Module toplevel_drag

Available on crate feature staging only.

This protocol enhances normal drag and drop with the ability to move a window at the same time. This allows having detachable parts of a window that when dragged out of it become a new window and can be dragged over an existing window to be reattached.

A typical workflow would be when the user starts dragging on top of a detachable part of a window, the client would create a wl_data_source and a xdg_toplevel_drag_v1 object and start the drag as normal via wl_data_device.start_drag. Once the client determines that the detachable window contents should be detached from the originating window, it creates a new xdg_toplevel with these contents and issues a xdg_toplevel_drag_v1.attach request before mapping it. From now on the new window is moved by the compositor during the drag as if the client called xdg_toplevel.move.

Dragging an existing window is similar. The client creates a xdg_toplevel_drag_v1 object and attaches the existing toplevel before starting the drag.

Clients use the existing drag and drop mechanism to detect when a window can be docked or undocked. If the client wants to snap a window into a parent window it should delete or unmap the dragged top-level. If the contents should be detached again it attaches a new toplevel as described above. If a drag operation is cancelled without being dropped, clients should revert to the previous state, deleting any newly created windows as appropriate. When a drag operation ends as indicated by wl_data_source.dnd_drop_performed the dragged toplevel window’s final position is determined as if a xdg_toplevel_move operation ended.

Modules

• v1
  Version 1