Exception is thrown when running RadDocking in separate thread.

When dragging item from the RadListBox the drag visual of the dragged item should be visible. The example should show an approach similar to the approach found here (http://www.telerik.com/community/code-library/wpf/docking/how-to-enable-drag-and-drop-from-radlistbox-to-raddocking-controls.aspx) but without the mentioned limitations.

Available in LIB version 2015.2.817, it will be also available in the 2015 Q3 Release.

The text in the Alt+Tab Manager is empty when there is a floating Pane in Windows XP

The close button in the document host is not higlighted (hovered-button-state-doc-host.png) as opposed to panes outside the DocumentHost area (hovered-button-state.png).

The workaround is to update the MouseOver visual state of the RadButtonDocumentCloseControlTemplate:

             <ControlTemplate x:Key="RadButtonDocumentCloseControlTemplate" TargetType="telerik:RadButton">
                <Grid x:Name="LayoutRoot" Background="Transparent" Width="18" Height="18">
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <DoubleAnimation Duration="0:0:0" To="0.3" Storyboard.TargetName="PathVisual" Storyboard.TargetProperty="Opacity"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Normal"/>
                            <VisualState x:Name="MouseOver">
                                <Storyboard>
                                    <DoubleAnimation Duration="0:0:0" To="1" Storyboard.TargetName="MouseOverVisual" Storyboard.TargetProperty="Opacity"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Pressed"/>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Border x:Name="MouseOverVisual" Background="{telerik:Office2013Resource ResourceKey=EffectHighBrush}" Opacity="0"/>
                    <Path x:Name="PathVisual"
                    Width="8"
                    Height="8"
                    Data="M2.5,0 L4.5,0 4.5,2.5 7,2.5 7,4.5 4.5,4.5 4.5,7 2.5,7 2.5,4.5 0,4.5 0,2.5 2.5,2.5 z"
                    Stretch="Fill"
                    Fill="{TemplateBinding Background}"
                    RenderTransformOrigin="0.5,0.5"
                    SnapsToDevicePixels="True">
                        <Path.RenderTransform>
                            <RotateTransform Angle="-135"/>
                        </Path.RenderTransform>
                    </Path>
                </Grid>
            </ControlTemplate>
            <Style x:Key="CustomRadButtonDocumentCloseStyle" BasedOn="{StaticResource RadButtonDocumentCloseStyle}" TargetType="telerik:RadButton">
                <Setter Property="Template" Value="{StaticResource RadButtonDocumentCloseControlTemplate}"/>
            </Style>
            <ControlTemplate x:Key="RadPaneGroupDocumentHostControlTemplate" TargetType="telerik:RadPaneGroup">
                <Grid>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Disabled"/>
                            <VisualState x:Name="Normal"/>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="FocusStates">
                            <VisualState x:Name="Focused"/>
                            <VisualState x:Name="Unfocused"/>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="AutoCollapseStates">
                            <VisualState x:Name="SingleItem"/>
                            <VisualState x:Name="TwoOrMoreItems"/>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="PaneHeaderVisibilityStates">
                            <VisualState x:Name="PaneHeaderHidden"/>
                            <VisualState x:Name="PaneHeaderVisible"/>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="ResizerStates">
                            <VisualState x:Name="ResizerLeft">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="Visibility" Duration="0">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Visibility>Visible</Visibility>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="(Grid.RowSpan)" Duration="0">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <sys:Int32>3</sys:Int32>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="Placement" Duration="0">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Dock>Left</Dock>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <DoubleAnimation BeginTime="00:00:00" From="4" To="4" Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="MinWidth"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="ResizerTop">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="Visibility" Duration="0">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Visibility>Visible</Visibility>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="(Grid.ColumnSpan)" Duration="0">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <sys:Int32>2</sys:Int32>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="Placement" Duration="0">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Dock>Top</Dock>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <DoubleAnimation BeginTime="00:00:00" From="4" To="4" Storyboard.TargetName="DockResizer" Storyboard.TargetProperty="MinHeight"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="HideResizer"/>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="DropDownDisplayStates">
                            <VisualState x:Name="DropDownButtonCollapsed"/>
