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<para>
This section explains the steps required to write a plugin for Parole using
the C language interface.
</para>
<para>
A simple example can be found in the parole plugins dir shipped with the source code, the sample
plugin.
</para>
<para>
As a basics, the plugin needs to implement <link linkend="ParoleProviderPlugin"><type>ParoleProviderPlugin</type></link>
interface, That is, the player use this interface to get if the plugin is configurable, to ask it to show
its properties dialog when needed, to set the <link linkend="ParoleProviderPlayer"><type>ParoleProviderPlayer</type></link>
interface used by plugins to access the the Parole player backend.
</para>
<sect1>
<title>Plugin structure.</title>
sample-plugin.c
<programlisting>
#include "sample-provider.h"
/* Avoid a no previous function declaration compiler warning*/
G_MODULE_EXPORT GType parole_plugin_initialize (ParoleProviderPlugin *plugin);
G_MODULE_EXPORT void parole_plugin_shutdown (void);
G_MODULE_EXPORT GType
parole_plugin_initialize (ParoleProviderPlugin *plugin)
{
xfce_textdomain (GETTEXT_PACKAGE, PACKAGE_LOCALE_DIR, "UTF-8");
sample_provider_register_type (plugin);
return SAMPLE_TYPE_PROVIDER;
}
G_MODULE_EXPORT void
parole_plugin_shutdown (void)
{
}
</programlisting>
sample-provider.h
<programlisting>
#ifndef SAMPLE_PROVIDER_H_
#define SAMPLE_PROVIDER_H_
#include <parole/parole.h>
G_BEGIN_DECLS
typedef struct _SampleProviderClass SampleProviderClass;
typedef struct _SampleProvider SampleProvider;
#define SAMPLE_TYPE_PROVIDER (sample_provider_get_type ())
#define SAMPLE_PROVIDER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), SAMPLE_TYPE_PROVIDER, SampleProvider))
#define SAMPLE_PROVIDER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), SAMPLE_TYPE_PROVIDER, SampleProviderClass))
#define SAMPLE_IS_PROVIDER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), SAMPLE_TYPE_PROVIDER))
#define SAMPLE_IS_PROVIDER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), SAMPLE_TYPE_PROVIDER))
#define SAMPLE_PROVIDER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), SAMPLE_TYPE_PROVIDER, SampleProviderClass))
GType sample_provider_get_type (void) G_GNUC_CONST G_GNUC_INTERNAL;
void sample_provider_register_type (ParoleProviderPlugin *plugin);
G_END_DECLS
</programlisting>
sample-provider.c
<programlisting>
#include "sample-provider.h"
static void sample_provider_iface_init (ParoleProviderPluginIface *iface);
static void sample_provider_finalize (GObject *object);
struct _SampleProviderClass
{
GObjectClass parent_class;
};
struct _SampleProvider
{
GObject parent;
ParoleProviderPlayer *player;
};
PAROLE_DEFINE_TYPE_WITH_CODE (SampleProvider,
sample_provider,
G_TYPE_OBJECT,
PAROLE_IMPLEMENT_INTERFACE (PAROLE_TYPE_PROVIDER_PLUGIN,
sample_provider_iface_init));
static void sample_provider_configure (ParoleProviderPlugin *provider, GtkWidget *parent)
{
/*Open the configuration dialog, parent is the window transient for*/
}
static gboolean sample_provider_is_configurable (ParoleProviderPlugin *plugin)
{
return TRUE; /*Returns FALSE and don't override the iface->configure function*/
}
static void
sample_provider_set_player (ParoleProviderPlugin *plugin, ParoleProviderPlayer *player)
{
SampleProvider *provider;
provider = SAMPLE_PROVIDER (plugin);
provider->player = player;
}
static void
sample_provider_iface_init (ParoleProviderPluginIface *iface)
{
iface->get_is_configurable = sample_provider_is_configurable;
iface->configure = sample_provider_configure;
iface->set_player = sample_provider_set_player;
}
static void sample_provider_class_init (SampleProviderClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->finalize = sample_provider_finalize;
}
static void sample_provider_init (SampleProvider *provider)
{
provider->player = NULL;
}
static void sample_provider_finalize (GObject *object)
{
G_OBJECT_CLASS (sample_provider_parent_class)->finalize (object);
}
</programlisting>
</sect1>
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