Major revision of page cycler UI.

chrome/common/extensions/docs/examples/apps/cycler/playback_tab.js

+// Copyright (c) 2012 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.
+
+/**
+ * Constructor for the tab UI governing playback selection and running.
+ * All HTML controls under tag #plaback-tab, plus the tab label
+ * #playback-tab-label are controlled by this class.
+ * @param {!Object} cyclerUI  The master UI class, needed for global state
+ *     such as current capture name.
+ * @param {!Object} cyclerData  The local FileSystem-based database of
+ *     available captures to play back.
+ */
+var PlaybackTab = function (cyclerUI, cyclerData) {
+  /**
+   * Enum for different playback tab states.
+   * @enum {number}
+   * @private
+   */
+  var EnableState_ = {
+    choosePlayback: 1,  // Choose a playback, if none already chosen.
+    showPlayback: 2,  // Show currently chosen playback, and offer options.
+    showNoCaptures: 3  // Show message indicating no captures are available.
+  };
+
+  this.cyclerUI_ = cyclerUI;
+  this.cyclerData_ = cyclerData;
+
+  /**
+   * Create members for all UI elements with which we'll interact.
+   */
+  this.tabLabel_ = $('#playback-tab-label');
+  this.playbackTab_ = $('#playback-tab');
+  this.noCaptures_ = $('#no-captures');
+  this.yesCaptures_ = $('#have-captures');
+
+  this.playbackName_ = $('#playback-name');
+  this.playbackDetails_ = $('#playback-details');
+  this.playbackURLs_ = $('#playback-urls');
+  this.playbackRepeats_ = $('#playback-repeats');
+  this.playbackExtension_ = $('#playback-extension');
+  this.doPlaybackButton_ = $('#do-playback');
+  this.doDeleteButton_ = $('#do-delete');
+
+  /*
+   * Enable the playback tab, showing no current playback choice, by
+   * hiding the playbackDetails_ div.
+   * @private
+   */
+  this.enableChoosePlayback_ = function() {
+    if (this.enableState != EnableState_.choosePlayback) {
+      this.enableState = EnableState_.choosePlayback;
+      this.yesCaptures_.hidden = false;
+      this.noCaptures_.hidden = true;
+      this.playbackDetails_.hidden = true;
+    }
+  };
+
+  /*
+   * Enable the playback tab, showing a current playback choice by showing
+   * the playbackDetails_ div.
+   * @private
+   */
+  this.enableShowPlayback_ = function() {
+    if (this.enableState != EnableState_.showPlayback) {
+      this.enableState = EnableState_.showPlayback;
+      this.yesCaptures_.hidden = false;
+      this.noCaptures_.hidden = true;
+      this.playbackDetails_.hidden = false;
+    }
+  };
+
+  /*
+   * Enable the playback tab and adjust tab labels appropriately. Show
+   * no available captures by hiding the yesCaptures_ div and showing the
+   * noCaptures_ div instead.
+   * @private
+   */
+  this.enableShowNoCaptures_ = function() {
+    if (this.enableState != EnableState_.showNoCaptures) {
+      this.enableState = EnableState_.showNoCaptures;
+      this.noCaptures_.hidden = false;
+      this.yesCaptures_.hidden = true;
+    }
+  };
+
+  /**
+   * Enable the playback tab, showing either its "no captures", "choose
+   * a capture" or "display chosen capture" form, depending on the state
+   * of existing captures and |currentCaptureName_|.
+   */
+  this.enable = function() {
+    this.tabLabel_.classList.add('selected');
+    this.updatePlaybackChoices_();
+
+    this.playbackTab_.hidden = false;
+    if (this.cyclerData_.getCaptures().length == 0) {
+      this.enableShowNoCaptures_();
+    } else if (this.cyclerUI_.currentCaptureName == null) {
+      this.enableChoosePlayback_();
+    } else {
+      this.enableShowPlayback_();
+    }
+  }
+
+  /**
+   * Disable the playback tab altogether, presumably in favor of some
+   * other tab.
+   */
+  this.disable = function() {
+    this.tabLabel_.classList.remove('selected');
+    this.playbackTab_.hidden = true;
+  }
+
+  /**
+   * Utility function to refresh the selection list of captures that may
+   * be chosen for playback. Show all current captures, and also a
+   * "Choose a capture" default text if no capture is currently selected.
