Add Brightness slider widget (#211)

README.md

@@ -53,6 +53,7 @@ These widgets can be customized, added, removed and even reordered
 - Menubar with dropdown and buttons
 - Button grid
 - Volume slider using PulseAudio
+- Backlight slider
 
 ## Planned Features
 

man/swaync.5.scd

@@ -206,6 +206,7 @@ config file to be able to detect config errors
 	multiple of same widget: ++
 		Append a # with any value to the end of the widget name. ++
 		Example: "title#TheMainTitle" ++
+		To address this widget specifically in the css file use the css class .TheMainTitle ++
 	example:
 ```
 {
@@ -223,6 +224,7 @@ config file to be able to detect config errors
 	multiple of same widget: ++
 		Append a # with any value to the end of the widget name. ++
 		Example: "title#TheMainTitle" ++
+		To address this widget specifically in the css file use the css class .TheMainTitle ++
 	Widgets to customize: ++
 		*title*++
 			type: object ++
@@ -379,7 +381,33 @@ config file to be able to detect config errors
 					optional: true ++
 					default: "Volume" ++
 					description: Text displayed in front of the volume slider ++
-			description: Slider to control pulse volume ++				
+			description: Slider to control pulse volume ++
+		*backlight*++
+			type: object ++
+			css class: widget-backlight ++
+			properties: ++
+				label: ++
+					type: string ++
+					optional: true ++
+					default: "Brightness" ++
+					description: Text displayed in front of the backlight slider ++
+				device: ++
+					type: string ++
+					optional: true ++
+					default: "intel_backlight" ++
+					description: Device in `/sys/class/backlight` or `/sys/class/leds` ++
+				subsystem: ++
+					type: string ++
+					optional: true ++
+					default: "backlight" ++
+					description: Kernel subsystem for brightness control ++
+					enum: ["backlight", "leds"] ++
+				min: ++
+					type: integer ++
+					optional: true ++
+					default: 0 ++
+					description: Lowest possible value for brightness ++
+			description: Slider to control screen brightness ++	
 
 	example:
 ```

src/configSchema.json

@@ -295,6 +295,9 @@
         },
         "^volume(#[a-zA-Z0-9_-]{1,}){0,1}?$": {
           "$ref": "#/widgets/volume"
+        },
+        "^backlight(#[a-zA-Z0-9_-]{1,}){0,1}?$": {
+          "$ref": "#/widgets/backlight"
         }
       }
     }
@@ -449,7 +452,35 @@
           "description": "Text displayed in front of the volume slider",
           "default": "Volume"
         }
-      }
+      }      
+    },
+    "backlight": {
+      "type": "object",
+      "description": "Slider to control monitor brightness",
+      "additionalProperties": false,
+      "properties": {
+        "label": {
+          "type": "string",
+          "description": "Text displayed in front of the backlight slider",
+          "default": "Brightness"
+        },
+        "device": {
+          "type": "string",
+          "description": "Name of monitor (find possible devices using `ls /sys/class/backlight` or `ls /sys/class/leds`)",
+          "default": "intel_backlight"
+        },
+        "subsystem": {
+          "type": "string",
+          "description": "Kernel subsystem for brightness control",
+          "default": "backlight",
+          "enum": ["backlight", "leds"]
+        },
+        "min": {
+          "type": "integer",
+          "default": 0,
+          "description": "Lowest possible value for brightness"
+        }
+      }      
     }
   }
 }

src/controlCenter/widgets/backlight/backlight.vala

+using GLib;
+
+namespace SwayNotificationCenter.Widgets {
+    public class Backlight : BaseWidget {
+        public override string widget_name {
+            get {
+                return "backlight";
+            }
+        }
+
+        BacklightUtil client;
+
+        Gtk.Label label_widget = new Gtk.Label (null);
+        Gtk.Scale slider = new Gtk.Scale.with_range (Gtk.Orientation.HORIZONTAL, 0, 100, 1);
+
+        public Backlight (string suffix, SwayncDaemon swaync_daemon, NotiDaemon noti_daemon) {
+            base (suffix, swaync_daemon, noti_daemon);
+
+            Json.Object ? config = get_config (this);
+            if (config != null) {
+                string ? label = get_prop<string> (config, "label");
+                label_widget.set_label (label ?? "Brightness");
+                string device = (get_prop<string> (config, "device") ?? "intel_backlight");
+                string subsystem = (get_prop<string> (config, "subsystem") ?? "backlight");
+                int min = int.max (0, get_prop<int> (config, "min"));
+
+                switch (subsystem) {
+                    default:
+                    case "backlight":
+                        if (subsystem != "backlight")
+                            info ("Invalid subsystem %s for device %s. " +
+                                  "Use 'backlight' or 'leds'. Using default: 'backlight'",
+                                  subsystem, device);
+                        client = new BacklightUtil ("backlight", device);
+                        slider.set_range (min, 100);
+                        break;
+                    case "leds":
+                        client = new BacklightUtil ("leds", device);
+                        slider.set_range (min, this.client.get_max_value ());
+                        break;
+                }
+            }
+
+            this.client.brightness_change.connect ((percent) => {
+                if (percent < 0) { // invalid device path
+                    hide ();
+                } else {
+                    slider.set_value (percent);
+                }
+            });
+
+            slider.set_draw_value (false);
+            slider.set_round_digits (0);
+            slider.value_changed.connect (() => {
+                this.client.set_brightness ((float) slider.get_value ());
+                slider.tooltip_text = ((int) slider.get_value ()).to_string ();
+            });
+
+            add (label_widget);
+            pack_start (slider, true, true, 0);
+
+            show_all ();
+        }
+
+        public override void on_cc_visibility_change (bool val) {
+            if (val) {
+                this.client.start ();
+            } else {
+                this.client.close ();
+            }
+        }
+    }
+}

