/*
 *			Sun Public License Notice
 *
 * The contents of this file are subject to the Sun Public License Version
 * 1.0 (the "License"). You may not use this file except in compliance
 * with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is Terminal Emulator.
 * The Initial Developer of the Original Code is Sun Microsystems, Inc..
 * Portions created by Sun Microsystems, Inc. are Copyright (C) 2001.
 * All Rights Reserved.
 *
 * Contributor(s): Ivan Soleimanipour.
 */

/*
 * "ActiveRegion.java"
 * ActiveRegion.java 1.8 01/07/16
 */

package org.netbeans.lib.terminalemulator;

import java.util.LinkedList;
import java.util.ListIterator;

public class ActiveRegion {
    public Coord begin = new Coord();
    public Coord end = new Coord();

    // accessible to RegionManager
    ActiveRegion parent;
    boolean nested;

    private LinkedList children;
    private boolean has_end;

    ActiveRegion(ActiveRegion parent, Coord begin, boolean nested) {
	this.parent = parent;
	this.begin.copyFrom(begin);
	this.nested = nested;
    } 

    public ActiveRegion parent() {
	return this.parent;
    } 

    public Extent getExtent() {
	if (has_end)
	    return new Extent(begin, end);
	else
	    return new Extent(begin, begin);
    }

    void setEnd(Coord end) {
	this.end.copyFrom(end);
	has_end = true;
    } 

    void addChild(ActiveRegion child) {
	if (children == null)
	    children = new LinkedList();
	children.add(child);
    } 

    void removeChild(ActiveRegion child) {
	if (children == null)
	    return;
	children.remove(child);
    } 

    ActiveRegion contains(Coord coord) {

	// System.out.println("ActiveRegion [ " + begin + "-" + end + "] vs " +	// NOI18N
	// coord);
	boolean coord_past_end = has_end && coord.compareTo(end) > 0;
	if (this.parent != null && (coord.compareTo(begin) < 0  ||
				    coord_past_end)) {
	    return null;	// outside of us entirely
	}

	if (children != null) {
	    ListIterator iter = children.listIterator();
	    while(iter.hasNext()) {
		ActiveRegion child = (ActiveRegion) iter.next();
		if (coord.compareTo(child.begin) < 0)
		    break;	// short circuit
		// 'target' is 'child' or one if it's children
		ActiveRegion target = child.contains(coord);
		if (target != null)
		    return target;
	    }
	}
	return this;
    }


    // absolute coordinate mgmt

    void relocate(int delta) {
	this.begin.row += delta;
	this.end.row += delta;
	if (children != null) {
	    ListIterator iter = children.listIterator();
	    while(iter.hasNext()) {
		ActiveRegion child = (ActiveRegion) iter.next();
		child.relocate(delta);
	    }
	}
    }

    void cull(int origin) {

	// See RegionManager.cull() for culling strategy.
	// This function isn't recursive. It's called only once on root.

	if (children == null)
	    return;

	int nculled = 0;

	ListIterator iter = children.listIterator();
	while(iter.hasNext()) {
	    ActiveRegion child = (ActiveRegion) iter.next();
	    if (child.begin.row < origin) {
		iter.remove();
		nculled++;
	    } else
		break;	// short circuit out
	}

	// System.out.println("cull'ed " + nculled + " regions");	// NOI18N
    } 


    /**
     * Mark this region as one that may be converted to a selection.
     * 

     * This is just a convenience state-keeping flag
     */
    public void setSelectable(boolean selectable) {
	this.selectable = selectable;
    } 

    /**
     * Return the value set using setSelectable().
     */
    public boolean isSelectable() {
	return selectable;
    } 
    private boolean selectable;


    /**
     * Mark this region as one that will provide feedback when the mouse moves
     * over it.
     * 

     * This is just a convenience state-keeping flag
     */
    public void setFeedbackEnabled(boolean feedback) {
	this.feedback_enabled = feedback;
    } 

    /**
     * Return the value set using setFeedback().
     */
    public boolean isFeedbackEnabled() {
	return feedback_enabled;
    } 
    private boolean feedback_enabled;

    /**
     * Mark this region as one that will provide feedback in it's containing
     * region.
     */
    public void setFeedbackViaParent(boolean feedback_via_parent) {
	this.feedback_via_parent = feedback_via_parent;
    } 

    public boolean isFeedbackViaParent() {
	return feedback_via_parent;
    } 

    private boolean feedback_via_parent;

    /*
     * Mark this region as a "link".
     */
    public void setLink(boolean link) {
	this.link = link;
    } 
    public boolean isLink() {
	return link;
    } 
    private boolean link;



    /**
     * Associate additional data with this ActiveRegion.
     */
    public void setUserObject(Object object) {
	this.user_object = object;
    } 

    /**
     * Retrieve the additional data associated with this ActiveRegion through 
     * setUserObject.
     */
    public Object getUserObject() {
	return user_object;
    } 
    private Object user_object;



    // siblings
    //
    // I've chosen to delegate finding of siblings to the parent instead of 
    // using explicit sibling links. Here are the reasons:
    // - explicit links take up memory. I believe in the long run that is 
    //   more costly than dumb searches.
    // - AR's get created when stuff gets rendered. We want to render stuff
    //   as fast as possible. So instead of doing work at creation time
    //   which needs to be supra-human speed, we do the work at query time
    //   which is usualy in reponse to human actions and need not be too fast.
    // 
    // Ultimately a Vector is probably a better substitute for LinkedList
    // In that case each child could remember it's index in it's parents
    // vector (less storage than two pointers, and vector has less overhead
    // than linkedlist to compensate). Note that this will work only
    // because ActiveRegions are not editable.


    /**
     * Return the first child of this
     */
    public ActiveRegion firstChild() {
	if (children == null)
	    return null;
	return (ActiveRegion) children.getFirst();
    } 

    /**
     * Return the last child of this
     */
    public ActiveRegion lastChild() {
	if (children == null)
	    return null;
	return (ActiveRegion) children.getLast();
    } 


    /**
     * Get the previous sibling of this region
     */
    public ActiveRegion getPreviousSibling() {
	if (parent != null)
	    return parent.previous_sibling_of(this);
	else
	    return null;
    } 

    /**
     * Get the next sibling of this region
     */
    public ActiveRegion getNextSibling() {
	if (parent != null)
	    return parent.next_sibling_of(this);
	else
	    return null;
    } 

    private ActiveRegion previous_sibling_of(ActiveRegion child) {
	ListIterator iter = children.listIterator();
        ActiveRegion previousChild = null;
	while (iter.hasNext()) {
	    ActiveRegion candidate = (ActiveRegion) iter.next();
	    if (candidate == child) {
                // bug: iterator is already shifted, so following command
                // returns again child
		//return (ActiveRegion) (iter.hasPrevious()? iter.previous(): null);
                return previousChild;
	    }
            previousChild = candidate;
	}
	return null;
    }

    private ActiveRegion next_sibling_of(ActiveRegion child) {
	ListIterator iter = children.listIterator();
	while (iter.hasNext()) {
	    ActiveRegion candidate = (ActiveRegion) iter.next();
	    if (candidate == child) {
		return (ActiveRegion) (iter.hasNext()? iter.next(): null);
	    }
	}
	return null;
    }
}