Latest code drop

chapter05/build.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0"?>
+<project name="chapter05" default="dist">
+  <property name="chapter" value="chapter05"/>
+  <import file="../build.xml"/>
+</project>

chapter05/paint-example/build.xml

@@ -0,0 +1,40 @@
+<?xml version="1.0"?>
+<project name="paint.example" default="dist">
+
+  <property name="version" value="5.0"/>
+  <dirname property="example.dir" file="${ant.file.paint.example}"/>
+  <import file="../build.xml"/>
+
+  <target name="shape">
+    <ant dir="${example.dir}/org.foo.shape" inheritAll="false"/>
+  </target>
+
+  <target name="circle">
+    <ant dir="${example.dir}/org.foo.shape.circle" inheritAll="false"/>
+  </target>
+
+  <target name="circle.resource-de">
+    <ant dir="${example.dir}/org.foo.shape.circle.resource-de" inheritAll="false"/>
+  </target>
+
+  <target name="triangle">
+    <ant dir="${example.dir}/org.foo.shape.triangle" inheritAll="false"/>
+  </target>
+
+  <target name="triangle.resource-de">
+    <ant dir="${example.dir}/org.foo.shape.triangle.resource-de" inheritAll="false"/>
+  </target>
+
+  <target name="square">
+    <ant dir="${example.dir}/org.foo.shape.square" inheritAll="false"/>
+  </target>
+
+  <target name="square.resource-de">
+    <ant dir="${example.dir}/org.foo.shape.square.resource-de" inheritAll="false"/>
+  </target>
+
+  <target name="paint">
+    <ant dir="${example.dir}/org.foo.paint" inheritAll="false"/>
+  </target>
+
+</project>

chapter05/paint-example/org.foo.paint/build.properties

@@ -0,0 +1,18 @@
+#-------------------------------------------------
+title=Paint Example - Paint Frame
+#-------------------------------------------------
+
+module=org.foo.paint
+custom=true
+
+Bundle-Activator: ${module}.Activator
+
+Private-Package: \
+ ${module}
+
+Import-Package: \
+ org.foo.shape;version="[5.0,6.0)", \
+ org.osgi.framework;version="[1.3,2.0)", \
+ org.osgi.util.tracker;version="[1.3,2.0)", \
+ javax.swing
+

chapter05/paint-example/org.foo.paint/build.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0"?>
+<project name="paint" default="dist">
+
+  <property file="build.properties"/>
+  <import file="../build.xml"/>
+
+  <target name="compile" depends="shape,common.compile"/>
+
+  <target name="local.dist" depends="common.local.dist,launcher,shell">
+    <copy file="${launcher.jar}" todir="${example.dir}"/>
+    <copy todir="${dist}">
+      <path refid="shell.tty"/>
+    </copy>
+  </target>
+
+  <target name="local.clean" depends="common.local.clean">
+    <delete file="${example.dir}/launcher.jar"/>
+  </target>
+
+</project>

chapter05/paint-example/org.foo.paint/src/org/foo/paint/Activator.java

@@ -0,0 +1,100 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.foo.paint;
+
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import javax.swing.JFrame;
+import javax.swing.SwingUtilities;
+import org.osgi.framework.*;
+
+/**
+ * The activator of the host application bundle. The activator creates the main
+ * application <tt>JFrame</tt> and starts tracking <tt>SimpleShape</tt>
+ * services. All activity is performed on the Swing event thread to avoid
+ * synchronization and repainting issues. Closing the application window will
+ * result in <tt>Bundle.stop()</tt> being called on the system bundle, which
+ * will cause the framework to shutdown and the JVM to exit.
+ **/
+public class Activator implements BundleActivator, Runnable {
+  private BundleContext m_context = null;
+  private PaintFrame m_frame = null;
+  private ShapeTracker m_shapetracker = null;
+
+  /**
+   * Displays the applications window and starts service tracking; everything is
+   * done on the Swing event thread to avoid synchronization and repainting
+   * issues.
+   * 
+   * @param context The context of the bundle.
+   **/
+  public void start(BundleContext context) {
+    m_context = context;
+    if (SwingUtilities.isEventDispatchThread()) {
+      run();
+    } else {
+      try {
+        javax.swing.SwingUtilities.invokeAndWait(this);
+      } catch (Exception ex) {
+        ex.printStackTrace();
+      }
+    }
+  }
+
+  /**
+   * Stops service tracking and disposes of the application window.
+   * 
+   * @param context The context of the bundle.
+   **/
+  public void stop(BundleContext context) {
+    m_shapetracker.close();
+    final PaintFrame frame = m_frame;
+    javax.swing.SwingUtilities.invokeLater(new Runnable() {
+      public void run() {
+        frame.setVisible(false);
+        frame.dispose();
+      }
+    });
+  }
+
+  /**
+   * This method actually performs the creation of the application window. It is
+   * intended to be called by the Swing event thread and should not be called
+   * directly.
+   **/
+  public void run() {
+    m_frame = new PaintFrame();
+
+    m_frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
+    m_frame.addWindowListener(new WindowAdapter() {
+      public void windowClosing(WindowEvent evt) {
+        try {
+          m_context.getBundle(0).stop();
+        } catch (BundleException ex) {
+          ex.printStackTrace();
+        }
+      }
+    });
+
+    m_frame.setVisible(true);
+
+    m_shapetracker = new ShapeTracker(m_context, m_frame);
+    m_shapetracker.open();
+  }
+}

