[RESOLVED] Children of tabcontrol

[colleen.boye]

I'm using this subroutine to recursively toggle disabled/invisible state for a control and its children:

    Public Sub ConcealObject(ByVal Parent As Control)
            For Each C As Control In Parent.Controls
                'conceals the control
            If C.Enabled = False OrElse C.Visible = False Then
                If CStr(C.Tag) <> "noconceal" Then 'a tag that are either never disabled or never hidden and thus shouldn't be toggled
                    Conceal(C)
                End If
            ElseIf C.HasChildren Then
                ConcealObject(C) 'repeats the loop at the next level down (will keep repeating for as many levels as there are)
                'NOTE: This can't turn into an endless loop because it's always going down a level and control inheritance can't be cyclical
            End If
        Next C
    End Sub

This works for everything except tabcontrols. On a tabcontrol, it hides/disables the correct fields on the front tabpage, but not any of the other pages. If I click on a different tabpage and then run the subroutine, it will hide/disable the controls on that page correctly, but that page only. How can I make it run through all the controls on all the tab pages every time?

[dunfiddlin]

Not sure why you'd need to, to be honest, as the contents of a tabpage other than the current one are de facto invisible and you could change the settings on page selection. However, your problem is that your failing to appreciate the relationships in a Tab Control

Tab Control = Parent
TabPages = Child of TabControl & Parent of page controls
Controls on tabpage = child of TabPage, grandchild of TabControl

[colleen.boye]

I fully appreciate the relationships in a tab control, but the subroutine is recursive, so it applies to children, grandchildren, great-grandchildren, great-great-grandchildren, etc.

And why does it work correctly for the current tab, but not for any of the others? Inheritance ought to be the same for all of them, and the others still have a visible state of true even when you can't see them.

[dunfiddlin]

and the others still have a visible state of true even when you can't see them.

Er .. no they don't. TabPages don't have a Visible property at all (well not a public one, anyway). But then I can't see how your Sub works at all. If the control is not visible you call Conceal() which does what? Toggles back to visible (in spite of its name)? If the control is visible and has children then it goes around again until the children run out. So what happens to a control that is visible but has no children (the last in the line of recursions)? Nothing as far as I can see. I can see where invisible controls might get restored to visibility but I can't for the life of me fathom where visible controls get turned invisible.

[.paul.]

you can't set properties or interact with controls on an unselected tabpage.
for instance, if you have a button on an unselected tabpage, calling .PerformClick doesn't work...

[techgnome]

It "works" because the TabControl's child is the active tabpage... the rest of the tabpages are in the TabPages collection... which is why it doesn't also do the other pages... they're not in the child.

-tg

[dunfiddlin]

you can't set properties or interact with controls on an unselected tabpage.

Say what now? It wouldn't be much use as a control if you couldn't change properties of pages and their controls while they were unselected. Interaction such as Click, I grant you.

[colleen.boye]

If the control is not visible you call Conceal() which does what?

It switches it to being visible but disabled:

    Public Sub Conceal(ByVal concealedObject As Object)
        'either hides or disables the object depending on the setting
        If HideDisabled = True Then
            concealedObject.Visible = False
            concealedObject.enabled = True
        Else
            concealedObject.Enabled = False
            concealedObject.visible = True
        End If
    End Sub

I added this because my primary user keeps trying to click on disabled buttons

It "works" because the TabControl's child is the active tabpage... the rest of the tabpages are in the TabPages collection... which is why it doesn't also do the other pages... they're not in the child.

That makes a lot of sense, but I tried this:

        For Each page As Control In tbEntry.Controls
            MessageBox.Show(page.Name)
        Next

And it returned all the pages. But dunfiddlin was right that they don't count as visible (my mistake there). So I fixed it by just adding a special case for tabpages:

    Public Sub ConcealObject(ByVal Parent As Control)
        For Each C As Control In Parent.Controls
            'conceals the control if necessary
            If (C.Enabled = False OrElse C.Visible = False) AndAlso Not TypeOf C Is TabPage Then
                If CStr(C.Tag) <> "noconceal" Then 'a tag that are either never disabled or never hidden and thus shouldn't be toggled
                    Conceal(C)
                End If
            ElseIf C.HasChildren Then
                If TypeOf C Is TabPage Then
                    C.Show()
                End If
                ConcealObject(C) 'repeats the loop at the next level down (will keep repeating for as many levels as there are)
            End If
        Next C
    End Sub

This fixes the visibility problem; unfortunately it leaves a different (apparently unrelated) problem that I'd better make a new thread for.