1 YUI.add('event-flick', function (Y, NAME) {

     2 

     3 /**

     4  * The gestures module provides gesture events such as "flick", which normalize user interactions

     5  * across touch and mouse or pointer based input devices. This layer can be used by application developers

     6  * to build input device agnostic components which behave the same in response to either touch or mouse based

     7  * interaction.

     8  *

     9  * <p>Documentation for events added by this module can be found in the event document for the <a href="../classes/YUI.html#events">YUI</a> global.</p>

    10  *

    11  *

    12  @example

    13 

    14      YUI().use('event-flick', function (Y) {

    15          Y.one('#myNode').on('flick', function (e) {

    16          });

    17      });

    18 

    19  *

    20  * @module event-gestures

    21  */

    22 

    23 /**

    24  * Adds support for a "flick" event, which is fired at the end of a touch or mouse based flick gesture, and provides

    25  * velocity of the flick, along with distance and time information.

    26  *

    27  * <p>Documentation for the flick event can be found on the <a href="../classes/YUI.html#event_flick">YUI</a> global,

    28  * along with the other supported events.</p>

    29  *

    30  * @module event-gestures

    31  * @submodule event-flick

    32  */

    33 var GESTURE_MAP = Y.Event._GESTURE_MAP,

    34     EVENT = {

    35         start: GESTURE_MAP.start,

    36         end: GESTURE_MAP.end,

    37         move: GESTURE_MAP.move

    38     },

    39     START = "start",

    40     END = "end",

    41     MOVE = "move",

    42 

    43     OWNER_DOCUMENT = "ownerDocument",

    44     MIN_VELOCITY = "minVelocity",

    45     MIN_DISTANCE = "minDistance",

    46     PREVENT_DEFAULT = "preventDefault",

    47 

    48     _FLICK_START = "_fs",

    49     _FLICK_START_HANDLE = "_fsh",

    50     _FLICK_END_HANDLE = "_feh",

    51     _FLICK_MOVE_HANDLE = "_fmh",

    52 

    53     NODE_TYPE = "nodeType";

    54 

    55 /**

    56  * Sets up a "flick" event, that is fired whenever the user initiates a flick gesture on the node

    57  * where the listener is attached. The subscriber can specify a minimum distance or velocity for

    58  * which the event is to be fired. The subscriber can also specify if there is a particular axis which

    59  * they are interested in - "x" or "y". If no axis is specified, the axis along which there was most distance

    60  * covered is used.

    61  *

    62  * <p>It is recommended that you use Y.bind to set up context and additional arguments for your event handler,

    63  * however if you want to pass the context and arguments as additional signature arguments to "on",

    64  * you need to provide a null value for the configuration object, e.g: <code>node.on("flick", fn, null, context, arg1, arg2, arg3)</code></p>

    65  *

    66  * @event flick

    67  * @for YUI

    68  * @param type {string} "flick"

    69  * @param fn {function} The method the event invokes. It receives an event facade with an e.flick object containing the flick related properties: e.flick.time, e.flick.distance, e.flick.velocity and e.flick.axis, e.flick.start.

    70  * @param cfg {Object} Optional. An object which specifies any of the following:

    71  * <dl>

    72  * <dt>minDistance (in pixels, defaults to 10)</dt>

    73  * <dd>The minimum distance between start and end points, which would qualify the gesture as a flick.</dd>

    74  * <dt>minVelocity (in pixels/ms, defaults to 0)</dt>

    75  * <dd>The minimum velocity which would qualify the gesture as a flick.</dd>

    76  * <dt>preventDefault (defaults to false)</dt>

    77  * <dd>Can be set to true/false to prevent default behavior as soon as the touchstart/touchend or mousedown/mouseup is received so that things like scrolling or text selection can be

    78  * prevented. This property can also be set to a function, which returns true or false, based on the event facade passed to it.</dd>

    79  * <dt>axis (no default)</dt>

    80  * <dd>Can be set to "x" or "y" if you want to constrain the flick velocity and distance to a single axis. If not

    81  * defined, the axis along which the maximum distance was covered is used.</dd>

    82  * </dl>

    83  * @return {EventHandle} the detach handle

    84  */

    85 

    86 Y.Event.define('flick', {

    87 

    88     on: function (node, subscriber, ce) {

    89 

    90         var startHandle = node.on(EVENT[START],

    91             this._onStart,

    92             this,

    93             node,

    94             subscriber,

    95             ce);

    96 

    97         subscriber[_FLICK_START_HANDLE] = startHandle;

    98     },

    99 

   100     detach: function (node, subscriber, ce) {

   101 

   102         var startHandle = subscriber[_FLICK_START_HANDLE],

   103             endHandle = subscriber[_FLICK_END_HANDLE];

   104 

   105         if (startHandle) {

   106             startHandle.detach();

   107             subscriber[_FLICK_START_HANDLE] = null;

   108         }

   109 

   110         if (endHandle) {

   111             endHandle.detach();

   112             subscriber[_FLICK_END_HANDLE] = null;

   113         }

   114     },

   115 

   116     processArgs: function(args) {

   117         var params = (args.length > 3) ? Y.merge(args.splice(3, 1)[0]) : {};

