Add optional meta control to ComponentProtocol and tidy up protocols.

praxiscore-api/src/main/java/org/praxislive/core/Info.java

@@ -619,7 +619,7 @@ public static abstract class ArgumentInfoBuilder<T extends ArgumentInfoBuilder<T
          * @return this
          */
         @SuppressWarnings("unchecked")
-        public T property(String key, Value value) {
+        public T property(String key, Object value) {
             if (ArgumentInfo.KEY_TYPE.equals(key)) {
                 throw new IllegalArgumentException("Reserved key");
             }

praxiscore-api/src/main/java/org/praxislive/core/protocols/ComponentProtocol.java

@@ -22,40 +22,57 @@
 package org.praxislive.core.protocols;
 
 import java.util.stream.Stream;
+import org.praxislive.core.ArgumentInfo;
 import org.praxislive.core.Component;
 import org.praxislive.core.ComponentInfo;
 import org.praxislive.core.ControlInfo;
 import org.praxislive.core.Info;
 import org.praxislive.core.Protocol;
+import org.praxislive.core.types.PMap;
 
 /**
- * Basic component protocol, providing access to the component info.
+ * Basic component protocol, providing access to the component info, and
+ * optional support for attaching metadata.
  */
-public class ComponentProtocol implements Protocol {
-
-    @Deprecated
-    public final static ComponentProtocol INSTANCE = new ComponentProtocol();
+public final class ComponentProtocol implements Protocol {
 
     /**
      * Name of the info control.
      */
-    public final static String INFO = "info";
+    public static final String INFO = "info";
+
+    /**
+     * Name of the optional meta control.
+     */
+    public static final String META = "meta";
 
     /**
      * Control info for the info control. A read-only property that returns the
      * component info. The response to calling this control should be the same
      * as calling {@link Component#getInfo}.
      */
-    public final static ControlInfo INFO_INFO
-            = ControlInfo.createReadOnlyPropertyInfo(
-                    ComponentInfo.info(),
-                    null);
+    public static final ControlInfo INFO_INFO
+            = Info.control(c -> c.readOnlyProperty().output(ComponentInfo.class));
+
+    /**
+     * Control info for the optional control. This control allows for arbitrary
+     * metadata to be attached to a component. The control works the same as a
+     * map property, except that the optional PMap input is replace merged with
+     * the existing value. This allows callers to replace or delete only the
+     * keys they are interested in.
+     * <p>
+     * See also {@link PMap#REPLACE}.
+     */
+    public static final ControlInfo META_INFO
+            = Info.control(c -> c.function()
+            .inputs(a -> a.type(PMap.class).property(ArgumentInfo.KEY_OPTIONAL, true))
+            .outputs(a -> a.type(PMap.class)));
 
     /**
      * A component info for this protocol. Can be used with
      * {@link Info.ComponentInfoBuilder#merge(org.praxislive.core.ComponentInfo)}.
      */
-    public final static ComponentInfo API_INFO = Info.component(cmp -> cmp
+    public static final ComponentInfo API_INFO = Info.component(cmp -> cmp
             .protocol(ComponentProtocol.class)
             .control(INFO, INFO_INFO)
     );
@@ -65,12 +82,21 @@ public Stream<String> controls() {
         return Stream.of(INFO);
     }
 
+    @Override
+    public Stream<String> optionalControls() {
+        return Stream.of(META);
+    }
+
     @Override
     public ControlInfo getControlInfo(String control) {
-        if (INFO.equals(control)) {
-            return INFO_INFO;
-        }
-        throw new IllegalArgumentException();
+        return switch (control) {
+            case INFO ->
+                INFO_INFO;
+            case META ->
+                META_INFO;
+            default ->
+                throw new IllegalArgumentException();
+        };
     }
 
 }

praxiscore-api/src/main/java/org/praxislive/core/protocols/ContainerProtocol.java

@@ -39,10 +39,7 @@
  * A container protocol that allows for calls to add / remove child components,
  * and connect / disconnect their ports.
  */
-public class ContainerProtocol implements Protocol {
-
-    @Deprecated
-    public final static ContainerProtocol INSTANCE = new ContainerProtocol();
+public final class ContainerProtocol implements Protocol {
 
     /**
      * Name of the add-child control.
@@ -187,23 +184,24 @@ public Stream<String> optionalControls() {
 
     @Override
     public ControlInfo getControlInfo(String control) {
-        switch (control) {
-            case ADD_CHILD:
-                return ADD_CHILD_INFO;
-            case REMOVE_CHILD:
-                return REMOVE_CHILD_INFO;
-            case CHILDREN:
-                return CHILDREN_INFO;
-            case CONNECT:
-                return CONNECT_INFO;
-            case DISCONNECT:
-                return DISCONNECT_INFO;
-            case CONNECTIONS:
-                return CONNECTIONS_INFO;
-            case SUPPORTED_TYPES:
-                return SUPPORTED_TYPES_INFO;
-        }
-        throw new IllegalArgumentException();
+        return switch (control) {
+            case ADD_CHILD ->
+                ADD_CHILD_INFO;
+            case REMOVE_CHILD ->
+                REMOVE_CHILD_INFO;
+            case CHILDREN ->
+                CHILDREN_INFO;
+            case CONNECT ->
+                CONNECT_INFO;
+            case DISCONNECT ->
+                DISCONNECT_INFO;
+            case CONNECTIONS ->
+                CONNECTIONS_INFO;
+            case SUPPORTED_TYPES ->
+                SUPPORTED_TYPES_INFO;
+            default ->
+                throw new IllegalArgumentException();
+        };
     }
 
 }

praxiscore-api/src/main/java/org/praxislive/core/protocols/StartableProtocol.java

@@ -34,9 +34,6 @@
  */
 public class StartableProtocol implements Protocol {
 
-    @Deprecated
-    public final static StartableProtocol INSTANCE = new StartableProtocol();
-
     /**
      * Name of the start control.
      */
@@ -94,14 +91,15 @@ public Stream<String> controls() {
 
     @Override
     public ControlInfo getControlInfo(String control) {
-        switch (control) {
-            case START:
-                return START_INFO;
-            case STOP:
-                return STOP_INFO;
-            case IS_RUNNING:
-                return IS_RUNNING_INFO;
-        }
-        throw new IllegalArgumentException();
+        return switch (control) {
+            case START ->
+                START_INFO;
+            case STOP ->
+                STOP_INFO;
+            case IS_RUNNING ->
+                IS_RUNNING_INFO;
+            default ->
+                throw new IllegalArgumentException();
+        };
     }
 }