polygerrit-ui/app/elements/shared/gr-button/gr-button.js

/**
 * @license
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
(function() {
  'use strict';

  Polymer({
    is: 'gr-button',

    properties: {
      tooltip: String,
      downArrow: {
        type: Boolean,
        reflectToAttribute: true,
      },
      link: {
        type: Boolean,
        value: false,
        reflectToAttribute: true,
      },
      loading: {
        type: Boolean,
        value: false,
        reflectToAttribute: true,
      },
      disabled: {
        type: Boolean,
        observer: '_disabledChanged',
        reflectToAttribute: true,
      },
      noUppercase: {
        type: Boolean,
        value: false,
      },
      _enabledTabindex: {
        type: String,
        value: '0',
      },
    },

    listeners: {
      tap: '_handleAction',
      click: '_handleAction',
      keydown: '_handleKeydown',
    },

    observers: [
      '_computeDisabled(disabled, loading)',
    ],

    behaviors: [
      Gerrit.KeyboardShortcutBehavior,
      Gerrit.TooltipBehavior,
    ],

    hostAttributes: {
      role: 'button',
      tabindex: '0',
    },

    _handleAction(e) {
      if (this.disabled) {
        e.preventDefault();
        e.stopImmediatePropagation();
      }
    },

    _disabledChanged(disabled) {
      if (disabled) {
        this._enabledTabindex = this.getAttribute('tabindex');
      }
      this.setAttribute('tabindex', disabled ? '-1' : this._enabledTabindex);
      this.updateStyles();
    },

    _computeDisabled(disabled, loading) {
      return disabled || loading;
    },

    _handleKeydown(e) {
      if (this.modifierPressed(e)) { return; }
      e = this.getKeyboardEvent(e);
      // Handle `enter`, `space`.
      if (e.keyCode === 13 || e.keyCode === 32) {
        e.preventDefault();
        e.stopPropagation();
        this.click();
      }
    },
  });
})();