Restore Scroll Bar Position on Tab

[Paul Engel]

I have an application on which I have a tab control with two tabs. When a
user double-clicks on an item in tab1 of my tabs collection, tab2 becomes
the visible tab. (tabImageTabs.S electedIndex = 1) When they double-click on
the content in tab2, they are taken back to tab1.
(tabImageTabs.S electedIndex = 0)

When tab1 is restored, I have lost the position of the scrollbar and the
user must re-scroll to get back to where they were. I've tried setting the
scroll value (grab the verticlescroll value when leaving tab1 and assigning
it that value when I go back, but it doesn't seem to work.

Any ideas?
Here's the code I use to capture the position of the scrollbar when changing
to tab2:
ScrollBarLocati on = tabThumbNails.V erticalScroll.V alue
tabImageTabs.Se lectedIndex = 1

Here's the code I am using to move back to the tab1 with the verticle scroll
value set:
tabImageTabs.Se lectedIndex = 0
tabThumbNails.V erticalScroll.V alue = ScrollBarLocati on

(At this point, I get my tab1 back in front, but the scroll bar is back at
the top.)

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RE: Restore Scroll Bar Position on Tab

Hello, Paul,
I tried a few experiments with this and it does indeed seem flaky. I
wasn't able to find any "nice" solution. But I guess that there is some
timing problem involved where the TabPage is trying to scroll the
top-leftmost control into view and so it only partly pays attention to the
value that you are setting into tabThumbNails.V erticalScroll.V alue.

The only thing I could do to get it to perform reasonably was to add a timer
and use it to set the scroll position. Even then, the value I tried to set
wouldn't "take" on the first attempt. Hence I kept the timer going until the
TabPage was finally persuaded to take the scroll value.

This is definitely not a pretty solution, but here it is anyway:

Public Class Form1
Private ScrollBarLocati on As Integer

Private Sub tabThumbNails_D oubleClick(ByVa l sender As Object, ByVal e As
System.EventArg s) Handles tabThumbNails.D oubleClick
ScrollBarLocati on = tabThumbNails.V erticalScroll.V alue
tabImageTabs.Se lectedIndex = 1
End Sub

Private Sub TabPage2_Double Click(ByVal sender As Object, ByVal e As
System.EventArg s) Handles tabPage2.Double Click
tabImageTabs.Se lectedIndex = 0
Timer1.Start()
End Sub

Private Sub Timer1_Tick(ByV al sender As System.Object, ByVal e As
System.EventArg s) Handles Timer1.Tick
tabThumbNails.V erticalScroll.V alue = ScrollBarLocati on
If (tabThumbNails. VerticalScroll. Value = ScrollBarLocati on) Then
Timer1.Stop()
End If
End Sub
End Class

Cheers,
Randy

[Paul Engel]

Re: Restore Scroll Bar Position on Tab

Thanks, Randy. Yup, it's a bit messy, but it solves the problem. I really
appreciate your taking the time to play w/ it. I'll implement your solution
ASAP!!!

Paul

"OmegaSquar ed" <OmegaSquared@d iscussions.micr osoft.comwrote in message
news:CD275837-5150-4E78-963F-E94BC87B1553@mi crosoft.com...

