Implement Clipboard Essentials API by jsuarezruiz · Pull Request #171 · AvaloniaUI/Avalonia.Controls.Maui

jsuarezruiz · 2026-03-23T09:29:36Z

Changes:

Clipboard (IClipboard): Full implementation with platform-specific paths for desktop (Avalonia TopLevel.Clipboard + Window.Activated change detection) and browser (navigator.clipboard via [JSImport])

Tested:

Copilot

Pull request overview

This PR adds missing “Essentials” building blocks for the Avalonia backend by implementing cross-platform Clipboard support and a MainThread-compatible dispatcher API (with an MSBuild alias to keep existing MainThread.* call sites working on Avalonia TFMs).

Changes:

Implement AvaloniaClipboard with desktop (TopLevel clipboard + window activation polling) and browser (JSImport navigator.clipboard) backends.
Add AvaloniaMainThread backed by Dispatcher.UIThread, plus a conditional MainThread alias on net11.0 / net11.0-browser.
Add a ControlGallery sample page and basic unit tests/documentation updates.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/Avalonia.Controls.Maui.Essentials.Tests/AvaloniaClipboardTests.cs	Adds basic null-TopLevel and event-subscription tests for clipboard.
STATUS-ESSENTIALS.md	Marks Clipboard + AvaloniaMainThread APIs as implemented and updates MainThread note.
src/Avalonia.Controls.Maui.targets	Adds conditional MSBuild `Using` alias mapping `MainThread` → `AvaloniaMainThread` for Avalonia TFMs.
src/Avalonia.Controls.Maui.Essentials/README.md	Documents Clipboard and MainThread availability/usage guidance.
src/Avalonia.Controls.Maui.Essentials/MauiEssentialsBuilderExtensions.cs	Registers `Clipboard.Default` with the Avalonia implementation.
src/Avalonia.Controls.Maui.Essentials/MainThread/AvaloniaMainThread.cs	Introduces dispatcher-backed MainThread-compatible API surface.
src/Avalonia.Controls.Maui.Essentials/Clipboard/ClipboardInterop.Browser.cs	Adds JSImport bindings for `navigator.clipboard` APIs.
src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.cs	Adds MAUI `IClipboard` implementation and shared state/event wiring.
src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.Default.cs	Desktop clipboard implementation using `TopLevel.Clipboard` + activation checks.
src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.Browser.cs	Browser clipboard implementation using JSImport interop.
samples/ControlGallery/ControlGallery/Pages/ClipboardPage.xaml	Adds UI for clipboard copy/paste/HasText/event demo.
samples/ControlGallery/ControlGallery/Pages/ClipboardPage.xaml.cs	Wires the sample page to Clipboard + MainThread APIs.
samples/ControlGallery/ControlGallery/MainPage.xaml.cs	Registers the new Clipboard sample in the gallery navigation.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

drasticactions

We shouldn't introduce a hack for MainThread, but Clipboard is fine. If you remove the MainThread code, then I'm 👍 .

drasticactions · 2026-03-23T13:40:59Z

+        if (_platformProvider.GetTopLevel() is Window window)
+        {
+            window.Activated += OnWindowActivated;
+            _isSubscribed = true;
+        }
+    }


I'm not sure if this is correct. EnsureSubscribedToWindowActivation runs whenever GetClipboard is called, which occurs when a user explicitly calls a clipboard API. If they had an event handle for ClipboardContentChanged, it will only ever run if they happen to call one of these methods first.

EnsureSubscribed now runs from the ClipboardContentChanged add accessor instead of GetClipboard.

drasticactions · 2026-03-23T13:42:00Z

+
+        if (_platformProvider.GetTopLevel() is Window window)
+        {
+            window.Activated += OnWindowActivated;


window.Activated is attached to, but nothing disposes of it.

