1 files changed, 162 insertions, 0 deletions
diff --git a/devtools/client/performance/panel.js b/devtools/client/performance/panel.js
new file mode 100644
index 0000000000..28fef793f0
--- /dev/null
+++ b/devtools/client/performance/panel.js
@@ -0,0 +1,162 @@
+/* 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";
+
+loader.lazyRequireGetter(this, "EventEmitter", "devtools/shared/event-emitter");
+
+function PerformancePanel(iframeWindow, toolbox) {
+  this.panelWin = iframeWindow;
+  this.toolbox = toolbox;
+  this._targetAvailablePromise = Promise.resolve();
+
+  this._onTargetAvailable = this._onTargetAvailable.bind(this);
+
+  EventEmitter.decorate(this);
+}
+
+exports.PerformancePanel = PerformancePanel;
+
+PerformancePanel.prototype = {
+  /**
+   * Open is effectively an asynchronous constructor.
+   *
+   * @return object
+   *         A promise that is resolved when the Performance tool
+   *         completes opening.
+   */
+  async open() {
+    if (this._opening) {
+      return this._opening;
+    }
+
+    this._checkRecordingStatus = this._checkRecordingStatus.bind(this);
+
+    const { PerformanceController, EVENTS } = this.panelWin;
+    PerformanceController.on(
+      EVENTS.RECORDING_ADDED,
+      this._checkRecordingStatus
+    );
+    PerformanceController.on(
+      EVENTS.RECORDING_STATE_CHANGE,
+      this._checkRecordingStatus
+    );
+
+    // In case that the target is switched across process, the corresponding front also
+    // will be changed. In order to detect that, watch the change.
+    // Also, we wait for `watchTargets` to end. Indeed the function `_onTargetAvailable
+    // will be called synchronously with current target as a parameter by
+    // the `watchTargets` function.
+    // So this `await` waits for initialization with current target, happening
+    // in `_onTargetAvailable`.
+    await this.toolbox.targetList.watchTargets(
+      [this.toolbox.targetList.TYPES.FRAME],
+      this._onTargetAvailable
+    );
+
+    // Fire this once incase we have an in-progress recording (console profile)
+    // that caused this start up, and no state change yet, so we can highlight the
+    // tab if we need.
+    this._checkRecordingStatus();
+
+    this.isReady = true;
+    this.emit("ready");
+
+    this._opening = new Promise(resolve => {
+      resolve(this);
+    });
+    return this._opening;
+  },
+
+  // DevToolPanel API
+
+  get target() {
+    return this.toolbox.target;
+  },
+
+  async destroy() {
+    // Make sure this panel is not already destroyed.
+    if (this._destroyed) {
+      return;
+    }
+
+    const { PerformanceController, PerformanceView, EVENTS } = this.panelWin;
+    PerformanceController.off(
+      EVENTS.RECORDING_ADDED,
+      this._checkRecordingStatus
+    );
+    PerformanceController.off(
+      EVENTS.RECORDING_STATE_CHANGE,
+      this._checkRecordingStatus
+    );
+
+    this.toolbox.targetList.unwatchTargets(
+      [this.toolbox.targetList.TYPES.FRAME],
+      this._onTargetAvailable
+    );
+    await PerformanceController.destroy();
+    await PerformanceView.destroy();
+    PerformanceController.disableFrontEventListeners();
+
+    this.emit("destroyed");
+    this._destroyed = true;
+  },
+
+  _checkRecordingStatus: function() {
+    if (this.panelWin.PerformanceController.isRecording()) {
+      this.toolbox.highlightTool("performance");
+    } else {
+      this.toolbox.unhighlightTool("performance");
+    }
+  },
+
+  /**
+   * This function executes actual logic for the target-switching.
+   *
+   * @param {TargetFront} - targetFront
+   *        As we are watching only FRAME type for this panel,
+   *        the target should be a instance of BrowsingContextTarget.
+   */
+  async _handleTargetAvailable({ targetFront }) {
+    if (targetFront.isTopLevel) {
+      const { PerformanceController, PerformanceView } = this.panelWin;
+      const performanceFront = await targetFront.getFront("performance");
+
+      if (!this._isPanelInitialized) {
+        await PerformanceController.initialize(
+          this.toolbox,
+          targetFront,
+          performanceFront
+        );
+        await PerformanceView.initialize();
+        PerformanceController.enableFrontEventListeners();
+        this._isPanelInitialized = true;
+      } else {
+        const isRecording = PerformanceController.isRecording();
+        if (isRecording) {
+          await PerformanceController.stopRecording();
+        }
+
+        PerformanceView.resetBufferStatus();
+        PerformanceController.updateFronts(targetFront, performanceFront);
+
+        if (isRecording) {
+          await PerformanceController.startRecording();
+        }
+      }
+    }
+  },
+
+  /**
+   * This function is called for every target is available.
+   */
+  _onTargetAvailable(parameters) {
+    // As this function is called asynchronous, while previous processing, this might be
+    // called. Thus, we wait until finishing previous one before starting next.
+    this._targetAvailablePromise = this._targetAvailablePromise.then(() =>
+      this._handleTargetAvailable(parameters)
+    );
+
+    return this._targetAvailablePromise;
+  },
+};