modules: add x11-bell module

It listens for X11 bell events and plays a sample with libcanberra.

Fixes #1668

doc/pipewire-modules.dox

@@ -75,6 +75,7 @@ List of known modules:
 - \subpage page_module_roc_source
 - \subpage page_module_rt
 - \subpage page_module_session_manager
+- \subpage page_module_x11_bell
 - \subpage page_module_zeroconf_discover
 
 

meson.build

@@ -349,6 +349,14 @@ avahi_dep = dependency('avahi-client', required : get_option('avahi'))
 summary({'Avahi DNS-SD (Zeroconf)': avahi_dep.found()}, bool_yn: true,
   section: 'Streaming between daemons')
 
+x11_dep = dependency('x11-xcb', required : get_option('x11'))
+summary({'X11 (x11-bell)': x11_dep.found()}, bool_yn: true,
+  section: 'Misc dependencies')
+
+canberra_dep = dependency('libcanberra', required : get_option('libcanberra'))
+summary({'libcanberra (x11-bell)': canberra_dep.found()}, bool_yn: true,
+  section: 'Misc dependencies')
+
 libusb_dep = dependency('libusb-1.0', required : get_option('libusb'))
 summary({'libusb (Bluetooth quirks)': libusb_dep.found()}, bool_yn: true, section: 'Backend')
 if libusb_dep.found()

meson_options.txt

@@ -225,3 +225,11 @@ option('lv2',
        description: 'Enable loading of LV2 plugins',
        type: 'feature',
        value: 'auto')
+option('x11',
+       description: 'Enable code that depends on X11',
+       type: 'feature',
+       value: 'auto')
+option('libcanberra',
+       description: 'Enable code that depends on libcanberra',
+       type: 'feature',
+       value: 'auto')

src/daemon/pipewire.conf.in

@@ -151,6 +151,16 @@ context.modules = [
 
     # Provides factories to make session manager objects.
     { name = libpipewire-module-session-manager }
+
+    # Use libcanberra to play X11 Bell
+    #{ name = libpipewire-module-x11-bell
+    #  args = {
+    #      #sink.name = "@DEFAULT_SINK@"
+    #      #sample.name = "bell-window-system"
+    #      #x11.display = null
+    #      #x11.xauthority = null
+    #  }
+    #}
 ]
 
 context.objects = [

src/modules/meson.build

@@ -26,6 +26,7 @@ module_sources = [
   'module-zeroconf-discover.c',
   'module-roc-source.c',
   'module-roc-sink.c',
+  'module-x11-bell.c',
 ]
 
 pipewire_module_access = shared_library('pipewire-module-access', [ 'module-access.c' ],
@@ -489,3 +490,16 @@ pipewire_module_roc_source = shared_library('pipewire-module-roc-source',
 endif
 summary({'roc-sink': build_module_roc}, bool_yn: true, section: 'Optional Modules')
 summary({'roc-source': build_module_roc}, bool_yn: true, section: 'Optional Modules')
+
+build_module_x11_bell = x11_dep.found() and canberra_dep.found()
+if build_module_x11_bell
+pipewire_module_x11_bell = shared_library('pipewire-module-x11-bell',
+  [ 'module-x11-bell.c' ],
+  include_directories : [configinc],
+  install : true,
+  install_dir : modules_install_dir,
+  install_rpath: modules_install_dir,
+  dependencies : [mathlib, dl_lib, rt_lib, pipewire_dep, x11_dep, canberra_dep],
+)
+endif
+summary({'x11-bell': build_module_x11_bell}, bool_yn: true, section: 'Optional Modules')

