/*
 * Copyright (c) 2003,2009 Declarative Engineering LLC.
 * All rights reserved.  This program and the accompanying materials
 * are made available under the terms of the Declarative Engineering LLC
 * verson 1 which accompanies this distribution, and is available at
 * http://declarativeengineering.com/legal/DE_Developer_License_v1.txt
 */
package com.foundation.view.swt;

import javax.management.RuntimeErrorException;

import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.ScrollBar;

import com.common.util.*;
import com.common.debug.*;
import com.foundation.view.*;
import com.foundation.view.swt.layout.Layout;
import com.foundation.view.swt.layout.LayoutData;
import com.foundation.util.*;
import com.foundation.controller.*;
import com.foundation.event.*;

public class Panel extends Container {
	/** The attribute that provides the collection of internal view controllers. */
	private IAttributeAssociation internalViewsAssociation = null;
	/** A support for receiving collection change events. */
	private EventSupport eventSupport = new EventSupport(null);
	/** The collection of internal view controllers. */
	private ICollection internalViewControllers = null;
	/** The collection of internal view controllers currently open.  Maintaining this collection is necessary in the event that all view controllers are removed from the collection. */
	private LiteList openViewControllers = null;
	/** The next location ? */
	private int nextLocation = 0;
	/** The location increment ? */
	private int locationIncrement = 20;
	/** The composite used to slide the contents around if the user has requested vertical and/or horizontal scrolling. */
	private ScrolledComposite scrolledComposite;
	/** The composite used to slide the contents around if the user has requested vertical and/or horizontal scrolling. */
	private Composite composite;
/**
 * Panel default constructor.
 * <p>Warning: This is only for use by the framework.  This should never be called to create a useable instance.</p>
 */
public Panel() {
}//Panel()//
/**
 * Panel constructor.
 * @param parent A composite control which will be the parent of the new instance (cannot be null).
 * @param name The unique component name.
 * @param style The style of control to construct.
 * @see #STYLE_NO_BACKGROUND
 * @see #STYLE_NO_FOCUS
 * @see #STYLE_NO_MERGE_PAINTS
 * @see #STYLE_NO_REDRAW_RESIZE
 * @see #STYLE_NO_RADIO_GROUP
 * @see #STYLE_EMBEDDED
 * @see #STYLE_DOUBLE_BUFFERED
 * @see #STYLE_H_SCROLL
 * @see #STYLE_V_SCROLL
 * @see #STYLE_BORDER
 * @see #STYLE_LEFT_TO_RIGHT
 * @see #STYLE_RIGHT_TO_LEFT
 */
public Panel(IAbstractContainer parent, String name, int style) {
	super(parent, name, style);
}//Panel()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#initializeControl(int)
 */
protected void initializeControl(int style, Object data) {
	boolean hScroll = ((style & SWT.H_SCROLL) != 0);
	boolean vScroll = ((style & SWT.V_SCROLL) != 0);
	
	if(hScroll || vScroll) {
		scrolledComposite = new ScrolledComposite(((IAbstractSwtContainer) getContainer()).getSwtParent(), style);
		scrolledComposite.setData(this);
		composite = new Composite(scrolledComposite, 0);
		composite.setData(this);
		scrolledComposite.setTabList(new Control[] {composite});
		scrolledComposite.setContent(composite);
		setSwtWidget(scrolledComposite);
		scrolledComposite.setAlwaysShowScrollBars(false);
		scrolledComposite.setExpandHorizontal(true);
		scrolledComposite.setExpandVertical(true);
		scrolledComposite.setMinSize(0, 0);
		
		if(hScroll) {
			getSwtComposite().getHorizontalBar().setVisible(false);
			getSwtComposite().getHorizontalBar().setIncrement(20);
		}//if//
		
		if(vScroll) {
			getSwtComposite().getVerticalBar().setVisible(false);
			getSwtComposite().getVerticalBar().setIncrement(20);
		}//if//
	}//if//
	else {
		setSwtWidget(new org.eclipse.swt.widgets.Composite(((IAbstractSwtContainer) getContainer()).getSwtParent(), style));
		getSwtWidget().setData(this);
	}//else//
}//initializeControl()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.Container#internalLayout()
 */
protected void internalLayout() {
	if(scrolledComposite != null) {
		composite.setSize(composite.computeSize(-1, -1, true));
	}//if//
	
	super.internalLayout();
}//internalLayout()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.Container#postResize()
 */
public void postResize() {
	super.postResize();
	
	if(scrolledComposite != null) {
		Rectangle interior = scrolledComposite.getClientArea();
		Rectangle interior2 = null;
		
		scrolledComposite.setMinSize(0, 0);
		
		while(!interior.equals(interior2)) {
			Point size = null;
			
			composite.computeSize(0, 0, true);
			
			if(composite.getLayout() instanceof com.foundation.view.swt.layout.Layout) {
				size = ((com.foundation.view.swt.layout.Layout) composite.getLayout()).computeCurrentSize(composite);
			}//if//
			else {
				Debug.log(new RuntimeException("Only Brainstorm based layouts may be used.  The layout must extend " + Layout.class.getName()));
			}//else//
			
			if(getSwtComposite().getHorizontalBar() != null) {
				scrolledComposite.setMinWidth(size.x);
			}//if//
			
			if(getSwtComposite().getVerticalBar() != null) {
				scrolledComposite.setMinHeight(size.y);
			}//if//
			
