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Diffstat (limited to 'csrc/services/brightness-service.c')
| -rw-r--r-- | csrc/services/brightness-service.c | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/csrc/services/brightness-service.c b/csrc/services/brightness-service.c new file mode 100644 index 0000000..32f0501 --- /dev/null +++ b/csrc/services/brightness-service.c @@ -0,0 +1,391 @@ +#include "services/brightness-service.h" +#include <gio/gio.h> +#include <math.h> + +// +// FoobarBrightnessService: +// +// Service managing the brightness level. This is implemented by +// - for read access: monitoring the "brightness" file in a "/sys/class/backlight" subdirectory, +// - for write access: invoking the "brightnessctl" command. +// + +struct _FoobarBrightnessService +{ + GObject parent_instance; + gint percentage; + GFileMonitor* file_monitor; + gulong file_monitor_handler_id; + gchar* device_name; + gchar* file_path; + gint max_brightness; +}; + +enum +{ + PROP_PERCENTAGE = 1, + N_PROPS, +}; + +static GParamSpec* props[N_PROPS] = { 0 }; + +static void foobar_brightness_service_class_init ( FoobarBrightnessServiceClass* klass ); +static void foobar_brightness_service_init ( FoobarBrightnessService* self ); +static void foobar_brightness_service_get_property ( GObject* object, + guint prop_id, + GValue* value, + GParamSpec* pspec ); +static void foobar_brightness_service_set_property ( GObject* object, + guint prop_id, + GValue const* value, + GParamSpec* pspec ); +static void foobar_brightness_service_finalize ( GObject* object ); +static void foobar_brightness_service_handle_changed ( GFileMonitor* monitor, + GFile* file, + GFile* other_file, + GFileMonitorEvent event_type, + gpointer userdata ); +static gint foobar_brightness_service_load_percentage ( FoobarBrightnessService* self ); +static void foobar_brightness_service_write_percentage ( FoobarBrightnessService* self ); +static void foobar_brightness_service_write_percentage_watch_cb( GPid pid, + gint status, + gpointer userdata ); +static void foobar_brightness_service_get_info ( gchar** out_device_name, + gchar** out_file_path, + gint* out_max_brightness ); +static gint foobar_brightness_service_read_value ( gchar const* path ); +static GFileMonitor* foobar_brightness_service_monitor ( gchar const* path ); + +G_DEFINE_FINAL_TYPE( FoobarBrightnessService, foobar_brightness_service, G_TYPE_OBJECT ) + +// --------------------------------------------------------------------------------------------------------------------- +// Service Implementation +// --------------------------------------------------------------------------------------------------------------------- + +// +// Static initialization for the brightness service. +// +void foobar_brightness_service_class_init( FoobarBrightnessServiceClass* klass ) +{ + GObjectClass* object_klass = G_OBJECT_CLASS( klass ); + object_klass->get_property = foobar_brightness_service_get_property; + object_klass->set_property = foobar_brightness_service_set_property; + object_klass->finalize = foobar_brightness_service_finalize; + + props[PROP_PERCENTAGE] = g_param_spec_int( + "percentage", + "Percentage", + "Current brightness percentage.", + 0, + 100, + 100, + G_PARAM_READWRITE ); + g_object_class_install_properties( object_klass, N_PROPS, props ); +} + +// +// Instance initialization for the brightness service. +// +void foobar_brightness_service_init( FoobarBrightnessService* self ) +{ + foobar_brightness_service_get_info( &self->device_name, &self->file_path, &self->max_brightness ); + self->percentage = foobar_brightness_service_load_percentage( self ); + if ( self->file_path ) + { + self->file_monitor = foobar_brightness_service_monitor( self->file_path ); + } + if ( self->file_monitor ) + { + self->file_monitor_handler_id = g_signal_connect( + self->file_monitor, + "changed", + G_CALLBACK( foobar_brightness_service_handle_changed ), + self ); + } + else + { + self->file_monitor_handler_id = 0; + } +} + +// +// Property getter implementation, mapping a property id to a method. +// +void