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share/status/app/lib/angular/angular-touch.js  view on Meta::CPAN

/**
 * @license AngularJS v1.2.6
 * (c) 2010-2014 Google, Inc. http://angularjs.org
 * License: MIT
 */
(function(window, angular, undefined) {'use strict';

/**
 * @ngdoc overview
 * @name ngTouch
 * @description
 *
 * # ngTouch
 *
 * The `ngTouch` module provides touch events and other helpers for touch-enabled devices.
 * The implementation is based on jQuery Mobile touch event handling 
 * ([jquerymobile.com](http://jquerymobile.com/)).
 *
 * {@installModule touch}
 *
 * See {@link ngTouch.$swipe `$swipe`} for usage.
 *
 * <div doc-module-components="ngTouch"></div>
 *
 */

// define ngTouch module
/* global -ngTouch */
var ngTouch = angular.module('ngTouch', []);

/* global ngTouch: false */

    /**
     * @ngdoc object
     * @name ngTouch.$swipe
     *
     * @description
     * The `$swipe` service is a service that abstracts the messier details of hold-and-drag swipe
     * behavior, to make implementing swipe-related directives more convenient.
     *
     * Requires the {@link ngTouch `ngTouch`} module to be installed.
     *
     * `$swipe` is used by the `ngSwipeLeft` and `ngSwipeRight` directives in `ngTouch`, and by
     * `ngCarousel` in a separate component.
     *
     * # Usage
     * The `$swipe` service is an object with a single method: `bind`. `bind` takes an element
     * which is to be watched for swipes, and an object with four handler functions. See the
     * documentation for `bind` below.
     */

ngTouch.factory('$swipe', [function() {
  // The total distance in any direction before we make the call on swipe vs. scroll.
  var MOVE_BUFFER_RADIUS = 10;

  function getCoordinates(event) {
    var touches = event.touches && event.touches.length ? event.touches : [event];
    var e = (event.changedTouches && event.changedTouches[0]) ||
        (event.originalEvent && event.originalEvent.changedTouches &&
            event.originalEvent.changedTouches[0]) ||
        touches[0].originalEvent || touches[0];

    return {
      x: e.clientX,
      y: e.clientY
    };
  }

  return {
    /**
     * @ngdoc method
     * @name ngTouch.$swipe#bind
     * @methodOf ngTouch.$swipe
     *
     * @description
     * The main method of `$swipe`. It takes an element to be watched for swipe motions, and an
     * object containing event handlers.
     *
     * The four events are `start`, `move`, `end`, and `cancel`. `start`, `move`, and `end`
     * receive as a parameter a coordinates object of the form `{ x: 150, y: 310 }`.
     *
     * `start` is called on either `mousedown` or `touchstart`. After this event, `$swipe` is
     * watching for `touchmove` or `mousemove` events. These events are ignored until the total
     * distance moved in either dimension exceeds a small threshold.
     *
     * Once this threshold is exceeded, either the horizontal or vertical delta is greater.
     * - If the horizontal distance is greater, this is a swipe and `move` and `end` events follow.
     * - If the vertical distance is greater, this is a scroll, and we let the browser take over.
     *   A `cancel` event is sent.
     *
     * `move` is called on `mousemove` and `touchmove` after the above logic has determined that
     * a swipe is in progress.
     *
     * `end` is called when a swipe is successfully completed with a `touchend` or `mouseup`.
     *
     * `cancel` is called either on a `touchcancel` from the browser, or when we begin scrolling
     * as described above.
     *
     */
    bind: function(element, eventHandlers) {
      // Absolute total movement, used to control swipe vs. scroll.
      var totalX, totalY;
      // Coordinates of the start position.
      var startCoords;
      // Last event's position.
      var lastPos;
      // Whether a swipe is active.
      var active = false;

      element.on('touchstart mousedown', function(event) {
        startCoords = getCoordinates(event);
        active = true;
        totalX = 0;
        totalY = 0;
        lastPos = startCoords;
        eventHandlers['start'] && eventHandlers['start'](startCoords, event);
      });

      element.on('touchcancel', function(event) {
        active = false;
        eventHandlers['cancel'] && eventHandlers['cancel'](event);
      });

      element.on('touchmove mousemove', function(event) {
        if (!active) return;

