AVLNode.java

/*******************************************************************************
 * Copyright (c) 2012-present Jakub Kováč, Jozef Brandýs, Katarína Kotrlová,
 * Pavol Lukča, Ladislav Pápay, Viktor Tomkovič, Tatiana Tóthová
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package algvis.ds.dictionaries.avltree;

import java.awt.Color;
import java.util.Hashtable;

import algvis.core.DataStructure;
import algvis.core.Node;
import algvis.core.NodeColor;
import algvis.core.history.HashtableStoreSupport;
import algvis.ds.dictionaries.bst.BSTNode;
import algvis.ui.Fonts;
import algvis.ui.view.View;

public class AVLNode extends BSTNode {
    private int bal = 0;

    public AVLNode(DataStructure D, int key, int zDepth) {
        super(D, key, zDepth);
    }

    @Override
    public AVLNode getLeft() {
        return (AVLNode) super.getLeft();
    }

    @Override
    public AVLNode getRight() {
        return (AVLNode) super.getRight();
    }

    @Override
    public AVLNode getParent() {
        return (AVLNode) super.getParent();
    }

    public int balance() {
        final int l = (getLeft() == null) ? 0 : getLeft().height, r = (getRight() == null) ? 0
            : getRight().height;
        setBalance(r - l);
        return bal;
    }

    void setBalance(int bal) {
        this.bal = bal;
    }

    @Override
    public void calc() {
        super.calc();
        balance();
    }

    @Override
    public void draw(View V) {
        if (state == Node.INVISIBLE || getKey() == NULL) {
            return;
        }
        drawBg(V);
        drawArrow(V);
        drawArc(V);

        final int xx = x - Node.RADIUS, yy = y - Node.RADIUS, dx = 2 * Node.RADIUS, dy = 2 * Node.RADIUS;
        String b = "";
        if (getBgColor() == NodeColor.NORMAL.bgColor) {
            V.setColor(Color.ORANGE);
            switch (bal) {
            case +2:
                b = "++";
                V.fillArc(xx, yy, dx, dy, 270, 180);
                break;
            case +1:
                b = "+";
                V.fillArc(xx, yy, dx, dy, 210, 180);
                break;
            case 0:
                b = "\u00b7";
                V.fillArc(xx, yy, dx, dy, 180, 180);
                break;
            case -1:
                b = "\u2013";
                V.fillArc(xx, yy, dx, dy, 150, 180);
                break;
            case -2:
                b = "\u2013\u2013";
                V.fillArc(xx, yy, dx, dy, 90, 180);
                break;
            }
            V.setColor(getFgColor());
            V.drawOval(x - Node.RADIUS, y - Node.RADIUS, 2 * Node.RADIUS,
                2 * Node.RADIUS);
        }

        drawKey(V);
        if (getParent() != null && getParent().getLeft() == this) {
            V.drawString(b, x - Node.RADIUS - 1, y - Node.RADIUS - 1,
                Fonts.NORMAL);
        } else {
            V.drawString(b, x + Node.RADIUS + 1, y - Node.RADIUS - 1,
                Fonts.NORMAL);
        }
    }

    @Override
    public void storeState(Hashtable<Object, Object> state) {
        super.storeState(state);
        HashtableStoreSupport.store(state, hash + "bal", bal);
    }

    @Override
    public void restoreState(Hashtable<?, ?> state) {
        super.restoreState(state);
        final Object bal = state.get(hash + "bal");
        if (bal != null) {
            this.bal = (Integer) HashtableStoreSupport.restore(bal);
        }
    }
}