md-settings: Added settings for fingerprint unlock.

chrome/browser/resources/settings/people_page/fingerprint_list.js

+// Copyright 2016 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.
+
+/**
+ * @fileoverview
+ * Polymer element for displaying a list of fingerprints.
+ *
+ * Example:
+ *    <settings-fingerprint-list></settings-fingerprint-list>

[Dan Beam, 2016/12/13 19:53:23]

can you drop this @fileoverview?  we decided these don't really add much value
and are just fluff

[sammiequon, 2016/12/13 23:33:34]

Done.

+ */
+

[Dan Beam, 2016/12/13 19:53:24]

if we stick with the object wrapper with a name key:

/** @typedef {{name: string}} */
var Fingerprint;

or

cr.exportPath('settings');

/** @typedef {{name: string}} */
settings.Fingerprint;

[sammiequon, 2016/12/13 23:33:33]

Changed to array of string.

+(function() {
+'use strict';
+
+/**
+ * The max number of fingerprints this list can hold.
+ * @type {number}
+ * @const

[Dan Beam, 2016/12/13 19:53:24]

nit: @const {number} or just @const

[sammiequon, 2016/12/13 23:33:34]

Done.

+ */
+var MAX_NUMBER_FINGERPRINTS_ALLOWED = 5;
+
+Polymer({
+  is: 'settings-fingerprint-list',
+
+  behaviors: [
+    I18nBehavior,
+  ],
+
+  properties: {
+    /**
+     * The list of fingerprint objects.
+     * @private {Array<Object>}

[Dan Beam, 2016/12/13 19:53:24]

!Array<!Fingerprint>

[sammiequon, 2016/12/13 23:33:34]

Done.

+     */
+    fingerprints_: {
+      type: Array,
+      value: function() {
+        return [];
+      },
+      notify: true

[Dan Beam, 2016/12/13 19:53:24]

why do you need this notify true?  it seems like you're using .push() and
.splice() so that should be notifying for you...

[sammiequon, 2016/12/13 23:33:34]

Done.

+    }
+  },
+
+  /**
+   * Check if |fingerprints_| has a fingerprint with name |name|.
+   * @param {string} name The name we are looking for.
+   * @return {boolean}
+   * @private
+   */
+  isNameUsed_: function(name) {
+    return !!this.fingerprints_.find(function(e) {
+      return e.name == name;
+    });
+  },
+
+  /**
+   * Adds a fingerprint with a default name.
+   * @private
+   */
+  onAddFingerprint_: function() {
+    // Determines what the newly added fingerprint's name should be.
+    // TODO(sammiequon): Add fingerprint using private API once it is ready.
+
+    var fingerprintName;
+    for (var i = 1; i <= MAX_NUMBER_FINGERPRINTS_ALLOWED; ++i) {
+      fingerprintName = this.i18n('lockScreenFingerprintNewName', i);
+      if (this.isNameUsed_(fingerprintName))
+        continue;
+      break;
+    }
+    this.push('fingerprints_', { 'name': fingerprintName });

[Dan Beam, 2016/12/13 19:53:23]

this.push('fingerprints_', {'name': fingerprintName});

(no spaces around curlies)

[Dan Beam, 2016/12/13 19:53:24]

wait, why are you using {name: <string>} as the item template?  and not just ...
<string>?

[sammiequon, 2016/12/13 23:33:34]

Done.

[sammiequon, 2016/12/13 23:33:34]

Done.

+    this.$.fingerprintsList.fire('iron-resize');

[Dan Beam, 2016/12/13 19:53:24]

nit: notifyResize() instead of fire('iron-resize')

[sammiequon, 2016/12/13 23:33:34]

Done.

+  },
+
+  /**
+   * Deletes a fingerprint from |fingerprints_|.
+   * @private
+   */
+  onFingerprintDelete_: function(e) {
+    // TODO(sammiequon): Remove fingerprint using private API once it is ready.
+    this.splice('fingerprints_', e.model.index, 1);
+    this.$.fingerprintsList.fire('iron-resize');
+  },
+
+  /**
+   * Returns the text to be displayed for the add fingerprint button.

[Dan Beam, 2016/12/13 19:53:24]

@param

[sammiequon, 2016/12/13 23:33:34]

Done.

+   * @return {string}
+   * @private
+   */
+  getFingerprintButtonText_: function(length) {

[Dan Beam, 2016/12/13 19:53:24]

can you name this argument something other than "length"?  it kind of already
exists. 
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Obje...

[sammiequon, 2016/12/13 23:33:34]

Done.

+    if (this.canAddNewFingerprint_(length))
+      return this.i18n('lockScreenAddFingerprint');
+
+    return this.i18n('lockScreenCannotAddFingerprint',
+                     MAX_NUMBER_FINGERPRINTS_ALLOWED);
+  },
+
+  /**
+   * Checks whether another fingerprint can be added.

[Dan Beam, 2016/12/13 19:53:24]

@param

[sammiequon, 2016/12/13 23:33:34]

Done.

+   * @return {boolean}
+   * @private
+   */
+  canAddNewFingerprint_: function(length) {
+    return length < MAX_NUMBER_FINGERPRINTS_ALLOWED;
+  }
+});
+})();