PaintFrame.java

/*
 * 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 java.awt.event.*;
import java.util.HashMap;
import java.util.Map;

import javax.swing.*;

import org.foo.shape.SimpleShape;

/**
 * This class represents the main application class, which is a JFrame subclass
 * that manages a toolbar of shapes and a drawing canvas. This class does not
 * directly interact with the underlying OSGi framework; instead, it is injected
 * with the available <tt>SimpleShape</tt> instances to eliminate any
 * dependencies on the OSGi application programming interfaces.
 **/
public class PaintFrame extends JFrame implements MouseListener, MouseMotionListener {
  private static final long serialVersionUID = 1L;
  private static final int BOX = 54;
  private JToolBar m_toolbar;
  private String m_selected;
  private JPanel m_panel;
  private ShapeComponent m_selectedComponent;
  private Map m_shapes = new HashMap();
  private ActionListener m_reusableActionListener = new ShapeActionListener();
  private SimpleShape m_defaultShape = new DefaultShape();

  /**
   * Default constructor that populates the main window.
   **/
  public PaintFrame() {
    super("PaintFrame");

    m_toolbar = new JToolBar("Toolbar");
    m_panel = new JPanel();
    m_panel.setBackground(Color.WHITE);
    m_panel.setLayout(null);
    m_panel.setMinimumSize(new Dimension(400, 400));
    m_panel.addMouseListener(this);
    getContentPane().setLayout(new BorderLayout());
    getContentPane().add(m_toolbar, BorderLayout.NORTH);
    getContentPane().add(m_panel, BorderLayout.CENTER);
    setSize(400, 400);
    setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
  }

  void activate(Map properties)
  {
    Integer w = (Integer) properties.get(".width");
    Integer h = (Integer) properties.get(".height");
    
    int width = w == null ? 400 : w;
    int height = h == null ? 400 : h;
    
    setSize(width, height);
    
    SwingUtils.invokeAndWait(new Runnable() {
      public void run() {
        setVisible(true);
      }
    });
  }
  

  void deactivate()
  {
    SwingUtils.invokeLater(new Runnable() {
      public void run() {
        setVisible(false);
        dispose();
      }
    });
  }
    
  /**
   * This method sets the currently selected shape to be used for drawing on the
   * canvas.
   * 
   * @param name The name of the shape to use for drawing on the canvas.
   **/
  public void selectShape(String name) {
    m_selected = name;
  }

  /**
   * Retrieves the available <tt>SimpleShape</tt> associated with the given
   * name.
   * 
   * @param name The name of the <tt>SimpleShape</tt> to retrieve.
   * @return The corresponding <tt>SimpleShape</tt> instance if available or
   *         <tt>null</tt>.
   **/
  public SimpleShape getShape(String name) {
    SimpleShape shape = (SimpleShape) m_shapes.get(name);
    if (shape == null) {
      return m_defaultShape;
    } else {
      return shape;
    }
  }

  /**
   * Injects an available <tt>SimpleShape</tt> into the drawing frame.
   * 
   * @param name The name of the injected <tt>SimpleShape</tt>.
   * @param icon The icon associated with the injected <tt>SimpleShape</tt>.
   * @param shape The injected <tt>SimpleShape</tt> instance.
   **/
  void addShape(SimpleShape shape, Map attrs) {
    final DefaultShape delegate = new DefaultShape(shape);
    final String name = (String) attrs.get(SimpleShape.NAME_PROPERTY);
    final Icon icon = delegate.getIcon();
    
    m_shapes.put(name, delegate);
    
    SwingUtils.invokeAndWait( new Runnable() {
      public void run() {
        JButton button = new JButton(icon);
        button.setActionCommand(name);
        button.setToolTipText(name);
        button.addActionListener(m_reusableActionListener);

        if (m_selected == null) {
          button.doClick();
        }

        m_toolbar.add(button);
        m_toolbar.validate();
        repaint();
      }      
    });
  }

