Continued work on registry (which I am now terming TypeManager).

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269079 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/DefaultTypeManager.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included with this distribution in
+ * the LICENSE file.
+ */
+package org.apache.myrmidon.components.type;
+
+import java.util.HashMap;
+import org.apache.avalon.framework.component.Component;
+import org.apache.avalon.framework.component.ComponentException;
+import org.apache.avalon.framework.component.ComponentSelector;
+
+/**
+ * The interface that is used to manage types.
+ *
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ */
+public class DefaultTypeManager
+    implements TypeManager
+{
+    ///Parent type manager to inherit values from.
+    private final TypeManager  m_parent;
+
+    ///Maps role to TypedComponentSelector.
+    private final HashMap      m_roleMap      = new HashMap();
+
+    public DefaultTypeManager( final TypeManager parent )
+    {
+        m_parent = parent;
+    }
+
+    public Component lookup( final String role )
+        throws ComponentException
+    {
+        final ComponentSelector selector = (ComponentSelector)m_roleMap.get( role );
+        if( null != selector )
+        {
+            return selector;
+        }
+        else
+        {
+            throw new ComponentException( "Unable to provide implementation for '" + 
+                                          role + "'" );
+        }
+    }
+
+    public void release( final Component component )
+    {
+    }
+
+    public void registerType( final String role, 
+                              final String shorthandName, 
+                              final ComponentFactory factory ) 
+        throws Exception
+    {
+        final TypedComponentSelector selector = createSelector( role );
+        selector.register( shorthandName, factory );
+    }
+
+    /**
+     * Get a selector of appropriate role.
+     * Create a Selector if none exists with same name.
+     *
+     * @param role the role name(must be name of work interface)
+     * @return the Selector for interface
+     * @exception ComponentException if role exists and not a selector, role does not 
+     *            specify accessible work interface, or 
+     */
+    private TypedComponentSelector createSelector( final String role )
+        throws ComponentException
+    {
+        TypedComponentSelector selector = (TypedComponentSelector)m_roleMap.get( role );
+        if( null != selector ) return selector;
+
+        if( null != m_parent )
+        {
+            final TypedComponentSelector parentSelector = getTypedSelector( m_parent, role );
+
+            if( null != parentSelector )
+            {
+                selector = new TypedComponentSelector( parentSelector );
+            }
+        }
+
+        ///If we haven't goa selector try to create a new one
+        if( null == selector )
+        {
+            try
+            {
+                //TODO: Should we use ContextClassLoader here ??? Or perhaps try that on failure??
+                final Class clazz = Class.forName( role );
+                selector = new TypedComponentSelector( clazz );
+            }
+            catch( final Exception e )
+            {
+                throw new ComponentException( "Role '" + role + "' does not specify " +
+                                              "accessible work interface" );
+            }
+        }        
+
+        m_roleMap.put( role, selector );
+
+        return selector;
+    }
+
+    private TypedComponentSelector getTypedSelector( final TypeManager typeManager, 
+                                                     final String role )
+    {
+        try
+        {
+            return (TypedComponentSelector)typeManager.lookup( role );
+        }
+        catch( final ComponentException ce ) {}
+        catch( final ClassCastException cce ) {}
+        
+        return null;
+    }
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/TypeManager.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) The Apache Software Foundation. All rights reserved.
+ *
+ * This software is published under the terms of the Apache Software License
+ * version 1.1, a copy of which has been included with this distribution in
+ * the LICENSE file.
+ */
+package org.apache.myrmidon.components.type;
+
+import org.apache.avalon.framework.component.ComponentManager;
+
+/**
+ * The interface that is used to manage types.
+ *
+ * @author <a href="mailto:donaldp@apache.org">Peter Donald</a>
+ */
+public interface TypeManager
+    extends ComponentManager
+{
+    String ROLE = "org.apache.myrmidon.components.type.TypeManager";
+
+    void registerType( String role, String shorthandName, ComponentFactory factory )
+        throws Exception;
+}

proposal/myrmidon/src/java/org/apache/myrmidon/components/type/TypedComponentSelector.java

@@ -21,13 +21,25 @@ import org.apache.avalon.framework.component.ComponentException;
 public class TypedComponentSelector
     implements ComponentSelector
 {
-    private final HashMap  m_factorys = new HashMap();
+    ///Parent Selector
+    private final TypedComponentSelector  m_parent;
 
-    private final Class    m_type;
+    ///Map of name->factory list
+    private final HashMap                 m_factorys = new HashMap();
+
+    ///Type expected to be created from factorys
+    private final Class                   m_type;
 
     public TypedComponentSelector( final Class type )
     {
         m_type = type;
+        m_parent = null;
+    }
+
+    public TypedComponentSelector( final TypedComponentSelector parent )
+    {
+        m_type = parent.getType();
+        m_parent = parent;
     }
 
     /**
@@ -46,14 +58,15 @@ public class TypedComponentSelector
             throw new ComponentException( "Invalid hint, expected a string not a " + 
                                           hint.getClass().getName() );
         }
-        
-        final Component component = createComponent( (String)hint );
+
+        final String name = (String)hint;
+        final Component component = createComponent( name );
 
         if( null != component )
         {
             if( m_type.isInstance( component ) )
             {
-                throw new ComponentException( "Implementation of " + hint + " is not of " +
+                throw new ComponentException( "Implementation of " + name + " is not of " +
                                               "correct type (" + m_type.getClass().getName() + ")" );
             }
 
@@ -61,7 +74,7 @@ public class TypedComponentSelector
         }
         else
         {
-            throw new ComponentException( "Unable to provide implementation for " + hint );
+            throw new ComponentException( "Unable to provide implementation for " + name );
         }
     }
 
@@ -77,11 +90,22 @@ public class TypedComponentSelector
     /**
      * Populate the ComponentSelector.
      */
-    public void put( final String name, final ComponentFactory factory )
+    public void register( final String name, final ComponentFactory factory )
     {
         m_factorys.put( name, factory );
     }
 
+    /**
+     * Retrieve type managed by selector.
+     * Used by other instances of TypedComponentSelector.
+     *
+     * @return the type class
+     */
+    protected final Class getType()
+    {
+        return m_type;
+    }
+
     /**
      * Helper method for subclasses to retrieve component map.
      *