                            <VisualState x:Name="DropDownButtonVisible">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="DropDownButtonElement" Storyboard.TargetProperty="Visibility">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <Visibility>Visible</Visibility>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <ColumnDefinition Width="*"/>
                    </Grid.ColumnDefinitions>
                    <dock:RadGridResizer x:Name="DockResizer" Placement="Left" ShowsPreview="True" Visibility="Collapsed"/>
                    <Grid x:Name="ItemsContainer" Grid.Row="1" Grid.Column="1">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition Width="*"/>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition Width="Auto"/>
                            <ColumnDefinition Width="Auto"/>
                        </Grid.ColumnDefinitions>
                        <RepeatButton x:Name="LeftScrollButtonElement" Visibility="{Binding ComputedHorizontalScrollBarVisibility, ElementName=ScrollViewerElement}" Style="{StaticResource RepeatButtonScrollLeftStyle}"/>
                        <ScrollViewer x:Name="ScrollViewerElement" Grid.Column="1" HorizontalScrollBarVisibility="{Binding (ScrollViewer.HorizontalScrollBarVisibility), RelativeSource={RelativeSource TemplatedParent}}">
                            <ScrollViewer.Template>
                                <ControlTemplate TargetType="ScrollViewer">
                                    <ScrollContentPresenter x:Name="ScrollContentPresenter"/>
                                </ControlTemplate>
                            </ScrollViewer.Template>
                            <ItemsPresenter x:Name="ItemsPresenterElement"/>
                        </ScrollViewer>
                        <RepeatButton x:Name="RightScrollButtonElement"
                        Grid.Column="2"
                        Visibility="{Binding ComputedHorizontalScrollBarVisibility, ElementName=ScrollViewerElement}"
                        Style="{StaticResource RepeatButtonScrollRightStyle}"/>
                        <telerik:RadDropDownButton x:Name="DropDownButtonElement"
                        Grid.Column="3"
                        Visibility="Collapsed"
                        IsOpen="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
                        DropDownPlacement="Bottom"
                        DropDownButtonPosition="Left"
                        Style="{StaticResource DropDownButtonDocumentDropDownStyle}"
                        Focusable="False">
                            <telerik:RadDropDownButton.DropDownContent>
                                <telerikTabControl:DropDownMenu x:Name="DropDownMenuElement"
                                StaysOpen="False"
                                IconColumnWidth="0"
                                Placement="Bottom"
                                ItemTemplate="{TemplateBinding ItemDropDownContentTemplate}"
                                ItemTemplateSelector="{TemplateBinding ItemDropDownContentTemplateSelector}"
                                DisplayMemberPath="{TemplateBinding DropDownDisplayMemberPath}"/>
                            </telerik:RadDropDownButton.DropDownContent>
                        </telerik:RadDropDownButton>
                        <telerik:RadButton x:Name="CloseButton"
                        Grid.Column="4"
                        Command="telerik:RadDockingCommands.Close"
                        Style="{StaticResource CustomRadButtonDocumentCloseStyle}"
                        Visibility="{Binding IsEnabled, RelativeSource={RelativeSource Self}, Converter={StaticResource BooleanToVisibilityConverter}}"/>
                    </Grid>
                    <Grid Grid.Row="2" Grid.Column="1" Background="{TemplateBinding Background}" Margin="0 -1 0 0">
                        <Rectangle StrokeThickness="1" Stroke="{telerik:Office2013Resource ResourceKey=HighDarkBrush}"/>
                        <Rectangle Stroke="{telerik:Office2013Resource ResourceKey=AccentBrush}" StrokeThickness="1" Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=SelectedPane.IsActive, Converter={StaticResource BooleanToVisibilityConverter}}"/>
                        <Rectangle Margin="1" StrokeThickness="3" Stroke="{telerik:Office2013Resource ResourceKey=AccentBrush}" Opacity="0.3"/>
                        <Grid Margin="5">
                            <ContentPresenter x:Name="ContentElement"
                            Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsContentPreserved, Converter={StaticResource InvertedBooleanToVisibilityConverter}}"
                            ContentTemplate="{TemplateBinding SelectedContentTemplate}"
                            ContentTemplateSelector="{TemplateBinding ContentTemplateSelector}"/>
                            <Grid x:Name="ContentElementsPanel" Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsContentPreserved, Converter={StaticResource BooleanToVisibilityConverter}}"/>
                        </Grid>
                    </Grid>
                </Grid>
            </ControlTemplate>
            <Style BasedOn="{StaticResource RadPaneGroupStyle}" TargetType="telerik:RadPaneGroup">
                <Setter Property="DocumentHostTemplate" Value="{StaticResource RadPaneGroupDocumentHostControlTemplate}"/>
            </Style>

