Bug 1468754 Part 1: Add a ChangesActor to devtools. r=pbro

MozReview-Commit-ID: 1Y8esljnLk9

Differential Revision: https://phabricator.services.mozilla.com/D4399

--HG--
extra : moz-landing-system : lando

devtools/server/actors/changes.js

@@ -0,0 +1,70 @@
+/* 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 protocol = require("devtools/shared/protocol");
+const { changesSpec } = require("devtools/shared/specs/changes");
+const TrackChangeEmitter = require("devtools/server/actors/utils/track-change-emitter");
+
+/**
+ * The ChangesActor stores a stack of changes made by devtools on
+ * the document in the associated tab.
+ */
+const ChangesActor = protocol.ActorClassWithSpec(changesSpec, {
+  /**
+   * Create a ChangesActor.
+   *
+   * @param {DebuggerServerConnection} conn
+   *    The server connection.
+   * @param {TargetActor} targetActor
+   *    The top-level Actor for this tab.
+   */
+  initialize: function(conn, targetActor) {
+    protocol.Actor.prototype.initialize.call(this, conn);
+    this.targetActor = targetActor;
+
+    this.onTrackChange = this.pushChange.bind(this);
+    TrackChangeEmitter.on("track-change", this.onTrackChange);
+
+    this.changes = [];
+  },
+
+  destroy: function() {
+    this.clearChanges();
+    TrackChangeEmitter.off("track-change", this.onTrackChange);
+    protocol.Actor.prototype.destroy.call(this);
+  },
+
+  changeCount: function() {
+    return this.changes.length;
+  },
+
+  change: function(index) {
+    if (index >= 0 && index < this.changes.length) {
+      // Return a copy of the change at index.
+      return Object.assign({}, this.changes[index]);
+    }
+    // No change at that index -- return undefined.
+    return undefined;
+  },
+
+  allChanges: function() {
+    return this.changes.slice();
+  },
+
+  pushChange: function(change) {
+    this.changes.push(change);
+  },
+
+  popChange: function() {
+    return this.changes.pop();
+  },
+
+  clearChanges: function() {
+    this.changes.length = 0;
+  },
+});
+
+exports.ChangesActor = ChangesActor;

devtools/server/actors/moz.build

@@ -28,6 +28,7 @@ DevToolsModules(
     'array-buffer.js',
     'breakpoint.js',
     'canvas.js',
+    'changes.js',
     'common.js',
     'css-properties.js',
     'csscoverage.js',

devtools/server/actors/utils/actor-registry.js

@@ -256,6 +256,11 @@ const ActorRegistry = {
       constructor: "ScreenshotActor",
       type: { target: true },
     });
+    this.registerModule("devtools/server/actors/changes", {
+      prefix: "changes",
+      constructor: "ChangesActor",
+      type: { target: true }
+    });
   },
 
   /**

devtools/shared/fronts/changes.js

@@ -0,0 +1,24 @@
+/* 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 protocol = require("devtools/shared/protocol");
+const {changesSpec} = require("devtools/shared/specs/changes");
+
+/**
+ * ChangesFront, the front object for the ChangesActor
+ */
+const ChangesFront = protocol.FrontClassWithSpec(changesSpec, {
+  initialize: function (client, {changesActor}) {
+    protocol.Front.prototype.initialize.call(this, client, {actor: changesActor});
+    this.manage(this);
+  },
+
+  destroy: function() {
+    protocol.Front.prototype.destroy.call(this);
+  },
+});
+
+exports.ChangesFront = ChangesFront;

devtools/shared/fronts/moz.build

@@ -14,6 +14,7 @@ DevToolsModules(
     'actor-registry.js',
     'animation.js',
     'canvas.js',
+    'changes.js',
     'css-properties.js',
     'csscoverage.js',
     'device.js',

devtools/shared/specs/changes.js

@@ -0,0 +1,24 @@
+/* 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 {
+  generateActorSpec,
+  RetVal,
+} = require("devtools/shared/protocol");
+
+const changesSpec = generateActorSpec({
+  typeName: "changes",
+
+  methods: {
+    "allChanges": {
+      response: {
+        changes: RetVal("array:json"),
+      },
+    },
+  },
+});
+
+exports.changesSpec = changesSpec;

devtools/shared/specs/index.js

@@ -219,6 +219,11 @@ const Types = exports.__TypesForTests = [
     spec: "devtools/shared/specs/styles",
     front: "devtools/shared/fronts/styles",
   },
+  {
+    types: ["changes"],
+    spec: "devtools/shared/specs/changes",
+    front: "devtools/shared/fronts/changes",
+  },
   {
     types: ["mediarule", "stylesheet", "stylesheets"],
     spec: "devtools/shared/specs/stylesheets",

devtools/shared/specs/moz.build

@@ -16,6 +16,7 @@ DevToolsModules(
     'animation.js',
     'breakpoint.js',
     'canvas.js',
+    'changes.js',
     'css-properties.js',
     'csscoverage.js',
     'device.js',