/* ************************************************************************



   qooxdoo - the new era of web development



   http://qooxdoo.org



   Copyright:

     2004-2010 1&1 Internet AG, Germany, http://www.1und1.de



   License:

     LGPL: http://www.gnu.org/licenses/lgpl.html

     EPL: http://www.eclipse.org/org/documents/epl-v10.php

     See the LICENSE file in the project's top-level directory for details.



   Authors:

     * Martin Wittemann (martinwittemann)

     * Tino Butz (tbtz)



************************************************************************ */





/**

 * EXPERIMENTAL - NOT READY FOR PRODUCTION

 *

 * Touch event object.

 *

 * For more information see:

 *     http://developer.apple.com/safari/library/documentation/UserExperience/Reference/TouchEventClassReference/TouchEvent/TouchEvent.html

 */

qx.Class.define("qx.event.type.Touch", 

{

    extend : qx.event.type.Dom,





    /*

    *****************************************************************************

       MEMBERS

    *****************************************************************************

    */



    members :

    {

      // overridden

      _cloneNativeEvent : function(nativeEvent, clone)

      {

        var clone = this.base(arguments, nativeEvent, clone);



        clone.pageX = nativeEvent.pageX;

        clone.pageY = nativeEvent.pageY;

        clone.layerX = nativeEvent.layerX;

        clone.layerY = nativeEvent.layerY;

        clone.scale = nativeEvent.scale;

        clone.rotation = nativeEvent.rotation;

        clone.srcElement = nativeEvent.srcElement;



        clone.targetTouches = [];

        for (var i = 0; i < nativeEvent.targetTouches.length; i++) {

          clone.targetTouches[i] = nativeEvent.targetTouches[i];

        };



        clone.changedTouches = [];

        for (var i = 0; i < nativeEvent.changedTouches.length; i++) {

          clone.changedTouches[i] = nativeEvent.changedTouches[i];

        };



        clone.touches = [];

        for (var i = 0; i < nativeEvent.touches.length; i++) {

          clone.touches[i] = nativeEvent.touches[i];

        };



        return clone;

      },





      // overridden

      stop : function() {

        this.stopPropagation();

      },





      /**

       * Returns an array of native Touch objects representing all current 

       * touches on the document.

       * Returns an empty array for the "touchend" event.

       * 

       * @return {Object[]} Array of touch objects. For more information see: 

       *     http://developer.apple.com/safari/library/documentation/UserExperience/Reference/TouchClassReference/Touch/Touch.html

       */

      getAllTouches : function() {

        return this._native.touches;

      },





      /**

       * Returns an array of native Touch objects representing all touches 

       * associated with the event target element.

       * Returns an empty array for the "touchend" event.

       *

       * @return {Object[]} Array of touch objects. For more information see: 

       *     http://developer.apple.com/safari/library/documentation/UserExperience/Reference/TouchClassReference/Touch/Touch.html

       */

      getTargetTouches : function() {

          return this._native.targetTouches;

      },





      /**

       * Returns an array of native Touch objects representing all touches of 

       * the target element that changed in this event.

       *

       * On the "touchstart" event the array contains all touches that were 

       * added to the target element.

       * On the "touchmove" event the array contains all touches that were 

       * moved on the target element.

       * On the "touchend" event the array contains all touches that used 

       * to be on the target element.

       *

       * @return {Object[]} Array of touch objects. For more information see: 

       *     http://developer.apple.com/safari/library/documentation/UserExperience/Reference/TouchClassReference/Touch/Touch.html

       */

      getChangedTargetTouches : function() {

          return this._native.changedTouches;

      },





      /**

       * Checks whether more than one touch is associated with the event target 

       * element.

       * 

       * @return {Boolean} Is multi-touch

       */

      isMultiTouch : function() {

        return this.__getEventSpecificTouches().length > 1;

      },





      /**

       * iOS only: Returns the distance between two fingers since the start of the event. 

       * The distance is a multiplier of the initial distance.

       * Initial value: 1.0.

       * Gestures: 

       * < 1.0, pinch close / zoom out. 

       * > 1.0, pinch open / to zoom in.

       * 

       * @return The scale distance between two fingers

       */

      getScale : function() {

        return this._native.scale;

      },





      /**

       * iOS only: Returns the delta of the rotation since the start of the event, in degrees.

       * Initial value is 0.0

       * Clockwise > 0 

       * Counter-clockwise < 0.

       *

       * @return {Float} The rotation delta

       */

      getRotation : function() {

        return this._native.rotation;

      },





      /**

       * Get the horizontal position at which the event occurred relative to the

       * left of the document. This property takes into account any scrolling of

       * the page.

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} The horizontal position of the touch in the document.

       */

      getDocumentLeft : function(touchIndex) {

        return this.__getEventSpecificTouch(touchIndex).pageX;

      },





      /**

       * Get the vertical position at which the event occurred relative to the

       * top of the document. This property takes into account any scrolling of

       * the page.

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} The vertical position of the touch in the document.

       */

      getDocumentTop : function(touchIndex) {

        return this.__getEventSpecificTouch(touchIndex).pageY;

      },





      /**

       * Get the horizontal coordinate at which the event occurred relative to

       * the origin of the screen coordinate system.

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} The horizontal position of the touch

       */

      getScreenLeft : function(touchIndex) {

        return this.__getEventSpecificTouch(touchIndex).screenX;

      },





      /**

       * Get the vertical coordinate at which the event occurred relative to

       * the origin of the screen coordinate system.

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} The vertical position of the touch

       */

      getScreenTop: function(touchIndex) {

          return this.__getEventSpecificTouch(touchIndex).screenY;

      },





      /**

       * Get the the horizontal coordinate at which the event occurred relative

       * to the viewport.

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} The horizontal position of the touch

       */

      getViewportLeft : function(touchIndex) {

          return this.__getEventSpecificTouch(touchIndex).clientX;

      },





      /**

       * Get the vertical coordinate at which the event occurred relative

       * to the viewport.

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} The vertical position of the touch

       */

      getViewportTop : function(touchIndex) {

          return this.__getEventSpecificTouch(touchIndex).clientY;

      },





      /**

       * Returns the unique identifier for a certain touch object.

       * 

       * @param touchIndex {Integer ? 0) The index of the Touch object

       * @return {Integer} Unique identifier of the touch object 

       */

      getIdentifier : function(touchIndex) {

        return this.__getEventSpecificTouch(touchIndex).identifier;

      },





      /**

       * Returns an event specific touch on the target element. This function is

       * used as the "touchend" event only offers Touch objects in the 

       * changedTouches array. 

       *

       * @param touchIndex {Integer ? 0) The index of the Touch object to 

       *     retrieve

       * @return {Object} A native Touch object

       */

      __getEventSpecificTouch : function(touchIndex)

      {

        touchIndex = touchIndex == null ? 0 : touchIndex;

        return this.__getEventSpecificTouches()[touchIndex];

      },





      /**

       * Returns the event specific touches on the target element. This function 

       * is used as the "touchend" event only offers Touch objects in the 

       * changedTouches array.

       *

       * @return {Object[]} Array of native Touch objects

       */

      __getEventSpecificTouches : function()

      {

        var isTouchEnd = this.getType() == "touchend" || this.getType() == "touchcancel";

        var touches = (isTouchEnd ? this.getChangedTargetTouches(): this.getTargetTouches());

        return touches;

      }

    }

  });