fa-touchstart

This directive allows you to specify custom behavior when an element is touched upon a touch surface.

Usage

<ANY fa-touchstart="expression">

</ANY>

Note: For development purposes, enable mobile emulation: https://developer.chrome.com/devtools/docs/mobile-emulation

API

Example

Upon a touchstart event firing, fa-touchstart will evaluate the expression bound to it.

Touchstart fires once when a touch point (finger) is first placed upon the touch surface. If the touch point moves or releases touch, it will not fire another touchstart; touchstart fires once upon the first touch. If the touch point is placed upon the touch surface again, it will fire another touchstart event.

Fa-touchstart on an fa-surface

Fa-touchstart can be used on an fa-surface. Internally, a Famous Surface has a .on() method that binds a callback function to an event type handled by that Surface. The function expression bound to fa-touchstart is bound to that fa-surface's touchstart eventHandler, and when touchstart fires, the function expression will be called.

<fa-app ng-controller="TouchStartCtrl">
  <fa-modifier fa-size="[200, 100]">
    <fa-surface fa-touchstart="touchStart($event)"
                fa-background-color="'red'">
      Touch start count: {{touchStartCount}}
    </fa-surface>
  </fa-modifier>
</fa-app>

<script>
  angular.module('faTouchStartExampleApp', ['famous.angular'])
    .controller('TouchStartCtrl', ['$scope', '$famous', function($scope, $famous) {
        
        $scope.touchStartCount = 0;

        $scope.touchStart = function($event) {
          console.log($event);
          $scope.touchStartCount++;
        };

    }]);
</script>

fa-app {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}

Fa-touchstart on an fa-view

Fa-touchstart may be used on an fa-view. The function expression bound to fa-touchstart will be bound to the fa-view's internal _eventInput, the aggregation point of all events received by the fa-view. When it receives a touchstart event, it will call the function expression bound to fa-touchstart.

In the example below, the fa-surface pipes its Surface events to an instantied Famous Event Handler called myEvents. Fa-view pipes from myEvents, receiving all events piped by the fa-surface.

When a touchstart event occurs on the fa-surface, it is piped to the fa-view.
fa-touchstart defines a callback function in which to handle touchstart events, and when it receives a touchstart event, it calls touchStart().

<fa-app ng-controller="TouchStartCtrl">

  <!-- The fa-view receives the touchstart event from the fa-surface, and calls $scope.touchStart, bound to fa-touchstart on the fa-view. -->

  <fa-view fa-touchstart="touchStart($event)" fa-pipe-from="myEvents">
    <fa-modifier fa-size="[200, 100]">
      <fa-surface fa-pipe-to="myEvents"
                  fa-background-color="'orange'">
        Touch start count: {{touchStartCount}}
      </fa-surface>
    </fa-modifier>
  </fa-view>
</fa-app>

<script>
  angular.module('faTouchStartExampleApp', ['famous.angular'])
    .controller('TouchStartCtrl', ['$scope', '$famous', function($scope, $famous) {
        
        var EventHandler = $famous['famous/core/EventHandler'];
        $scope.myEvents = new EventHandler();

        $scope.touchStartCount = 0;
        
        $scope.touchStart = function($event) {
          console.log($event);
          $scope.touchStartCount++;
        };

    }]);
</script>

fa-app {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}