The DocumentHost RadPane support overflow scrolling and drop down menu similar to the DocumentHost in VisualStudio and RadTabControl. We would like this feature implemented for the non DocumentHost areas as well.

 With code below the radPane will remain hidden (radPane is floating pane):radPane.IsHidden = true; radPane.IsHidden = false;

Available in LIB version 2016.2.530, it will be also available in the 2016 R2 SP1.

Initially HeaderDropDownMenu button is shown on window's caption bar of docked RadPanes but after undocking that button mysteriously disappears. The RadPane is still "Dockable" but for some reason there is no HeaderDropDownMenu button on it. This behavior leads to user confusion.

The the keyboard focus is also lost if you undock a RadPane from its docked state.
As a workaround you can persist the focus as shown in the RestoreFocusOnStateChanged SDK example, that can be found here:
https://github.com/telerik/xaml-sdk/tree/master/Docking/RestoreFocusOnStateChanged

It happens when the Pane is dragged and dropped not on the Compass several times, quickly.

When changing the DragDropMode in runtime, the panes behave unexpectedly.

If changing from Immediate to Deferred:

* Docked panes are not movable (no compass and no deferred adorner is being shows)

* Floating panes that are being docked do have the compass and the deferred adorner, when you try to move them after they were docked. 

 

If you change is back from Deferred to Immediate:

* Panes that you could not move can be moved (and then become floating) again/

* The panes that did have  the compass and the deferred adorner, don't move when you try to drag them. However, when you release the mouse button, then the start moving with the mouse pointer... without any mouse button pressed.


I've debugged the controls using the source code, and I've concluded that.

RadPane.UdateAllowDrag() is being called on PaneLoaded, which happens when I drag a floating pane into the Docking area.

In this case, when the DragDropMode is set to Deferred, then AllowDrag is set to True (with the call of DragDropManager.SetAllowDrag)

This is why that pane does have the Deferred Drag Adorner (The Drag Cue), while other panes doesn't.

 

On the other hand, when I change the DragDropMode to be Immediate again, then that pane is left with AllowDrag set to true, and it is registered to the DragDropManager events, which causes the second problem.

 

In my opinion, the RadPane.UpdateAllowDrag() should be called also when the DragDropMode is changed.

On Deferred mode, you can still undock panes (for example, but context menu).
The problem starts when you want to dock them back, When moving a pane above the compass, it hides the compass (And this problem is a PITA when you docking with the inner compass (rather than the root compass), since the left,top, center etc.. arrows are near to each other (so you are not 100% sure you hit the right arrow).

On some rare cases, RadPane.OnPaneLoaded is being called before ApplyTemplate was called, and therefore, UpdateAllowDrag which tries to find the first child of the rad pane (the "wrapper" grid) fails, and pane remains undraggable.

To reproduce this issue, I have a button that when clicking on it, it adds a new pane (There is a collection of View Models, that when items are added or removed, then a code that is using binding to that collection adds or removes a pane.

The scenario happens when the system is laggy (For example, heavy UI on the panes content), and I'm adding several view models to that collection.
It doesn't always happen, but sometimes, one of more of the panes are not draggable.
I can clearly see that the OnPaneLoaded was called before the OnApplyTemplate was.

Maybe it can be a good idea to call UpdateAllowDrag on the OnApplyTemplate function if the OnLoad was called first.