render_object_element_test.dart 11.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12
// Copyright 2014 The Flutter 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/foundation.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';

@immutable
class Pair<T> {
  const Pair(this.first, this.second);
13
  final T? first;
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
  final T second;

  @override
  bool operator ==(Object other) {
    return other is Pair<T> && other.first == first && other.second == second;
  }

  @override
  int get hashCode => hashValues(first, second);

  @override
  String toString() => '($first,$second)';
}

/// Widget that will layout one child in the top half of this widget's size
/// and the other child in the bottom half. It will swap which child is on top
/// and which is on bottom every time the widget is rendered.
abstract class Swapper extends RenderObjectWidget {
32
  const Swapper({ this.stable, this.swapper });
33

34 35
  final Widget? stable;
  final Widget? swapper;
36 37 38 39 40 41 42 43 44 45

  @override
  SwapperElement createElement();

  @override
  RenderObject createRenderObject(BuildContext context) => RenderSwapper();
}

class SwapperWithProperOverrides extends Swapper {
  const SwapperWithProperOverrides({
46 47
    Widget? stable,
    Widget? swapper,
48 49 50 51 52 53 54 55
  }) : super(stable: stable, swapper: swapper);

  @override
  SwapperElement createElement() => SwapperElementWithProperOverrides(this);
}

class SwapperWithNoOverrides extends Swapper {
  const SwapperWithNoOverrides({
56 57
    Widget? stable,
    Widget? swapper,
58 59 60 61 62 63 64 65
  }) : super(stable: stable, swapper: swapper);

  @override
  SwapperElement createElement() => SwapperElementWithNoOverrides(this);
}

class SwapperWithDeprecatedOverrides extends Swapper {
  const SwapperWithDeprecatedOverrides({
66 67
    Widget? stable,
    Widget? swapper,
68 69 70 71 72 73 74 75 76
  }) : super(stable: stable, swapper: swapper);

  @override
  SwapperElement createElement() => SwapperElementWithDeprecatedOverrides(this);
}

abstract class SwapperElement extends RenderObjectElement {
  SwapperElement(Swapper widget) : super(widget);

77 78
  Element? stable;
  Element? swapper;
79 80 81 82 83 84 85 86 87 88 89 90 91 92
  bool swapperIsOnTop = true;
  List<dynamic> insertSlots = <dynamic>[];
  List<Pair<dynamic>> moveSlots = <Pair<dynamic>>[];
  List<dynamic> removeSlots = <dynamic>[];

  @override
  Swapper get widget => super.widget as Swapper;

  @override
  RenderSwapper get renderObject => super.renderObject as RenderSwapper;

  @override
  void visitChildren(ElementVisitor visitor) {
    if (stable != null)
93
      visitor(stable!);
94
    if (swapper != null)
95
      visitor(swapper!);
96 97 98 99 100 101 102 103 104
  }

  @override
  void update(Swapper newWidget) {
    super.update(newWidget);
    _updateChildren(newWidget);
  }

  @override
105
  void mount(Element? parent, dynamic newSlot) {
106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183
    super.mount(parent, newSlot);
    _updateChildren(widget);
  }

  void _updateChildren(Swapper widget) {
    stable = updateChild(stable, widget.stable, 'stable');
    swapper = updateChild(swapper, widget.swapper, swapperIsOnTop);
    swapperIsOnTop = !swapperIsOnTop;
  }
}

class SwapperElementWithProperOverrides extends SwapperElement {
  SwapperElementWithProperOverrides(Swapper widget) : super(widget);

  @override
  void insertRenderObjectChild(RenderBox child, dynamic slot) {
    insertSlots.add(slot);
    assert(child != null);
    if (slot == 'stable')
      renderObject.stable = child;
    else
      renderObject.setSwapper(child, slot as bool);
  }

  @override
  void moveRenderObjectChild(RenderBox child, bool oldIsOnTop, bool newIsOnTop) {
    moveSlots.add(Pair<bool>(oldIsOnTop, newIsOnTop));
    assert(oldIsOnTop == !newIsOnTop);
    renderObject.setSwapper(child, newIsOnTop);
  }

  @override
  void removeRenderObjectChild(RenderBox child, dynamic slot) {
    removeSlots.add(slot);
    if (slot == 'stable')
      renderObject.stable = null;
    else
      renderObject.setSwapper(null, slot as bool);
  }
}

class SwapperElementWithNoOverrides extends SwapperElement {
  SwapperElementWithNoOverrides(Swapper widget) : super(widget);
}

class SwapperElementWithDeprecatedOverrides extends SwapperElement {
  SwapperElementWithDeprecatedOverrides(Swapper widget) : super(widget);

