Floating RadPane flashes on screen during load if IsHidden is set to True

10 posts, 2 answers
  1. Joe Biggert
    Joe Biggert avatar
    17 posts
    Member since:
    Feb 2010

    Posted 27 Feb 2012 Link to this post

    In multiple projects, I've had RadPanes set to only be shown when a button is clicks and they show as floating RadPanes. So in my XAML, I have their IsHidden property set to True so that they aren't shown until a button is clicked. The problem tough is that during the form load, you can see a "flash" of the RadPane(s) closing themselves. It's only on screen for maybe 1 second but it's annoying especially when there are multiple RadPanes. How can I prevent this?

    For example code, simple put the code below in a RadDocking container and watch your application close in the middle of the screen during startup. You'll see the RadPane closing.

    <telerik:RadSplitContainer InitialPosition="FloatingDockable"                                 
            telerik:RadDocking.FloatingLocation="450, 250"
            telerik:RadDocking.FloatingSize="300, 220" x:Name="uxWindowRadSplitContainer" >
        <telerik:RadPaneGroup>
            <telerik:RadPane Header="Test" CanDockInDocumentHost="False" IsHidden="True" x:Name="uxToolWindowRadPane">
                <TextBlock Text="Hi" />
            </telerik:RadPane>
        </telerik:RadPaneGroup>
    </telerik:RadSplitContainer>
  2. Answer
    Georgi
    Admin
    Georgi avatar
    350 posts

    Posted 02 Mar 2012 Link to this post

    Hello,

    This is a known issue and we are working on it. PITS issue about the problem you can find  here.
    We will do our best to fix it for the Service Pack , which is scheduled for the middle of March.

    Kind regards,
    Georgi
    the Telerik team
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  4. Joe Biggert
    Joe Biggert avatar
    17 posts
    Member since:
    Feb 2010

    Posted 29 Jul 2012 Link to this post

    This item shows it has been resolved in your issue tracker and is in the latest service pack (2012 Q2 SP1) but it has not been fixed. It still occurs.
  5. Answer
    Georgi
    Admin
    Georgi avatar
    350 posts

    Posted 01 Aug 2012 Link to this post

    Hello Joe,

    The issue with flickering unpined panes is resolved, but there is still a flashing moment with panes with IsHidden = True. At first it seemed that this is the same problem , but this was not the case. Therefore we have created new work item and the corresponding PITS issue you can find here.

    All the best,
    Georgi
    the Telerik team

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  6. Joe Biggert
    Joe Biggert avatar
    17 posts
    Member since:
    Feb 2010

    Posted 01 Aug 2012 Link to this post

    This is one of our biggest blocking issues with shipping our application (which isn't ready to ship but will be in alpha in a month) because it is a very visible issue with to the end user. Also, I strongly believe a number of the comments in the original PITS item you referenced are actually referring to this problem and not the problem that was fixed... this may very well be more popular than the original item. Because we need this fixed and there hasn't been any workarounds either suggested by y'all or figured out by us, I'll submit a support ticket via our premium subscription to hopefully get this addressed as soon as possible or at least included in the Q3 release.

    Thank you.
  7. Georgi
    Admin
    Georgi avatar
    350 posts

    Posted 02 Aug 2012 Link to this post

    Hi Joe,

    We have done some more research on this issue and it seems like we have a fix for it. Of course some more testing need to be done, but so far as you can see in the attached video there is no flickering of the Panes. Also I am attaching my simple project so you can get a better look at it.
    So if everything is ok the fix should be available in one of our next Internal Builds (usually every week).


    All the best,
    Georgi
    the Telerik team

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  8. Joe Biggert
    Joe Biggert avatar
    17 posts
    Member since:
    Feb 2010

    Posted 06 Aug 2012 Link to this post

    Thank you for the update Georgi!
  9. Joe
    Joe avatar
    9 posts
    Member since:
    Mar 2012

    Posted 13 Nov 2012 Link to this post

    I wanted to make sure I updated this thread per my support ticket on this issue. While the flickering was resolved, the introducing of the fix causes an exception when the IsHidden property is set to True on startup but is later changed to False. The only workaround is to forcibly cause the flickering by having the IsHidden property set to False and change it to True in the form load.


    The exception is:


    System.InvalidOperationException was unhandled by user code
      Message=Element already has a logical parent. It must be detached from the old parent before it is attached to a new one.
      Source=PresentationFramework
      StackTrace:
           at MS.Internal.Controls.InnerItemCollectionView.AssertPristineModelChild(Object item)
           at MS.Internal.Controls.InnerItemCollectionView.Insert(Int32 index, Object item)
           at System.Windows.Controls.ItemCollection.Insert(Int32 insertIndex, Object insertItem)
           at Telerik.Windows.Controls.RadPaneGroup.ShowPane(RadPane pane) in c:\TB\105\WPF_Scrum\Release_WPF\Sources\Development\Controls\Docking\Docking\Docking\Rad
  10. Joe
    Joe avatar
    9 posts
    Member since:
    Mar 2012

    Posted 13 Nov 2012 Link to this post

    I want to add that this is actually now much worse. If you start the application with multiple RadPanes showing (floating) and then, in the window load event, set their IsHidden to True, you get an Object Referenced error (see below). My workaround now is to fire off multiple threads on window load that do nothing but asynchronous set these properties on the UI thread. This is MUCH worse than the original problem.

    System.NullReferenceException was unhandled by user code
      Message=Object reference not set to an instance of an object.
      Source=Telerik.Windows.Controls.Navigation
      StackTrace:
           at Telerik.Windows.Controls.InternalWindow.WindowWithNoChromeWindowHost.Open(Boolean isModal) in c:\TB\105\WPF_Scrum\Release_WPF\Sources\Development\Controls\Navigation\Window\InternalWindow\WindowWithNoChromeWindowHost.cs:line 38
           at Telerik.Windows.Controls.WindowBase.ShowWindow(Boolean isModal) in c:\TB\105\WPF_Scrum\Release_WPF\Sources\Development\Controls\Navigation\Window\WindowBase.cs:line 719
           at Telerik.Windows.Controls.Docking.ToolWindow.OnOwnerLoaded(Object sender, RoutedEventArgs e) in c:\TB\105\WPF_Scrum\Release_WPF\Sources\Development\Controls\Docking\Docking\Parts\ToolWindow.cs:line 131
           at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
           at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
           at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
           at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
           at System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent)
           at System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root)
           at MS.Internal.LoadedOrUnloadedOperation.DoWork()
           at System.Windows.Media.MediaContext.FireLoadedPendingCallbacks()
           at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
           at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
           at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
           at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
           at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
      InnerException: 

  11. Boyan
    Admin
    Boyan avatar
    758 posts

    Posted 16 Nov 2012 Link to this post

    Hello Joe,

    I am pasting the answer for the support thread here as well so it can help other clients as well.

    Indeed we introduced such bug with our latest release, but it is already handled and is fixed. You can download our latest internal build from your account and give it a try. Note that currently we have a known problem with the RadDocking in the latest LIB and you may encounter it (you can't resize ToolWindows). We will do our best to polish this problems for the service pack which is scheduled for the end of the month.


    Regards,
    Boyan
    the Telerik team

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