sliver_list_test.dart 11.9 KB
Newer Older
Ian Hickson's avatar
Ian Hickson committed
1
// Copyright 2014 The Flutter Authors. All rights reserved.
2 3 4 5 6
// 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';
7
import 'package:flutter/material.dart';
8 9 10

void main() {
  testWidgets('SliverList reverse children (with keys)', (WidgetTester tester) async {
11
    final List<int> items = List<int>.generate(20, (int i) => i);
12 13 14 15
    const double itemHeight = 300.0;
    const double viewportHeight = 500.0;

    const double scrollPosition = 18 * itemHeight;
16
    final ScrollController controller = ScrollController(initialScrollOffset: scrollPosition);
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

    await tester.pumpWidget(_buildSliverList(
      items: items,
      controller: controller,
      itemHeight: itemHeight,
      viewportHeight: viewportHeight,
    ));
    await tester.pumpAndSettle();

    expect(controller.offset, scrollPosition);
    expect(find.text('Tile 0'), findsNothing);
    expect(find.text('Tile 1'), findsNothing);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsOneWidget);

    await tester.pumpWidget(_buildSliverList(
      items: items.reversed.toList(),
      controller: controller,
      itemHeight: itemHeight,
      viewportHeight: viewportHeight,
    ));
    final int frames = await tester.pumpAndSettle();
    expect(frames, 1); // ensures that there is no (animated) bouncing of the scrollable

    expect(controller.offset, scrollPosition);
    expect(find.text('Tile 19'), findsNothing);
    expect(find.text('Tile 18'), findsNothing);
    expect(find.text('Tile 1'), findsOneWidget);
    expect(find.text('Tile 0'), findsOneWidget);

    controller.jumpTo(0.0);
    await tester.pumpAndSettle();

    expect(controller.offset, 0.0);
    expect(find.text('Tile 19'), findsOneWidget);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 1'), findsNothing);
    expect(find.text('Tile 0'), findsNothing);
  });

  testWidgets('SliverList replace children (with keys)', (WidgetTester tester) async {
58
    final List<int> items = List<int>.generate(20, (int i) => i);
59 60 61 62
    const double itemHeight = 300.0;
    const double viewportHeight = 500.0;

    const double scrollPosition = 18 * itemHeight;
63
    final ScrollController controller = ScrollController(initialScrollOffset: scrollPosition);
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79

    await tester.pumpWidget(_buildSliverList(
      items: items,
      controller: controller,
      itemHeight: itemHeight,
      viewportHeight: viewportHeight,
    ));
    await tester.pumpAndSettle();

    expect(controller.offset, scrollPosition);
    expect(find.text('Tile 0'), findsNothing);
    expect(find.text('Tile 1'), findsNothing);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsOneWidget);

    await tester.pumpWidget(_buildSliverList(
80
      items: items.map<int>((int i) => i + 100).toList(),
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
      controller: controller,
      itemHeight: itemHeight,
      viewportHeight: viewportHeight,
    ));
    final int frames = await tester.pumpAndSettle();
    expect(frames, 1); // ensures that there is no (animated) bouncing of the scrollable

    expect(controller.offset, scrollPosition);
    expect(find.text('Tile 0'), findsNothing);
    expect(find.text('Tile 1'), findsNothing);
    expect(find.text('Tile 18'), findsNothing);
    expect(find.text('Tile 19'), findsNothing);

    expect(find.text('Tile 100'), findsNothing);
    expect(find.text('Tile 101'), findsNothing);
    expect(find.text('Tile 118'), findsOneWidget);
    expect(find.text('Tile 119'), findsOneWidget);

    controller.jumpTo(0.0);
    await tester.pumpAndSettle();

    expect(controller.offset, 0.0);
    expect(find.text('Tile 100'), findsOneWidget);
    expect(find.text('Tile 101'), findsOneWidget);
    expect(find.text('Tile 118'), findsNothing);
    expect(find.text('Tile 119'), findsNothing);
  });