src/modules/module-x11-bell.c

@@ -0,0 +1,289 @@
+/* PipeWire
+ *
+ * Copyright © 2022 Wim Taymans <wim.taymans@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "config.h"
+
+#include <spa/utils/string.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xlib-xcb.h>
+#include <X11/XKBlib.h>
+
+#include <canberra.h>
+
+#include "pipewire/pipewire.h"
+#include "pipewire/impl.h"
+
+/** \page page_module_x11_bell PipeWire Module: X11 Bell
+ *
+ * The `x11-bell` module intercept the X11 bell events and uses libcanberra to
+ * play a sound.
+ *
+ * ## Module Options
+ *
+ * - `sink.name = <str>`: node.name of the sink to connect to
+ * - `sample.name = <str>`: the name of the sample to play, default 'bell-window-system'
+ * - `x11.display = <str>`: the X11 display to use
+ * - `x11.xauthority = <str>`: the X11 XAuthority string placed in XAUTHORITY env
+ *
+ * ## General options
+ *
+ * There are no general options for this module.
+ *
+ * ## Example configuration
+ *\code{.unparsed}
+ * context.modules = [
+ *  {   name = libpipewire-x11-bell }
+ *      args = {
+ *          #sink.name = @DEFAULT_SINK@
+ *          sample.name = "bell-window-system"
+ *          #x11.display = ":1"
+ *          #x11.xauthority = "test"
+ * ]
+ *\endcode
+ *
+ */
+
+#define NAME "x11-bell"
+
+PW_LOG_TOPIC_STATIC(mod_topic, "mod." NAME);
+#define PW_LOG_TOPIC_DEFAULT mod_topic
+
+struct impl {
+	struct pw_context *context;
+	struct pw_thread_loop *thread_loop;
+	struct pw_loop *loop;
+	struct spa_source *source;
+
+	struct pw_properties *properties;
+
+	struct spa_hook module_listener;
+
+	Display *display;
+	int xkb_event_base;
+};
+
+static int play_sample(struct impl *impl, const char *sample)
+{
+	int res;
+	ca_context *ca;
+
+	if ((res = ca_context_create(&ca)) < 0) {
+		pw_log_error("canberra context create error: %s", ca_strerror(res));
+		res = -EIO;
+		goto exit;
+	}
+	if ((res = ca_context_open(ca)) < 0) {
+		pw_log_error("canberra context open error: %s", ca_strerror(res));
+		res = -EIO;
+		goto exit_destroy;
+	}
+	res = ca_context_play(ca, 0,
+			CA_PROP_EVENT_ID, sample,
+			CA_PROP_MEDIA_NAME, "X11 bell event",
+			CA_PROP_CANBERRA_CACHE_CONTROL, "permanent",
+			NULL);
+
+exit_destroy:
+	ca_context_destroy(ca);
+exit:
+	return res;
+}
+static void display_io(void *data, int fd, uint32_t mask)
+{
+	struct impl *impl = data;
+	XEvent e;
+	const char *sample;
+
+	while (XPending(impl->display)) {
+		XNextEvent(impl->display, &e);
+
+		if (((XkbEvent*) &e)->any.xkb_type != XkbBellNotify)
+			continue;
+
+		if (impl->properties)
+			sample = pw_properties_get(impl->properties, "sample.name");
+		else
+			sample = "bell-window-system";
+
+		pw_log_debug("play sample %s", sample);
+		play_sample(impl, sample);
+	}
+}
+
+static void x11_close(struct impl *impl)
+{
+	if (impl->source) {
+		pw_loop_destroy_source(impl->loop, impl->source);
+		impl->source = NULL;
+	}
+	if (impl->display) {
+		XCloseDisplay(impl->display);
+		impl->display = NULL;
+	}
+}
+
+static int x11_connect(struct impl *impl, const char *name)
+{
+	int res, major, minor;
+	unsigned int auto_ctrls, auto_values;
+
+	if (!(impl->display = XOpenDisplay(name))) {
+		pw_log_warn("XOpenDisplay() failed");
+		res = -EIO;
+		goto error;
+	}
+
+	impl->source = pw_loop_add_io(impl->loop,
+			ConnectionNumber(impl->display),
