Revert "Disable cursor opacity animation on macOS, make iOS cursor animation...

Revert "Disable cursor opacity animation on macOS, make iOS cursor animation discrete (#104335)" (#106762)

packages/flutter/lib/src/material/text_field.dart

@@ -1168,7 +1168,7 @@ class _TextFieldState extends State<TextField> with RestorationMixin implements
         forcePressEnabled = false;
         textSelectionControls ??= cupertinoDesktopTextSelectionControls;
         paintCursorAboveText = true;
-        cursorOpacityAnimates = false;
+        cursorOpacityAnimates = true;
         cursorColor = widget.cursorColor ?? selectionStyle.cursorColor ?? cupertinoTheme.primaryColor;
         selectionColor = selectionStyle.selectionColor ?? cupertinoTheme.primaryColor.withOpacity(0.40);
         cursorRadius ??= const Radius.circular(2.0);

packages/flutter/test/cupertino/text_field_test.dart

@@ -702,6 +702,40 @@ void main() {
     expect(editableText.cursorOffset, const Offset(-2.0 / 3.0, 0));
   });
 
+  testWidgets('Cursor animates', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const CupertinoApp(
+        home: CupertinoTextField(),
+      ),
+    );
+
+    final Finder textFinder = find.byType(CupertinoTextField);
+    await tester.tap(textFinder);
+    await tester.pump();
+
+    final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
+    final RenderEditable renderEditable = editableTextState.renderEditable;
+
+    expect(renderEditable.cursorColor!.alpha, 255);
+
+    await tester.pump(const Duration(milliseconds: 100));
+    await tester.pump(const Duration(milliseconds: 400));
+
+    expect(renderEditable.cursorColor!.alpha, 255);
+
+    await tester.pump(const Duration(milliseconds: 200));
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(renderEditable.cursorColor!.alpha, 110);
+
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(renderEditable.cursorColor!.alpha, 16);
+    await tester.pump(const Duration(milliseconds: 50));
+
+    expect(renderEditable.cursorColor!.alpha, 0);
+  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
+
   testWidgets('Cursor radius is 2.0', (WidgetTester tester) async {
     await tester.pumpWidget(
       const CupertinoApp(

packages/flutter/test/material/text_field_test.dart

@@ -609,6 +609,42 @@ void main() {
     await checkCursorToggle();
   });
 
+  testWidgets('Cursor animates', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const MaterialApp(
+        home: Material(
+          child: TextField(),
+        ),
+      ),
+    );
+
+    final Finder textFinder = find.byType(TextField);
+    await tester.tap(textFinder);
+    await tester.pump();
+
+    final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
+    final RenderEditable renderEditable = editableTextState.renderEditable;
+
+    expect(renderEditable.cursorColor!.alpha, 255);
+
+    await tester.pump(const Duration(milliseconds: 100));
+    await tester.pump(const Duration(milliseconds: 400));
+
+    expect(renderEditable.cursorColor!.alpha, 255);
+
+    await tester.pump(const Duration(milliseconds: 200));
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(renderEditable.cursorColor!.alpha, 110);
+
+    await tester.pump(const Duration(milliseconds: 100));
+
+    expect(renderEditable.cursorColor!.alpha, 16);
+    await tester.pump(const Duration(milliseconds: 50));
+
+    expect(renderEditable.cursorColor!.alpha, 0);
+  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
   // Regression test for https://github.com/flutter/flutter/issues/78918.
   testWidgets('RenderEditable sets correct text editing value', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(text: 'how are you');
@@ -1292,7 +1328,7 @@ void main() {
 
     editText = (findRenderEditable(tester).text! as TextSpan).text!;
     expect(editText.substring(editText.length - 1), '\u2022');
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android }));
+  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.android }));
 
   testWidgets('desktop obscureText control test', (WidgetTester tester) async {
     await tester.pumpWidget(

packages/flutter/test/widgets/editable_text_cursor_test.dart

@@ -166,75 +166,61 @@ void main() {
     );
   });
 
-  testWidgets('Cursor animates on iOS', (WidgetTester tester) async {
-    await tester.pumpWidget(
-      const MaterialApp(
-        home: Material(
-          child: TextField(),
+  testWidgets('Cursor animates', (WidgetTester tester) async {
+    const Widget widget = MaterialApp(
+      home: Material(
+        child: TextField(
+          maxLines: 3,
         ),
       ),
     );
+    await tester.pumpWidget(widget);
 
