/*
 * Copyright (c) 2005,2009 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 org.eclipse.swt.custom.StackLayout;
import org.eclipse.swt.widgets.Layout;

import com.common.util.ICollection;
import com.common.util.IIterator;
import com.common.util.IList;
import com.common.util.LiteList;
import com.foundation.controller.ViewController;
import com.foundation.util.IInlineCollectionObservable;
import com.foundation.util.IInlineCollectionObserver;
import com.foundation.util.IInlineIndexedCollectionObservable;
import com.foundation.util.IInlineIndexedCollectionObserver;
import com.foundation.view.IEventAssociation;
import com.foundation.view.SingleAssociationContainer;
import com.foundation.view.SingleResourceAssociation;
import com.foundation.view.swt.util.SwtUtilities;

/*
 * Displays components in a stack such that only one component is visible at a time.
 */
public class StackViewer extends Container implements IInlineIndexedCollectionObserver, IInlineCollectionObserver {
	/** The association that results in a collection of view controllers. */
	private SingleResourceAssociation views = null;
	/** The association that tracks which view is being displayed. */
	private SingleResourceAssociation visibleView = null;
	/** The previous collection of view controllers. */
	private IList viewControllers = new LiteList(1, 15);
	/** Temporarily suspends processing of events fired by registered collections. */
	private boolean suspendCollectionEvents = false;
/**
 * StackViewer 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_H_SCROLL
 * @see #STYLE_V_SCROLL
 * @see #STYLE_BORDER
 * @see #STYLE_LEFT_TO_RIGHT
 * @see #STYLE_RIGHT_TO_LEFT
 */
public StackViewer(Container parent, String name, int style) {
	super(parent, name, style);
	this.views = new SingleResourceAssociation(this, this, getViewContext(), SingleResourceAssociation.TYPE_OBJECT, false, null);
	this.visibleView = new SingleResourceAssociation(this, this, getViewContext(), SingleResourceAssociation.TYPE_OBJECT, false, null);
}//StackViewer()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#initializeControl(int)
 */
protected void initializeControl(int style, Object data) {
	setSwtWidget(new org.eclipse.swt.widgets.Composite(((Container) getContainer()).getSwtParent(), style));
	getSwtWidget().setData(this);
	getSwtComposite().setLayout(new StackLayout());
}//initializeControl()//
/**
 * Gets the stack layout used with the wizard.
 * @return The wizard's stack layout.
 */
protected StackLayout getLayout() {
	return (StackLayout) getSwtComposite().getLayout();
}//getLayout()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.Container#setLayout(org.eclipse.swt.widgets.Layout)
 */
public void setLayout(Layout layout) {
	//Does nothing.  Layouts are not allowed here.//
}//setLayout()//
/**
 * Gets the SWT composite that represents this panel.
 * @return The SWT composite providing visualization for this panel.
 */
public org.eclipse.swt.widgets.Composite getSwtComposite() {
	return (org.eclipse.swt.widgets.Composite) getSwtControl();
}//getSwtComposite()//
/**
 * Sets the association container used to access the views in the stack.
 * @param container The views association metadata.
 */
public void setViewsAssociation(SingleAssociationContainer container) {
	verifyThread();
	this.views.setAssociations(container);
}//setViewsAssociation()//
/**
 * Sets the association container used to access the visible view.
 * @param container The visible view association metadata.
 */
public void setVisibleViewAssociation(SingleAssociationContainer container) {
	verifyThread();
	this.visibleView.setAssociations(container);
}//setVisibleViewAssociation()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalOnEventFired(com.foundation.view.swt.IEventAssociation, java.lang.Object[])
 */
protected void internalOnEventFired(IEventAssociation eventAssociation, Object[] eventArguments) {
}//internalOnEventFired()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewInitialize()
 */
protected void internalViewInitialize() {
	views.initialize();
	visibleView.initialize();
	super.internalViewInitialize();
}//internalViewInitialize()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewRelease()
 */
protected void internalViewRelease() {
	super.internalViewRelease();
	views.release();
	visibleView.release();
	
	for(int index = 0; index < viewControllers.getSize(); index++) {
		((ViewController) viewControllers.get(index)).close();
	}//for//
}//internalViewRelease()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewRefresh()
 */
protected void internalViewRefresh() {
	super.internalViewRefresh();

	internalRefreshViews();
	internalRefreshVisibleView();
}//internalViewRefresh()//
/**
 * Refreshes the currently visible component.
 */
protected void internalRefreshViews() {
	Object oldValue = views.getValue();
	
	if(views.refresh()) {
		stopRendering();
		
		try {
			Object newValue = views.getValue();
	
			//Remove listeners from the old value.//
			if(oldValue instanceof IInlineIndexedCollectionObservable) {
				((IInlineIndexedCollectionObservable) oldValue).removeCollectionObserver(this);
			}//if//
			else if(oldValue instanceof IInlineCollectionObservable) {
				((IInlineCollectionObservable) oldValue).removeCollectionObserver(this);
			}//else if//
			
