com.sciencegadgets.client.algebra.transformations.specification.NumberQuiz.java Source code

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Here is the source code for com.sciencegadgets.client.algebra.transformations.specification.NumberQuiz.java

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/*******************************************************************************
 *     This file is part of ScienceGadgets, a collection of educational tools
 *     Copyright (C) 2012-2015 by John Gralyan
 *
 *     ScienceGadgets is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU Affero General Public License as
 *     published by the Free Software Foundation, either version 3 of
 *     the License, or (at your option) any later version.
 *
 *     ScienceGadgets 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 Affero General Public License for more details.
 *
 *     You should have received a copy of the GNU Affero General Public License
 *     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *     
 *     Contact us at info@sciencegadgets.org
 *******************************************************************************/
package com.sciencegadgets.client.algebra.transformations.specification;

import java.math.BigDecimal;
import java.math.MathContext;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.sciencegadgets.client.ui.CSS;
import com.sciencegadgets.client.ui.KeyPadNumerical;
import com.sciencegadgets.client.ui.Prompt;
import com.sciencegadgets.client.ui.Quiz;
import com.sciencegadgets.client.ui.SymbolDisplay;

public abstract class NumberQuiz extends Quiz {

    static final BigDecimal ACCEPTABLE_ERROR = new BigDecimal(".01");
    private static final int same = 0;
    private static final int lessThan = -1;
    final KeyPadNumerical keyPad = new KeyPadNumerical();
    final SymbolDisplay display = keyPad.getSymbolDisplay();

    public NumberQuiz(String question, final BigDecimal totalValue) {

        HTML questionDisplay = new HTML(question + " = ");
        questionDisplay.addStyleName(CSS.LAYOUT_ROW + " " + CSS.DOUBLE_FONT_SIZE);
        add(questionDisplay);

        display.addStyleName(CSS.LAYOUT_ROW + " " + CSS.DOUBLE_FONT_SIZE);
        display.setWidth("3em");

        add(display);
        add(keyPad);

        final HTML incorrectResponse = new HTML("<b>Incorrect</b>");

        addOkHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                try {
                    BigDecimal inputValue = new BigDecimal(display.getText());

                    // acceptable error
                    BigDecimal error;
                    if (totalValue.compareTo(new BigDecimal(0)) == same) {
                        error = totalValue.subtract(inputValue).abs();
                    } else {
                        error = inputValue.divide(totalValue, MathContext.DECIMAL32).subtract(new BigDecimal("1"))
                                .abs();
                    }

                    if (error.compareTo(ACCEPTABLE_ERROR) == lessThan) {
                        // correct
                        disappear();
                        onCorrect();
                    } else {
                        // incorrect
                        incorrectResponse.setHTML(incorrectResponse.getHTML() + "<br/>" + inputValue);
                        add(incorrectResponse);
                        keyPad.displaySelect();
                        onIncorrect();
                    }
                } catch (NumberFormatException e) {
                    if ("".equals(display.getText())) {
                        disappear();
                    } else {
                        incorrectResponse.setHTML(incorrectResponse.getHTML() + "<br/>Not a number");
                        add(incorrectResponse);
                        keyPad.displaySelect();
                    }
                }
            }
        });
    }

    @Override
    public void appear() {
        super.appear();
        //      keyPad.getSymbolDisplay().setFocus(true);
    }
}