The AG_Socket widget is a place holder for one or more drag-and-droppable AG_Icon(3) widgets (or subclasses of it). AG_Socket also provides a boolean state binding and a numerical count binding.

AG_Object(3)-> AG_Widget(3)-> AG_Socket.

The AG_SocketNew() function allocates, initializes, and attaches a new AG_Socket widget. The AG_SocketFromSurface() and AG_SocketFromBMP() variants also set a background image for the socket, typically used to show the type of icons that can be drag-and-dropped onto the socket. Acceptable flags include:

AG_SOCKET_STICKY_STATE	Mouse click should toggle the boolean state.
AG_SOCKET_HFILL	Expand horizontally in parent container.
AG_SOCKET_VFILL	Expand vertically in parent container.
AG_SOCKET_EXPAND	Shorthand for AG_SOCKET_HFILL AG_SOCKET_VFILL|.

The AG_SocketInsertFn() function configures a callback routine fn() that will be invoked whenever the user tries to drop an icon onto the socket. A pointer to the socket and the icon being dropped will be passed to that function. Typically, this routine will use AG_SocketInsertIcon() to assign the icon to the socket. If fn() returns 1, the drag-and-drop item will be destroyed.

The AG_SocketRemoveFn() function registers a callback routine that will be invoked before an icon is removed from a socket.

The AG_SocketOverlayFn() registers a routine that will be invoked in rendering context to draw items on top of the socket (and any contained icons).

The AG_SocketSetPadding() function sets the padding around the socket's icon area in pixels.

AG_SocketBgRect() configures the socket to use a rectangular shape of the given dimensions in pixels.

AG_SocketBgCircle() arranges for the socket to use a circular shape of the given radius in pixels.

AG_SocketBgPixmap() uses (a duplicate of) the given surface as background image. The AG_SocketBgPixmapNODUP() variant uses the surface without copy (potentially unsafe).

The AG_Socket widget generates the following events:

socket-mouseoverlap (int state)	Cursor has moved inside or outside socket area.
socket-click (int state)	User has clicked on the socket area.

The AG_Socket widget provides the following bindings.

BOOL *state	A generic boolean state associated with the socket.
INT *count	A generic "count" associated with the socket. Typically used when the socket contains a stack of items.

See tests/sockets.c in the Agar source distribution.

For the AG_Socket object:

AG_Icon *icon

Icon in socket or NULL (read-only).

AG_Button(3), AG_Intro(3), AG_Pixmap(3), AG_Surface(3), AG_Widget(3), AG_Window(3)

The AG_Socket widget first appeared in Agar 1.0.