com.algorithmstudy.visualizer.client.sort.BarChartVisualizer.java Source code

Introduction

Here is the source code for com.algorithmstudy.visualizer.client.sort.BarChartVisualizer.java

Source

/*
 * Copyright (C) 2009 The Algorithm Study Project
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2.0 as published by the Free Software Foundation.
 *
 * 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 version
 * 2.0 along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 * or find it on the GNU website at:
 *
 *    http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */
package com.algorithmstudy.visualizer.client.sort;

import com.algorithmstudy.visualizer.client.model.Algorithm;
import com.algorithmstudy.visualizer.client.model.ListVisualizer;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * 
 */
public class BarChartVisualizer extends VerticalPanel implements ListVisualizer {

    private static final String STYLE_BAR_CHART = "bar-chart-visualizer";
    private static final String STYLE_CHART_SINGLE = "chart-single-";
    private static final String STYLE_CHART_DOUBLE = "chart-double-";
    private static final String STYLE_INVISIBLE_BAR = "invisible-bar";
    private static final String STYLE_VISIBLE_BAR = "visible-bar";
    private static final String STYLE_MOVES_LABEL = "moves";
    private static final String STYLE_MOVES_LABEL_FINISHED = "moves-finished";

    private static final String MOVES_BASE = "Moves: ";

    private Label movesLabel;
    private int numberOfMoves;

    private Chart chart;

    private Algorithm algorithm;

    public BarChartVisualizer(int[] elements, boolean isSingle) {
        setStyleName(STYLE_BAR_CHART);

        HorizontalPanel timePanel = new HorizontalPanel();
        timePanel.setWidth("100%");
        timePanel.setHorizontalAlignment(HorizontalPanel.ALIGN_RIGHT);

        movesLabel = new Label();
        movesLabel.setStyleName(STYLE_MOVES_LABEL);
        movesLabel.setText(MOVES_BASE + "0");
        movesLabel.setWidth("8em");
        numberOfMoves = 0;

        timePanel.add(movesLabel);

        this.add(timePanel);

        chart = new Chart(elements, isSingle);
        this.add(chart);
    }

    public void setAlgorithm(Algorithm a) {
        this.algorithm = a;
    }

    public boolean tick() {
        if (algorithm.canMakeMove()) {
            algorithm.makeMove();
            ++numberOfMoves;
            movesLabel.setText(MOVES_BASE + Integer.toString(numberOfMoves));
            if (!algorithm.canMakeMove()) {
                movesLabel.setStyleName(STYLE_MOVES_LABEL_FINISHED);
            }
            return algorithm.canMakeMove();
        } else {
            return false;
        }
    }

    public void swap(int left, int right) {
        chart.swap(left, right);
    }

    private static class Chart extends HorizontalPanel {

        private int numBars;

        Chart(int[] barHeights, boolean isSingle) {
            numBars = barHeights.length;

            if (isSingle) {
                setStyleName(STYLE_CHART_SINGLE + Integer.toString(barHeights.length));
            } else {
                setStyleName(STYLE_CHART_DOUBLE + Integer.toString(barHeights.length));
            }
            setVerticalAlignment(HorizontalPanel.ALIGN_BOTTOM);

            // generate the elements
            populate(barHeights);
        }

        /**
         * Populates the chart with a new set of bars.
         * 
         * @param barHeights
         *          The heights of the bars with which to populate the chart.
         */
        void setNewBarHeights(int[] barHeights) {
            clear();
            numBars = barHeights.length;
            populate(barHeights);
        }

        /**
         * Swaps the left and the right indices.
         * 
         * @param left
         * @param right
         * @throws IndexOutOfBoundsException
         *           Thrown if the left or right index is < 0 or > the number of bars in the chart.
         * @throws IllegalArgumentException
         *           Thrown if the left index >= the right index.
         */
        void swap(int left, int right) {
            if (0 > left || left > numBars) {
                throw new IndexOutOfBoundsException("The left index is out of bounds.  left index=[" + left + "]");
            }

            if (0 > right || right > numBars) {
                throw new IndexOutOfBoundsException(
                        "The right index is out of bounds.  right index=[" + right + "]");
            }

            if (left >= right) {
                throw new IllegalArgumentException("Left must be < right");
            }

            int leftLocation = (left * 2) + 1;
            int rightLocation = (right * 2) + 1;
            Widget oldLeft = getWidget(leftLocation);
            Widget oldRight = getWidget(rightLocation);

            remove(rightLocation);
            remove(leftLocation);
            insert(oldRight, leftLocation);
            insert(oldLeft, rightLocation);
        }

        private void populate(int[] elements) {
            float multiplier = 1;
            if (elements.length == 50) {
                multiplier = 8;
            } else if (elements.length == 75) {
                multiplier = 5.33f;
            } else if (elements.length == 100) {
                multiplier = 4;
            } else if (elements.length == 150) {
                multiplier = 2.67f;
            } else if (elements.length == 200) {
                multiplier = 2;
            } else if (elements.length == 300) {
                multiplier = 1.33f;
            }

            for (int i = 0; i < elements.length; i++) {
                this.add(createSpacerBar());
                this.add(createBar((int) (elements[i] * multiplier)));
            }
            this.add(createSpacerBar());
        }

        private Label createSpacerBar() {
            Label bar = new Label();
            bar.setHeight("1px");
            bar.setStyleName(STYLE_INVISIBLE_BAR);
            return bar;
        }

        private Label createBar(int height) {
            Label bar = new Label();
            bar.setHeight(Integer.toString(height) + "px");
            bar.setStyleName(STYLE_VISIBLE_BAR);
            return bar;
        }

    }

}