-    final Finder textFinder = find.byType(TextField);
-    await tester.tap(textFinder);
+    await tester.tap(find.byType(TextField));
     await tester.pump();
 
     final EditableTextState editableTextState = tester.firstState(find.byType(EditableText));
     final RenderEditable renderEditable = editableTextState.renderEditable;
 
-    expect(renderEditable.cursorColor!.opacity, 1.0);
-
-    int walltimeMicrosecond = 0;
-    double lastVerifiedOpacity = 1.0;
-
-    Future<void> verifyKeyFrame({ required double opacity, required int at }) async {
-      const int delta = 1;
-      assert(at - delta > walltimeMicrosecond);
-      await tester.pump(Duration(microseconds: at - delta - walltimeMicrosecond));
-
-      // Instead of verifying the opacity at each key frame, this function
-      // verifies the opacity immediately *before* each key frame to avoid
-      // fp precision issues.
-      expect(
-        renderEditable.cursorColor!.opacity,
-        closeTo(lastVerifiedOpacity, 0.01),
-        reason: 'opacity at ${at-delta} microseconds',
-      );
-
-      walltimeMicrosecond = at - delta;
-      lastVerifiedOpacity = opacity;
-    }
-
-    await verifyKeyFrame(opacity: 1.0,  at: 500000);
-    await verifyKeyFrame(opacity: 0.75, at: 537500);
-    await verifyKeyFrame(opacity: 0.5,  at: 575000);
-    await verifyKeyFrame(opacity: 0.25, at: 612500);
-    await verifyKeyFrame(opacity: 0.0,  at: 650000);
-    await verifyKeyFrame(opacity: 0.0,  at: 850000);
-    await verifyKeyFrame(opacity: 0.25, at: 887500);
-    await verifyKeyFrame(opacity: 0.5,  at: 925000);
-    await verifyKeyFrame(opacity: 0.75, at: 962500);
-    await verifyKeyFrame(opacity: 1.0,  at: 1000000);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS }));
-
-  testWidgets('Cursor does not animate on non-iOS platforms', (WidgetTester tester) async {
-    await tester.pumpWidget(
-      const MaterialApp(
-        home: Material(child: TextField(maxLines: 3)),
-      ),
-    );
+    expect(renderEditable.cursorColor!.alpha, 255);
 
-    await tester.tap(find.byType(TextField));
+    // Trigger initial timer. When focusing the first time, the cursor shows
+    // for slightly longer than the average on time.
     await tester.pump();
-    // Wait for the current animation to finish. If the cursor never stops its
-    // blinking animation the test will timeout.
-    await tester.pumpAndSettle();
+    await tester.pump(const Duration(milliseconds: 200));
+    // Start timing standard cursor show period.
+    expect(renderEditable.cursorColor!.alpha, 255);
+    expect(renderEditable, paints..rrect(color: const Color(0xff2196f3)));
+
+    await tester.pump(const Duration(milliseconds: 500));
+    // Start to animate the cursor away.
+    expect(renderEditable.cursorColor!.alpha, 255);
+    expect(renderEditable, paints..rrect(color: const Color(0xff2196f3)));
 
-    for (int i = 0; i < 40; i += 1) {
-      await tester.pump(const Duration(milliseconds: 100));
-      expect(tester.hasRunningAnimations, false);
-    }
-  }, variant: TargetPlatformVariant.all(excluding: <TargetPlatform>{ TargetPlatform.iOS }));
+    await tester.pump(const Duration(milliseconds: 100));
+    expect(renderEditable.cursorColor!.alpha, 110);
+    expect(renderEditable, paints..rrect(color: const Color(0x6e2196f3)));
+
+    await tester.pump(const Duration(milliseconds: 100));
+    expect(renderEditable.cursorColor!.alpha, 16);
+    expect(renderEditable, paints..rrect(color: const Color(0x102196f3)));
+
+    await tester.pump(const Duration(milliseconds: 100));
+    expect(renderEditable.cursorColor!.alpha, 0);
+    // Don't try to draw the cursor.
+    expect(renderEditable, paintsExactlyCountTimes(#drawRRect, 0));
+
+    // Wait some more while the cursor is gone. It'll trigger the cursor to
+    // start animating in again.
+    await tester.pump(const Duration(milliseconds: 300));
+    expect(renderEditable.cursorColor!.alpha, 0);
+    expect(renderEditable, paintsExactlyCountTimes(#drawRRect, 0));
+
+    await tester.pump(const Duration(milliseconds: 50));
+    // Cursor starts coming back.
+    expect(renderEditable.cursorColor!.alpha, 79);
+    expect(renderEditable, paints..rrect(color: const Color(0x4f2196f3)));
+  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
 
