| // 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. |
| |
| [PermissiveDictionaryConversion] |
| dictionary CanvasContextCreationAttributes { |
| // Canvas 2D attributes |
| boolean alpha = true; // Also used for WebGL. |
| |
| // WebGL attributes |
| boolean depth = true; |
| boolean stencil = false; |
| boolean antialias = true; |
| boolean premultipliedAlpha = true; |
| boolean preserveDrawingBuffer = false; |
| boolean failIfMajorPerformanceCaveat = false; |
| }; |
