blob: 752714c9933030067cfca095ed98cc013c442255 [file] [log] [blame]
// Copyright 2014 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.
// The spec for HTMLCanvasElement.getContext() defines the context
// creation attributes as type "any". In order to eliminate custom
// bindings for getContext(), we define a dictionary that contains the
// union of all of the context types' attributes. Note that it is not
// possible to use a union type for this purpose because two dictionary
// types are not distinguishable.
// Fortunately, there aren't any context creation attributes which are
// defined with different default values in different context
// specifications. (The "alpha" value, in particular, has a default
// value of true for both the Canvas2D and WebGL specifications.)
// The PermissiveDictionaryConversion extended attribute ignores
// non-object types (like 'true' and 'false') passed to getContext() for
// the attributes instead of raising TypeError, following the behavior
// of the previous custom binding.
// N.B.: Web IDL doesn't support multiple inheritance of dictionaries.
enum CanvasColorSpace {
"srgb", // default
enum CanvasPixelFormat {
"8-8-8-8", // default
dictionary CanvasContextCreationAttributes {
// Canvas 2D attributes
boolean alpha = true; // Also used for WebGL.
// TODO( Do we keep "legacy-srgb" as the default?
// Must decide before shipping.
[RuntimeEnabled=ExperimentalCanvasFeatures] CanvasColorSpace colorSpace = "legacy-srgb";
[RuntimeEnabled=ExperimentalCanvasFeatures] CanvasPixelFormat pixelFormat = "8-8-8-8";
[RuntimeEnabled=ExperimentalCanvasFeatures] boolean linearPixelMath = false;
// WebGL attributes
boolean depth = true;
boolean stencil = false;
boolean antialias = true;
boolean premultipliedAlpha = true;
boolean preserveDrawingBuffer = false;
boolean failIfMajorPerformanceCaveat = false;