com.algorithmstudy.visualizer.client.AlgorithmSelectionPanel.java Source code

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

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/*
 * 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;

import com.algorithmstudy.visualizer.client.sort.SortingDisplayPanel;
import com.algorithmstudy.visualizer.client.sort.SortingSubSelectionPanel;
import com.google.gwt.user.client.ui.ChangeListener;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.ListBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Implements and manages the bar containing the algorithm selection options and manages the
 * creation/deletion of the panel showing the current algorithm being visualized.
 */
public class AlgorithmSelectionPanel extends HorizontalPanel {

    private HorizontalPanel selectBoxPanel;
    private VerticalPanel contentsPanel;
    private ListBox algorithmChoice;
    private int lastAlgorithmChoice;

    public AlgorithmSelectionPanel(VerticalPanel contentsPanel) {
        this.contentsPanel = contentsPanel;

        selectBoxPanel = new HorizontalPanel();
        add(selectBoxPanel);

        algorithmChoice = new ListBox();
        algorithmChoice.addItem("Select Algorithm Class ...");
        algorithmChoice.addItem("Sorting");
        selectBoxPanel.add(algorithmChoice);

        algorithmChoice.addChangeListener(new ChangeListener() {
            public void onChange(Widget w) {
                algorithmChoiceChange(w);
            }
        });

        lastAlgorithmChoice = 0;
    }

    private void algorithmChoiceChange(Widget w) {
        if (!algorithmChoice.equals(w)) {
            return;
        }

        int selected = algorithmChoice.getSelectedIndex();

        if (selected == lastAlgorithmChoice) {
            return;
        }

        switch (selected) {
        case 0:
            clearSelection();
            lastAlgorithmChoice = 0;
            break;
        case 1:
            clearSelection();
            setupSorting();
            lastAlgorithmChoice = 1;
            break;
        }
    }

    private void setupSorting() {
        SortingDisplayPanel displayPanel = new SortingDisplayPanel();
        contentsPanel.add(displayPanel);

        SortingSubSelectionPanel subSelectPanel = new SortingSubSelectionPanel(displayPanel);
        selectBoxPanel.add(subSelectPanel);
    }

    private void clearSelection() {
        // Remove the sub algorithm selection options
        for (int i = selectBoxPanel.getWidgetCount() - 1; i > 0; i--) {
            selectBoxPanel.remove(i);
        }

        // Remove the displayed visualization panels
        for (int i = contentsPanel.getWidgetCount() - 1; i >= 0; i--) {
            contentsPanel.remove(i);
        }
    }

}