducer:

To achieve the undesirable effect I described, simply run the script, scroll down and then resize window. You will notice that new blank space is created either on top or on bottom of the window depending on scrolling/resizing direction. Easiest way to see how bad it is, is to scroll down the page about half-way and then maximise the window. You will notice now a whole bunch of blank space is added to the top of the window and scrolling up simply shows nothing, scrolling down shows controls but they are cut off because of the blank space created on top of the page.

This is all happening within the yellow bg  child gui. I need to make it so that even if the GUI is resized the contents of the yellow bg child gui do not move and the scrollable area within the child gui remains the same.

expandcollapse popup

#NoTrayIcon
#include-once
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
#include <GUIScroll.au3>
#include <SendMessage.au3>
Opt("GUIResizeMode", 802)

Global $parentgui_w = 880, $parentgui_h = 810, $childgui_w = $parentgui_w - 2, $childgui_h = $parentgui_h - 292

$parentgui = GUICreate("Scrollbar resize problem", $parentgui_w, $parentgui_h, -1, -1, BitOR($WS_MINIMIZEBOX, $WS_MAXIMIZEBOX, $WS_SIZEBOX))
GUISetBkColor(0xFFFFFF, $parentgui)

$childgui = GUICreate("", $childgui_w, $childgui_h, -5, 263, $WS_POPUP, $WS_EX_MDICHILD, $parentgui)
GUISetBkColor(0xFFF123, $childgui)
Dim $buttons[25]

For $i = 0 to 24
    If $i > 0 Then
        $cPos = ControlGetPos($childgui, "", $buttons[$i - 1])
        $buttons[$i] = GUICtrlCreateButton("Button " & $i + 1, ($childgui_w - 200) / 2, $cPos[1] + $cPos[3] + 50, 200, 80)
    Else
        $buttons[$i] = GUICtrlCreateButton("Button " & $i + 1, ($childgui_w - 200) / 2, 20, 200, 80)
    EndIf
Next

Scrollbar_Create($childgui, $SB_VERT, 130 * 25)
Scrollbar_Step(15, $childgui, $SB_VERT)

GUIRegisterMsg($WM_SIZE, "WM_SIZE")
GUIRegisterMsg($WM_NCACTIVATE, "WM_NCACTIVATE")
GUIRegisterMsg($WM_MOUSEWHEEL, "WM_MOUSEWHEEL")

GUISetState(@SW_SHOW, $parentgui)
GUISetState(@SW_SHOWNOACTIVATE, $childgui)

While 1
    $msg = GUIGetMsg(1)
    Switch $msg[1]
        Case $parentgui
            Switch $msg[0]
                Case $GUI_EVENT_CLOSE
                    Exit
                Case $GUI_EVENT_RESTORE
                    $pPos = WinGetPos($parentgui)
                    WinMove($parentgui, "", Default, Default, $pPos[2]+1, $pPos[3]+1)
                    WinMove($parentgui, "", Default, Default, $pPos[2]-1, $pPos[3]-1)
            EndSwitch
    EndSwitch
WEnd

Func WM_MOUSEWHEEL($hWnd, $iMsg, $wParam, $lParam)
    Local $iMw = BitShift($wParam, 16)
    $scroll_lines = 5

    If $iMw > 0 Then
        For $i = 0 to $scroll_lines
            _SendMessage($childgui, $WM_VSCROLL, $SB_LINEUP)
        Next
    Else
        For $i = 0 to $scroll_lines
            _SendMessage($childgui, $WM_VSCROLL, $SB_LINEDOWN)
        Next
    EndIf
    Return $GUI_RUNDEFMSG
EndFunc

Func WM_SIZE($hwnd, $uMsg, $wParam, $lParam)
    If $hwnd = $parentgui Then
        $wPos = WinGetPos($parentgui)
        $pgui_wdiff = ($wPos[2] - $parentgui_w) / 2
        $pgui_hdiff = ($wPos[3] - $parentgui_h) / 2
        If $pgui_wdiff > 7 Then
            If $pgui_hdiff <> 0 Then
                If $wPos[2] > $parentgui_w Then
                    WinMove($childgui, "", $wPos[0] + 2 + $pgui_wdiff, Default, $parentgui_w - 2, $wPos[3] - 306)
                Else
                    WinMove($childgui, "", $wPos[0] + 2 + $pgui_wdiff, Default, $wPos[2] - 16, $wPos[3] - 306)
                EndIf
            Else
                WinMove($childgui, "", $wPos[0] + 2 + $pgui_wdiff, Default)
            EndIf
        ElseIf $pgui_wdiff < 7 Then
            If $wPos[0] <> -32000 Then
                WinMove($childgui, "", $wPos[0] + 8, Default, $wPos[2] - 16, $wPos[3] - 306)
            EndIf
        ElseIf $pgui_hdiff > 42 Then
            WinMove($childgui, "", Default, Default, Default, $wPos[3] - 306)
        EndIf
    EndIf
    Return 0
EndFunc

Func WM_NCACTIVATE($hwnd, $imsg, $wparam)
    If $hwnd = $parentgui Then
        If NOT $wparam Then Return 1
    EndIf
    Return $gui_rundefmsg
EndFunc

 

Edited April 21, 2016 by mpower

[InunoTaishou]

I'd recommend getting the dialog metrics for the system so you can make your child fit a little better.