  testWidgets('SliverList replace with shorter children list (with keys)', (WidgetTester tester) async {
110
    final List<int> items = List<int>.generate(20, (int i) => i);
111 112 113 114
    const double itemHeight = 300.0;
    const double viewportHeight = 500.0;

    final double scrollPosition = items.length * itemHeight - viewportHeight;
115
    final ScrollController controller = ScrollController(initialScrollOffset: scrollPosition);
116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147

    await tester.pumpWidget(_buildSliverList(
      items: items,
      controller: controller,
      itemHeight: itemHeight,
      viewportHeight: viewportHeight,
    ));
    await tester.pumpAndSettle();

    expect(controller.offset, scrollPosition);
    expect(find.text('Tile 0'), findsNothing);
    expect(find.text('Tile 1'), findsNothing);
    expect(find.text('Tile 17'), findsNothing);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsOneWidget);

    await tester.pumpWidget(_buildSliverList(
      items: items.sublist(0, items.length - 1),
      controller: controller,
      itemHeight: itemHeight,
      viewportHeight: viewportHeight,
    ));
    final int frames = await tester.pumpAndSettle();
    expect(frames, greaterThan(1)); // ensure animation to bring tile17 into view

    expect(controller.offset, scrollPosition - itemHeight);
    expect(find.text('Tile 0'), findsNothing);
    expect(find.text('Tile 1'), findsNothing);
    expect(find.text('Tile 17'), findsOneWidget);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsNothing);
  });
148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165

  testWidgets('SliverList should layout first child in case of child reordering', (WidgetTester tester) async {
    // Regression test for https://github.com/flutter/flutter/issues/35904.
    List<String> items = <String>['1', '2'];

    await tester.pumpWidget(_buildSliverListRenderWidgetChild(items));
    await tester.pumpAndSettle();

    expect(find.text('Tile 1'), findsOneWidget);
    expect(find.text('Tile 2'), findsOneWidget);

    items = items.reversed.toList();
    await tester.pumpWidget(_buildSliverListRenderWidgetChild(items));
    await tester.pumpAndSettle();

    expect(find.text('Tile 1'), findsOneWidget);
    expect(find.text('Tile 2'), findsOneWidget);
  });
166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277

  testWidgets('SliverList should recalculate inaccurate layout offset case 1', (WidgetTester tester) async {
    // Regression test for https://github.com/flutter/flutter/issues/42142.
    final List<int> items = List<int>.generate(20, (int i) => i);
    final ScrollController controller = ScrollController();
    await tester.pumpWidget(
      _buildSliverList(
        items: List<int>.from(items),
        controller: controller,
        itemHeight: 50,
        viewportHeight: 200,
      )
    );
    await tester.pumpAndSettle();

    await tester.drag(find.text('Tile 2'), const Offset(0.0, -1000.0));
    await tester.pumpAndSettle();

    // Viewport should be scrolled to the end of list.
    expect(controller.offset, 800.0);
    expect(find.text('Tile 15'), findsNothing);
    expect(find.text('Tile 16'), findsOneWidget);
    expect(find.text('Tile 17'), findsOneWidget);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsOneWidget);

    // Prepends item to the list.
    items.insert(0, -1);
    await tester.pumpWidget(
      _buildSliverList(
        items: List<int>.from(items),
        controller: controller,
        itemHeight: 50,
        viewportHeight: 200,
      )
    );
    await tester.pump();
    // We need second pump to ensure the scheduled animation gets run.
    await tester.pumpAndSettle();
    // Scroll offset should stay the same, and the items in viewport should be
    // shifted by one.
    expect(controller.offset, 800.0);
    expect(find.text('Tile 14'), findsNothing);
    expect(find.text('Tile 15'), findsOneWidget);
    expect(find.text('Tile 16'), findsOneWidget);
    expect(find.text('Tile 17'), findsOneWidget);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsNothing);