  /**
   * Removes a no longer available <tt>SimpleShape</tt> from the drawing frame.
   * 
   * @param name The name of the <tt>SimpleShape</tt> to remove.
   **/
  void removeShape(SimpleShape shape, Map attrs) {
    final String name = (String) attrs.get(SimpleShape.NAME_PROPERTY);

    DefaultShape delegate = null;
    
    synchronized( m_shapes ) {
      delegate = (DefaultShape) m_shapes.remove(name);
    }
    
    if ( delegate != null ) {
      delegate.dispose();
      SwingUtils.invokeAndWait( new Runnable() {
        public void run() {
          if ((m_selected != null) && m_selected.equals(name)) {
            m_selected = null;
          }
      
          for (int i = 0; i < m_toolbar.getComponentCount(); i++) {
            JButton sb = (JButton) m_toolbar.getComponent(i);
            if (sb.getActionCommand().equals(name)) {
              m_toolbar.remove(i);
              m_toolbar.invalidate();
              validate();
              repaint();
              break;
            }
          }
      
          if ((m_selected == null) && (m_toolbar.getComponentCount() > 0)) {
            ((JButton) m_toolbar.getComponent(0)).doClick();
          }
        }      
      });
    }
  }

  /**
   * Implements method for the <tt>MouseListener</tt> interface to draw the
   * selected shape into the drawing canvas.
   * 
   * @param evt The associated mouse event.
   **/
  public void mouseClicked(MouseEvent evt) {
    if (m_selected == null) {
      return;
    }

    if (m_panel.contains(evt.getX(), evt.getY())) {
      ShapeComponent sc = new ShapeComponent(this, m_selected);
      sc.setBounds(evt.getX() - BOX / 2, evt.getY() - BOX / 2, BOX, BOX);
      m_panel.add(sc, 0);
      m_panel.validate();
      m_panel.repaint(sc.getBounds());
    }
  }

  /**
   * Implements an empty method for the <tt>MouseListener</tt> interface.
   * 
   * @param evt The associated mouse event.
   **/
  public void mouseEntered(MouseEvent evt) {}

  /**
   * Implements an empty method for the <tt>MouseListener</tt> interface.
   * 
   * @param evt The associated mouse event.
   **/
  public void mouseExited(MouseEvent evt) {}

  /**
   * Implements method for the <tt>MouseListener</tt> interface to initiate
   * shape dragging.
   * 
   * @param evt The associated mouse event.
   **/
  public void mousePressed(MouseEvent evt) {
    Component c = m_panel.getComponentAt(evt.getPoint());
    if (c instanceof ShapeComponent) {
      m_selectedComponent = (ShapeComponent) c;
      m_panel.setCursor(Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));
      m_panel.addMouseMotionListener(this);
      m_selectedComponent.repaint();
    }
  }

  /**
   * Implements method for the <tt>MouseListener</tt> interface to complete
   * shape dragging.
   * 
   * @param evt The associated mouse event.
   **/
  public void mouseReleased(MouseEvent evt) {
    if (m_selectedComponent != null) {
      m_panel.removeMouseMotionListener(this);
      m_panel.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
      m_selectedComponent.setBounds(evt.getX() - BOX / 2, evt.getY() - BOX / 2, BOX, BOX);
      m_selectedComponent.repaint();
      m_selectedComponent = null;
    }
  }

  /**
   * Implements method for the <tt>MouseMotionListener</tt> interface to move a
   * dragged shape.
   * 
   * @param evt The associated mouse event.
   **/
  public void mouseDragged(MouseEvent evt) {
    m_selectedComponent.setBounds(evt.getX() - BOX / 2, evt.getY() - BOX / 2, BOX, BOX);
  }

  /**
   * Implements an empty method for the <tt>MouseMotionListener</tt> interface.
   * 
   * @param evt The associated mouse event.
   **/
  public void mouseMoved(MouseEvent evt) {}

  /**
   * Simple action listener for shape tool bar buttons that sets the drawing
   * frame's currently selected shape when receiving an action event.
   **/
  private class ShapeActionListener implements ActionListener {
    public void actionPerformed(ActionEvent evt) {
      selectShape(evt.getActionCommand());
    }
  }
}