Dynamically adding RadPane to PaneGroup, the header of the pane does not appear on the second added pane.

To workaround this the OnApplyTemplate() method can be called after the RadPane is added to the RadPaneGroup.

After upgrading to Telerik WPF 2019.1.116 from 2018.3.1010 we receive a lot of:

System.ComponentModel.Win32Exception (0x80004005): Invalid window handle
   MS.Win32.UnsafeNativeMethods.GetWindowText(HandleRef hWnd, StringBuilder lpString, Int32 nMaxCount)

Exceptions. It makes out application very slow.

In version 2018 everyting was OK. See attached scerenshots.

The RadDocking control template hosts several AutoHideArea elements, one for each auto-hide placement - left, top, right, bottom. When you unpin a RadPane, it goes into one of those areas. The active auto-hide area where the pane will go is determined by the State of the topmost RadSplitContainer.

Allow manually setting the auto-hide area where the RadPane will go when unpinned.

The RadPaneGroup inherits RadTabControl and the TabStripPlacement property. Currently the RadPaneGroup does not support setting this property as the corresponding ControlTemplates are not implemented.

A possible workaround has been demonstrated in the attached project.

The compass elements are not on the proper places when the docking is on the second monitor. To reproduce this the DPI of the monitors should be different for example 125% (main) and 150% (secondary). Also, to reproduce this you will need to enable the DPI awareness of the application by setting the dpiAware and dpiAwareness settings in the app.manifest file.

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 fix for this issue will be available in the next LIB version (2018.3.1022) expected on Monday, October 22.

The fix will be available in the R1 2018 SP2 Release.

Available in LIB version 2017.3.1225, it will be also available in the R1 2018 Release.

The compasses of the other ToolWindow appear.

workaround:
add the following visual state to the DocumentHostTemplate of the RadPaneGroup:

<VisualStateManager.VisualStateGroups>
    <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>

and remove the trigger targeting the drop down button.