org.nightlabs.base.ui.pref.DoubleFieldEditor.java Source code

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Here is the source code for org.nightlabs.base.ui.pref.DoubleFieldEditor.java

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/* *****************************************************************************
 * org.nightlabs.base.ui - NightLabs Eclipse utilities                            *
 * Copyright (C) 2004-2005 NightLabs - http://NightLabs.org                    *
 *                                                                             *
 * This library is free software; you can redistribute it and/or               *
 * modify it under the terms of the GNU Lesser General Public                  *
 * License as published by the Free Software Foundation; either                *
 * version 2.1 of the License, or (at your option) any later version.          *
 *                                                                             *
 * This library 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           *
 * Lesser General Public License for more details.                             *
 *                                                                             *
 * You should have received a copy of the GNU Lesser General Public            *
 * License along with this library; if not, write to the                       *
 *     Free Software Foundation, Inc.,                                         *
 *     51 Franklin St, Fifth Floor,                                            *
 *     Boston, MA  02110-1301  USA                                             *
 *                                                                             *
 * Or get it online :                                                          *
 *     http://www.gnu.org/copyleft/lesser.html                                 *
 *                                                                             *
 *                                                                             *
 ******************************************************************************/

package org.nightlabs.base.ui.pref;

import org.eclipse.jface.preference.FieldEditor;
import org.eclipse.jface.preference.StringFieldEditor;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Text;
import org.nightlabs.base.ui.resource.Messages;

/**
 * {@link FieldEditor} for editing {@link Double} values. 
 */
public class DoubleFieldEditor extends StringFieldEditor {
    private double minValidValue = 0;
    private double maxValidValue = Double.MAX_VALUE;
    private static final int DEFAULT_TEXT_LIMIT = 10;

    /**
     * Creates a new double field editor
     */
    protected DoubleFieldEditor() {
    }

    /**
     * Creates a double field editor.
     * 
     * @param name the name of the preference this field editor works on
     * @param labelText the label text of the field editor
     * @param parent the parent of the field editor's control
     */
    public DoubleFieldEditor(String name, String labelText, Composite parent) {
        this(name, labelText, parent, DEFAULT_TEXT_LIMIT);
    }

    /**
     * Creates an double field editor.
     * 
     * @param name the name of the preference this field editor works on
     * @param labelText the label text of the field editor
     * @param parent the parent of the field editor's control
     * @param textLimit the maximum number of characters in the text.
     */
    public DoubleFieldEditor(String name, String labelText, Composite parent, int textLimit) {
        init(name, labelText);
        setTextLimit(textLimit);
        setEmptyStringAllowed(false);
        setErrorMessage(Messages.getString("org.nightlabs.base.ui.pref.DoubleFieldEditor.errorMessage")); //$NON-NLS-1$
        createControl(parent);
    }

    /**
     * Sets the range of valid values for this field.
     * 
     * @param min the minimum allowed value (inclusive)
     * @param max the maximum allowed value (inclusive)
     */
    public void setValidRange(double min, double max) {
        minValidValue = min;
        maxValidValue = max;
    }

    /* (non-Javadoc)
     * Method declared on StringFieldEditor.
     * Checks whether the entered String is a valid integer or not.
     */
    @Override
    protected boolean checkState() {

        Text text = getTextControl();

        if (text == null)
            return false;

        String numberString = text.getText();
        try {
            double number = Double.valueOf(numberString).intValue();
            if (number >= minValidValue && number <= maxValidValue) {
                clearErrorMessage();
                return true;
            }

            showErrorMessage();
            return false;

        } catch (NumberFormatException e1) {
            showErrorMessage();
        }

        return false;
    }

    /* (non-Javadoc)
     * Method declared on FieldEditor.
     */
    @Override
    protected void doLoad() {
        Text text = getTextControl();
        if (text != null) {
            double value = getPreferenceStore().getDouble(getPreferenceName());
            text.setText("" + value);//$NON-NLS-1$
        }

    }

    /* (non-Javadoc)
     * Method declared on FieldEditor.
     */
    @Override
    protected void doLoadDefault() {
        Text text = getTextControl();
        if (text != null) {
            double value = getPreferenceStore().getDefaultDouble(getPreferenceName());
            text.setText("" + value);//$NON-NLS-1$
        }
        valueChanged();
    }

    /* (non-Javadoc)
     * Method declared on FieldEditor.
     */
    @Override
    protected void doStore() {
        Text text = getTextControl();
        if (text != null) {
            Double d = new Double(text.getText());
            getPreferenceStore().setValue(getPreferenceName(), d.doubleValue());
        }
    }

    /**
     * Returns this field editor's current value as double.
     *
     * @return the value
     * @exception NumberFormatException if the <code>String</code> does not
     *   contain a parsable double
     */
    public double getDoubleValue() throws NumberFormatException {
        return new Double(getStringValue()).doubleValue();
    }
}