lib/vttregion.js

/**
 * Copyright 2013 vtt.js Contributors
 *
 * 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(root) {

  var scrollSetting = {
    "": true,
    "up": true
  };

  function findScrollSetting(value) {
    if (typeof value !== "string") {
      return false;
    }
    var scroll = scrollSetting[value.toLowerCase()];
    return scroll ? value.toLowerCase() : false;
  }

  function isValidPercentValue(value) {
    return typeof value === "number" && (value >= 0 && value <= 100);
  }

http:// vttregion shim http://dev.w3.org/html5/webvtt/#vttregion-interface
  function VTTRegion() {
    var _width = 100;
    var _lines = 3;
    var _regionAnchorX = 0;
    var _regionAnchorY = 100;
    var _viewportAnchorX = 0;
    var _viewportAnchorY = 100;
    var _scroll = "";

    Object.defineProperties(this, {
      "width": {
        enumerable: true,
        get: function() {
          return _width;
        },
        set: function(value) {
          if (!isValidPercentValue(value)) {
            throw new Error("Width must be between 0 and 100.");
          }
          _width = value;
        }
      },
      "lines": {
        enumerable: true,
        get: function() {
          return _lines;
        },
        set: function(value) {
          if (typeof value !== "number") {
            throw new TypeError("Lines must be set to a number.");
          }
          _lines = value;
        }
      },
      "regionAnchorY": {
        enumerable: true,
        get: function() {
          return _regionAnchorY;
        },
        set: function(value) {
          if (!isValidPercentValue(value)) {
            throw new Error("RegionAnchorX must be between 0 and 100.");
          }
          _regionAnchorY = value;
        }
      },
      "regionAnchorX": {
        enumerable: true,
        get: function() {
          return _regionAnchorX;
        },
        set: function(value) {
          if(!isValidPercentValue(value)) {
            throw new Error("RegionAnchorY must be between 0 and 100.");
          }
          _regionAnchorX = value;
        }
      },
      "viewportAnchorY": {
        enumerable: true,
        get: function() {
          return _viewportAnchorY;
        },
        set: function(value) {
          if (!isValidPercentValue(value)) {
            throw new Error("ViewportAnchorY must be between 0 and 100.");
          }
          _viewportAnchorY = value;
        }
      },
      "viewportAnchorX": {
        enumerable: true,
        get: function() {
          return _viewportAnchorX;
        },
        set: function(value) {
          if (!isValidPercentValue(value)) {
            throw new Error("ViewportAnchorX must be between 0 and 100.");
          }
          _viewportAnchorX = value;
        }
      },
      "scroll": {
        enumerable: true,
        get: function() {
          return _scroll;
        },
        set: function(value) {
          var setting = findScrollSetting(value);
          // Have to check for false as an empty string is a legal value.
          if (setting === false) {
            throw new SyntaxError("An invalid or illegal string was specified.");
          }
          _scroll = setting;
        }
      }
    });
  }

  root.VTTRegion = root.VTTRegion || VTTRegion;
}(this));