Add a settings screen that lets the user choose how they unlock their device.

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

Index: chrome/browser/resources/settings/people_page/quick_unlock_choose_method.js
diff --git a/chrome/browser/resources/settings/people_page/quick_unlock_choose_method.js b/chrome/browser/resources/settings/people_page/quick_unlock_choose_method.js
new file mode 100644
index 0000000000000000000000000000000000000000..db0a57993622827f94dbf33c74d096ee2db6ca6b
--- /dev/null
+++ b/chrome/browser/resources/settings/people_page/quick_unlock_choose_method.js
@@ -0,0 +1,183 @@
+// 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
+ * 'settings-quick-unlock-choose-method' allows the user to change how they
+ * unlock their device. Note that setting up the unlock method is delegated
+ * to other elements.
+ *
+ * Example:
+ *
+ * <settings-quick-unlock-choose-method
+ *   set-modes="[[quickUnlockSetModes]]"
+ *   current-route="{{currentRoute}}"
+ *   prefs="{{prefs}}">
+ * </settings-quick-unlock-choose-method>
+ */
+
+(function() {
+'use strict';
+
+/** @const */ var ENABLE_LOCK_SCREEN_PREF = 'settings.enable_screen_lock';
+
+/** @enum {string} */
+var QuickUnlockUnlockType = {
+  VALUE_PENDING: 'value_pending',
+  NONE: 'none',
+  PASSWORD: 'password',
+  PIN_PASSWORD: 'pin+password'
+};
+
+Polymer({
+  is: 'settings-quick-unlock-choose-method',
+
+  behaviors: [
+    PrefsBehavior, QuickUnlockPasswordDetectBehavior
+  ],
+
+  properties: {
+    /** Preferences state. */
+    prefs: {
+      type: Object,
+      notify: true,
+    },
+
+    /**
+     * The currently selected unlock type.
+     * @type {!QuickUnlockUnlockType}
+     * @private
+     */
+    selectedUnlockType_: {
+      type: String,
+      notify: true,
+      value: QuickUnlockUnlockType.VALUE_PENDING,
+      observer: 'selectedUnlockTypeChanged_'
+    }
+  },
+
+  observers: [
+    'onRouteChanged_(currentRoute)',
+    'onSetModesChanged_(setModes)'
+  ],
+
+  /** @override */
+  attached: function() {
+    CrSettingsPrefs.initialized.then(this.updateUnlockType_.bind(this));
+
+    this.boundOnPrefsChanged_ = function(prefs) {
+      for (var i = 0; i < prefs.length; ++i) {
+        if (prefs[i].key == ENABLE_LOCK_SCREEN_PREF)
+          this.updateUnlockType_();
+      }
+    }.bind(this);
+    this.boundOnActiveModesChanged_ = this.updateUnlockType_.bind(this);
+
+    chrome.settingsPrivate.onPrefsChanged.addListener(
+        this.boundOnPrefsChanged_);
+    chrome.quickUnlockPrivate.onActiveModesChanged.addListener(
+        this.boundOnActiveModesChanged_);
+
+    this.askForPasswordIfUnset();
+  },
+
+  /** @override */
+  detached: function() {
+    chrome.settingsPrivate.onPrefsChanged.removeListener(
+        this.boundOnPrefsChanged_);
+    chrome.quickUnlockPrivate.onActiveModesChanged.removeListener(
+        this.boundOnActiveModesChanged_);
+  },
+
+  /** @private */
+  onRouteChanged_: function() {
+    if (this.isScreenActive(QuickUnlockScreen.CHOOSE_METHOD))
+      this.askForPasswordIfUnset();
+  },
+
+  /** @private */
+  onSetModesChanged_: function() {
+    if (this.isScreenActive(QuickUnlockScreen.CHOOSE_METHOD))
+      this.askForPasswordIfUnset();
+  },
+
+  /**
+   * Updates the selected unlock type radio group. This function will get called
+   * after preferences are initialized, after the quick unlock mode has been
+   * changed, and after the lockscreen preference has changed.
+   *
+   * @private
+   */
+  updateUnlockType_: function() {
+    // The quickUnlockPrivate.onActiveModesChanged event could trigger this
+    // function before CrSettingsPrefs is initialized if another settings page
+    // changes the quick unlock state.
+    if (!CrSettingsPrefs.isInitialized)
+      return;
+
+    if (!this.getPref(ENABLE_LOCK_SCREEN_PREF).value) {
+      this.selectedUnlockType_ = QuickUnlockUnlockType.NONE;
+      return;
+    }
+
+    chrome.quickUnlockPrivate.getActiveModes(function(modes) {
+      if (modes.includes(chrome.quickUnlockPrivate.QuickUnlockMode.PIN)) {
+        this.selectedUnlockType_ = QuickUnlockUnlockType.PIN_PASSWORD;
+      } else if (this.selectedUnlockType_ !=
+                 QuickUnlockUnlockType.PIN_PASSWORD) {
+        // We don't want to clobber an existing PIN+PASSWORD state because the
+        // user needs to configure that option before actually using it.
+        //
+        // Specifically, this check is needed because this function gets called
+        // by the pref system after changing the unlock type from NONE to
+        // PIN+PASSWORD. Without the conditional assignment, this function would
+        // change the PIN+PASSWORD lock type to PASSWORD because the PIN hasn't
+        // been configured yet.
+        this.selectedUnlockType_ = QuickUnlockUnlockType.PASSWORD;
+      }
+    }.bind(this));
+  },
+
+  /**
+   * Called when the unlock type has changed.
+   * @param {!string} selected The current unlock type.
+   * @param {?string} previous The old unlock type. undefined if not present.
+   * @private
+   */
+  selectedUnlockTypeChanged_: function(selected, previous) {
+    // This method gets invoked when setting the initial value from the existing
+    // state. In that case, we don't need to bother updating the prefs.
+    if (!previous)
+      return;
+
+    this.setPrefValue(ENABLE_LOCK_SCREEN_PREF,
+                      selected != QuickUnlockUnlockType.NONE);
+    if (selected != QuickUnlockUnlockType.PIN_PASSWORD && this.setModes) {
+      this.setModes.call(null, [], [], function(didSet) {
+        assert(didSet, 'Failed to clear quick unlock modes');
+      });
+    }
+  },
+
+  /**
+   * Retruns true if the setup pin section should be shown.
+   * @param {!string} selectedUnlockType The current unlock type. Used to let
+   * polymer know about the dependency.
+   * @private
+   */
+  showSetupPin_: function(selectedUnlockType) {
+    return selectedUnlockType === QuickUnlockUnlockType.PIN_PASSWORD;
+  },
+
+  /** @private */
+  onConfigurePin_: function() {
+    this.currentRoute = {
+      page: 'basic',
+      section: 'people',
+      subpage: [QuickUnlockScreen.CHOOSE_METHOD, QuickUnlockScreen.SETUP_PIN]
+    };
+  },
+});
+
+})();