Add Translate to iOS selection context menu by LouiseHsu · Pull Request #180021 · flutter/flutter

LouiseHsu · 2025-12-17T21:28:05Z

This PR adds a "Translate" action to the ios selection context menu using this swiftui translate api announce during WWDC 2024.
Includes the ipad implementation as well.

Simulator.Screen.Recording.-.iPad.Air.11-inch.M3.-.2025-05-28.at.14.11.58.mp4

Simulator.Screen.Recording.-.iPhone.16.Plus.-.2025-05-28.at.14.09.13.mp4

Pre-launch Checklist

I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
I read the [Tree Hygiene] wiki page, which explains my responsibilities.
I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
I signed the [CLA].
I listed at least one issue that this PR fixes in the description above.
I updated/added relevant documentation (doc comments with ///).
I added new tests to check the change I am making, or this PR is [test-exempt].
I followed the [breaking change policy] and added [Data Driven Fixes] where supported.
All existing and new tests are passing.

hellohuanlin

This is exciting!

Renzo-Olivares · 2026-04-17T22:37:54Z

  /// Label for "search web" edit buttons and menu items.
  String get searchWebButtonLabel;

+  /// The term used for presenting a translation menu for a selection.


nit: consider changing to Label for "translate" edit buttons and menu items. similar to the other context menu button labels documentation.

Renzo-Olivares · 2026-04-17T22:59:04Z

+
+    return !widget.obscureText &&
+        !textEditingValue.selection.isCollapsed &&
+        textEditingValue.selection.textInside(textEditingValue.text).trim() != '';


I tried on a physical iPhone and was able to get the translate button to show up on a native app (iMessage) if the only text selected was whitespace.

I would usually lean towards matching native even though I don't think translating whitespace adds value here. Definetely not a blocker.

Renzo-Olivares · 2026-04-17T23:06:07Z

      expect(find.text('Search Web'), findsOneWidget);
+
+      // Adding Translate pushes both Share and Translate to the next page
+      // So just check that they exist on the tool bar.


nit: tool bar -> toolbar.

Renzo-Olivares · 2026-04-17T23:06:38Z

      expect(find.text('Search Web'), findsOneWidget);
+
+      // Adding Translate pushes both Share and Translate to the next page
+      // So just check that they exist on the tool bar.


nit: tool bar -> toolbar.

Renzo-Olivares · 2026-04-17T23:24:08Z

+
+      // Adding Translate pushes both Share and Translate to the next page
+      // So just check that they exist on the tool bar.
+      expect(cupertinoToolbarHasText('Share...'), isTrue);


Consider using find.text('Translate', skipOffstage: false) instead of using cupertinoToolbarHasText.

Renzo-Olivares · 2026-04-17T23:28:12Z

        expect(findOverflowNextButton(), findsOneWidget);

-        // Tapping the next button again shows the last page and the Share button
+        // Tapping the next button again shows the Share button


nit: end comments with a ., here and in the comment below.

hellohuanlin · 2026-04-20T04:32:55Z

+@available(iOS 17.4, *)
+fileprivate struct ContentView: View {
+  fileprivate let termToTranslate: String
+  fileprivate let ipadBounds: CGRect?


these 2 are not accessed outside of ContentView so should be private rather than fileprivate

hellohuanlin · 2026-04-20T04:33:58Z

+  fileprivate let termToTranslate: String
+  fileprivate let ipadBounds: CGRect?
+
+  fileprivate var onDismiss: (() -> Void)?


it's file for this to be default (i.e. internal), because the struct itself is already fileprivate

LongCatIsLooong · 2026-04-20T21:33:40Z

+    CGRect lastRect = [(FlutterTextInputView*)_textInputPlugin.textInputView
+        caretRectForPosition:(FlutterTextPosition*)range.end];
+    CGRect transformedLastRect = [(FlutterTextInputView*)_textInputPlugin.textInputView
+        localRectFromFrameworkTransform:lastRect];


Is this trying to get the bounding boxes of the current selection? So the assumption here is "term" is the same as the selected text? In that case why does the framework have to send "term" over if we know it's going to be the selected text?

LongCatIsLooong · 2026-04-20T21:44:33Z

+    CGRect transformedLastRect = [(FlutterTextInputView*)_textInputPlugin.textInputView
+        localRectFromFrameworkTransform:lastRect];
+
+    // In case of RTL Language, get the minimum x coordinate too


I don't think this works in bidi text (I'm not sure if there's a valid use case for selecting across bidi regions, but the UI may look out of place if the user actually does that).

LongCatIsLooong · 2026-04-20T22:01:42Z

+
+    swiftUIViewController.view.translatesAutoresizingMaskIntoConstraints = false
+    NSLayoutConstraint.activate([
+      swiftUIViewController.view.topAnchor.constraint(equalTo: view.topAnchor),


So swiftUIViewController can use a different coordinate system even from FlutterView (if topAnchor is not 0 for example), and iPadBounds is calculated in the textInputView's coordinates?

LongCatIsLooong · 2026-04-20T22:03:23Z

+      termToTranslate: termToTranslate,
+      ipadBounds: ipadBounds
+    )
+    contentView.onDismiss = { [weak self] in


Would it be possible to make onDismiss a let variable? Looks like it's not changing.

LongCatIsLooong · 2026-04-20T22:05:10Z

+    swiftUIViewController.didMove(toParent: self)
+  }
+
+  @objc func makeTranslateHostingController(termToTranslate: String) -> UIViewController {


Why's this method @objc and internal? It seems it's only called in viewDidLoad?

LongCatIsLooong · 2026-04-20T22:13:18Z

+  /// Currently this is only implemented for iOS.
+  ///
+  /// When 'obscureText' is true or the selection is empty, this function will not do anything.
+  Future<void> translateSelection(SelectionChangedCause cause) async {


Why does this take a SelectionChangedCause? Doesn't seem to be used anywhere.