   118 

   119         if (!(MIN_VELOCITY in params)) {

   120             params[MIN_VELOCITY] = this.MIN_VELOCITY;

   121         }

   122 

   123         if (!(MIN_DISTANCE in params)) {

   124             params[MIN_DISTANCE] = this.MIN_DISTANCE;

   125         }

   126 

   127         if (!(PREVENT_DEFAULT in params)) {

   128             params[PREVENT_DEFAULT] = this.PREVENT_DEFAULT;

   129         }

   130 

   131         return params;

   132     },

   133 

   134     _onStart: function(e, node, subscriber, ce) {

   135 

   136         var start = true, // always true for mouse

   137             endHandle,

   138             moveHandle,

   139             doc,

   140             preventDefault = subscriber._extra.preventDefault,

   141             origE = e;

   142 

   143         if (e.touches) {

   144             start = (e.touches.length === 1);

   145             e = e.touches[0];

   146         }

   147 

   148         if (start) {

   149 

   150             if (preventDefault) {

   151                 // preventDefault is a boolean or function

   152                 if (!preventDefault.call || preventDefault(e)) {

   153                     origE.preventDefault();

   154                 }

   155             }

   156 

   157             e.flick = {

   158                 time : new Date().getTime()

   159             };

   160 

   161             subscriber[_FLICK_START] = e;

   162 

   163             endHandle = subscriber[_FLICK_END_HANDLE];

   164 

   165             doc = (node.get(NODE_TYPE) === 9) ? node : node.get(OWNER_DOCUMENT);

   166             if (!endHandle) {

   167                 endHandle = doc.on(EVENT[END], Y.bind(this._onEnd, this), null, node, subscriber, ce);

   168                 subscriber[_FLICK_END_HANDLE] = endHandle;

   169             }

   170 

   171             subscriber[_FLICK_MOVE_HANDLE] = doc.once(EVENT[MOVE], Y.bind(this._onMove, this), null, node, subscriber, ce);

   172         }

   173     },

   174 

   175     _onMove: function(e, node, subscriber, ce) {

   176         var start = subscriber[_FLICK_START];

   177 

   178         // Start timing from first move.

   179         if (start && start.flick) {

   180             start.flick.time = new Date().getTime();

   181         }

   182     },

   183 

   184     _onEnd: function(e, node, subscriber, ce) {

   185 

   186         var endTime = new Date().getTime(),

   187             start = subscriber[_FLICK_START],

   188             valid = !!start,

   189             endEvent = e,

   190             startTime,

   191             time,

   192             preventDefault,

   193             params,

   194             xyDistance,

   195             distance,

   196             velocity,

   197             axis,

   198             moveHandle = subscriber[_FLICK_MOVE_HANDLE];

   199 

   200         if (moveHandle) {

   201             moveHandle.detach();

   202             delete subscriber[_FLICK_MOVE_HANDLE];

   203         }

   204 

   205         if (valid) {

   206 

   207             if (e.changedTouches) {

   208                 if (e.changedTouches.length === 1 && e.touches.length === 0) {

   209                     endEvent = e.changedTouches[0];

   210                 } else {

   211                     valid = false;

   212                 }

   213             }

   214 

   215             if (valid) {

   216 

   217                 params = subscriber._extra;

   218                 preventDefault = params[PREVENT_DEFAULT];

   219 

   220                 if (preventDefault) {

   221                     // preventDefault is a boolean or function

   222                     if (!preventDefault.call || preventDefault(e)) {

   223                         e.preventDefault();

   224                     }

   225                 }

   226 

   227                 startTime = start.flick.time;

   228                 endTime = new Date().getTime();

   229                 time = endTime - startTime;

   230 

   231                 xyDistance = [

   232                     endEvent.pageX - start.pageX,

   233                     endEvent.pageY - start.pageY

   234                 ];

   235 

   236                 if (params.axis) {

   237                     axis = params.axis;

   238                 } else {

   239                     axis = (Math.abs(xyDistance[0]) >= Math.abs(xyDistance[1])) ? 'x' : 'y';

   240                 }

   241 

   242                 distance = xyDistance[(axis === 'x') ? 0 : 1];

   243                 velocity = (time !== 0) ? distance/time : 0;

   244 

   245                 if (isFinite(velocity) && (Math.abs(distance) >= params[MIN_DISTANCE]) && (Math.abs(velocity)  >= params[MIN_VELOCITY])) {

   246 

   247                     e.type = "flick";

   248                     e.flick = {

   249                         time:time,

   250                         distance: distance,

   251                         velocity:velocity,

   252                         axis: axis,

   253                         start : start

   254                     };

   255 

   256                     ce.fire(e);

   257 

   258                 }

   259 

   260                 subscriber[_FLICK_START] = null;

   261             }

   262         }

   263     },

   264 

   265     MIN_VELOCITY : 0,

   266     MIN_DISTANCE : 0,

   267     PREVENT_DEFAULT : false

   268 });

   269 

   270 

   271 }, '@VERSION@', {"requires": ["node-base", "event-touch", "event-synthetic"]});