Add sample extension that allows setting plugin-specific content settings.

chrome/common/extensions/docs/examples/extensions/plugin_settings/domui/js/cr/ui/list_single_selection_model.js

Index: chrome/common/extensions/docs/examples/extensions/plugin_settings/domui/js/cr/ui/list_single_selection_model.js
diff --git a/chrome/common/extensions/docs/examples/extensions/plugin_settings/domui/js/cr/ui/list_single_selection_model.js b/chrome/common/extensions/docs/examples/extensions/plugin_settings/domui/js/cr/ui/list_single_selection_model.js
new file mode 100644
index 0000000000000000000000000000000000000000..2cf43a92ca9b9c88dc1759590cde51313316eb6a
--- /dev/null
+++ b/chrome/common/extensions/docs/examples/extensions/plugin_settings/domui/js/cr/ui/list_single_selection_model.js
@@ -0,0 +1,221 @@
+// Copyright (c) 2011 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.
+
+cr.define('cr.ui', function() {
+  const Event = cr.Event;
+  const EventTarget = cr.EventTarget;
+
+  /**
+   * Creates a new selection model that is to be used with lists. This only
+   * allows a single index to be selected.
+   *
+   * @param {number=} opt_length The number items in the selection.
+   *
+   * @constructor
+   * @extends {!cr.EventTarget}
+   */
+  function ListSingleSelectionModel(opt_length) {
+    this.length_ = opt_length || 0;
+    this.selectedIndex = -1;
+  }
+
+  ListSingleSelectionModel.prototype = {
+    __proto__: EventTarget.prototype,
+
+    /**
+     * The number of items in the model.
+     * @type {number}
+     */
+    get length() {
+      return this.length_;
+    },
+
+    /**
+     * @type {!Array} The selected indexes.
+     */
+    get selectedIndexes() {
+      var i = this.selectedIndex;
+      return i != -1 ? [this.selectedIndex] : [];
+    },
+
+    /**
+     * Convenience getter which returns the first selected index.
+     * @type {number}
+     */
+    get selectedIndex() {
+      return this.selectedIndex_;
+    },
+    set selectedIndex(selectedIndex) {
+      var oldSelectedIndex = this.selectedIndex;
+      var i = Math.max(-1, Math.min(this.length_ - 1, selectedIndex));
+
+      if (i != oldSelectedIndex) {
+        this.beginChange();
+        this.selectedIndex_ = i
+        this.endChange();
+      }
+    },
+
+    /**
+     * Selects a range of indexes, starting with {@code start} and ends with
+     * {@code end}.
+     * @param {number} start The first index to select.
+     * @param {number} end The last index to select.
+     */
+    selectRange: function(start, end) {
+      // Only select first index.
+      this.selectedIndex = Math.min(start, end);
+    },
+
+    /**
+     * Selects all indexes.
+     */
+    selectAll: function() {
+      // Select all is not allowed on a single selection model
+    },
+
+    /**
+     * Clears the selection
+     */
+    clear: function() {
+      this.beginChange();
+      this.length_ = 0;
+      this.selectedIndex = this.anchorIndex = this.leadIndex = -1;
+      this.endChange();
+    },
+
+    /**
+     * Unselects all selected items.
+     */
+    unselectAll: function() {
+      this.selectedIndex = -1;
+    },
+
+    /**
+     * Sets the selected state for an index.
+     * @param {number} index The index to set the selected state for.
+     * @param {boolean} b Whether to select the index or not.
+     */
+    setIndexSelected: function(index, b) {
+      // Only allow selection
+      var oldSelected = index == this.selectedIndex_;
+      if (oldSelected == b)
+        return;
+
+      if (b)
+        this.selectedIndex = index;
+      else if (index == this.selectedIndex_)
+        this.selectedIndex = -1;
+    },
+
+    /**
+     * Whether a given index is selected or not.
+     * @param {number} index The index to check.
+     * @return {boolean} Whether an index is selected.
+     */
+    getIndexSelected: function(index) {
+      return index == this.selectedIndex_;
+    },
+
+    /**
+     * This is used to begin batching changes. Call {@code endChange} when you
+     * are done making changes.
+     */
+    beginChange: function() {
+      if (!this.changeCount_) {
+        this.changeCount_ = 0;
+        this.selectedIndexBefore_ = this.selectedIndex_;
+      }
+      this.changeCount_++;
+    },
+
+    /**
+     * Call this after changes are done and it will dispatch a change event if
+     * any changes were actually done.
+     */
+    endChange: function() {
+      this.changeCount_--;
+      if (!this.changeCount_) {
+        if (this.selectedIndexBefore_ != this.selectedIndex_) {
+          var e = new Event('change');
+          var indexes = [this.selectedIndexBefore_, this.selectedIndex_];
+          e.changes = indexes.filter(function(index) {
+            return index != -1;
+          }).map(function(index) {
+            return {
+              index: index,
+              selected: index == this.selectedIndex_
+            };
+          }, this);
+          this.dispatchEvent(e);
+        }
+      }
+    },
+
+    leadIndex_: -1,
+
+    /**
+     * The leadIndex is used with multiple selection and it is the index that
+     * the user is moving using the arrow keys.
+     * @type {number}
+     */
+    get leadIndex() {
+      return this.leadIndex_;
+    },
+    set leadIndex(leadIndex) {
+      var li = Math.max(-1, Math.min(this.length_ - 1, leadIndex));
+      if (li != this.leadIndex_) {
+        var oldLeadIndex = this.leadIndex_;
+        this.leadIndex_ = li;
+        cr.dispatchPropertyChange(this, 'leadIndex', li, oldLeadIndex);
+        cr.dispatchPropertyChange(this, 'anchorIndex', li, oldLeadIndex);
+      }
+    },
+
+    /**
+     * The anchorIndex is used with multiple selection.
+     * @type {number}
+     */
+    get anchorIndex() {
+      return this.leadIndex;
+    },
+    set anchorIndex(anchorIndex) {
+      this.leadIndex = anchorIndex;
+    },
+
+    /**
+     * Whether the selection model supports multiple selected items.
+     * @type {boolean}
+     */
+    get multiple() {
+      return false;
+    },
+
+    /**
+     * Adjusts the selection after reordering of items in the table.
+     * @param {!Array.<number>} permutation The reordering permutation.
+     */
+    adjustToReordering: function(permutation) {
+      if (this.leadIndex != -1)
+        this.leadIndex = permutation[this.leadIndex];
+
+      var oldSelectedIndex = this.selectedIndex;
+      if (oldSelectedIndex != -1) {
+        this.selectedIndex = permutation[oldSelectedIndex];
+      }
+    },
+
+    /**
+     * Adjusts selection model length.
+     * @param {number} length New selection model length.
+     */
+    adjustLength: function(length) {
+      this.length_ = length;
+    }
+  };
+
+  return {
+    ListSingleSelectionModel: ListSingleSelectionModel
+  };
+});