/* *************************************************************************
 
                               IT Mill Toolkit 

               Development of Browser User Interfaces Made Easy

                    Copyright (C) 2000-2006 IT Mill Ltd
                     
   *************************************************************************

   This product is distributed under commercial license that can be found
   from the product package on license.pdf. Use of this product might 
   require purchasing a commercial license from IT Mill Ltd. For guidelines 
   on usage, see licensing-guidelines.html

   *************************************************************************
   
   For more information, contact:
   
   IT Mill Ltd                           phone: +358 2 4802 7180
   Ruukinkatu 2-4                        fax:   +358 2 4802 7181
   20540, Turku                          email:  info@itmill.com
   Finland                               company www: www.itmill.com
   
   Primary source for information and releases: www.itmill.com

   ********************************************************************** */

package com.itmill.toolkit.ui;

import com.itmill.toolkit.terminal.PaintException;
import com.itmill.toolkit.terminal.PaintTarget;

import java.util.Iterator;
import java.util.HashMap;

/** <p>A container component with freely designed layout and style. The
 * container consists of items with textually represented locations. Each
 * item contains one sub-component. The adapter and theme are resposible for
 * rendering the layout with given style by placing the items on the screen
 * in defined locations.</p>
 *
 * <p>The definition of locations is not fixed - the each style can define
 * its locations in a way that is suitable for it. One typical example would
 * be to create visual design for a website as a custom layout: the visual
 * design could define locations for "menu", "body" and "title" for example.
 * The layout would then be implemented as XLS-template with for given
 * style.</p>
 *
 * <p>The default theme handles the styles that are not defined by just
 * drawing the subcomponents with flowlayout.</p>
 *
 * @author IT Mill Ltd.
 * @version @VERSION@
 * @since 3.0
 */
public class CustomLayout extends AbstractComponentContainer implements Layout {

	/** Custom layout slots containing the components */
	private HashMap slots = new HashMap();

	/** Constructor for custom layout with given style */
	public CustomLayout(String style) {
		setStyle(style);
	}

	/** Get component UIDL tag.
	 * @return Component UIDL tag as string.
	 */
	public String getTag() {
		return "customlayout";
	}

	/** Add a component into this container to given location.
	 * @param c The component to be added.
	 * @param location The location of the component
	 */
	public void addComponent(Component c, String location) {
		Component old = (Component)slots.get(location);
		if (old != null) {
			removeComponent(old);
		}
		slots.put(location, c);
		c.setParent(this);
		fireComponentAttachEvent(c);
		requestRepaint();
	}

	/** Add a component into this container. The component is added without
	 * specifying the location (empty string is then used as location). Only 
	 * one component can be added to the default "" location and adding
	 * more components into that location overwrites the old components.
	 * @param c The component to be added.
	 */
	public void addComponent(Component c) {
		this.addComponent(c, "");
	}

	/** Remove a component from this container.
	 * @param c The component to be removed.
	 */
	public void removeComponent(Component c) {
		if (c == null) return;
		slots.values().remove(c);
		c.setParent(null);
		fireComponentDetachEvent(c);
		requestRepaint();
	}

	/** Remove a component from this container from given location.
	 * @param location Location identifier of the component
	 */
	public void removeComponent(String location) {
		this.removeComponent((Component) slots.get(location));
	}

	/** Get component container iterator for going trough all the components in 
	 * the container.
	 * @return Iterator of the components inside the container.
	 */
	public Iterator getComponentIterator() {
		return slots.values().iterator();
	}

	/** Get child-component by its location.
	 * 
	 * @param location The name of the location where the requested 
	 *         component resides
	 * @return Component in the given location or null if not found.
	 */
	public Component getComponent(String location) {
		return (Component) slots.get(location);
	}

	/** Paint the content of this component.
	 * @param event PaintEvent.
	 * @throws PaintException The paint operation failed.
	 */
	public void paintContent(PaintTarget target) throws PaintException {

		// Add all items in all the locations
		for (Iterator i = slots.keySet().iterator(); i.hasNext();) {

			// Get the (location,component)
			String location = (String) i.next();
			Component c = (Component) slots.get(location);

			// Write the item
			target.startTag("location");
			target.addAttribute("name", location);
			c.paint(target);
			target.endTag("location");
		}
	}
	
	/* Documented in superclass */
	public void replaceComponent(
		Component oldComponent,
		Component newComponent) {

		// Get the locations			
		String oldLocation = null;
		String newLocation  = null;
		for (Iterator i=slots.keySet().iterator(); i.hasNext();) {
			String location = (String) i.next();
			Component component = (Component) slots.get(location);
			if (component == oldComponent) oldLocation = location;
			if (component == newComponent) newLocation = location;
		}	

		if (oldLocation == null)
			addComponent(newComponent);
		else if (newLocation == null) {
			removeComponent(oldLocation);
			addComponent(newComponent,oldLocation);
		} else {
			slots.put(newLocation,oldComponent);
			slots.put(oldLocation,newComponent);	
			requestRepaint();
		}
	}

}