Hello, Paul,
I tried a few experiments with this and it does indeed seem flaky. I
wasn't able to find any "nice" solution. But I guess that there is some
timing problem involved where the TabPage is trying to scroll the
top-leftmost control into view and so it only partly pays attention to the
value that you are setting into tabThumbNails.V erticalScroll.V alue.
>
The only thing I could do to get it to perform reasonably was to add a
timer
and use it to set the scroll position. Even then, the value I tried to
set
wouldn't "take" on the first attempt. Hence I kept the timer going until
the
TabPage was finally persuaded to take the scroll value.
>
This is definitely not a pretty solution, but here it is anyway:
>
Public Class Form1
Private ScrollBarLocati on As Integer
>
Private Sub tabThumbNails_D oubleClick(ByVa l sender As Object, ByVal e
As
System.EventArg s) Handles tabThumbNails.D oubleClick
ScrollBarLocati on = tabThumbNails.V erticalScroll.V alue
tabImageTabs.Se lectedIndex = 1
End Sub
>
Private Sub TabPage2_Double Click(ByVal sender As Object, ByVal e As
System.EventArg s) Handles tabPage2.Double Click
tabImageTabs.Se lectedIndex = 0
Timer1.Start()
End Sub
>
Private Sub Timer1_Tick(ByV al sender As System.Object, ByVal e As
System.EventArg s) Handles Timer1.Tick
tabThumbNails.V erticalScroll.V alue = ScrollBarLocati on
If (tabThumbNails. VerticalScroll. Value = ScrollBarLocati on) Then
Timer1.Stop()
End If
End Sub
End Class
>
Cheers,
Randy
>

[Paul Engel]

Re: Restore Scroll Bar Position on Tab

Randy,

I have tried this and what I find is that the scroll bar verticle value
changes immediately, but when the tab is returned to the focus, the scroll
bar does not move. It stays at the 0 position. Any ideas?

Paul
"OmegaSquar ed" <OmegaSquared@d iscussions.micr osoft.comwrote in message
news:CD275837-5150-4E78-963F-E94BC87B1553@mi crosoft.com...

Hello, Paul,
I tried a few experiments with this and it does indeed seem flaky. I
wasn't able to find any "nice" solution. But I guess that there is some
timing problem involved where the TabPage is trying to scroll the
top-leftmost control into view and so it only partly pays attention to the
value that you are setting into tabThumbNails.V erticalScroll.V alue.
>
The only thing I could do to get it to perform reasonably was to add a
timer
and use it to set the scroll position. Even then, the value I tried to
set
wouldn't "take" on the first attempt. Hence I kept the timer going until
the
TabPage was finally persuaded to take the scroll value.
>
This is definitely not a pretty solution, but here it is anyway:
>
Public Class Form1
Private ScrollBarLocati on As Integer
>
Private Sub tabThumbNails_D oubleClick(ByVa l sender As Object, ByVal e
As
System.EventArg s) Handles tabThumbNails.D oubleClick
ScrollBarLocati on = tabThumbNails.V erticalScroll.V alue
tabImageTabs.Se lectedIndex = 1
End Sub
>
Private Sub TabPage2_Double Click(ByVal sender As Object, ByVal e As
System.EventArg s) Handles tabPage2.Double Click
tabImageTabs.Se lectedIndex = 0
Timer1.Start()
End Sub
>
Private Sub Timer1_Tick(ByV al sender As System.Object, ByVal e As
System.EventArg s) Handles Timer1.Tick
tabThumbNails.V erticalScroll.V alue = ScrollBarLocati on
If (tabThumbNails. VerticalScroll. Value = ScrollBarLocati on) Then
Timer1.Stop()
End If
End Sub
End Class
>
Cheers,
Randy
>

[Paul Engel]

Re: Restore Scroll Bar Position on Tab

I've solved this problem. Instead of setting the value of the scroll bar,
which does not reposition it, I have used the ScrollControlIn toView method
of the container object. I run through my collection of thumbnails and grab
their Y coordiante. Since the ScrollControlIn toView method simply makes sure
the control is showing at the bottom of the viewable container, I have to
subtract the height of the container from my calculation to position the
control at 0,0. Here's the button I wrote to test this:

Private Sub Button1_Click(B yVal sender As System.Object, ByVal e As
System.EventArg s) Handles Button1.Click

Dim ICPosition As Point

Dim ICY As Integer

For Each ImageControl As Windows.Forms.C ontrol In tabThumbNails.C ontrols

ICPosition = ImageControl.Lo cation

ICY = ICPosition.Y

If ImageControl.He ight - tabThumbNails.H eight + ICY 0 Then

tabThumbNails.S crollControlInt oView(ImageView ers.Item(CInt(I mageControl.Nam e)))

End If

Next



End Sub