xref: /external/chromium_org/third_party/polymer/components-chromium/core-iconset/core-iconset-extracted.js

    Polymer('core-iconset', {

      /**
       * The URL of the iconset image.
       *
       * @attribute src
       * @type string
       * @default ''
       */
      src: '',

      /**
       * The width of the iconset image. This must only be specified if the
       * icons are arranged into separate rows inside the image.
       *
       * @attribute width
       * @type number
       * @default 0
       */
      width: 0,

      /**
       * A space separated list of names corresponding to icons in the iconset
       * image file. This list must be ordered the same as the icon images
       * in the image file.
       *
       * @attribute icons
       * @type string
       * @default ''
       */
      icons: '',

      /**
       * The size of an individual icon. Note that icons must be square.
       *
       * @attribute iconSize
       * @type number
       * @default 24
       */
      iconSize: 24,

      /**
       * The horizontal offset of the icon images in the inconset src image.
       * This is typically used if the image resource contains additional images
       * beside those intended for the iconset.
       *
       * @attribute offsetX
       * @type number
       * @default 0
       */
      offsetX: 0,
      /**
       * The vertical offset of the icon images in the inconset src image.
       * This is typically used if the image resource contains additional images
       * beside those intended for the iconset.
       *
       * @attribute offsetY
       * @type number
       * @default 0
       */
      offsetY: 0,
      type: 'iconset',

      created: function() {
        this.iconMap = {};
        this.iconNames = [];
        this.themes = {};
      },

      ready: function() {
        // TODO(sorvell): ensure iconset's src is always relative to the main
        // document
        if (this.src && (this.ownerDocument !== document)) {
          this.src = this.resolvePath(this.src, this.ownerDocument.baseURI);
        }
        this.super();
        this.updateThemes();
      },

      iconsChanged: function() {
        var ox = this.offsetX;
        var oy = this.offsetY;
        this.icons && this.icons.split(/\s+/g).forEach(function(name, i) {
          this.iconNames.push(name);
          this.iconMap[name] = {
            offsetX: ox,
            offsetY: oy
          }
          if (ox + this.iconSize < this.width) {
            ox += this.iconSize;
          } else {
            ox = this.offsetX;
            oy += this.iconSize;
          }
        }, this);
      },

      updateThemes: function() {
        var ts = this.querySelectorAll('property[theme]');
        ts && ts.array().forEach(function(t) {
          this.themes[t.getAttribute('theme')] = {
            offsetX: parseInt(t.getAttribute('offsetX')) || 0,
            offsetY: parseInt(t.getAttribute('offsetY')) || 0
          };
        }, this);
      },

      // TODO(ffu): support retrived by index e.g. getOffset(10);
      /**
       * Returns an object containing `offsetX` and `offsetY` properties which
       * specify the pixel locaion in the iconset's src file for the given
       * `icon` and `theme`. It's uncommon to call this method. It is useful,
       * for example, to manually position a css backgroundImage to the proper
       * offset. It's more common to use the `applyIcon` method.
       *
       * @method getOffset
       * @param {String|Number} icon The name of the icon or the index of the
       * icon within in the icon image.
       * @param {String} theme The name of the theme.
       * @returns {Object} An object specifying the offset of the given icon
       * within the icon resource file; `offsetX` is the horizontal offset and
       * `offsetY` is the vertical offset. Both values are in pixel units.
       */
      getOffset: function(icon, theme) {
        var i = this.iconMap[icon];
        if (!i) {
          var n = this.iconNames[Number(icon)];
          i = this.iconMap[n];
        }
        var t = this.themes[theme];
        if (i && t) {
          return {
            offsetX: i.offsetX + t.offsetX,
            offsetY: i.offsetY + t.offsetY
          }
        }
        return i;
      },

      /**
       * Applies an icon to the given element as a css background image. This
       * method does not size the element, and it's often necessary to set
       * the element's height and width so that the background image is visible.
       *
       * @method applyIcon
       * @param {Element} element The element to which the background is
       * applied.
       * @param {String|Number} icon The name or index of the icon to apply.
       * @param {Number} scale (optional, defaults to 1) A scaling factor
       * with which the icon can be magnified.
       * @return {Element} The icon element.
       */
      applyIcon: function(element, icon, scale) {
        var offset = this.getOffset(icon);
        scale = scale || 1;
        if (element && offset) {
          var icon = element._icon || document.createElement('div');
          var style = icon.style;
          style.backgroundImage = 'url(' + this.src + ')';
          style.backgroundPosition = (-offset.offsetX * scale + 'px') +
             ' ' + (-offset.offsetY * scale + 'px');
          style.backgroundSize = scale === 1 ? 'auto' :
             this.width * scale + 'px';
          if (icon.parentNode !== element) {
            element.appendChild(icon);
          }
          return icon;
        }
      }

    });