gecko-dev/devtools/shared/fronts/canvas.js

92 строки
2.7 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const {
frameSnapshotSpec,
canvasSpec,
CANVAS_CONTEXTS,
ANIMATION_GENERATORS,
LOOP_GENERATORS,
DRAW_CALLS,
INTERESTING_CALLS,
} = require("devtools/shared/specs/canvas");
const protocol = require("devtools/shared/protocol");
const promise = require("promise");
/**
* The corresponding Front object for the FrameSnapshotActor.
*/
const FrameSnapshotFront = protocol.FrontClassWithSpec(frameSnapshotSpec, {
initialize: function (client, form) {
protocol.Front.prototype.initialize.call(this, client, form);
this._animationFrameEndScreenshot = null;
this._cachedScreenshots = new WeakMap();
},
/**
* This implementation caches the animation frame end screenshot to optimize
* frontend requests to `generateScreenshotFor`.
*/
getOverview: protocol.custom(function () {
return this._getOverview().then(data => {
this._animationFrameEndScreenshot = data.screenshot;
return data;
});
}, {
impl: "_getOverview"
}),
/**
* This implementation saves a roundtrip to the backend if the screenshot
* was already generated and retrieved once.
*/
generateScreenshotFor: protocol.custom(function (functionCall) {
if (CanvasFront.ANIMATION_GENERATORS.has(functionCall.name) ||
CanvasFront.LOOP_GENERATORS.has(functionCall.name)) {
return promise.resolve(this._animationFrameEndScreenshot);
}
let cachedScreenshot = this._cachedScreenshots.get(functionCall);
if (cachedScreenshot) {
return cachedScreenshot;
}
let screenshot = this._generateScreenshotFor(functionCall);
this._cachedScreenshots.set(functionCall, screenshot);
return screenshot;
}, {
impl: "_generateScreenshotFor"
})
});
exports.FrameSnapshotFront = FrameSnapshotFront;
/**
* The corresponding Front object for the CanvasActor.
*/
const CanvasFront = protocol.FrontClassWithSpec(canvasSpec, {
initialize: function (client, { canvasActor }) {
protocol.Front.prototype.initialize.call(this, client, { actor: canvasActor });
this.manage(this);
}
});
/**
* Constants.
*/
CanvasFront.CANVAS_CONTEXTS = new Set(CANVAS_CONTEXTS);
CanvasFront.ANIMATION_GENERATORS = new Set(ANIMATION_GENERATORS);
CanvasFront.LOOP_GENERATORS = new Set(LOOP_GENERATORS);
CanvasFront.DRAW_CALLS = new Set(DRAW_CALLS);
CanvasFront.INTERESTING_CALLS = new Set(INTERESTING_CALLS);
CanvasFront.THUMBNAIL_SIZE = 50;
CanvasFront.WEBGL_SCREENSHOT_MAX_HEIGHT = 256;
CanvasFront.INVALID_SNAPSHOT_IMAGE = {
index: -1,
width: 0,
height: 0,
pixels: []
};
exports.CanvasFront = CanvasFront;