Fix Binding errors when Ribbon is outside of RibbonWindow

[vchaillou-arpege]

Fixes #11860

Description

The Binding errors happened when using the default template for the Ribbon. It has two conditions that may try to bind to the parent RibbonWindow but it did not check if there was a parent RibbonWindow before, so the two Bindings ended up failing if the Ribbon was outside of a RibbonWindow.

This fix ensures that the Ribbon is hosted in a RibbonWindow before binding to the parent RibbonWidow by having a condition that binds to IsHostedInRibbonWindow first. if IsHostedInRibbonWindow == false, the following conditions are not evaluated.

FYI, this was already done this way there (and there).

Customer Impact

Without this PR, there will still be the Binding errors as described in #11860.

Regression

No (or at least not that I am aware of).

Testing

For now, I only tested with the simple case linked in #11860.

Risk

I believe that there are no real risks given the changes I made but correct me if I am wrong.

Microsoft Reviewers: Open in CodeFlow

[Copilot]

Pull request overview

Updates Ribbon templates to avoid evaluating RibbonWindow ancestor bindings when the Ribbon is hosted elsewhere.

Changes:

• Adds IsHostedInRibbonWindow guards to both affected multi-condition triggers.
• Mirrors changes in source and generated theme XAML.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/Microsoft.DotNet.Wpf/src/System.Windows.Controls.Ribbon/Themes/XAML/Ribbon.xaml	Updated as part of this pull request.
src/Microsoft.DotNet.Wpf/src/System.Windows.Controls.Ribbon/Themes/Generic.xaml	Updated as part of this pull request.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[vchaillou-arpege]

@dotnet-policy-service agree company="Arpège"

[miloush]

RibbonWindow inherits Windows which is where the IsActive and WindowState properties are defined, why does the binding just not look for a Window?

[vchaillou-arpege]

RibbonWindow inherits Windows which is where the IsActive and WindowState properties are defined, why does the binding just not look for a Window?

I guess this is because the Ribbon behaves slightly differently inside and outside of RibbonWindow. The two triggers that this PR fixes set properties on two elements that are placed differently in a RibbonWindow (PART_TitleHost and QatTopHost which is part of the Quick Access Toolbar) so I assume that these conditions are only valid inside RibbonWindows specifically. At least, that is the current behavior.

In a regular Window:

In a RibbonWindow:

Since this PR is solely about fixing Binding errors, I would rather not add any unneccessary change or any behavior change. So unless this is a requirement for merging, I would prefer not to touch these Bindings and keep the changes as minimal as possible.