Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components-chromium/iron-behaviors/iron-control-state-extracted.js

+
+
+  Polymer.IronControlState = {
+
+    properties: {
+
+      /**
+       * If true, the element currently has focus.
+       *
+       * @attribute focused
+       * @type boolean
+       * @default false
+       */
+      focused: {
+        type: Boolean,
+        value: false,
+        notify: true,
+        readOnly: true,
+        reflectToAttribute: true
+      },
+
+      /**
+       * If true, the user cannot interact with this element.
+       *
+       * @attribute disabled
+       * @type boolean
+       * @default false
+       */
+      disabled: {
+        type: Boolean,
+        value: false,
+        notify: true,
+        observer: '_disabledChanged',
+        reflectToAttribute: true
+      },
+
+      _oldTabIndex: {
+        type: String
+      }
+    },
+
+    observers: [
+      '_changedControlState(focused, disabled)'
+    ],
+
+    listeners: {
+      focus: '_focusHandler',
+      blur: '_blurHandler'
+    },
+
+    ready: function() {
+      // TODO(sjmiles): ensure read-only property is valued so the compound
+      // observer will fire
+      if (this.focused === undefined) {
+        this._setFocused(false);
+      }
+    },
+
+    _focusHandler: function() {
+      this._setFocused(true);
+    },
+
+    _blurHandler: function() {
+      this._setFocused(false);
+    },
+
+    _disabledChanged: function(disabled, old) {
+      this.setAttribute('aria-disabled', disabled ? 'true' : 'false');
+      this.style.pointerEvents = disabled ? 'none' : '';
+      if (disabled) {
+        this._oldTabIndex = this.tabIndex;
+        this.focused = false;
+        this.tabIndex = -1;
+      } else if (this._oldTabIndex !== undefined) {
+        this.tabIndex = this._oldTabIndex;
+      }
+    },
+
+    _changedControlState: function() {
+      // _controlStateChanged is abstract, follow-on behaviors may implement it
+      if (this._controlStateChanged) {
+        this._controlStateChanged();
+      }
+    }
+
+  };
+