foobar_brightness_service_get_property( + GObject* object, + guint prop_id, + GValue* value, + GParamSpec* pspec ) +{ + FoobarBrightnessService* self = (FoobarBrightnessService*)object; + + switch ( prop_id ) + { + case PROP_PERCENTAGE: + g_value_set_int( value, foobar_brightness_service_get_percentage( self ) ); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec ); + break; + } +} + +// +// Property setter implementation, mapping a property id to a method. +// +void foobar_brightness_service_set_property( + GObject* object, + guint prop_id, + GValue const* value, + GParamSpec* pspec ) +{ + FoobarBrightnessService* self = (FoobarBrightnessService*)object; + + switch ( prop_id ) + { + case PROP_PERCENTAGE: + foobar_brightness_service_set_percentage( self, g_value_get_int( value ) ); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID( object, prop_id, pspec ); + break; + } +} + +// +// Instance cleanup for the brightness service. +// +void foobar_brightness_service_finalize( GObject* object ) +{ + FoobarBrightnessService* self = (FoobarBrightnessService*)object; + + g_clear_signal_handler( &self->file_monitor_handler_id, self->file_monitor ); + g_clear_object( &self->file_monitor ); + g_clear_pointer( &self->device_name, g_free ); + g_clear_pointer( &self->file_path, g_free ); + + G_OBJECT_CLASS( foobar_brightness_service_parent_class )->finalize( object ); +} + +// --------------------------------------------------------------------------------------------------------------------- +// Public API +// --------------------------------------------------------------------------------------------------------------------- + +// +// Create a new brightness service instance. +// +FoobarBrightnessService* foobar_brightness_service_new( void ) +{ + return g_object_new( FOOBAR_TYPE_BRIGHTNESS_SERVICE, NULL ); +} + +// +// Get the current brightness percentage value. +// +gint foobar_brightness_service_get_percentage( FoobarBrightnessService* self ) +{ + g_return_val_if_fail( FOOBAR_IS_BRIGHTNESS_SERVICE( self ), 0 ); + + return self->percentage; +} + +// +// Update the current brightness percentage value. +// +void foobar_brightness_service_set_percentage( + FoobarBrightnessService* self, + gint value ) +{ + g_return_if_fail( FOOBAR_IS_BRIGHTNESS_SERVICE( self ) ); + + value = CLAMP( value, 0, 100 ); + if ( self->percentage != value ) + { + self->percentage = value; + g_object_notify_by_pspec( G_OBJECT( self ), props[PROP_PERCENTAGE] ); + foobar_brightness_service_write_percentage( self ); + } +} + +// --------------------------------------------------------------------------------------------------------------------- +// Signal Handlers +// --------------------------------------------------------------------------------------------------------------------- + +// +// Called by the file monitor when the contents of the "brightness" file have changed. +// +void foobar_brightness_service_handle_changed( + GFileMonitor* monitor, + GFile* file, + GFile* other_file, + GFileMonitorEvent event_type, + gpointer userdata ) +{ + (void)monitor; + (void)file; + (void)other_file; + (void)event_type; + FoobarBrightnessService* self = (FoobarBrightnessService*)userdata; + + gint new_percentage = foobar_brightness_service_load_percentage( self ); + if ( self->percentage != new_percentage ) + { + self->percentage = new_percentage; + g_object_notify_by_pspec( G_OBJECT( self ), props[PROP_PERCENTAGE] ); + } +} + +// --------------------------------------------------------------------------------------------------------------------- +// Helper Methods +// --------------------------------------------------------------------------------------------------------------------- + +// +// Load the current percentage value from the file at self->file_path. +// +// This requires file_path and max_brightness to be initialized, otherwise the brightness is assumed to be 100%. +// +gint foobar_brightness_service_load_percentage( FoobarBrightnessService* self ) +{ + if ( !self->file_path || self->max_brightness == -1 ) { return 100; } + + gint value = foobar_brightness_service_read_value( self->file_path ); + if ( value == -1 ) { return 100; } + + gdouble rel = value / (gdouble)self->max_brightness; + gint percentage = (gint)round( rel * 100. ); + return CLAMP( percentage, 0, 100 ); +} + +// +// Asynchronously update the current percentage value by invoking brightnessctl. +// +// This requires device_name to be initialized. +// +void foobar_brightness_service_write_percentage( FoobarBrightnessService* self ) +{ + if ( !self->device_name ) { return; } + + g_autofree gchar* percentage_string = g_strdup_printf( "%d%%", self->percentage ); + gchar* args[] = { "brightnessctl", "-d", self->device_name, "s", percentage_string, NULL }; + + g_autoptr( GError ) error = NULL; + GPid child_pid; + if ( !g_spawn_async( + NULL, + args, + NULL, + G_SPAWN_DO_NOT_REAP_CHILD + | G_SPAWN_SEARCH_PATH + | G_SPAWN_STDIN_FROM_DEV_NULL + | G_SPAWN_STDOUT_TO_DEV_NULL + | G_SPAWN_STDERR_TO_DEV_NULL, + NULL, + NULL, + &child_pid, + &error ) ) + { + g_warning( "Unable to spawn brightnessctl: %s", error->message ); + return; + } + + g_child_watch_add( child_pid, foobar_brightness_service_write_percentage_watch_cb, NULL ); +} + +// +// Called when the brightnessctl child process has finished. +// +void foobar_brightness_service_write_percentage_watch_cb( + GPid pid, + gint status, + gpointer userdata ) +{ + (void)userdata; + + g_autoptr( GError ) error = NULL; + if ( !g_spawn_check_wait_status( status, &error ) ) + { + g_warning( "Unable to set brightness with brightnessctl: %s", error->message ); + } + + g_spawn_close_pid( pid ); +} + +// +// Initialize information for the brightness device. +// +// This looks for the first directory in the /sys/class/backlight directories and uses it as the device name. It also +// populates out_file_path to the path of this directory and out_max_brightness to the contents of the corresponding +// max_brightness file. +// +void foobar_brightness_service_get_info( + gchar** out_device_name, + gchar** out_file_path, + gint* out_max_brightness ) +{ + *out_device_name = NULL; + *out_file_path = NULL; + *out_max_brightness = -1; + + g_autoptr( GFile ) dir = g_file_new_for_path( "/sys/class/backlight" ); + if ( !dir ) { return; } + + g_autoptr( GFileEnumerator ) enumerator = g_file_enumerate_children( + dir, + "standard::", + G_FILE_QUERY_INFO_NONE, + NULL, + NULL ); + if ( !enumerator ) { return; } + + g_autoptr( GFileInfo ) info = g_file_enumerator_next_file( enumerator, NULL, NULL ); + g_file_enumerator_close( enumerator, NULL, NULL ); + if ( !info ) { return; } + + gchar* device_name = g_strdup( g_file_info_get_name( info ) ); + gchar* current_file_path = g_strdup_printf( "/sys/class/backlight/%s/brightness", device_name ); + gchar* max_file_path = g_strdup_printf( "/sys/class/backlight/%s/max_brightness", device_name ); + *out_device_name = device_name; + *out_file_path = current_file_path; + *out_max_brightness = foobar_brightness_service_read_value( max_file_path ); + g_free( max_file_path ); +} + +// +// Read the current brightness integer (not percentage) from the given file path. +// +gint foobar_brightness_service_read_value( gchar const* path ) +{ + g_autofree gchar* contents = NULL; + g_autoptr( GError ) error = NULL; + if ( !g_file_get_contents( path, &contents, NULL, &error ) ) + { + g_warning( "Unable to read %s: %s", path, error->message ); + return -1; + } + + errno = 0; + char* endptr; + long result = strtol( contents, &endptr, 10 ); + if ( errno != 0 || endptr == contents || result > INT_MAX || result < 0 ) + { + g_warning( "Expected integer in %s, but got: %s", path, contents ); + return -1; + } + + return (gint)result; +} + +// +// Set up a file monitor for the given path. +// +GFileMonitor* foobar_brightness_service_monitor( gchar const* path ) +{ + g_autoptr( GFile ) file = g_file_new_for_path( path ); + if ( !file ) { return NULL; } + + g_autoptr( GError ) error = NULL; + GFileMonitor* monitor = g_file_monitor_file( file, G_FILE_MONITOR_NONE, NULL, &error ); + if ( !monitor ) { g_warning( "Unable to monitor brightness: %s", error->message ); } + + return monitor; +} |