  @override
  // ignore: must_call_super
  void insertChildRenderObject(RenderBox child, dynamic slot) {
    insertSlots.add(slot);
    assert(child != null);
    if (slot == 'stable')
      renderObject.stable = child;
    else
      renderObject.setSwapper(child, slot as bool);
  }

  @override
  // ignore: must_call_super
  void moveChildRenderObject(RenderBox child, bool isOnTop) {
    moveSlots.add(Pair<bool>(null, isOnTop));
    renderObject.setSwapper(child, isOnTop);
  }

  @override
  // ignore: must_call_super
  void removeChildRenderObject(RenderBox child) {
    removeSlots.add(null);
    if (child == renderObject._stable)
      renderObject.stable = null;
    else
      renderObject.setSwapper(null, swapperIsOnTop);
  }
}

class RenderSwapper extends RenderBox {
184 185 186
  RenderBox? _stable;
  RenderBox? get stable => _stable;
  set stable(RenderBox? child) {
187 188 189
    if (child == _stable)
      return;
    if (_stable != null)
190
      dropChild(_stable!);
191 192 193 194 195
    _stable = child;
    if (child != null)
      adoptChild(child);
  }

196 197 198 199
  bool? _swapperIsOnTop;
  RenderBox? _swapper;
  RenderBox? get swapper => _swapper;
  void setSwapper(RenderBox? child, bool isOnTop) {
200 201 202 203 204 205 206
    if (isOnTop != _swapperIsOnTop) {
      _swapperIsOnTop = isOnTop;
      markNeedsLayout();
    }
    if (child == _swapper)
      return;
    if (_swapper != null)
207
      dropChild(_swapper!);
208 209 210 211 212 213 214 215
    _swapper = child;
    if (child != null)
      adoptChild(child);
  }

  @override
  void visitChildren(RenderObjectVisitor visitor) {
    if (_stable != null)
216
      visitor(_stable!);
217
    if (_swapper != null)
218
      visitor(_swapper!);
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
  }

  @override
  void attach(PipelineOwner owner) {
    super.attach(owner);
    visitChildren((RenderObject child) => child.attach(owner));
  }

  @override
  void detach() {
    super.detach();
    visitChildren((RenderObject child) => child.detach());
  }

  @override
  void performLayout() {
    assert(constraints.hasBoundedWidth);
    assert(constraints.hasTightHeight);
    size = constraints.biggest;
    const Offset topOffset = Offset.zero;
    final Offset bottomOffset = Offset(0, size.height / 2);
    final BoxConstraints childConstraints = constraints.copyWith(
      minHeight: constraints.minHeight / 2,
      maxHeight: constraints.maxHeight / 2,
    );
    if (_stable != null) {
245 246 247
      final BoxParentData stableParentData = _stable!.parentData! as BoxParentData;
      _stable!.layout(childConstraints);
      stableParentData.offset = _swapperIsOnTop! ? bottomOffset : topOffset;
248 249
    }
    if (_swapper != null) {
250 251 252
      final BoxParentData swapperParentData = _swapper!.parentData! as BoxParentData;
      _swapper!.layout(childConstraints);
      swapperParentData.offset = _swapperIsOnTop! ? topOffset : bottomOffset;
253 254 255 256 257 258
    }
  }

  @override
  void paint(PaintingContext context, Offset offset) {
    visitChildren((RenderObject child) {
259
      final BoxParentData childParentData = child.parentData! as BoxParentData;
260 261 262 263 264 265 266 267 268 269
      context.paintChild(child, offset + childParentData.offset);
    });
  }

  @override
  void redepthChildren() {
    visitChildren((RenderObject child) => redepthChild(child));
  }
}

