Align Touch/Pen capture semantics with Mouse

[miloush]

What does the pull request do?

Removes Capture(null) from Pointer.Disposable(), expecting callers to call it explicitly with the appropriate source.

What is the current behavior?

PenUp and TouchUp are treated as explicit capture loss, resulting in popups closed unexpectedly.

What is the updated/expected behavior with this PR?

Like with mouse, the captures on down and up are marked as implicit. TouchCancel is treated as loss from platform.

How was the solution implemented (if it's not obvious)?

Pointer.Dispose() is now no-op - keeping Pointer : IDisposable for ABI compatibility. Added explicit Capture(null, source) to call sites.

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

The only Dispose() that was not complemented with Capture(null, source) is in PenDevice.ProcessRawEvent for shouldReleasePointer = true, which happens on LeaveWindow and XButton2Up. The former is no-op for mouse too, and the latter is already handled in PenUp it calls.

Obsoletions / Deprecations

Fixed issues

[MrJul]

Pointer is public, so callers can cast it to IDisposable or use with using. We do not expect any 3rd party disposing our pointers, but to alleviate the breaking change, we could keep it IDisposable with empty Dispose() method. However, that would only mask the change of behavior that it no longer results in capture disposal.

It's not so much about third-party code unexpectedly calling Dispose, but about ABI compatibility that we can't break. Please keep an empty Dispose() implementation for now and add a TODO13 comment so we can remove in it v13.

[miloush]

updated

[avaloniaui-bot]

You can test this PR using the following package version. 12.1.999-cibuild0065260-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[miloush]

the failing tests look legit, will look into them

[miloush]

though weirdly none seem to be related to pointer or touch

[miloush]

@MrJul I cannot repro the failing integration tests locally (and they do not look like they should be affected by the PR), can you try run it again?

[MrJul]

LGTM