package org.glassbox.widgets;
   
   import org.glassbox.executor.*;
   import org.glassbox.gui.*;
   import org.glassbox.Theme;
   import org.glassbox.SwingFactory;
   import org.glassbox.SwingThread;
   
   import java.util.HashMap;
  import javax.swing.*;
  import java.awt.*;
  import java.awt.event.ComponentAdapter;
  import java.awt.event.ComponentEvent;
  
  import org.apache.log4j.Logger;
  
  /***
     A widget which executes tasks sequentially on a background thread.
     The widget allows to execute <code>VisibleTasks</code>. The view of a
     <code>VisibleTask</code> is added to the view of this widget during it's execution.<br><br>
     This widget has the following properties which can be configured by the application's theme:
     <ul>
     <li>glassbox.widgets.VisibleExecutor.background.color</li>
     <li>glassbox.widgets.VisibleExecutor.insets</li>
     </ul>
   */
  public class VisibleExecutor extends TaskQueue implements VisibleMember {
      public static final String IDENTIFIER = "glassbox.widgets.VisibleExecutor";
  
      public interface VisibleTask extends Visible, Runnable {
  	/***
  	   Get the view of the task.
  	 */
  	JComponent getView();	
  	/***
  	   Run the task.
  	 */
  	void run();
      }
  
      protected static final String THEME_PREFIX = "glassbox.widgets.VisibleExecutor";
  
      private JComponent _view;
      private Visible _idleview;
      private Group _group;
      private ViewHandler _viewhandler;
  
      public VisibleExecutor() {
  	this(new Visible() {
  		private JPanel _view = null;
  		
  		public JComponent getView() {
  		    if (_view==null) {
  			_view = new JPanel();
  			_view.setOpaque(false);
  		    }
  		    return _view;
  		}
  	    });
      }
      
      public VisibleExecutor(Visible idleview) {
   	super();
  	_viewhandler = new ViewHandler();
  	setHandler(_viewhandler);
  	_view = null;
  	_idleview = idleview;
      }
      
  
      public JComponent getView() {
  	if (_view==null) {
  	    _view = SwingFactory.createPanel(THEME_PREFIX);
  	    _view.setLayout(new BorderLayout());
  	    if (_idleview!=null) {
  		_view.setVisible(true);		
  		_view.add(_idleview.getView(), BorderLayout.CENTER);
  		//_view.setSize(_view.getLayout().preferredLayoutSize(_view));
  		_view.validate();
  		_idleview.getView().addComponentListener(_viewhandler);
  	    } else {
  		_view.setVisible(false);
  	    }
  	}
  	return _view;
      }
  
      public String getIdentifier() {
  	return IDENTIFIER;
      }
  
      public Group getGroup() {
  	return _group;
      }
  
      public void setGroup(Group group) {
  	_group = group;
      }
  
     public void groupPropertyChanged(String name, Object oldvalue, Object newvalue) {
 	Logger.getLogger(VisibleExecutor.class).debug("groupPropertyChanged("+name+", "+oldvalue+", "+newvalue+")");
 
 	/***
 	   if (Group.APPLICATION_STATUS_KEY.equals(name)) {
 	   if (Group.EXITING.equals(newvalue)) {
 	   stop();
 	   }
 	   }
 	*/
 
 	Logger.getLogger(VisibleExecutor.class).debug("groupPropertyChanged.exit");
     }
 
     private class ViewHandler extends ComponentAdapter implements Handler {
 	public void beforeRun(Runnable task) {
 	    if (task instanceof VisibleTask) {
 		final VisibleTask vtask = (VisibleTask)task;
 		SwingThread.invokeAndWaitSilently(new Runnable() {
 			public void run() {
 			    _view.invalidate();
 			    if (_idleview!=null && _idleview.getView().getParent()==_view) {
 				_idleview.getView().removeComponentListener(ViewHandler.this);
 				_view.remove(_idleview.getView());
 			    }
 			    _view.add(vtask.getView(), BorderLayout.CENTER);
 			    //_view.setSize(_view.getLayout().preferredLayoutSize(_view));
 			    _view.validate();
 			    vtask.getView().addComponentListener(ViewHandler.this);
 			    ((VisibleGroup)getGroup()).memberViewUpdated(VisibleExecutor.this);
 			    getGroup().setProperty(VisibleGroup.MODAL_MEMBER_KEY, VisibleExecutor.this);
 			}
 		    });
 	    } else if (_idleview!=null && _idleview.getView().getParent()!=_view) {
 		SwingThread.invokeAndWaitSilently(new Runnable() {
 			public void run() {
 			    _view.invalidate();
 			    _view.add(_idleview.getView(), BorderLayout.CENTER);
 			    //_view.setSize(_view.getLayout().preferredLayoutSize(_view));
 			    _view.validate();
 			    _idleview.getView().addComponentListener(ViewHandler.this);
 			    getGroup().setProperty(VisibleGroup.MODAL_MEMBER_KEY, null);
 			    ((VisibleGroup)getGroup()).memberViewUpdated(VisibleExecutor.this);
 			}
 		    });
 	    }
 	}
 
 	public void afterRun(Runnable task) {
 	    if (task instanceof VisibleTask) {
 		final VisibleTask vtask = (VisibleTask)task;
 		SwingThread.invokeAndWaitSilently(new Runnable() {
 			public void run() {
 			    vtask.getView().removeComponentListener(ViewHandler.this);
 			    _view.invalidate();
 			    _view.remove(vtask.getView());
 			    if (isEmpty()) {
 				if (_idleview!=null && _idleview.getView().getParent()!=_view) {
 				    _view.add(_idleview.getView(), BorderLayout.CENTER);
 				    //_view.setSize(_view.getLayout().preferredLayoutSize(_view));
 				    _view.validate();
 				    _idleview.getView().addComponentListener(ViewHandler.this);
 				} 
 				getGroup().setProperty(VisibleGroup.MODAL_MEMBER_KEY, null);
 			    }
 			    ((VisibleGroup)getGroup()).memberViewUpdated(VisibleExecutor.this);
 
 			}
 		    });
 	    } 
 	}
 
 	// TODO: add a message to the output.
 	public void afterFailure(Runnable task, RuntimeException x) {
 	    afterRun(task);  
 	}
 
 	public void componentResized(ComponentEvent e) {
 	    //_view.invalidate();	    
 	    //_view.setSize(_view.getLayout().preferredLayoutSize(_view));
 	    //_view.validate();
 	    //((VisibleGroup)getGroup()).memberViewUpdated(VisibleExecutor.this);
 	}
     }
 }