src/controlCenter/widgets/backlight/backlightUtil.vala

+namespace SwayNotificationCenter.Widgets {
+    class BacklightUtil {
+
+        [DBus (name = "org.freedesktop.login1.Session")]
+        interface Login1 : Object {
+            public abstract void set_brightness (string subsystem,
+                                                 string name, uint32 brightness) throws GLib.Error;
+        }
+
+        string path_current;
+        string path_max;
+        File fd;
+        FileMonitor monitor = null;
+
+        int max;
+
+        Login1 login1;
+        string device;
+        string subsystem;
+
+        public signal void brightness_change (int percent);
+
+        public BacklightUtil (string s, string d) {
+            this.subsystem = s;
+            this.device = d;
+
+            path_current = Path.build_path (Path.DIR_SEPARATOR_S,
+                                            "/sys", "class", subsystem, device, "brightness");
+            path_max = Path.build_path (Path.DIR_SEPARATOR_S,
+                                        "/sys", "class", subsystem, device, "max_brightness");
+            fd = File.new_for_path (path_current);
+            if (fd.query_exists ()) {
+                set_max_value ();
+                try {
+                    monitor = fd.monitor (FileMonitorFlags.NONE, null);
+                } catch (Error e) {
+                    error ("Error %s\n", e.message);
+                }
+            } else {
+                this.brightness_change (-1);
+                warning ("Could not find device %s\n", path_current);
+                close ();
+            }
+
+            try {
+                // setup DBus for setting brightness
+                login1 = Bus.get_proxy_sync (BusType.SYSTEM,
+                                             "org.freedesktop.login1", "/org/freedesktop/login1/session/auto");
+            } catch (Error e) {
+                error ("Error %s\n", e.message);
+            }
+        }
+
+        public void start () {
+            if (fd.query_exists ()) {
+                // get changes made while controlCenter not shown
+                get_brightness ();
+
+                connect_monitor ();
+            } else {
+                this.brightness_change (-1);
+                warning ("Could not find device %s\n", path_current);
+                close ();
+            }
+        }
+
+        private void connect_monitor () {
+            if (monitor != null) {
+                // connect monitor to monitor changes
+                monitor.changed.connect ((src, dest, event) => {
+                    get_brightness ();
+                });
+            }
+        }
+
+        public void close () {
+            if (monitor != null) monitor.cancel ();
+        }
+
+        public void set_brightness (float percent) {
+            this.close ();
+            try {
+                if (subsystem == "backlight") {
+                    int actual = calc_actual (percent);
+                    login1.set_brightness (subsystem, device, actual);
+                } else {
+                    login1.set_brightness (subsystem, device, (uint32) percent);
+                }
+            } catch (Error e) {
+                error ("Error %s\n", e.message);
+            }
+            connect_monitor ();
+        }
+
+        // get current brightness and emit signal
+        private void get_brightness () {
+            try {
+                var dis = new DataInputStream (fd.read (null));
+                string data = dis.read_line (null);
+                int val = calc_percent (int.parse (data));
+                this.brightness_change (val);
+            } catch (Error e) {
+                error ("Error %s\n", e.message);
+            }
+        }
+
+        private void set_max_value () {
+            try {
+                File fd_max = File.new_for_path (path_max);
+                DataInputStream dis_max = new DataInputStream (fd_max.read (null));
+                string data = dis_max.read_line (null);
+                max = int.parse (data);
+            } catch (Error e) {
+                error ("Error %s\n", e.message);
+            }
+        }
+
+        private int calc_percent (int val) {
+            return val * 100 / max;
+        }
+
+        private int calc_actual (float val) {
+            return (int) val * max / 100;
+        }
+
+        public int get_max_value () {
+            return this.max;
+        }
+    }
+}

src/controlCenter/widgets/factory.vala

@@ -29,6 +29,9 @@ namespace SwayNotificationCenter.Widgets {
             case "volume":
                 widget = new Volume (suffix, swaync_daemon, noti_daemon);
                 break;
+            case "backlight":
+                widget = new Backlight (suffix, swaync_daemon, noti_daemon);
+                break;
             default:
                 warning ("Could not find widget: \"%s\"!", key);
                 return null;

src/meson.build

@@ -44,6 +44,9 @@ widget_sources = [
   'controlCenter/widgets/volume/volume.vala',
   'controlCenter/widgets/volume/pulseDaemon.vala',
   'controlCenter/widgets/volume/pulseDevice.vala',
+  # Widget: Backlight Slider
+  'controlCenter/widgets/backlight/backlight.vala',
+  'controlCenter/widgets/backlight/backlightUtil.vala',
 ]
 
 app_sources = [

src/style.css

@@ -290,3 +290,11 @@
   margin: 8px;
   border-radius: 12px;
 }
+
+/* Backlight widget */
+.widget-backlight {
+  background-color: @noti-bg;
+  padding: 8px;
+  margin: 8px;
+  border-radius: 12px;
+}