fix: Dialog prevents scroll

[MartinZikmund]

GitHub Issue: closes

PR Type: 🐞 Bugfix

What is the current behavior? 🤔

What is the new behavior? 🚀

PR Checklist ✅

Please check if your PR fulfills the following requirements:

• 📝 Commits must be following the Conventional Commits specification.
• 🧪 Added Runtime tests, UI tests, or a manual test sample for the changes have been added (for bug fixes / features) (if applicable)
• 📚 Docs have been added/updated which fit documentation template (for bug fixes / features)
• 🖼️ Validated PR Screenshots Compare Test Run results.
• ❗ Contains NO breaking changes

Other information ℹ️

[Copilot]

Pull request overview

This PR fixes a bug where dialogs were preventing scrolling in background content. The fix adds a check in ScrollContentPresenter.Managed.cs to respect already-handled pointer events, preventing the scroll presenter from enabling direct manipulation on events that dialogs or other controls have already processed. A new sample (ColorPickerDialogSample) is included to demonstrate and test the fix.

• Added args.Handled check in TryEnableDirectManipulation to prevent scroll conflicts when dialogs handle pointer events
• Created a sample application with a ContentDialog containing a ColorPicker and background ScrollViewer to test the fix
• Added project file entries to include the new sample files in the build

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/Uno.UI/UI/Xaml/Controls/ScrollContentPresenter/ScrollContentPresenter.Managed.cs	Core fix: Added check for args.Handled to prevent enabling direct manipulation on already-handled pointer events
src/SamplesApp/UITests.Shared/UITests.Shared.projitems	Added project references for the new ColorPickerDialog sample files and removed trailing whitespace
src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/ColorPickerTests/ColorPickerDialogSample.xaml.cs	Code-behind for the sample page that demonstrates the dialog scroll fix
src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/ColorPickerTests/ColorPickerDialogSample.xaml	XAML for the sample page with a scrollable area and button to show the dialog
src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/ColorPickerTests/ColorPickerDialog.xaml.cs	Code-behind for the ContentDialog containing a ColorPicker
src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/ColorPickerTests/ColorPickerDialog.xaml	XAML definition for the ContentDialog with ColorPicker control

[Copilot]

These empty event handlers (ContentDialog_PrimaryButtonClick and ContentDialog_SecondaryButtonClick) appear to be unused. If these handlers are not needed for the sample's functionality, consider removing them along with their corresponding event subscriptions in the XAML (lines 7 and 9 in ColorPickerDialog.xaml) to keep the code clean and maintainable.

Suggested change

	private void ContentDialog_PrimaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
	{
	}
	private void ContentDialog_SecondaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
	{
	}

[unodevops]

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[unodevops]

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🤖 Your Docs stage site is ready! Visit it here: https://unodocsprstaging.z13.web.core.windows.net/pr-21987/docs/index.html

[unodevops]

🤖 Your WebAssembly Skia Sample App stage site is ready! Visit it here: https://unowasmprstaging.z20.web.core.windows.net/pr-21987/wasm-skia-net9/index.html

[unodevops]

⚠️⚠️ The build 185602 has failed on Uno.UI - CI.