DragPane

DragPane (source) is a wrapper around a WidgetGroup that allows its children to be dragged. Actors dragged into the pane will be added to its actors (in the correct place, unless the widget uses some unusual paddings), unless a DragPaneListener does not accept it. DragPane was added in VisUI 0.9.3.

DragPane children are not draggable by default: not unless Draggable listener is set with setDraggable method. This method will automatically attach - or clear, if null - draggable listener to its children, adding the actual dragging functionality. DragPane itself is just a container of actors that allows to add children by dropping. ##Sample

// Creating a drag pane using an internal GridGroup:
DragPane dragPane = new DragPane(new GridGroup()); 
// Creating dragging listener:
Draggable draggable = new Draggable();
// Children cannot be dragged out of the pane:
draggable.setKeepWithinParent(true);
// Other widgets will not receive mouse events during dragging:
draggable.setBlockInput(true);
// Original child actor is invisible during dragging; only dragged actor mimic is rendered:
draggable.setInvisibleWhenDragged(true);
// All dragPane children will have the listener attached:
dragPane.setDraggable(draggable);
// This listener filters actors dropped on the pane. Only actors that were originally pane's children are accepted:
dragPane.setListener(new DragPane.DragPaneListener.AcceptOwnChildren());

##DragPaneListener If you need to filter dropped actors, implement DragPaneListener and use DragPane#setListener method. Some common implementations are already provided:

• AcceptOwnChildren: accepts actors that are already on the pane; this allows to move pane's actors around, but will not accept new, foreign actors.
• LimitChildren: takes a max amount of children that cannot be exceeded. Once children array size is equal to (or greater than) max, new children are rejected.

##Draggable You're not forced to work with DragPane. Draggable can be attached to any actor, even to these not in a DragPane. If you need custom dragging functionality, you can implement your own DragListener and set it with Draggable#setListener.

Note that default listener implementation handles DragPane functionality; if you set a custom listener without extending the DragPane$DefaultDragListener, actors with this Draggable will no longer be added to DragPanes. This actually might be desired, as you can drop DragPane altogether and use your custom containers of dragged actors.

Also, Draggable contains a few static, modifiable fields that allow you to change default settings. If you want to globally change initial DragListener or general look settings, modify static fields - they are used while constructing new Draggable objects.