{
    "domain": "Canvas",
    "availability": ["web"],
    "description": "Canvas domain allows tracking of canvases that have an associated graphics context. Tracks canvases in the DOM and CSS canvases created with -webkit-canvas.",
    "types": [
        {
            "id": "CanvasId",
            "type": "string",
            "description": "Unique canvas identifier."
        },
        {
            "id": "ProgramId",
            "type": "string",
            "description": "Unique shader program identifier."
        },
        {
            "id": "ContextType",
            "type": "string",
            "enum": ["canvas-2d", "bitmaprenderer", "webgl", "webgl2", "webmetal"],
            "description": "The type of rendering context backing the canvas element."
        },
        {
            "id": "ShaderType",
            "type": "string",
            "enum": ["fragment", "vertex"],
            "description": "Shader type. WebGL supports vertex and fragment shaders."
        },
        {
            "id": "ContextAttributes",
            "type": "object",
            "description": "Drawing surface attributes.",
            "properties": [
                { "name": "alpha", "type": "boolean", "optional": true },
                { "name": "depth", "type": "boolean", "optional": true },
                { "name": "stencil", "type": "boolean", "optional": true },
                { "name": "antialias", "type": "boolean", "optional": true },
                { "name": "premultipliedAlpha", "type": "boolean", "optional": true },
                { "name": "preserveDrawingBuffer", "type": "boolean", "optional": true },
                { "name": "failIfMajorPerformanceCaveat", "type": "boolean", "optional": true }
            ]
        },
        {
            "id": "Canvas",
            "type": "object",
            "description": "Information about a canvas for which a rendering context has been created.",
            "properties": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Canvas identifier." },
                { "name": "contextType", "$ref": "ContextType", "description": "The type of rendering context backing the canvas." },
                { "name": "nodeId", "$ref": "DOM.NodeId", "optional": true, "description": "The corresponding DOM node id." },
                { "name": "cssCanvasName", "type": "string", "optional": true, "description": "The CSS canvas identifier, for canvases created with <code>document.getCSSCanvasContext</code>." },
                { "name": "contextAttributes", "$ref": "ContextAttributes", "optional": true, "description": "Context attributes for rendering contexts." },
                { "name": "memoryCost", "type": "number", "optional": true, "description": "Memory usage of the canvas in bytes." },
                { "name": "backtrace", "type": "array", "items": { "$ref": "Console.CallFrame" }, "optional": true, "description": "Backtrace that was captured when this canvas context was created." }
            ]
        }
    ],
    "commands": [
        {
            "name": "enable",
            "description": "Enables Canvas domain events."
        },
        {
            "name": "disable",
            "description": "Disables Canvas domain events."
        },
        {
            "name": "requestNode",
            "description": "Gets the NodeId for the canvas node with the given CanvasId.",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Canvas identifier." }
            ],
            "returns": [
                { "name": "nodeId", "$ref": "DOM.NodeId", "description": "Node identifier for given canvas." }
            ]
        },
        {
            "name": "requestContent",
            "description": "Gets the data for the canvas node with the given CanvasId.",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Canvas identifier." }
            ],
            "returns": [
                { "name": "content", "type": "string", "description": "Base64-encoded data of the canvas' contents." }
            ]
        },
        {
            "name": "requestCSSCanvasClientNodes",
            "description": "Gets all the nodes that are using this canvas via -webkit-canvas.",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" }
            ],
            "returns": [
                { "name": "clientNodeIds", "type": "array", "items": { "$ref": "DOM.NodeId" } }
            ]
        },
        {
            "name": "resolveCanvasContext",
            "description": "Resolves JavaScript canvas context object for given canvasId.",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Canvas identifier." },
                { "name": "objectGroup", "type": "string", "optional": true, "description": "Symbolic group name that can be used to release multiple objects." }
            ],
            "returns": [
                { "name": "object", "$ref": "Runtime.RemoteObject", "description": "JavaScript object wrapper for given canvas context." }
            ]
        },
        {
            "name": "setRecordingAutoCaptureFrameCount",
            "description": "Tells the backend to record `count` frames whenever a new context is created.",
            "parameters": [
                { "name": "count", "type": "integer", "description": "Number of frames to record (0 means don't record anything)." }
            ]
        },
        {
            "name": "startRecording",
            "description": "Record the next frame, or up to the given number of bytes of data, for the given canvas.",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" },
                { "name": "frameCount", "type": "integer", "optional": true, "description": "Number of frames to record (unlimited when not specified)." },
                { "name": "memoryLimit", "type": "integer", "optional": true, "description": "Memory limit of recorded data (100MB when not specified)." }
            ]
        },
        {
            "name": "stopRecording",
            "description": "Stop recording the given canvas.",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" }
            ]
        },
        {
            "name": "requestShaderSource",
            "description": "Requests the source of the shader of the given type from the program with the given id.",
            "parameters": [
                { "name": "programId", "$ref": "ProgramId" },
                { "name": "shaderType", "$ref": "ShaderType" }
            ],
            "returns": [
                { "name": "content", "type": "string" }
            ]
        },
        {
            "name": "updateShader",
            "description": "Compiles and links the shader with identifier and type with the given source code.",
            "parameters": [
                { "name": "programId", "$ref": "ProgramId" },
                { "name": "shaderType", "$ref": "ShaderType" },
                { "name": "source", "type": "string" }
            ]
        },
        {
            "name": "setShaderProgramDisabled",
            "description": "Enable/disable the visibility of the given shader program.",
            "parameters": [
                { "name": "programId", "$ref": "ProgramId" },
                { "name": "disabled", "type": "boolean" }
            ]
        },
        {
            "name": "setShaderProgramHighlighted",
            "description": "Enable/disable highlighting of the given shader program.",
            "parameters": [
                { "name": "programId", "$ref": "ProgramId" },
                { "name": "highlighted", "type": "boolean" }
            ]
        }
    ],
    "events": [
        {
            "name": "canvasAdded",
            "parameters": [
                { "name": "canvas", "$ref": "Canvas", "description": "Canvas object." }
            ]
        },
        {
            "name": "canvasRemoved",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Removed canvas identifier." }
            ]
        },
        {
            "name": "canvasMemoryChanged",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Identifier of canvas that changed." },
                { "name": "memoryCost", "type": "number", "description": "New memory cost value for the canvas in bytes." }
            ]
        },
        {
            "name": "extensionEnabled",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" },
                { "name": "extension", "type": "string", "description": "Name of the extension that was enabled." }
            ]
        },
        {
            "name": "cssCanvasClientNodesChanged",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Identifier of canvas that changed." }
            ]
        },
        {
            "name": "recordingStarted",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" },
                { "name": "initiator", "$ref": "Recording.Initiator" }
            ]
        },
        {
            "name": "recordingProgress",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" },
                { "name": "frames", "type": "array", "items": { "$ref": "Recording.Frame" }},
                { "name": "bufferUsed", "type": "integer", "description": "Total memory size in bytes of all data recorded since the recording began." }
            ]
        },
        {
            "name": "recordingFinished",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId" },
                { "name": "recording", "$ref": "Recording.Recording", "optional": true }
            ]
        },
        {
            "name": "programCreated",
            "parameters": [
                { "name": "canvasId", "$ref": "CanvasId", "description": "Canvas identifier." },
                { "name": "programId", "$ref": "ProgramId", "description": "Program identifier." }
            ]
        },
        {
            "name": "programDeleted",
            "parameters": [
                { "name": "programId", "$ref": "ProgramId", "description": "Program identifier." }
            ]
        }
    ]
}