Show and control channel subscriptions

Track the subscription state from the notifychannelsubscribed events, draw
subscribed and unsubscribed channels apart with the pack's icons (and the
built-in glyph as a hollow cone), and offer subscribe/unsubscribe entries —
channel and family — in the channel context menu.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

ts3-client/swing/src/main/java/com/ts3client/ui/Icons.java

@@ -32,6 +32,18 @@ public final class Icons {
         return IconTheme.icon(key);
     }
 
+    /**
+     * @return the pack's icon for the first key it has, or {@code null} when it has none
+     * of them — packs differ in which variants they ship
+     */
+    public static ImageIcon ofAny(String... keys) {
+        for (String key : keys) {
+            ImageIcon icon = IconTheme.icon(key);
+            if (icon != null) return icon;
+        }
+        return null;
+    }
+
     /** @return the pack's icon at a given size, or {@code null} when it has none */
     public static ImageIcon of(String key, int size) {
         return IconTheme.icon(key, size);
@@ -46,6 +58,18 @@ public final class Icons {
         return icon != null ? icon : make(fallback);
     }
 
+    /**
+     * Like {@link #themed(String, Painter)}, but tries the keys in turn — packs need not
+     * ship every variant (none of TeamSpeak's own has a subscribed password channel).
+     */
+    private static ImageIcon themed(String[] keys, Painter fallback) {
+        for (String key : keys) {
+            ImageIcon icon = IconTheme.icon(key, SZ);
+            if (icon != null) return icon;
+        }
+        return make(fallback);
+    }
+
     private static ImageIcon make(Painter p) {
         BufferedImage img = new BufferedImage(SZ, SZ, BufferedImage.TYPE_INT_ARGB);
         Graphics2D g = img.createGraphics();
@@ -62,18 +86,26 @@ public final class Icons {
         return themed("SERVER_GREEN", Icons::paintServer);
     }
 
-    public static ImageIcon channel() {
-        return themed("CHANNEL_GREEN", g -> paintChannel(g, new Color(0x3E7CB1), false));
+    public static ImageIcon channel(boolean subscribed) {
+        return themed(keys("CHANNEL_GREEN", subscribed),
+                g -> paintChannel(g, new Color(0x3E7CB1), false, subscribed));
     }
 
     /** A channel nobody can join without its password. */
-    public static ImageIcon channelLocked() {
-        return themed("CHANNEL_PRIVATE", g -> paintChannel(g, new Color(0x8A6D3B), true));
+    public static ImageIcon channelLocked(boolean subscribed) {
+        return themed(keys("CHANNEL_PRIVATE", subscribed),
+                g -> paintChannel(g, new Color(0x8A6D3B), true, subscribed));
     }
 
     /** A channel that has reached its client limit. */
-    public static ImageIcon channelFull() {
-        return themed("CHANNEL_RED", g -> paintChannel(g, new Color(0xA53F3F), false));
+    public static ImageIcon channelFull(boolean subscribed) {
+        return themed(keys("CHANNEL_RED", subscribed),
+                g -> paintChannel(g, new Color(0xA53F3F), false, subscribed));
+    }
+
+    /** The pack keys to try for a channel icon, most specific first. */
+    private static String[] keys(String base, boolean subscribed) {
+        return subscribed ? new String[]{base + "_SUBSCRIBED", base} : new String[]{base};
     }
 
     // ---- client status icons ----
@@ -172,16 +204,24 @@ public final class Icons {
         g.fillOval(4, 10, 2, 2);
     }
 
-    private static void paintChannel(Graphics2D g, Color c, boolean lock) {
-        g.setColor(c);
-        g.setStroke(new BasicStroke(1.6f));
-        // simple speaker-cone glyph
-        g.fillRect(2, 6, 3, 4);
+    /**
+     * The speaker-cone glyph. An unsubscribed channel is drawn hollow and without the
+     * sound waves, so the two states stay apart even without an icon pack.
+     */
+    private static void paintChannel(Graphics2D g, Color c, boolean lock, boolean subscribed) {
         int[] xs = {5, 9, 9, 5};
         int[] ys = {6, 3, 13, 10};
-        g.fillPolygon(xs, ys, 4);
-        g.setStroke(new BasicStroke(1.4f));
-        g.drawArc(9, 5, 4, 6, -60, 120);
+        g.setColor(c);
+        g.setStroke(new BasicStroke(subscribed ? 1.6f : 1.2f));
+        if (subscribed) {
+            g.fillRect(2, 6, 3, 4);
+            g.fillPolygon(xs, ys, 4);
+            g.setStroke(new BasicStroke(1.4f));
+            g.drawArc(9, 5, 4, 6, -60, 120);
+        } else {
+            g.drawRect(2, 6, 3, 4);
+            g.drawPolygon(xs, ys, 4);
+        }
         if (lock) {
             g.setColor(new Color(0xB8860B));
             g.fillRoundRect(10, 9, 5, 5, 1, 1);