    // Drags back to beginning and newly added item is visible.
    await tester.drag(find.text('Tile 16'), const Offset(0.0, 1000.0));
    await tester.pumpAndSettle();
    expect(controller.offset, 0.0);
    expect(find.text('Tile -1'), findsOneWidget);
    expect(find.text('Tile 0'), findsOneWidget);
    expect(find.text('Tile 1'), findsOneWidget);
    expect(find.text('Tile 2'), findsOneWidget);
    expect(find.text('Tile 3'), findsNothing);

  });

  testWidgets('SliverList should recalculate inaccurate layout offset case 2', (WidgetTester tester) async {
    // Regression test for https://github.com/flutter/flutter/issues/42142.
    final List<int> items = List<int>.generate(20, (int i) => i);
    final ScrollController controller = ScrollController();
    await tester.pumpWidget(
      _buildSliverList(
        items: List<int>.from(items),
        controller: controller,
        itemHeight: 50,
        viewportHeight: 200,
      )
    );
    await tester.pumpAndSettle();

    await tester.drag(find.text('Tile 2'), const Offset(0.0, -1000.0));
    await tester.pumpAndSettle();

    // Viewport should be scrolled to the end of list.
    expect(controller.offset, 800.0);
    expect(find.text('Tile 15'), findsNothing);
    expect(find.text('Tile 16'), findsOneWidget);
    expect(find.text('Tile 17'), findsOneWidget);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 19'), findsOneWidget);

    // Reorders item to the front. This should make item 19 to be first child
    // with layout offset = null.
    final int swap = items[19];
    items[19] = items[3];
    items[3] = swap;

    await tester.pumpWidget(
      _buildSliverList(
        items: List<int>.from(items),
        controller: controller,
        itemHeight: 50,
        viewportHeight: 200,
      )
    );
    await tester.pump();
    // We need second pump to ensure the scheduled animation gets run.
    await tester.pumpAndSettle();
    // Scroll offset should stay the same
    expect(controller.offset, 800.0);
    expect(find.text('Tile 14'), findsNothing);
    expect(find.text('Tile 15'), findsNothing);
    expect(find.text('Tile 16'), findsOneWidget);
    expect(find.text('Tile 17'), findsOneWidget);
    expect(find.text('Tile 18'), findsOneWidget);
    expect(find.text('Tile 3'), findsOneWidget);
  });
278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305
}

Widget _buildSliverListRenderWidgetChild(List<String> items) {
  return MaterialApp(
    home: Directionality(
      textDirection: TextDirection.ltr,
      child: Material(
        child: Container(
          height: 500,
          child: CustomScrollView(
            controller: ScrollController(),
            slivers: <Widget>[
              SliverList(
                delegate: SliverChildListDelegate(
                  items.map<Widget>((String item) {
                    return Chip(
                      key: Key(item),
                      label: Text('Tile $item'),
                    );
                  }).toList(),
                ),
              ),
            ],
          ),
        ),
      ),
    ),
  );
306 307 308
}

Widget _buildSliverList({
309
  List<int> items = const <int>[],
310
  ScrollController controller,
311 312
  double itemHeight = 500.0,
  double viewportHeight = 300.0,
313
}) {
314
  return Directionality(
315
    textDirection: TextDirection.ltr,
316 317
    child: Center(
      child: Container(
318
        height: viewportHeight,
319
        child: CustomScrollView(
320 321
          controller: controller,
          slivers: <Widget>[
322 323
            SliverList(
              delegate: SliverChildBuilderDelegate(
324
                (BuildContext context, int i) {
325 326
                  return Container(
                    key: ValueKey<int>(items[i]),
327
                    height: itemHeight,
328
                    child: Text('Tile ${items[i]}'),
329 330
                  );
                },
331 332 333 334 335
                findChildIndexCallback: (Key key) {
                  final ValueKey<int> valueKey = key as ValueKey<int>;
                  final int index = items.indexOf(valueKey.value);
                  return index == -1 ? null : index;
                },
336 337 338 339 340 341 342 343 344
                childCount: items.length,
              ),
            ),
          ],
        ),
      ),
    ),
  );
}