270
BoxParentData parentDataFor(RenderObject renderObject) => renderObject.parentData! as BoxParentData;
271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356

void main() {
  testWidgets('RenderObjectElement *RenderObjectChild methods get called with correct arguments', (WidgetTester tester) async {
    const Key redKey = ValueKey<String>('red');
    const Key blueKey = ValueKey<String>('blue');
    Widget widget() {
      return SwapperWithProperOverrides(
        stable: ColoredBox(
          key: redKey,
          color: Color(nonconst(0xffff0000)),
        ),
        swapper: ColoredBox(
          key: blueKey,
          color: Color(nonconst(0xff0000ff)),
        ),
      );
    }

    await tester.pumpWidget(widget());
    final SwapperElement swapper = tester.element<SwapperElement>(find.byType(SwapperWithProperOverrides));
    final RenderBox redBox = tester.renderObject<RenderBox>(find.byKey(redKey));
    final RenderBox blueBox = tester.renderObject<RenderBox>(find.byKey(blueKey));
    expect(swapper.insertSlots.length, 2);
    expect(swapper.insertSlots, contains('stable'));
    expect(swapper.insertSlots, contains(true));
    expect(swapper.moveSlots, isEmpty);
    expect(swapper.removeSlots, isEmpty);
    expect(parentDataFor(redBox).offset, const Offset(0, 300));
    expect(parentDataFor(blueBox).offset, Offset.zero);
    await tester.pumpWidget(widget());
    expect(swapper.insertSlots.length, 2);
    expect(swapper.moveSlots.length, 1);
    expect(swapper.moveSlots, contains(const Pair<bool>(true, false)));
    expect(swapper.removeSlots, isEmpty);
    expect(parentDataFor(redBox).offset, Offset.zero);
    expect(parentDataFor(blueBox).offset, const Offset(0, 300));
    await tester.pumpWidget(const SwapperWithProperOverrides());
    expect(redBox.attached, false);
    expect(blueBox.attached, false);
    expect(swapper.insertSlots.length, 2);
    expect(swapper.moveSlots.length, 1);
    expect(swapper.removeSlots.length, 2);
    expect(swapper.removeSlots, contains('stable'));
    expect(swapper.removeSlots, contains(false));
  });

  testWidgets('RenderObjectElement *RenderObjectChild methods delegate to deprecated methods', (WidgetTester tester) async {
    const Key redKey = ValueKey<String>('red');
    const Key blueKey = ValueKey<String>('blue');
    Widget widget() {
      return SwapperWithDeprecatedOverrides(
        stable: ColoredBox(
          key: redKey,
          color: Color(nonconst(0xffff0000)),
        ),
        swapper: ColoredBox(
          key: blueKey,
          color: Color(nonconst(0xff0000ff)),
        ),
      );
    }

    await tester.pumpWidget(widget());
    final SwapperElement swapper = tester.element<SwapperElement>(find.byType(SwapperWithDeprecatedOverrides));
    final RenderBox redBox = tester.renderObject<RenderBox>(find.byKey(redKey));
    final RenderBox blueBox = tester.renderObject<RenderBox>(find.byKey(blueKey));
    expect(swapper.insertSlots.length, 2);
    expect(swapper.insertSlots, contains('stable'));
    expect(swapper.insertSlots, contains(true));
    expect(swapper.moveSlots, isEmpty);
    expect(swapper.removeSlots, isEmpty);
    expect(parentDataFor(redBox).offset, const Offset(0, 300));
    expect(parentDataFor(blueBox).offset, Offset.zero);
    await tester.pumpWidget(widget());
    expect(swapper.insertSlots.length, 2);
    expect(swapper.moveSlots.length, 1);
    expect(swapper.moveSlots, contains(const Pair<bool>(null, false)));
    expect(swapper.removeSlots, isEmpty);
    expect(parentDataFor(redBox).offset, Offset.zero);
    expect(parentDataFor(blueBox).offset, const Offset(0, 300));
    await tester.pumpWidget(const SwapperWithDeprecatedOverrides());
    expect(redBox.attached, false);
    expect(blueBox.attached, false);
    expect(swapper.insertSlots.length, 2);
    expect(swapper.moveSlots.length, 1);
    expect(swapper.removeSlots.length, 2);
357
    expect(swapper.removeSlots, <bool?>[null,null]);
358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381
  });

  testWidgets('RenderObjectElement *ChildRenderObject methods fail with deprecation message', (WidgetTester tester) async {
    const Key redKey = ValueKey<String>('red');
    const Key blueKey = ValueKey<String>('blue');
    Widget widget() {
      return SwapperWithNoOverrides(
        stable: ColoredBox(
          key: redKey,
          color: Color(nonconst(0xffff0000)),
        ),
        swapper: ColoredBox(
          key: blueKey,
          color: Color(nonconst(0xff0000ff)),
        ),
      );
    }

    await tester.pumpWidget(widget());
    final FlutterError error = tester.takeException() as FlutterError;
    final ErrorSummary summary = error.diagnostics.first as ErrorSummary;
    expect(summary.toString(), contains('deprecated'));
  });
}