Question

I have a TabControl with multiple TabItems, with each TabItem containing multiple sections in the content area. When the user hovers over any Tab, I’d like to show a Popup that shows a list of the sections in that Tab and allow the user to click on the section and navigate to it.

For this question, the portion that I need help with is the closing/opening of the Popups as the user hovers over each Tab. The main sticking points are:

1. Allowing the user to move the cursor into the Popup area from the Tab. Once the Popup has been opened, it refuses to close on TabItem MouseLeave.
2. If the user moves from Tab to Tab, the Popup from the previous Tab should close and a new one should open.
3. The user should only need one click to navigate. This means they shouldn’t have to “click away” the popup from one tab in order for another popup to show.

My thought is to expose a DependencyProperty that hit tests which Tab the mouse is over, and trigger the Popup off of that.

Edited for clarity: When moving the mouse over a tab, I show a popup. When I move the mouse away from the Tab, I want the Popup to go close. It has to be a Popup (and not a Tooltip), because the user has to be able to click on the content inside the Popup.

I’ve sub-classed and re-templated the TabControl, but I would like some help with how to close the Popup on the MouseLeave event. I’ve triggered on the MouseLeave event, but when the Popup opens, the focus shifts to the Popup so the TabItem MouseLeave event isn’t fired properly.

Answer 1

You can use the Interaction.Triggers from the Blend SDK to trigger the popup to close whenever the mouse leaves the popup. Here is a short example:

<Popup Height="300" x:Name="MyPopup">
        <Label Content="MyLabel"></Label>
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="MouseLeave">
                <ei:ChangePropertyAction TargetObject="{Binding ElementName=MyPopup}" PropertyName="IsOpen" Value="False"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
</Popup>

You’ll need the following namespaces:

xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"                  
xmlns:ei="clr-namespace:Microsoft.Expression.Interactivity.Core;assembly=Microsoft.Expression.Interactions"