   testWidgets('Cursor does not animate on Android', (WidgetTester tester) async {
     final Color defaultCursorColor = Color(ThemeData.fallback().colorScheme.primary.value);
@@ -970,40 +956,4 @@ void main() {
     );
     EditableText.debugDeterministicCursor = false;
   }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
-
-  testWidgets('password briefly does not show last character when disabled by system', (WidgetTester tester) async {
-    final bool debugDeterministicCursor = EditableText.debugDeterministicCursor;
-    EditableText.debugDeterministicCursor = false;
-    addTearDown(() {
-      EditableText.debugDeterministicCursor = debugDeterministicCursor;
-    });
-
-    await tester.pumpWidget(MaterialApp(
-      home: EditableText(
-        backgroundCursorColor: Colors.grey,
-        controller: controller,
-        obscureText: true,
-        focusNode: focusNode,
-        style: textStyle,
-        cursorColor: cursorColor,
-      ),
-    ));
-
-    await tester.enterText(find.byType(EditableText), 'AA');
-    await tester.pump();
-    await tester.enterText(find.byType(EditableText), 'AAA');
-    await tester.pump();
-
-    tester.binding.platformDispatcher.brieflyShowPasswordTestValue = false;
-    addTearDown(() {
-      tester.binding.platformDispatcher.brieflyShowPasswordTestValue = true;
-    });
-    expect((findRenderEditable(tester).text! as TextSpan).text, '••A');
-    await tester.pump(const Duration(milliseconds: 500));
-    expect((findRenderEditable(tester).text! as TextSpan).text, '•••');
-    await tester.pump(const Duration(milliseconds: 500));
-    await tester.pump(const Duration(milliseconds: 500));
-    await tester.pump(const Duration(milliseconds: 500));
-    expect((findRenderEditable(tester).text! as TextSpan).text, '•••');
-  });
 }

packages/flutter/test/widgets/editable_text_test.dart

@@ -3943,6 +3943,42 @@ void main() {
     expect((findRenderEditable(tester).text! as TextSpan).text, '•••');
   });
 
+  testWidgets('password briefly does not show last character on Android if turned off', (WidgetTester tester) async {
+    final bool debugDeterministicCursor = EditableText.debugDeterministicCursor;
+    EditableText.debugDeterministicCursor = false;
+    addTearDown(() {
+      EditableText.debugDeterministicCursor = debugDeterministicCursor;
+    });
+
+    await tester.pumpWidget(MaterialApp(
+      home: EditableText(
+        backgroundCursorColor: Colors.grey,
+        controller: controller,
+        obscureText: true,
+        focusNode: focusNode,
+        style: textStyle,
+        cursorColor: cursorColor,
+      ),
+    ));
+
+    await tester.enterText(find.byType(EditableText), 'AA');
+    await tester.pump();
+    await tester.enterText(find.byType(EditableText), 'AAA');
+    await tester.pump();
+
+    tester.binding.platformDispatcher.brieflyShowPasswordTestValue = false;
+    addTearDown(() {
+      tester.binding.platformDispatcher.brieflyShowPasswordTestValue = true;
+    });
+    expect((findRenderEditable(tester).text! as TextSpan).text, '••A');
+    await tester.pump(const Duration(milliseconds: 500));
+    expect((findRenderEditable(tester).text! as TextSpan).text, '•••');
+    await tester.pump(const Duration(milliseconds: 500));
+    await tester.pump(const Duration(milliseconds: 500));
+    await tester.pump(const Duration(milliseconds: 500));
+    expect((findRenderEditable(tester).text! as TextSpan).text, '•••');
+  });
+
   group('a11y copy/cut/paste', () {
     Future<void> buildApp(MockTextSelectionControls controls, WidgetTester tester) {
       return tester.pumpWidget(MaterialApp(