+			SPA_IO_IN, false, display_io, impl);
+
+	major = XkbMajorVersion;
+	minor = XkbMinorVersion;
+
+	if (!XkbLibraryVersion(&major, &minor)) {
+		pw_log_warn("XkbLibraryVersion() failed");
+		res = -EIO;
+		goto error;
+	}
+
+	major = XkbMajorVersion;
+	minor = XkbMinorVersion;
+
+	if (!XkbQueryExtension(impl->display, NULL, &impl->xkb_event_base,
+				NULL, &major, &minor)) {
+		res = -EIO;
+		pw_log_warn("XkbQueryExtension() failed");
+		goto error;
+	}
+
+	XkbSelectEvents(impl->display, XkbUseCoreKbd, XkbBellNotifyMask, XkbBellNotifyMask);
+	auto_ctrls = auto_values = XkbAudibleBellMask;
+	XkbSetAutoResetControls(impl->display, XkbAudibleBellMask, &auto_ctrls, &auto_values);
+	XkbChangeEnabledControls(impl->display, XkbUseCoreKbd, XkbAudibleBellMask, 0);
+
+	res = 0;
+error:
+	if (res < 0)
+		x11_close(impl);
+	return res;
+}
+
+static void module_destroy(void *data)
+{
+	struct impl *impl = data;
+
+	spa_hook_remove(&impl->module_listener);
+
+	if (impl->thread_loop)
+		pw_thread_loop_lock(impl->thread_loop);
+
+	x11_close(impl);
+
+	if (impl->thread_loop) {
+		pw_thread_loop_unlock(impl->thread_loop);
+		pw_thread_loop_destroy(impl->thread_loop);
+	}
+
+	pw_properties_free(impl->properties);
+
+	free(impl);
+}
+
+static const struct pw_impl_module_events module_events = {
+	PW_VERSION_IMPL_MODULE_EVENTS,
+	.destroy = module_destroy,
+};
+
+static const struct spa_dict_item module_x11_bell_info[] = {
+	{ PW_KEY_MODULE_AUTHOR, "Wim Taymans <wim.taymans@gmail.com>" },
+	{ PW_KEY_MODULE_DESCRIPTION, "X11 Bell interceptor" },
+	{ PW_KEY_MODULE_USAGE,	"sink.name=<name for the sink> "
+				"sample.name=<the sample name> "
+				"x11.display=<the X11 display> "
+				"x11.xauthority=<the X11 XAuthority> " },
+	{ PW_KEY_MODULE_VERSION, PACKAGE_VERSION },
+};
+SPA_EXPORT
+int pipewire__module_init(struct pw_impl_module *module, const char *args)
+{
+	struct pw_context *context = pw_impl_module_get_context(module);
+	struct impl *impl;
+	const char *name = NULL, *str;
+	int res;
+
+	PW_LOG_TOPIC_INIT(mod_topic);
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		return -ENOMEM;
+
+	pw_log_debug("module %p: new", impl);
+
+	impl->context = context;
+	impl->thread_loop = pw_thread_loop_new("X11 Bell", NULL);
+	if (impl->thread_loop == NULL) {
+		res = -errno;
+		pw_log_error("can't create thread loop: %m");
+		goto error;
+	}
+	impl->loop = pw_thread_loop_get_loop(impl->thread_loop);
+	impl->properties = args ? pw_properties_new_string(args) : NULL;
+
+	pw_impl_module_add_listener(module, &impl->module_listener, &module_events, impl);
+	pw_impl_module_update_properties(module, &SPA_DICT_INIT_ARRAY(module_x11_bell_info));
+
+	if (impl->properties) {
+		if ((str = pw_properties_get(impl->properties, "x11.xauthority")) != NULL) {
+			if (setenv("XAUTHORITY", str, 1)) {
+				res = -errno;
+				pw_log_error("XAUTHORITY setenv failed: %m");
+				goto error;
+			}
+		}
+		name = pw_properties_get(impl->properties, "x11.display");
+	}
+
+	/* we need to use a thread loop because this module will connect
+	 * to pipewire eventually and will then block the mainloop. */
+	pw_thread_loop_start(impl->thread_loop);
+
+	pw_thread_loop_lock(impl->thread_loop);
+	x11_connect(impl, name);
+	pw_thread_loop_unlock(impl->thread_loop);
+
+	return 0;
+error:
+	module_destroy(impl);
+	return res;
+
+}