+   * @private
+   */
+  this.updatePlaybackChoices_ = function() {
+    var captureNames = this.cyclerData_.getCaptures();
+    var options = this.playbackName_.options;
+    var nextIndex = 0;
+    var chooseOption;
+
+    options.length = 0;
+
+    if (this.cyclerUI_.currentCaptureName == null) {
+      chooseOption = new Option('Choose a capture', null);
+      chooseOption.disabled = true;
+      options.add(chooseOption);
+      options.selectedIndex = nextIndex++;
+    }
+    for (var i = 0; i < captureNames.length; i++) {
+      options.add(new Option(captureNames[i], captureNames[i]));
+      if (captureNames[i] == this.cyclerUI_.currentCaptureName) {
+        options.selectedIndex = nextIndex;
+      }
+      nextIndex++;
+    }
+  }
+
+  /**
+   * Event callback for selection of a capture to play back. Save the
+   * choice in |currentCaptureName_|. Update the selection list because the
+   * default reminder message is no longer needed when a capture is chosen.
+   * Change playback tab to show-chosen-capture mode.
+   */
+  this.selectPlaybackName = function() {
+    this.cyclerUI_.currentCaptureName = this.playbackName_.value;
+    this.updatePlaybackChoices_();
+    this.enableShowPlayback_();
+  }
+
+  /**
+   * Event callback for pressing the playback button, which button is only
+   * enabled if a capture has been chosen for playback. Check for errors
+   * on playback page, and either display a message with such errors, or
+   * call the extenion api to initiate a playback.
+   * @private
+   */
+  this.doPlayback_ = function() {
+    var extensionPath = this.playbackExtension_.value;
+    var repeatCount = parseInt(this.playbackRepeats_.value);
+    var errors = [];
+
+    // Check local errors
+    if (isNaN(repeatCount)) {
+      errors.push('Enter a number for repeat count');
+    } else if (repeatCount < 1 || repeatCount > 100) {
+      errors.push('Repeat count must be between 1 and 100');
+    }
+
+    if (errors.length > 0) {
+      this.cyclerUI_.showMessage(errors.join('\n'), 'Ok');
+    } else {
+      this.doPlaybackButton_.disabled = true;
+      chrome.experimental.record.replayURLs(
+          this.cyclerUI_.currentCaptureName,
+          repeatCount,
+          {'extensionPath': extensionPath},
+          this.onPlaybackDone.bind(this));
+    }
+  }
+
+  /**
+   * Extension API calls this back when a playback is done.
+   * @param {!{
+   *   runTime: number,
+   *   stats: string,
+   *   errors: !Array.<string>
+   * }} results  The results of the playback, including running time in ms,
+   *     a string of statistics information, and a string array of errors.
+   */
+  this.onPlaybackDone = function(results) {
+    this.doPlaybackButton_.disabled = false;
+
+    if (results.errors.length > 0) {
+      this.cyclerUI_.showMessage(results.errors.join('\n'), 'Ok');
+    } else {
+      this.cyclerUI_.showMessage('Test took ' + results.runTime + 'mS :\n' +
+          results.stats, 'Ok');
+    }
+  }
+
+  /**
+   * Delete the capture with name |currentCaptureName_|. For this method
+   * to be callable, there must be a selected currentCaptureName_. Change
+   * the displayed HTML to show no captures if none exist now, or to show
+   * none selected (since we just deleted the selected one).
+   * @private
+   */
+  this.doDelete_ = function() {
+    this.cyclerData_.deleteCapture(this.cyclerUI_.currentCaptureName);
+    this.cyclerUI_.currentCaptureName = null;
+    this.updatePlaybackChoices_();
+    if (this.cyclerData_.getCaptures().length == 0) {
+      this.enableShowNoCaptures_();
+    } else {
+      this.enableChoosePlayback_();
+    }
+  }
+
+  // Set up listeners on buttons.
+  this.doPlaybackButton_.addEventListener('click', this.doPlayback_.bind(this));
+  this.doDeleteButton_.addEventListener('click', this.doDelete_.bind(this));
+
+  // Set up initial selection list for existing captures, and selection
+  // event listener.
+  this.updatePlaybackChoices_();
+  this.playbackName_.addEventListener('change',
+      this.selectPlaybackName.bind(this));
+};