			//Close the old view controllers.//
			for(int index = 0; index < viewControllers.getSize(); index++) {
				((ViewController) viewControllers.get(index)).close();
			}//for//
			
			viewControllers.removeAll();
			
			//If the new value is a collection or object then add and remove pages as required, and add listeners as required.//
			if(newValue instanceof ICollection) {
				IIterator iterator = ((ICollection) newValue).iterator();
				
				//Add tabs for all the view controllers.//
				while(iterator.hasNext()) {
					Object next = iterator.next();
					
					//Ignore non-view controller objects.//
					if(next instanceof ViewController) {
						ViewController controller = (ViewController) next;
						
						controller.openPartial(this, getViewContext());
					}//if//
					else {
						throw new RuntimeException("Expecting a view controller.");
					}//else//
				}//while//

				//Add the controllers to the list of view controllers.//
				viewControllers.addAll((ICollection) newValue);
				//Prevent collection events from notifying us of existing items in the collection.//
				suspendCollectionEvents = true;
				
				//Add a listener to the collection so we get change events.//
				if(newValue instanceof IInlineIndexedCollectionObservable) {
					((IInlineIndexedCollectionObservable) newValue).addCollectionObserver(this);
				}//if//
				else if(newValue instanceof IInlineCollectionObservable) {
					((IInlineCollectionObservable) newValue).addCollectionObserver(this);
				}//else if//
				
				//Re-enable the collection events.//
				suspendCollectionEvents = false;
			}//if//
			else if(newValue instanceof ViewController) {
				ViewController controller = (ViewController) newValue;

				controller.openPartial(this, getViewContext());
				//Add the one controller to the list of view controllers.//
				viewControllers.add(controller);
			}//else if//
		}//try//
		finally {
			startRendering();
		}//finally//
	}//if//
}//internalRefreshViews()//
/**
 * Refreshes the currently visible component.
 */
protected void internalRefreshVisibleView() {
	if(visibleView.refresh()) {
		Object view = (Object) visibleView.getValue();
		int index = viewControllers.getIndexOf(view);
		
		if(index >= 0) {
			((StackLayout) getSwtComposite().getLayout()).topControl = getSwtComposite().getChildren()[index];
			getSwtComposite().layout(true, false);
		}//if//
	}//if//
}//internalRefreshVisibleView()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.AbstractComponent#internalViewSynchronize()
 */
protected void internalViewSynchronize() {
	//Since the page can only be set manually, this method should do nothing.//
	super.internalViewSynchronize();
}//internalViewSynchronize()//
/* (non-Javadoc)
 * @see com.foundation.view.swt.Component#internalOnValueChanged(com.foundation.view.SingleResourceAssociation, int)
 */
protected void internalOnValueChanged(SingleResourceAssociation association, int flags) {
	if(association == visibleView) {
		internalRefreshVisibleView();
	}//if//
	else if(association == views) {
		internalRefreshViews();
	}//else if//
	else {
		super.internalOnValueChanged(association, flags);
	}//else//
}//internalOnValueChanged()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineIndexedCollectionObserver#startChanges(int)
 */
public void startChanges(int changeCount) {
	startRendering();
}//startChanges()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineIndexedCollectionObserver#stopChanges()
 */
public void stopChanges() {
	stopRendering();
}//stopChanges()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineCollectionObserver#valueAdded(java.lang.Object)
 */
public void valueAdded(Object value) {
	if((!suspendCollectionEvents) && (value instanceof ViewController)) {
		viewControllers.add(value);
		((ViewController) value).openPartial(this, getViewContext());
	}//if//
}//valueAdded()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineIndexedCollectionObserver#valueAdded(java.lang.Object, int)
 */
public void valueAdded(Object value, int index) {
	valueAdded(value);
}//valueAdded()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineCollectionObserver#valueRemoved(java.lang.Object)
 */
public void valueRemoved(Object value) {
	if((!suspendCollectionEvents) && (viewControllers.remove(value))) {
		((ViewController) value).close();
	}//if//
}//valueRemoved()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineIndexedCollectionObserver#valueRemoved(java.lang.Object, int)
 */
public void valueRemoved(Object value, int index) {
	valueRemoved(value);
}//valueRemoved()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineIndexedCollectionObserver#removingAll()
 */
public void removingAll() {
	if(!suspendCollectionEvents) {
		IIterator iterator = viewControllers.iterator();
		
		startChanges(viewControllers.getSize());
		
		try {
			while(iterator.hasNext()) {
				valueRemoved(iterator.next());
			}//while//
		}//try//
		finally {
			stopChanges();
		}//finally//
	}//if//
}//removingAll()//
/* (non-Javadoc)
 * @see com.foundation.util.IInlineIndexedCollectionObserver#valuesSorted(int[])
 */
public void valuesSorted(int[] mapping) {
	//Does nothing.//
}//valuesSorted()//
}//StackViewer//