Add:创建 flutter go web 版

packages/flutter_web/test/rendering/rendering_tester.dart

@@ -0,0 +1,152 @@
+// Copyright 2015 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_web_ui/ui.dart' as ui;
+
+import 'package:flutter_web/foundation.dart';
+import 'package:flutter_web/gestures.dart';
+import 'package:flutter_web/rendering.dart';
+import 'package:flutter_web/scheduler.dart';
+import 'package:flutter_web/services.dart';
+
+import 'package:flutter_web_test/flutter_web_test.dart'
+    show EnginePhase, TestViewConfiguration;
+export 'package:flutter_web_test/flutter_web_test.dart' show EnginePhase;
+
+class TestRenderingFlutterBinding extends BindingBase
+    with
+        ServicesBinding,
+        GestureBinding,
+        SchedulerBinding,
+        PaintingBinding,
+        SemanticsBinding,
+        RendererBinding {
+  EnginePhase phase = EnginePhase.composite;
+
+  @override
+  void drawFrame() {
+    assert(phase != EnginePhase.build,
+        'rendering_tester does not support testing the build phase; use flutter_test instead');
+    pipelineOwner.flushLayout();
+    if (phase == EnginePhase.layout) return;
+    pipelineOwner.flushCompositingBits();
+    if (phase == EnginePhase.compositingBits) return;
+    pipelineOwner.flushPaint();
+    if (phase == EnginePhase.paint) return;
+    renderView.compositeFrame();
+    if (phase == EnginePhase.composite) return;
+    pipelineOwner.flushSemantics();
+    if (phase == EnginePhase.flushSemantics) return;
+    assert(phase == EnginePhase.flushSemantics ||
+        phase == EnginePhase.sendSemanticsUpdate);
+  }
+
+  @override
+  ViewConfiguration createViewConfiguration() {
+    return TestViewConfiguration(size: const Size(800.0, 600.0));
+  }
+}
+
+TestRenderingFlutterBinding _renderer;
+TestRenderingFlutterBinding get renderer {
+  ui.webOnlyScheduleFrameCallback ??= () {};
+  _renderer ??= TestRenderingFlutterBinding();
+  return _renderer;
+}
+
+/// Place the box in the render tree, at the given size and with the given
+/// alignment on the screen.
+///
+/// If you've updated `box` and want to lay it out again, use [pumpFrame].
+///
+/// Once a particular [RenderBox] has been passed to [layout], it cannot easily
+/// be put in a different place in the tree or passed to [layout] again, because
+/// [layout] places the given object into another [RenderBox] which you would
+/// need to unparent it from (but that box isn't itself made available).
+///
+/// The EnginePhase must not be [EnginePhase.build], since the rendering layer
+/// has no build phase.
+void layout(
+  RenderBox box, {
+  BoxConstraints constraints,
+  Alignment alignment = Alignment.center,
+  EnginePhase phase = EnginePhase.layout,
+}) {
+  assert(box !=
+      null); // If you want to just repump the last box, call pumpFrame().
+  assert(box.parent ==
+      null); // We stick the box in another, so you can't reuse it easily, sorry.
+
+  renderer.renderView.child = null;
+  if (constraints != null) {
+    box = RenderPositionedBox(
+        alignment: alignment,
+        child: RenderConstrainedBox(
+            additionalConstraints: constraints, child: box));
+  }
+  renderer.renderView.child = box;
+
+  pumpFrame(phase: phase);
+}
+
+void pumpFrame({EnginePhase phase = EnginePhase.layout}) {
+  assert(renderer != null);
+  assert(renderer.renderView != null);
+  assert(renderer.renderView.child != null); // call layout() first!
+  renderer.phase = phase;
+  renderer.drawFrame();
+}
+
+class TestCallbackPainter extends CustomPainter {
+  const TestCallbackPainter({this.onPaint});
+
+  final VoidCallback onPaint;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    onPaint();
+  }
+
+  @override
+  bool shouldRepaint(TestCallbackPainter oldPainter) => true;
+}
+
+class RenderSizedBox extends RenderBox {
+  RenderSizedBox(this._size);
+
+  final Size _size;
+
+  @override
+  double computeMinIntrinsicWidth(double height) {
+    return _size.width;
+  }
+
+  @override
+  double computeMaxIntrinsicWidth(double height) {
+    return _size.width;
+  }
+
+  @override
+  double computeMinIntrinsicHeight(double width) {
+    return _size.height;
+  }
+
+  @override
+  double computeMaxIntrinsicHeight(double width) {
+    return _size.height;
+  }
+
+  @override
+  bool get sizedByParent => true;
+
+  @override
+  void performResize() {
+    size = constraints.constrain(_size);
+  }
+
+  @override
+  void performLayout() {}
+
+  @override
+  bool hitTestSelf(Offset position) => true;
+}