Not very familiar with context menus, but it looks like this is going to be called to trigger translation in a Flutter rendered context menu while the new logic in system_context_menu.dart is going to be used when the app is using an iOS rendered context menu? If that's the case, how does the app developer determine whether translation is available (i.e. the app is running on iOS 17.4+) and hide the button in the translationEnabled implementation (to prevent a "translate" button that does nothing from showing up).

LongCatIsLooong · 2026-04-20T22:13:47Z

    }
  }

+  /// Launch a translation interface for the selected text.


nit:

Suggested change

/// Launch a translation interface for the selected text.

/// Launches a translation interface for the selected text.

LongCatIsLooong · 2026-04-20T22:15:43Z


+  /// Launch a translation interface for the selected text.
+  ///
+  /// Currently this is only implemented for iOS.


And only for iOS 17.4+ I think?

LongCatIsLooong · 2026-04-20T22:25:23Z

 #import <OCMock/OCMock.h>
 #import <XCTest/XCTest.h>

+#import "flutter/shell/platform/darwin/common/InternalFlutterSwiftCommon/InternalFlutterSwiftCommon.h"


I thought this was the bridging header? Why is the import needed?

LongCatIsLooong · 2026-04-20T22:30:04Z

+  var body: some View {
+    Color.clear
+      .frame(maxWidth: .infinity, maxHeight: .infinity)
+      .translationPresentation(


Just curious, is this API only available in SwiftUI?

Piinks · 2026-06-24T20:11:30Z

I've marked this PR as not ready to port to flutter/packages yet.
We'll provide instructions to move this change over to material_ui/cupertino_ui once ready to receive PRs. Thank you!

The changes not in the material or cupertino libraries will remain here.

Piinks · 2026-06-24T23:30:19Z

Advice for PR splitting: Since this touches material/cupertino along with other parts of flutter/flutter, it will need to be split up.

If the material/cupertino changes are dependent on the other non-material/cupertino changes in this PR, then the material/cupertino changes will need to wait for them to roll to stable before they can be ported over to material_ui/cupertino_ui in flutter/packages (which uses the stable branch).

If that is the case here, consider opening a new PR with the non-material/cupertino changes to move forward with so that waiting period can be reduced. Up to you!

Piinks · 2026-08-18T20:29:09Z

material_ui and cupertino_ui are now accepting contributions. :)

The portions of this PR that affect the material and cupertino libraries can be ported over to flutter/packages, although they may have to wait for the changes in the core SDK to reach stable first.

Guidance and instructions for easily porting over can be found in #188444

jmagman · 2026-09-08T18:28:55Z

Closing in favor of #189878

Split out engine portion of flutter#180021 b/c of cupertino/material freeze. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing.

LouiseHsu added 3 commits December 11, 2025 12:20

changing branche

b19445c

most files?

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format >:(

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LouiseHsu changed the title ~~Translation redux~~ Add Translate to iOS selection context menu Dec 17, 2025

translations

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github-actions Bot added the a: internationalization Supporting other languages or locales. (aka i18n) label Jan 7, 2026

LouiseHsu and others added 6 commits January 6, 2026 16:30

more translations

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ok

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tests heh

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format

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Merge branch 'master' into translation-redux

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conflict

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LouiseHsu marked this pull request as ready for review January 9, 2026 00:44

LouiseHsu requested a review from a team as a code owner January 9, 2026 00:44

hellohuanlin reviewed Jan 9, 2026

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LouiseHsu and others added 7 commits January 12, 2026 13:31

Merge branch 'master' into translation-redux

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pr changes

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remove public

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rename

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LouiseHsu requested a review from hellohuanlin January 13, 2026 23:44

LongCatIsLooong requested review from Renzo-Olivares and removed request for Renzo-Olivares April 16, 2026 21:13

Renzo-Olivares requested review from LongCatIsLooong and Renzo-Olivares April 16, 2026 21:33

pr comments

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LouiseHsu dismissed hellohuanlin’s stale review via b9fa723 April 17, 2026 22:16

github-actions Bot removed the CICD Run CI/CD label Apr 17, 2026

Merge branch 'master' into translation-redux

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LouiseHsu added the CICD Run CI/CD label Apr 17, 2026

Renzo-Olivares reviewed Apr 17, 2026

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oopsies merge conflict

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github-actions Bot removed the CICD Run CI/CD label Apr 17, 2026

Renzo-Olivares reviewed Apr 17, 2026

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hellohuanlin reviewed Apr 20, 2026

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LongCatIsLooong reviewed Apr 20, 2026

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LouiseHsu marked this pull request as draft May 14, 2026 20:59

Piinks added the Decoupling: Not ready to port yet Instructions will be provided when this is ready to move to flutter/packages. label Jun 24, 2026

Piinks added the Decoupling: Split PR The PR will need to be split to separate Material & Cupertino changes label Jun 24, 2026

LouiseHsu mentioned this pull request Jul 22, 2026

[iOS] Add Translate API support to Engine #189878

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Piinks added Decoupling: Port to flutter/packages This PR is ready to be ported to flutter/packages. We will provide instructions to do so. and removed Decoupling: Not ready to port yet Instructions will be provided when this is ready to move to flutter/packages. labels Aug 18, 2026

jmagman closed this Sep 8, 2026

LouiseHsu mentioned this pull request Sep 29, 2026

Migrate ContextMenuButtonType to an enum-like class #193527

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	/// Launch a translation interface for the selected text.
	/// Launches a translation interface for the selected text.

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LouiseHsu commented Dec 17, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Piinks commented Jun 24, 2026

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LouiseHsu commented Dec 17, 2025 •

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