FontSetToNull.java

/*
 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */

import java.awt.Font;

import javax.swing.JSpinner;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.plaf.UIResource;

import static javax.swing.JSpinner.DefaultEditor;
import static javax.swing.UIManager.getInstalledLookAndFeels;

/**
 * @test
 * @key headful
 * @bug 8210739
 */
public final class FontSetToNull {

    private static final Font USERS_FONT = new Font("dialog", Font.BOLD, 41);

    public static void main(final String[] args) throws Exception {
        for (final UIManager.LookAndFeelInfo laf : getInstalledLookAndFeels()) {
            SwingUtilities.invokeAndWait(() -> setLookAndFeel(laf));
            SwingUtilities.invokeAndWait(() -> {
                // default spinner
                test(new JSpinner());
                // spinner which always uses the null font
                test(new JSpinner(){
                    @Override
                    public Font getFont() {
                        return null;
                    }
                });
            });
        }
    }

    /**
     * A sequence of methods that test a possible NPE.
     */
    private static void test(JSpinner spinner) {
        final DefaultEditor de = (DefaultEditor) spinner.getEditor();

        spinner.setFont(null); // Check possible NPE
        SwingUtilities.updateComponentTreeUI(de); // Check possible NPE
        spinner.setFont(null); // Check possible NPE

        // should not replace the font of the TextField
        de.getTextField().setFont(USERS_FONT);
        spinner.setFont(null);

        final Font tff = de.getTextField().getFont();
        if (tff instanceof UIResource || !tff.equals(USERS_FONT)) {
            throw new RuntimeException("Wrong font: " + tff);
        }

        spinner.setEditor(new JSpinner().getEditor()); // Check possible NPE
    }

    private static void setLookAndFeel(final UIManager.LookAndFeelInfo laf) {
        try {
            UIManager.setLookAndFeel(laf.getClassName());
            System.out.println("LookAndFeel: " + laf.getClassName());
        } catch (ClassNotFoundException | InstantiationException |
                UnsupportedLookAndFeelException | IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }
}