Func GetDialogMetrics()
    Local $tStruct = DllStructCreate("struct;long caption;long xBorder;long yBorder;long xDlgFrame;long yDlgFrame;endstruct")
    For $iSysMetric = $SM_CYCAPTION To $SM_CYDLGFRAME
        DllStructSetData($tStruct, $iSysMetric - $SM_CYCAPTION + 1, _WinAPI_GetSystemMetrics($iSysMetric))
    Next
    Return $tStruct
EndFunc   ;==>GetDialogMetrics

As for the sizing, you can get the new width and height of the main gui using the lParam from the WM_SIZE function

Func WM_SIZE($hwnd, $uMsg, $wParam, $lParam)
    Local $iWidth = _WinAPI_LoWord($lParam)
    Local $iHeight = _WinAPI_HiWord($lParam)

    If $hwnd = $parentgui Then
        WinMove($childgui, "", x, y, $iWidth - 2, $iHeight - 292)
    EndIf
    Return 0
EndFunc

Also, if you use _WinApi_SetParent you can make your child GUI a real mdi child gui, so it's drawn inside the parent. It will get rid of that nasty effect where the child and parent minimize separately.

[mpower]

49 minutes ago, InunoTaishou said:

I'd recommend getting the dialog metrics for the system so you can make your child fit a little better.

Func GetDialogMetrics()
    Local $tStruct = DllStructCreate("struct;long caption;long xBorder;long yBorder;long xDlgFrame;long yDlgFrame;endstruct")
    For $iSysMetric = $SM_CYCAPTION To $SM_CYDLGFRAME
        DllStructSetData($tStruct, $iSysMetric - $SM_CYCAPTION + 1, _WinAPI_GetSystemMetrics($iSysMetric))
    Next
    Return $tStruct
EndFunc   ;==>GetDialogMetrics

As for the sizing, you can get the new width and height of the main gui using the lParam from the WM_SIZE function

Func WM_SIZE($hwnd, $uMsg, $wParam, $lParam)
    Local $iWidth = _WinAPI_LoWord($lParam)
    Local $iHeight = _WinAPI_HiWord($lParam)

    If $hwnd = $parentgui Then
        WinMove($childgui, "", x, y, $iWidth - 2, $iHeight - 292)
    EndIf
    Return 0
EndFunc

Also, if you use _WinApi_SetParent you can make your child GUI a real mdi child gui, so it's drawn inside the parent. It will get rid of that nasty effect where the child and parent minimize separately.

Thanks for these! I will take this into account, especially _WinApi_SetParent. 

Scrollbar issues still persists though

 

EDIT: Hmm I tried using _WinApi_SetParent($childgui, $parentgui) however its not working correctly

Edited April 21, 2016 by mpower

[mpower]

Does anyone know of an effective way of dealing with the issue of scrollable area when resizing? Is there a way to perhaps retain the scroll position, resize the gui and adjust the scrollable area to fit the new window size?

[mpower]

So the only solution I've been able to come up with is to set the vertical scroll position to 0 when resizing. Whilst its not very good for user experience, it does negate the blank white space that would be padded to the top of the gui and end up cutting of controls further down below.

If anyone does come up with a better solution I'd be super keen to see it!

 

P.S. Here's the updated WM_SIZE function with the scroll to top line added:

Func WM_SIZE($hwnd, $uMsg, $wParam, $lParam)
    Local $iWidth = _WinAPI_LoWord($lParam)
    Local $iHeight = _WinAPI_HiWord($lParam)

    If $hwnd = $parentgui Then
        Scrollbar_Scroll($childgui, $SB_VERT, 0)
        WinMove($childgui, "", Default, Default, $iWidth - 2, $iHeight - 292)
    EndIf
    Return 0
EndFunc

 

Edited May 5, 2016 by mpower

[Melba23]

mpower,

Quote

the only solution I've been able to come up with is to set the vertical scroll position to 0 when resizing

That was my conclusion too - see GUIScrollBars_Ex_Example_5 in my Scrollbars UDF (the link is in my sig). The _Scrollbars_WM_ENTER/EXITSIZEMOVE functions in the main UDF do all the work.

M23

Edited May 5, 2016 by Melba23
Fixed formatting