packages/flutter/test/widgets/text_selection_test.dart

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/widgets.dart';

void main() {
  int tapCount;
  int singleTapUpCount;
  int singleTapCancelCount;
  int singleLongTapDownCount;
  int doubleTapDownCount;

  void _handleTapDown(TapDownDetails details) { tapCount++; }
  void _handleSingleTapUp(TapUpDetails details) { singleTapUpCount++; }
  void _handleSingleTapCancel() { singleTapCancelCount++; }
  void _handleSingleLongTapDown() { singleLongTapDownCount++; }
  void _handleDoubleTapDown(TapDownDetails details) { doubleTapDownCount++; }

  setUp(() {
    tapCount = 0;
    singleTapUpCount = 0;
    singleTapCancelCount = 0;
    singleLongTapDownCount = 0;
    doubleTapDownCount = 0;
  });

  Future<void> pumpGestureDetector(WidgetTester tester) async {
    await tester.pumpWidget(
      TextSelectionGestureDetector(
        behavior: HitTestBehavior.opaque,
        onTapDown: _handleTapDown,
        onSingleTapUp: _handleSingleTapUp,
        onSingleTapCancel: _handleSingleTapCancel,
        onSingleLongTapDown: _handleSingleLongTapDown,
        onDoubleTapDown: _handleDoubleTapDown,
        child: Container(),
      ),
    );
  }

  testWidgets('a series of taps all call onTaps', (WidgetTester tester) async {
    await pumpGestureDetector(tester);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 150));
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 150));
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 150));
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 150));
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 150));
    await tester.tapAt(const Offset(200, 200));
    expect(tapCount, 6);
  });

  testWidgets('in a series of rapid taps, onTapDown and onDoubleTapDown alternate', (WidgetTester tester) async {
    await pumpGestureDetector(tester);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 50));
    expect(singleTapUpCount, 1);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 50));
    expect(singleTapUpCount, 1);
    expect(doubleTapDownCount, 1);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 50));
    expect(singleTapUpCount, 2);
    expect(doubleTapDownCount, 1);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 50));
    expect(singleTapUpCount, 2);
    expect(doubleTapDownCount, 2);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 50));
    expect(singleTapUpCount, 3);
    expect(doubleTapDownCount, 2);
    await tester.tapAt(const Offset(200, 200));
    expect(singleTapUpCount, 3);
    expect(doubleTapDownCount, 3);
    expect(tapCount, 6);
  });

  testWidgets('quick tap-tap-hold is a double tap down', (WidgetTester tester) async {
    await pumpGestureDetector(tester);
    await tester.tapAt(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 50));
    expect(singleTapUpCount, 1);
    final TestGesture gesture = await tester.startGesture(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 200));
    expect(singleTapUpCount, 1);
    // Every down is counted.
    expect(tapCount, 2);
    // No cancels because the second tap of the double tap is a second successful
    // single tap behind the scene.
    expect(singleTapCancelCount, 0);
    expect(doubleTapDownCount, 1);
    // The double tap down hold supersedes the single tap down.
    expect(singleLongTapDownCount, 0);

    await gesture.up();
    // Nothing else happens on up.
    expect(singleTapUpCount, 1);
    expect(tapCount, 2);
    expect(singleTapCancelCount, 0);
    expect(doubleTapDownCount, 1);
    expect(singleLongTapDownCount, 0);
  });

  testWidgets('a very quick swipe is just a canceled tap', (WidgetTester tester) async {
    await pumpGestureDetector(tester);
    final TestGesture gesture = await tester.startGesture(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 20));
    await gesture.moveBy(const Offset(100, 100));
    await tester.pump();
    expect(singleTapUpCount, 0);
    expect(tapCount, 0);
    expect(singleTapCancelCount, 1);
    expect(doubleTapDownCount, 0);
    expect(singleLongTapDownCount, 0);

    await gesture.up();
    // Nothing else happens on up.
    expect(singleTapUpCount, 0);
    expect(tapCount, 0);
    expect(singleTapCancelCount, 1);
    expect(doubleTapDownCount, 0);
    expect(singleLongTapDownCount, 0);
  });

  testWidgets('a slower swipe has a tap down and a canceled tap', (WidgetTester tester) async {
    await pumpGestureDetector(tester);
    final TestGesture gesture = await tester.startGesture(const Offset(200, 200));
    await tester.pump(const Duration(milliseconds: 120));
    await gesture.moveBy(const Offset(100, 100));
    await tester.pump();
    expect(singleTapUpCount, 0);
    expect(tapCount, 1);
    expect(singleTapCancelCount, 1);
    expect(doubleTapDownCount, 0);
    expect(singleLongTapDownCount, 0);
  });
}