External plug/socket infrastructure to remote canvases

These functions allow 1 process to create a "socket" was pluged into which another process can create a "plug" remotely to plug into. More...

Functions

Ecore_Evasecore_evas_extn_socket_new (int w, int h)
 Create a new Ecore_Evas canvas for the new external ecore evas socket.
 
Eina_Bool ecore_evas_extn_socket_listen (Ecore_Evas *ee, const char *svcname, int svcnum, Eina_Bool svcsys)
 Create a socket to provide the service for external ecore evas socket.
 
void ecore_evas_extn_plug_object_data_lock (Evas_Object *obj)
 Lock the pixel data so the socket cannot change it.
 
void ecore_evas_extn_plug_object_data_unlock (Evas_Object *obj)
 Unlock the pixel data so the socket can change it again.
 
Evas_Objectecore_evas_extn_plug_new (Ecore_Evas *ee_target)
 Create a new external ecore evas plug.
 
Eina_Bool ecore_evas_extn_plug_connect (Evas_Object *obj, const char *svcname, int svcnum, Eina_Bool svcsys)
 Connect an external ecore evas plug to service provided by external ecore evas socket.
 

Variables

int ECORE_EVAS_EXTN_CLIENT_ADD
 this event is received when a plug has connected to an extn socket
 
int ECORE_EVAS_EXTN_CLIENT_DEL
 this event is received when a plug has disconnected from an extn socket
 

Detailed Description

These functions allow 1 process to create a "socket" was pluged into which another process can create a "plug" remotely to plug into.

Socket can provides content for several plugs. This is best for small sized objects (about the size range of a small icon up to a few large icons). Sine the plug is actually an image object, you can fetch the pixel data

Since
1.2

Function Documentation

Ecore_Evas* ecore_evas_extn_socket_new ( int  w,
int  h 
)

Create a new Ecore_Evas canvas for the new external ecore evas socket.

Parameters
wThe width of the canvas, in pixels
hThe height of the canvas, in pixels
Returns
A new Ecore_Evas instance or NULL, on failure

This creates a new extn_socket canvas wrapper, with image data array bound to the ARGB format, 8 bits per pixel.

If creation is successful, an Ecore_Evas handle is returned or NULL if creation fails. Also focus, show, hide etc. callbacks will also be called if the plug object is shown, or already visible on connect, or if it is hidden later, focused or unfocused.

This function has to be flowed by ecore_evas_extn_socket_listen(), for starting ecore ipc service.

if (!res) return;
ecore_evas_resize(ee, 240, 400);

or

if (!res) return;

When a client(plug) connects, you will get the ECORE_EVAS_EXTN_CLIENT_ADD event in the ecore event queue, with event_info being the image object pointer passed as a void pointer. When a client disconnects you will get the ECORE_EVAS_EXTN_CLIENT_DEL event.

You can set up event handles for these events as follows:

static void client_add_cb(void *data, int event, void *event_info)
{
Evas_Object *obj = event_info;
printf("client added to image object %p\n", obj);
}
static void client_del_cb(void *data, int event, void *event_info)
{
Evas_Object *obj = event_info;
printf("client deleted from image object %p\n", obj);
}
void setup(void)
{
client_add_cb, NULL);
client_del_cb, NULL);
}

Note that events come in later after the event happened. You may want to be careful as data structures you had associated with the image object may have been freed after deleting, but the object may still be around awating cleanup and thus still be valid.You can change the size with something like:

See Also
ecore_evas_extn_socket_listen()
ecore_evas_extn_plug_new()
ecore_evas_extn_plug_object_data_lock()
ecore_evas_extn_plug_object_data_unlock()
Since
1.2

References eina_module_symbol_get(), and EINA_SAFETY_ON_NULL_RETURN_VAL.

Eina_Bool ecore_evas_extn_socket_listen ( Ecore_Evas ee,
const char *  svcname,
int  svcnum,
Eina_Bool  svcsys 
)

Create a socket to provide the service for external ecore evas socket.

Parameters
eeThe Ecore_Evas.
svcnameThe name of the service to be advertised. ensure that it is unique (when combined with svcnum) otherwise creation may fail.
svcnumA number (any value, 0 being the common default) to differentiate multiple instances of services with the same name.
svcsysA boolean that if true, specifies to create a system-wide service all users can connect to, otherwise the service is private to the user ide that created the service.
Returns
EINA_TRUE if creation is successful, EINA_FALSE if it does not.

