WPF LayoutTransform: ToolTip size not modified - wpf

Question

I'm using LayoutTransform in my windows' top level 'Grid' control, to do perform a ScaleTransform and implement a zoom factor on the UI (similar to how browsers do it).
Things work well, but somehow tooltips show up with the unadjusted size.
If there a way to for example enumerate all toolTips in a window and adjust their size from the .cs file? ...or any other way to deal with this?

Answer 1

The reason why the tooltips are unaffected is because tooltips are popups that are not part of the window's visual tree. Thus, any layout transformation performed on the componenets of the window will not carry over to the tooltips. If you have mostly generic tooltips (text basically), you can create a non-keyed style in your window resources and WPF will automatically apply that to all your tooltips:
<Window.Resources>
<Style TargetType="ToolTip">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToolTip}">
<Border x:Name="Border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" SnapsToDevicePixels="True">
<Border.LayoutTransform>
<ScaleTransform ScaleX="{Binding ScaleFactor}"></ScaleTransform>
</Border.LayoutTransform>
<ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<StackPanel x:Name="MainPanel">
<StackPanel.LayoutTransform>
<ScaleTransform ScaleX="{Binding ScaleFactor}" ScaleY="{Binding ScaleFactor}"></ScaleTransform>
</StackPanel.LayoutTransform>
<TextBlock ToolTip="blah">haha!</TextBlock>
</StackPanel>
In the example I have ScaleX/Y for the tooltip bound to a ScaleFactor property on my window's View Model. You can keep it dynamic this way I believe.

Answer 2

Like what Rowbear has mentioned, Tooltips are popups (which are windows), so they have their own visual tree. But, as far as I know, the big problem is, these popups do not inherit DataContext from the spawning control, too.
<Window.Resources>
<Style TargetType="ToolTip">
<Setter Property="LayoutTransform" Value="{Binding RelativeSource={RelativeSource Self}, Path=PlacementTarget.LayoutTransform}" />
</Style>
</Window.Resources>