        // Android will send a touchcancel if it thinks we're starting to scroll.
        // So when the total distance (+ or - or both) exceeds 10px in either direction,
        // we either:
        // - On totalX > totalY, we send preventDefault() and treat this as a swipe.
        // - On totalY > totalX, we let the browser handle it as a scroll.

        if (!startCoords) return;
        var coords = getCoordinates(event);

        totalX += Math.abs(coords.x - lastPos.x);
        totalY += Math.abs(coords.y - lastPos.y);

        lastPos = coords;

        if (totalX < MOVE_BUFFER_RADIUS && totalY < MOVE_BUFFER_RADIUS) {
          return;
        }

        // One of totalX or totalY has exceeded the buffer, so decide on swipe vs. scroll.
        if (totalY > totalX) {
          // Allow native scrolling to take over.
          active = false;
          eventHandlers['cancel'] && eventHandlers['cancel'](event);
          return;
        } else {
          // Prevent the browser from scrolling.
          event.preventDefault();
          eventHandlers['move'] && eventHandlers['move'](coords, event);
        }
      });

      element.on('touchend mouseup', function(event) {
        if (!active) return;
        active = false;

share/status/app/lib/angular/angular-touch.js  view on Meta::CPAN

 *
 * @description
 * Specify custom behavior when an element is swiped to the right on a touchscreen device.
 * A rightward swipe is a quick, left-to-right slide of the finger.
 * Though ngSwipeRight is designed for touch-based devices, it will work with a mouse click and drag
 * too.
 *
 * Requires the {@link ngTouch `ngTouch`} module to be installed.
 *
 * @element ANY
 * @param {expression} ngSwipeRight {@link guide/expression Expression} to evaluate
 * upon right swipe. (Event object is available as `$event`)
 *
 * @example
    <doc:example>
      <doc:source>
        <div ng-show="!showActions" ng-swipe-left="showActions = true">
          Some list content, like an email in the inbox
        </div>
        <div ng-show="showActions" ng-swipe-right="showActions = false">
          <button ng-click="reply()">Reply</button>
          <button ng-click="delete()">Delete</button>
        </div>
      </doc:source>
    </doc:example>
 */

function makeSwipeDirective(directiveName, direction, eventName) {
  ngTouch.directive(directiveName, ['$parse', '$swipe', function($parse, $swipe) {
    // The maximum vertical delta for a swipe should be less than 75px.
    var MAX_VERTICAL_DISTANCE = 75;
    // Vertical distance should not be more than a fraction of the horizontal distance.
    var MAX_VERTICAL_RATIO = 0.3;
    // At least a 30px lateral motion is necessary for a swipe.
    var MIN_HORIZONTAL_DISTANCE = 30;

    return function(scope, element, attr) {
      var swipeHandler = $parse(attr[directiveName]);

      var startCoords, valid;

      function validSwipe(coords) {
        // Check that it's within the coordinates.
        // Absolute vertical distance must be within tolerances.
        // Horizontal distance, we take the current X - the starting X.
        // This is negative for leftward swipes and positive for rightward swipes.
        // After multiplying by the direction (-1 for left, +1 for right), legal swipes
        // (ie. same direction as the directive wants) will have a positive delta and
        // illegal ones a negative delta.
        // Therefore this delta must be positive, and larger than the minimum.
        if (!startCoords) return false;
        var deltaY = Math.abs(coords.y - startCoords.y);
        var deltaX = (coords.x - startCoords.x) * direction;
        return valid && // Short circuit for already-invalidated swipes.
            deltaY < MAX_VERTICAL_DISTANCE &&
            deltaX > 0 &&
            deltaX > MIN_HORIZONTAL_DISTANCE &&
            deltaY / deltaX < MAX_VERTICAL_RATIO;
      }

      $swipe.bind(element, {
        'start': function(coords, event) {
          startCoords = coords;
          valid = true;
        },
        'cancel': function(event) {
          valid = false;
        },
        'end': function(coords, event) {
          if (validSwipe(coords)) {
            scope.$apply(function() {
              element.triggerHandler(eventName);
              swipeHandler(scope, {$event: event});
            });
          }
        }
      });
    };
  }]);
}

// Left is negative X-coordinate, right is positive.
makeSwipeDirective('ngSwipeLeft', -1, 'swipeleft');
makeSwipeDirective('ngSwipeRight', 1, 'swiperight');



})(window, window.angular);