This creates socket specified by svcname, svcnum and svcsys. If creation is successful, EINA_TRUE is returned or EINA_FALSE if creation fails.

See Also
ecore_evas_extn_socket_new()
ecore_evas_extn_plug_new()
ecore_evas_extn_plug_object_data_lock()
ecore_evas_extn_plug_object_data_unlock()
Since
1.2

References EINA_FALSE, and EINA_SAFETY_ON_NULL_RETURN_VAL.

void ecore_evas_extn_plug_object_data_lock ( Evas_Object obj)

Lock the pixel data so the socket cannot change it.

Parameters
objThe image object returned by ecore_evas_extn_plug_new() to lock

You may need to get the image pixel data with evas_object_image_data_get() from the image object, but need to ensure that it does not change while you are using the data. This function lets you set an advisory lock on the image data so the external plug process will not render to it or alter it.

You should only hold the lock for just as long as you need to read out the image data or otherwise deal with it, and then unlock it with ecore_evas_extn_plug_object_data_unlock(). Keeping a lock over more than 1 iteration of the main ecore loop will be problematic, so avoid it. Also forgetting to unlock may cause the socket process to freeze and thus create odd behavior.

See Also
ecore_evas_extn_plug_new()
ecore_evas_extn_plug_object_data_unlock()
Since
1.2

References ecore_evas_object_ecore_evas_get(), and EINA_SAFETY_ON_NULL_RETURN.

void ecore_evas_extn_plug_object_data_unlock ( Evas_Object obj)

Unlock the pixel data so the socket can change it again.

Parameters
objThe image object returned by ecore_evas_extn_plug_new() to unlock

This unlocks after an advisor lock has been taken by ecore_evas_extn_plug_object_data_lock().

See Also
ecore_evas_extn_plug_new()
ecore_evas_extn_plug_object_data_lock()
Since
1.2

References ecore_evas_object_ecore_evas_get(), and EINA_SAFETY_ON_NULL_RETURN.

Evas_Object* ecore_evas_extn_plug_new ( Ecore_Evas ee_target)

Create a new external ecore evas plug.

Parameters
ee_targetThe Ecore_Evas containing the canvas in which the new image object will live.
Returns
An evas image object that will contain the image output of a socket.

This creates an image object that will contain the output of another processes socket canvas when it connects. All input will be sent back to this process as well, effectively swallowing or placing the socket process in the canvas of the plug process in place of the image object. The image object by default is created to be filled (equivalent of evas_object_image_filled_add() on creation) so image content will scale to fill the image unless otherwise reconfigured. The Ecore_Evas size of the plug is the master size and determines size in pixels of the plug canvas. You can change the size with something like:

if (!res) return;
ecore_evas_resize(ee, 240, 400);
See Also
ecore_evas_extn_socket_new()
ecore_evas_extn_plug_connect()
Since
1.2

References eina_module_symbol_get(), and EINA_SAFETY_ON_NULL_RETURN_VAL.

Eina_Bool ecore_evas_extn_plug_connect ( Evas_Object obj,
const char *  svcname,
int  svcnum,
Eina_Bool  svcsys 
)

Connect an external ecore evas plug to service provided by external ecore evas socket.

Parameters
objThe Ecore_Evas containing the canvas in which the new image object will live.
svcnameThe service name to connect to set up by the socket.
svcnumThe service number to connect to (set up by socket).
svcsysBoolean to set if the service is a system one or not (set up by socket).
Returns
EINA_TRUE if creation is successful, EINA_FALSE if it does not.
See Also
ecore_evas_extn_plug_new()
Since
1.2

References ecore_evas_object_ecore_evas_get(), EINA_FALSE, and EINA_SAFETY_ON_NULL_RETURN_VAL.

Variable Documentation

int ECORE_EVAS_EXTN_CLIENT_ADD

this event is received when a plug has connected to an extn socket

Since
1.2
int ECORE_EVAS_EXTN_CLIENT_DEL

this event is received when a plug has disconnected from an extn socket

Since
1.2