// Copyright 2016 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 'dart:typed_data' show Uint8List; import 'dart:ui' as ui show instantiateImageCodec, Codec; import 'package:flutter/foundation.dart'; import 'package:flutter/services.dart' show ServicesBinding; import 'image_cache.dart'; import 'shader_warm_up.dart'; /// Binding for the painting library. /// /// Hooks into the cache eviction logic to clear the image cache. /// /// Requires the [ServicesBinding] to be mixed in earlier. mixin PaintingBinding on BindingBase, ServicesBinding { @override void initInstances() { super.initInstances(); _instance = this; _imageCache = createImageCache(); if (shaderWarmUp != null) { shaderWarmUp.execute(); } } /// The current [PaintingBinding], if one has been created. static PaintingBinding get instance => _instance; static PaintingBinding _instance; /// [ShaderWarmUp] to be executed during [initInstances]. /// /// If the application has scenes that require the compilation of complex /// shaders that are not covered by [DefaultShaderWarmUp], it may cause jank /// in the middle of an animation or interaction. In that case, set /// [shaderWarmUp] to a custom [ShaderWarmUp] before calling [initInstances] /// (usually before [runApp] for normal Flutter apps, and before /// [enableFlutterDriverExtension] for Flutter driver tests). Paint the scene /// in the custom [ShaderWarmUp] so Flutter can pre-compile and cache the /// shaders during startup. The warm up is only costly (100ms-200ms, /// depending on the shaders to compile) during the first run after the /// installation or a data wipe. The warm up does not block the main thread /// so there should be no "Application Not Responding" warning. /// /// Currently the warm-up happens synchronously on the GPU thread which means /// the rendering of the first frame on the GPU thread will be postponed until /// the warm-up is finished. /// /// See also: /// /// * [ShaderWarmUp], the interface of how this warm up works. static ShaderWarmUp shaderWarmUp = const DefaultShaderWarmUp(); /// The singleton that implements the Flutter framework's image cache. /// /// The cache is used internally by [ImageProvider] and should generally not /// be accessed directly. /// /// The image cache is created during startup by the [createImageCache] /// method. ImageCache get imageCache => _imageCache; ImageCache _imageCache; /// Creates the [ImageCache] singleton (accessible via [imageCache]). /// /// This method can be overridden to provide a custom image cache. @protected ImageCache createImageCache() => ImageCache(); /// Calls through to [dart:ui] with [decodedCacheRatioCap] from [ImageCache]. Future<ui.Codec> instantiateImageCodec(Uint8List list) { return ui.instantiateImageCodec(list); } @override void evict(String asset) { super.evict(asset); imageCache.clear(); } } /// The singleton that implements the Flutter framework's image cache. /// /// The cache is used internally by [ImageProvider] and should generally not be /// accessed directly. /// /// The image cache is created during startup by the [PaintingBinding]'s /// [PaintingBinding.createImageCache] method. ImageCache get imageCache => PaintingBinding.instance.imageCache;