chapter05/paint-example/org.foo.paint/src/org/foo/paint/DefaultShape.java

@@ -0,0 +1,124 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.foo.paint;
+
+import java.awt.*;
+import javax.swing.ImageIcon;
+import org.foo.shape.SimpleShape;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.ServiceReference;
+
+/**
+ * This class is used as a proxy to defer object creation from shape provider
+ * bundles and also as a placeholder shape when previously used shapes are no
+ * longer available. These two purposes are actually orthogonal, but were
+ * combined into a single class to reduce the number of classes in the
+ * application. The proxy-related functionality is introduced as a way to lazily
+ * create shape objects in an effort to improve performance; this level of
+ * indirection could be removed if eager creation of objects is not a concern.
+ * Since this application uses the service-based extension appraoch, lazy shape
+ * creation will only come into effect if service providers register service
+ * factories instead of directly registering <tt>SimpleShape</tt> or if they use
+ * a technology like Declarative Services or iPOJO to register services. Since
+ * the example providers register services instances directly there is no
+ * laziness in the example, but the proxy approach is still used to demonstrate
+ * how to make laziness possible and to keep it similar to the extender-based
+ * approach.
+ **/
+class DefaultShape implements SimpleShape {
+  private SimpleShape m_shape;
+  private ImageIcon m_icon;
+  private BundleContext m_context;
+  private ServiceReference m_ref;
+
+  /**
+   * This constructs a placeholder shape that draws a default icon. It is used
+   * when a previously drawn shape is no longer available.
+   **/
+  public DefaultShape() {
+  // Do nothing.
+  }
+
+  /**
+   * This constructs a proxy shape that lazily gets the shape service.
+   * 
+   * @param context The bundle context to use for retrieving the shape service.
+   * @param ref The service reference of the service.
+   **/
+  public DefaultShape(BundleContext context, ServiceReference ref) {
+    m_context = context;
+    m_ref = ref;
+  }
+
+  /**
+   * This method tells the proxy to dispose of its service object; this is
+   * called when the underlying service goes away.
+   **/
+  public void dispose() {
+    if (m_shape != null) {
+      m_context.ungetService(m_ref);
+      m_context = null;
+      m_ref = null;
+      m_shape = null;
+    }
+  }
+
+  /**
+   * Implements the <tt>SimpleShape</tt> interface method. When acting as a
+   * proxy, this method gets the shape service and then uses it to draw the
+   * shape. When acting as a placeholder shape, this method draws the default
+   * icon.
+   * 
+   * @param g2 The graphics object used for painting.
+   * @param p The position to paint the triangle.
+   **/
+  public void draw(Graphics2D g2, Point p) {
+    // If this is a proxy shape, instantiate the shape class
+    // and use it to draw the shape.
+    if (m_context != null) {
+      try {
+        if (m_shape == null) {
+          // Get the shape service.
+          m_shape = (SimpleShape) m_context.getService(m_ref);
+        }
+        // Draw the shape.
+        m_shape.draw(g2, p);
+        // If everything was successful, then simply return.
+        return;
+      } catch (Exception ex) {
+        // This generally should not happen, but if it does then
+        // we can just fall through and paint the default icon.
+      }
+    }
+
+    // If the proxied shape could not be drawn for any reason or if
+    // this shape is simply a placeholder, then draw the default icon.
+    if (m_icon == null) {
+      try {
+        m_icon = new ImageIcon(this.getClass().getResource("underc.png"));
+      } catch (Exception ex) {
+        ex.printStackTrace();
+        g2.setColor(Color.red);
+        g2.fillRect(0, 0, 60, 60);
+        return;
+      }
+    }
+    g2.drawImage(m_icon.getImage(), 0, 0, null);
+  }
+}