summaryrefslogtreecommitdiffstats
path: root/doc/tutorial6.dox
blob: 0cee850d9de027b56c95d55427ec7133f98e05b2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
/** \page page_tutorial6 Tutorial - Part 6: Binding Objects

\ref page_tutorial5 | \ref page_tutorial "Index"

In this tutorial we show how to bind to an object so that we can
receive events and call methods on the object.

Let take a look at the following application to start.

\snippet tutorial6.c code

To compile the simple test application, copy it into a tutorial6.c file and
use:

    gcc -Wall tutorial6.c -o tutorial6 $(pkg-config --cflags --libs libpipewire-0.3)

Most of this is the same as \ref page_tutorial2 where we simply
enumerated all objects on the server. Instead of just printing the object
id and some other properties, in this example we also bind to the object.

We use the `pw_registry_bind()` method on our registry object like this:

\snippet tutorial6.c registry_event_global

We bind to the first client object that we see. This gives us a pointer
to a `struct pw_proxy` that we can also cast to a `struct pw_client`.

On the proxy we can call methods and listen for events. PipeWire will
automatically serialize the method calls and events between client and
server for us.

We can now listen for events by adding a listener. We're going to
listen to the info event on the client object that is emitted right
after we bind to it or when it changes. This is not very different
from the registry listener we added before:

\snippet tutorial6.c client_info

\code{.c}
static void registry_event_global(void *_data, uint32_t id,
			uint32_t permissions, const char *type,
			uint32_t version, const struct spa_dict *props)
{
		/* ... */
		pw_client_add_listener(data->client,
				&data->client_listener,
				&client_events, data);
		/* ... */
}
\endcode

We're also quitting the mainloop after we get the info to nicely stop
our tutorial application.

When we stop the application, don't forget to destroy all proxies that
you created. Otherwise, they will be leaked:

\code{.c}
	/* ... */
	pw_proxy_destroy((struct pw_proxy *)data.client);
	/* ... */

	return 0;
}
\endcode

\ref page_tutorial5 | \ref page_tutorial "Index"

*/