Create a usercontrol with overlapping content - wpf

Question

I need to make a (user/custom) control which when 'folded open' displays content over other controls.
Like a popup, combo or menu except that the content will still open (think toggle button style).
Any leads?

Answer 1

Depends on many issues.
I know at least two ways to achive it. First - using <Popup />. Its easy to bind its IsOpen property to bool variable. And if you need to close it, I have got some smart behavior (which close popup when Esc key is pressed or when it lost focus).
The second way is to have a <ContentControl /> which have a style, which have a trigger, which changing ContentTemplate depending on what ever you want:
<ContentControl Grid.Row="3" Grid.ColumnSpan="2" Grid.RowSpan="2" Content="{Binding}">
<ContentControl.Style>
<Style>
<Setter Property="ContentControl.ContentTemplate" Value="{StaticResource OneTemplate}"/>
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding Property1}" Value="False"/>
<Condition Binding="{Binding Property2}" Value="True"/>
</MultiDataTrigger.Conditions>
<Setter Property="ContentPresenter.ContentTemplate" Value="{StaticResource TwoTemplate}"/>
</MultiDataTrigger>
</Style.Triggers>
</Style>
</ContentControl.Style>
</ContentControl>
I believe that there are exists many more possible ways to solve your problem!

Answer 2

Simplified description.
Main form
<Window>
<StackPanel Orientation="Vertical">
<ToolButton StackPanel.ZIndex="999"/>
<TextBlock>Other content</TextBlock>
</StackPanel>
</Window>
You'll need the ZIndex to indicate the overflowing control is on top
Custom control
<UserControl x:Class="ToolButton" Height="32">
<Canvas>
<ToggleButton x:Name="button">
<TextBlock>Content</TextBlock>
</ToggleButton>
<TextBlock Canvas.Top="32" Visibility="{Binding ElementName=button, Path=IsChecked, Converter={converter:BooleanToVisibility}}">Popup</TextBlock>
</Canvas>
</UserControl>
Bool to visibility Converter
public sealed class BooleanToVisibility : MarkupExtension, IValueConverter
{
public BooleanToVisibility() { }
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var flag = false;
if (value is bool)
{
flag = (bool)value;
}
else if (value is bool?)
{
var nullable = (bool?)value;
flag = nullable.GetValueOrDefault();
}
if (parameter != null)
{
if (bool.Parse((string)parameter))
{
flag = !flag;
}
}
if (flag)
{
return Visibility.Visible;
}
else
{
return Visibility.Collapsed;
}
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
var back = ((value is Visibility) && (((Visibility)value) == Visibility.Visible));
if (parameter != null)
{
if ((bool)parameter)
{
back = !back;
}
}
return back;
}
public override object ProvideValue(IServiceProvider serviceProvider)
{
return this;
}
}