Fixed. Applied changes and storing the subscribed Window reference and unsubscribing both Activated and Closed handlers in OnWindowClosed.

drasticactions · 2026-03-23T13:43:11Z

+            UpdateState(currentText);
+
+            if (changed)
+                ClipboardContentChanged?.Invoke(this, EventArgs.Empty);


If you're in the app and you copy text from another text field, without activating the window, this event won't get invoked. It only activates when the window is activated.

drasticactions · 2026-04-27T06:26:37Z

+        <!-- Avalonia.FreeDesktop still declares the vulnerable version; force the patched one. -->
+        <PackageReference Include="Tmds.DBus.Protocol" Version="0.92.0" />
+    </ItemGroup>
+


This shouldn't be needed with the version bumps made elsewhere, and if something like this happens in the future, we should always fix the root versions rather than work around them.

drasticactions · 2026-04-27T06:40:38Z

+    }
+
+    /// <inheritdoc/>
+    public bool HasText => _hasText;


Checking in the maui repo, these values are computed when called via OS values, (Ex, https://github.com/dotnet/maui/blob/388b82f166d937c69a4553556b0042f441eadcd6/src/Essentials/src/Clipboard/Clipboard.ios.cs#L20-L21)

Here, it's cached, so as far as I can tell, SetTextAsync, GetTextAsync, or Activated would need to be called to update the value. Since Activate should be called when you touch the window, that might be fine, but there might be a better way to handle this. @maxkatz6 @MrJul, what do you think about this?

With async-only nature of current clipboard implementation, it would be hard to implement something like this.
On desktop, you we can use DispatcherFrame hack to (probably) safely run async code in-sync.

Otherwise, always returning true might be the safest bet (there is never a guarantee clipboard is not cleared between HasText and GeText calls anyway).

We need to have a new API on the Avalonia side, for clipboard changed events.

We need to have a new API on the Avalonia side, for clipboard changed events.

Yeah, that sounds good. It may be best to hold off on this PR for now and implement it in Avalonia first, then here. I don't think this is so important that we need to hack around it right now for the sake of the previews. We have time to implement it properly in Avalonia and use that instead.

Implement Essentials Clipboard

17d4097

Copilot AI review requested due to automatic review settings March 23, 2026 09:29

Copilot started reviewing on behalf of jsuarezruiz March 23, 2026 09:30 View session

Copilot AI reviewed Mar 23, 2026

View reviewed changes

Comment thread src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.cs Outdated

Comment thread src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.Default.cs Outdated

Comment thread src/Avalonia.Controls.Maui.Essentials/MainThread/AvaloniaMainThread.cs Outdated

jsuarezruiz added 3 commits March 23, 2026 10:38

More tests

d366272

Changes based on feedback

c38631c

Merge branch 'main' into essentials-clipboard

b1e6ac8

drasticactions requested changes Mar 23, 2026

View reviewed changes

Comment thread src/Avalonia.Controls.Maui.targets Outdated

maxkatz6 reviewed Mar 23, 2026

View reviewed changes

Comment thread src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.Browser.cs Outdated

Changes based on feedback

e4ce291

jsuarezruiz requested review from drasticactions and maxkatz6 March 23, 2026 13:19

drasticactions reviewed Mar 23, 2026

View reviewed changes

Fixes to unsubscribe events

2eb1628

jsuarezruiz requested a review from drasticactions March 23, 2026 16:05

jsuarezruiz changed the title ~~Implement Clipboard and MainThread Essentials APIs~~ Implement Clipboard Essentials API Mar 23, 2026

jsuarezruiz and others added 6 commits March 23, 2026 17:13

More changes

42b9d74

More changes

3ff0c11

Revert unnecessary change

ce3dcff

Merge branch 'main' into essentials-clipboard

4a84193

Fix Build

a06a955

Merge branch 'main' into essentials-clipboard

1d605d4

drasticactions reviewed Apr 27, 2026

View reviewed changes

maxkatz6 reviewed Apr 27, 2026

View reviewed changes

Comment thread src/Avalonia.Controls.Maui.Essentials/Clipboard/AvaloniaClipboard.Platform.cs

drasticactions mentioned this pull request Apr 27, 2026

Use control specific Dispatcher and avoid global UIThread #188

Open

Conversation

jsuarezruiz commented Mar 23, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

drasticactions left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

maxkatz6 Apr 27, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

jsuarezruiz commented Mar 23, 2026 •

edited

Loading

maxkatz6 Apr 27, 2026 •

edited

Loading