core/local/reactive/dragdrop

Drag and drop helper component.

This component is used to delegate drag and drop handling.

To delegate the logic to this particular element the component should create a new instance passing "this" as param. The component will use all the necessary callbacks and add all the necessary listeners to the component element.

Component attributes used by dragdrop module:

• element: the draggable or dropzone element.
• (optional) classes: object with alternative CSS classes
• (optional) fullregion: page element affeted by the elementy dragging. Use this attribute if the draggable element affects a bigger region (for example a draggable title).
• (optional) autoconfigDraggable: by default, the component will be draggable if it has a getDraggableData method. If this value is false draggable property must be defined using setDraggable method.
• (optional) relativeDrag: by default the drag image is located at point (0,0) relative to the mouse position to prevent the mouse from covering it. If this attribute is true the drag image will be located at the click offset.

Methods the parent component should have for making it draggable:

• getDraggableData(): Object|data Return the data that will be passed to any valid dropzone while it is dragged. If the component has this method, the dragdrop module will enable the dragging, this is the only required method for dragging. If at the dragging moment this method returns a false|null|undefined, the dragging actions won't be captured.

• (optional) dragStart(Object dropdata, Event event): void

• (optional) dragEnd(Object dropdata, Event event): void Callbacks dragdrop will call when the element is dragged and getDraggableData return some data.

Methods the parent component should have for enabling it as a dropzone:

• validateDropData(Object dropdata): boolean If that method exists, the dragdrop module will automathically configure the element as dropzone. This method will return true if the dropdata is accepted. In case it returns false, no drag and drop event will be listened for this specific dragged dropdata.

• (Optional) showDropZone(Object dropdata, Event event): void

• (Optional) hideDropZone(Object dropdata, Event event): void Methods called when a valid dragged data pass over the element.

• (Optional) drop(Object dropdata, Event event): void Called when a valid dragged element is dropped over the element.

  Note that none of this methods will be called if validateDropData returns a false value.

This module will also add or remove several CSS classes from both dragged elements and dropzones. See the "this.classes" in the create method for more details. In case the parent component wants to use the same classes, it can use the getClasses method. On the other hand, if the parent component has an alternative "classes" attribute, this will override the default drag and drop classes.