			interior2 = interior;
			interior = scrolledComposite.getClientArea();
		}//while//
	}//if//
}//postResize()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.Container#getSwtParent()
 */
public org.eclipse.swt.widgets.Composite getSwtParent() {
	return scrolledComposite != null ? composite : getSwtComposite();
}//getSwtParent()//
/**
 * Sets the internal view controller collection.
 * @param internalViewsAssociation The association containing the collection of view controllers representing views that exist within this panel.
 */
public void setInternalViewsAssociation(IAttributeAssociation internalViewsAssociation) {
	this.internalViewsAssociation = internalViewsAssociation;
}//setInternalViewsAssociation()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewInitialize()
 */
protected void internalViewInitialize() {
	if(internalViewsAssociation != null) {
		openViewControllers = new LiteList(10, 50);
		internalViewsAssociation.register();
	}//if//
	
	super.internalViewInitialize();
}//internalViewInitialize()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewRelease()
 */
protected void internalViewRelease() {
	super.internalViewRelease();
	
	if(internalViewsAssociation != null) {
		internalViewsAssociation.unregister();
		eventSupport.unregisterAll();
		closeAllViews();
	}//if//
}//internalViewRelease()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewRefresh()
 */
protected void internalViewRefresh() {
	super.internalViewRefresh();
	
	if(internalViewsAssociation != null) {
		ICollection internalViewControllers = (ICollection) internalViewsAssociation.getAttributeValue();
		ICollection copy = null;
		
		if(this.internalViewControllers != internalViewControllers) {
			//Unregister the old event hooks.//
			if(this.internalViewControllers instanceof IEventEmitter) {
				eventSupport.unregisterAll((IEventEmitter) this.internalViewControllers);
			}//if//
			
			closeAllViews();
			//Save a reference to the current collection in the model.//
			this.internalViewControllers = internalViewControllers;
			
			if(internalViewControllers instanceof IManagedCollection) {
				//Register the new event hooks.//
				synchronized(internalViewControllers) {
					eventSupport.register(((IManagedCollection) internalViewControllers), IManagedCollection.EVENT.getNumber(), this, true);
					
					copy = new LiteList(internalViewControllers);
				}//synchronized//
			}//if//
		}//if//
		
		if(copy != null) {
			IIterator iterator = copy.iterator();
				
			while(iterator.hasNext()) {
				Object next = iterator.next();
				
				if(next instanceof ViewController) {
					closeView((ViewController) next);
					openViewControllers.add(next);
				}//if//
				else {
					Debug.log("Error: Only view controllers may populate the collection of internal frames attached to the panel.");
				}//else//
			}//while//
		}//if//
	}//if//
}//internalViewRefresh()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewSynchronize()
 */
protected void internalViewSynchronize() {
	super.internalViewSynchronize();
}//internalViewSynchronize()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalEvaluate(com.common.event.IEventEmitter, int, java.lang.Object[])
 */
protected void internalEvaluate(IEventEmitter eventEmitter, int eventNumber, Object[] arguments) {
	//Add, remove, or replace items from the list.//
	if(eventEmitter == internalViewControllers) {
		if(eventNumber == IManagedCollection.EVENT.getNumber()) {
			CollectionChangeEvent event = (CollectionChangeEvent) arguments[0];
			
			if(event.hasAdds()) {
				if(event.getAddedObjects() != null) {
					IIterator iterator = event.getAddedObjects().iterator();
					
					while(iterator.hasNext()) {
						Object next = iterator.next();
						
						openView((ViewController) next);
					}//while//
				}//if//
				else {
					openView((ViewController) event.getAddedObject());
				}//else//
			}//if//
			
			if(event.hasRemoves()) {
				if(event.getRemovedObjects() != null) {
					IIterator iterator = event.getRemovedObjects().iterator();
	
					while(iterator.hasNext()) {
						Object next = iterator.next();
		
						openViewControllers.remove(next);
						closeView((ViewController) next);
					}//while//
				}//if//
				else {
					openViewControllers.remove(event.getRemovedObject());
					closeView((ViewController) event.getRemovedObject());
				}//else//
			}//if//
		}//if//
	}//if//
	else {
		super.internalEvaluate(eventEmitter, eventNumber, arguments);
	}//else//
}//internalEvaluate()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.Component#onValueChanged(com.foundation.view.swt.IAttributeAssociation)
 */
protected void internalOnValueChanged(IAttributeAssociation attributeAssociation) {
	if(attributeAssociation == internalViewsAssociation) {
		internalViewRefresh();
	}//if//
	else {
		super.internalOnValueChanged(attributeAssociation);
	}//else//
}//internalOnValueChanged()//
/**
 * Opens the view for the associated view controller.
 * @param viewController The view controller that will provide the view.
 */
private void openView(ViewController viewController) {
	IView view = viewController.openPartial(this, null);
	
	if(view instanceof Frame) {
		int location = nextLocation;
		
		if(location + ((Frame) view).getSwtControl().getSize().x > getSwtControl().getSize().x) {
			location = 0;
		}//if//
		else if(location + ((Frame) view).getSwtControl().getSize().y > getSwtControl().getSize().y) {
			location = 0;
		}//else if//
		
		nextLocation = location + locationIncrement;
		((Frame) view).setLocation(location, location);
	}//if//
	else {
		//I could at some point wrapper the view component with a frame.//
		Debug.log("Error: The view must be a frame for it to be a valid internal view.");
	}//else//
}//openView()//
/**
 * Closes the view for the associated view controller.
 * @param viewController The view controller that provided the view.
 */
private void closeView(ViewController viewController) {
	viewController.close();
}//closeView()//
/**
 * Closes all the internal views.
 */
private void closeAllViews() {
	IIterator iterator = openViewControllers.iterator();
					
	while(iterator.hasNext()) {
		closeView((ViewController) iterator.next());
	}//while//
					
	openViewControllers.removeAll();
}//closeAllViews()//
}//Panel//