Helper class that makes it easy to create Elements that can be dragged by the mouse or touch.

Hierarchy (view full)

Constructors

Accessors

Methods

  • Fire an event, all additional arguments are passed on to the event listener.

    Parameters

    • name: string

      Name of event to fire.

    • Optional arg1: any

      First argument that is passed to the event handler.

    • Optional arg2: any

      Second argument that is passed to the event handler.

    • Optional arg3: any

      Third argument that is passed to the event handler.

    • Optional arg4: any

      Fourth argument that is passed to the event handler.

    • Optional arg5: any

      Fifth argument that is passed to the event handler.

    • Optional arg6: any

      Sixth argument that is passed to the event handler.

    • Optional arg7: any

      Seventh argument that is passed to the event handler.

    • Optional arg8: any

      Eighth argument that is passed to the event handler.

    Returns EventHandler

    Self for chaining.

    Example

    obj.fire('test', 'This is the message');
    
  • Test if there are any handlers bound to an event name.

    Parameters

    • name: string

      The name of the event to test.

    Returns boolean

    True if the object has handlers bound to the specified event name.

    Example

    obj.on('test', function () { }); // bind an event to 'test'
    obj.hasEvent('test'); // returns true
    obj.hasEvent('hello'); // returns false
  • Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.

    Parameters

    • Optional name: string

      Name of the event to unbind.

    • Optional callback: HandleEventCallback

      Function to be unbound.

    • Optional scope: object

      Scope that was used as the this when the event is fired.

    Returns EventHandler

    Self for chaining.

    Example

    const handler = function () {
    };
    obj.on('test', handler);

    obj.off(); // Removes all events
    obj.off('test'); // Removes all events called 'test'
    obj.off('test', handler); // Removes all handler functions, called 'test'
    obj.off('test', handler, this); // Removes all handler functions, called 'test' with scope this
  • Attach an event handler to an event.

    Parameters

    • name: string

      Name of the event to bind the callback to.

    • callback: HandleEventCallback

      Function that is called when event is fired. Note the callback is limited to 8 arguments.

    • Optional scope: object = ...

      Object to use as 'this' when the event is fired, defaults to current this.

    Returns EventHandle

    Can be used for removing event in the future.

    Example

    obj.on('test', function (a, b) {
    console.log(a + b);
    });
    obj.fire('test', 1, 2); // prints 3 to the console

    Example

    const evt = obj.on('test', function (a, b) {
    console.log(a + b);
    });
    // some time later
    evt.off();
  • Attach an event handler to an event. This handler will be removed after being fired once.

    Parameters

    • name: string

      Name of the event to bind the callback to.

    • callback: HandleEventCallback

      Function that is called when event is fired. Note the callback is limited to 8 arguments.

    • Optional scope: object = ...

      Object to use as 'this' when the event is fired, defaults to current this.

    Returns EventHandle

    • can be used for removing event in the future.

    Example

    obj.once('test', function (a, b) {
    console.log(a + b);
    });
    obj.fire('test', 1, 2); // prints 3 to the console
    obj.fire('test', 1, 2); // not going to get handled

Events

EVENT_DRAGEND: string = 'drag:end'

Fired when the current new drag operation ends.

Example

elementDragHelper.on('drag:end', () => {
console.log('Drag ended');
});
EVENT_DRAGMOVE: string = 'drag:move'

Fired whenever the position of the dragged element changes. The handler is passed the current Vec3 position of the dragged element.

Example

elementDragHelper.on('drag:move', (position) => {
console.log(`Dragged element position is ${position}`);
});
EVENT_DRAGSTART: string = 'drag:start'

Fired when a new drag operation starts.

Example

elementDragHelper.on('drag:start', () => {
console.log('Drag started');
});