Granite.Symbol: improve API

src/Widgets/DisplayWidget.vala

@@ -60,14 +60,14 @@ public class BluetoothIndicator.Widgets.DisplayWidget : Granite.Bin {
         if (state) {
             context = _("Middle-click to turn Bluetooth off");
             if (connected) {
-                symbol.state = Granite.Symbol.STATE_CHECKED;
+                symbol.state = Granite.SymbolState.ACTIVE;
                 description = _("Bluetooth connected");
             } else {
-                symbol.state = Granite.Symbol.STATE_NORMAL;
+                symbol.state = Granite.SymbolState.NORMAL;
                 description = _("Bluetooth is on");
             }
         } else {
-            symbol.state = Granite.Symbol.STATE_DISABLED;
+            symbol.state = Granite.SymbolState.DISABLED;
             description = _("Bluetooth is off");
             context = _("Middle-click to turn Bluetooth on");
         }

src/Widgets/Symbol.vala

@@ -3,21 +3,57 @@
 * SPDX-FileCopyrightText: 2026 elementary, Inc. (https://elementary.io)
 */
 
-public class Granite.Symbol : Granite.Bin {
-    public const int STATE_NORMAL = 0;
-    public const int STATE_DISABLED = 1;
-    public const int STATE_CHECKED = 2;
+namespace Granite.SymbolState {
+    // The default state
+    public const string NORMAL = "normal";
+    // Disabled state represented by a slash
+    public const string DISABLED = "disabled";
+    // e.g. paired, connected, needs attention
+    public const string ACTIVE = "active";
+}
 
+public class Granite.Symbol : Granite.Bin {
     public string resource_path { get; construct; }
 
     public int pixel_size {
         get { return image.pixel_size; }
         set { image.pixel_size = value; }
     }
 
-    public uint state {
+    public uint state_index {
         get { return svg.state; }
-        set { svg.state = value; }
+        set {
+            uint length = -1;
+            svg.get_state_names (out length);
+
+            if (value > length - 1) {
+                warning ("Granite.Symbol set to undefined state. Ignoring.");
+                return;
+            }
+
+            svg.state = value;
+            notify_property ("state");
+        }
+    }
+
+    public string state {
+        get {
+            uint length = -1;
+            return svg.get_state_names (out length)[state_index];
+        }
+        set {
+            uint length = -1;
+            var names = svg.get_state_names (out length);
+
+            for (int i = 0; i < length; i++) {
+                if (names[i] == value) {
+                    state_index = i;
+                    return;
+                }
+            }
+
+            warning ("Granite.Symbol set to undefined state. Ignoring.");
+        }
     }
 
     private Gtk.Image image;