// 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/foundation.dart'; import 'package:flutter/gestures.dart'; import 'package:flutter/rendering.dart'; import 'package:flutter/scheduler.dart'; import 'package:flutter/services.dart'; import 'package:flutter_test/flutter_test.dart' show EnginePhase, fail; export 'package:flutter/foundation.dart' show FlutterError, FlutterErrorDetails; export 'package:flutter_test/flutter_test.dart' show EnginePhase; class TestRenderingFlutterBinding extends BindingBase with ServicesBinding, GestureBinding, SchedulerBinding, PaintingBinding, SemanticsBinding, RendererBinding { /// Creates a binding for testing rendering library functionality. /// /// If [onErrors] is not null, it is called if [FlutterError] caught any errors /// while drawing the frame. If [onErrors] is null and [FlutterError] caught at least /// one error, this function fails the test. A test may override [onErrors] and /// inspect errors using [takeFlutterErrorDetails]. TestRenderingFlutterBinding({ this.onErrors }); final List<FlutterErrorDetails> _errors = <FlutterErrorDetails>[]; /// A function called after drawing a frame if [FlutterError] caught any errors. /// /// This function is expected to inspect these errors and decide whether they /// are expected or not. Use [takeFlutterErrorDetails] to take one error at a /// time, or [takeAllFlutterErrorDetails] to iterate over all errors. VoidCallback onErrors; /// Returns the error least recently caught by [FlutterError] and removes it /// from the list of captured errors. /// /// Returns null if no errors were captures, or if the list was exhausted by /// calling this method repeatedly. FlutterErrorDetails takeFlutterErrorDetails() { if (_errors.isEmpty) { return null; } return _errors.removeAt(0); } /// Returns all error details caught by [FlutterError] from least recently caught to /// most recently caught, and removes them from the list of captured errors. /// /// The returned iterable takes errors lazily. If, for example, you iterate over 2 /// errors, but there are 5 errors total, this binding will still fail the test. /// Tests are expected to take and inspect all errors. Iterable<FlutterErrorDetails> takeAllFlutterErrorDetails() sync* { // sync* and yield are used for lazy evaluation. Otherwise, the list would be // drained eagerly and allow a test pass with unexpected errors. while (_errors.isNotEmpty) { yield _errors.removeAt(0); } } /// Returns all exceptions caught by [FlutterError] from least recently caught to /// most recently caught, and removes them from the list of captured errors. /// /// The returned iterable takes errors lazily. If, for example, you iterate over 2 /// errors, but there are 5 errors total, this binding will still fail the test. /// Tests are expected to take and inspect all errors. Iterable<dynamic> takeAllFlutterExceptions() sync* { // sync* and yield are used for lazy evaluation. Otherwise, the list would be // drained eagerly and allow a test pass with unexpected errors. while (_errors.isNotEmpty) { yield _errors.removeAt(0).exception; } } EnginePhase phase = EnginePhase.composite; @override void drawFrame() { assert(phase != EnginePhase.build, 'rendering_tester does not support testing the build phase; use flutter_test instead'); final FlutterExceptionHandler oldErrorHandler = FlutterError.onError; FlutterError.onError = (FlutterErrorDetails details) { _errors.add(details); }; try { 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); } finally { FlutterError.onError = oldErrorHandler; if (_errors.isNotEmpty) { if (onErrors != null) { onErrors(); if (_errors.isNotEmpty) { _errors.forEach(FlutterError.dumpErrorToConsole); fail('There are more errors than the test inspected using TestRenderingFlutterBinding.takeFlutterErrorDetails.'); } } else { _errors.forEach(FlutterError.dumpErrorToConsole); fail('Caught error while rendering frame. See preceding logs for details.'); } } } } } TestRenderingFlutterBinding _renderer; TestRenderingFlutterBinding get renderer { _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. /// /// If `onErrors` is not null, it is set as [TestRenderingFlutterBinding.onError]. void layout( RenderBox box, { BoxConstraints constraints, Alignment alignment = Alignment.center, EnginePhase phase = EnginePhase.layout, VoidCallback onErrors, }) { 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, onErrors: onErrors); } /// Pumps a single frame. /// /// If `onErrors` is not null, it is set as [TestRenderingFlutterBinding.onError]. void pumpFrame({ EnginePhase phase = EnginePhase.layout, VoidCallback onErrors }) { assert(renderer != null); assert(renderer.renderView != null); assert(renderer.renderView.child != null); // call layout() first! if (onErrors != null) { renderer.onErrors = onErrors; } 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; }