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 * published by the Free Software Foundation.  Oracle designates this

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 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 *

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package javax.swing.table;

import javax.swing.*;

import javax.swing.border.*;

import java.awt.Component;

import java.awt.Color;

import java.awt.Rectangle;

import java.io.Serializable;

import sun.swing.DefaultLookup;

/**

 * The standard class for rendering (displaying) individual cells

 * in a <code>JTable</code>.

 * <p>

 *

 * <strong><a name="override">Implementation Note:</a></strong>

 * This class inherits from <code>JLabel</code>, a standard component class.

 * However <code>JTable</code> employs a unique mechanism for rendering

 * its cells and therefore requires some slightly modified behavior

 * from its cell renderer.

 * The table class defines a single cell renderer and uses it as a

 * as a rubber-stamp for rendering all cells in the table;

 * it renders the first cell,

 * changes the contents of that cell renderer,

 * shifts the origin to the new location, re-draws it, and so on.

 * The standard <code>JLabel</code> component was not

 * designed to be used this way and we want to avoid

 * triggering a <code>revalidate</code> each time the

 * cell is drawn. This would greatly decrease performance because the

 * <code>revalidate</code> message would be

 * passed up the hierarchy of the container to determine whether any other

 * components would be affected.

 * As the renderer is only parented for the lifetime of a painting operation

 * we similarly want to avoid the overhead associated with walking the

 * hierarchy for painting operations.

 * So this class

 * overrides the <code>validate</code>, <code>invalidate</code>,

 * <code>revalidate</code>, <code>repaint</code>, and

 * <code>firePropertyChange</code> methods to be

 * no-ops and override the <code>isOpaque</code> method solely to improve

 * performance.  If you write your own renderer,

 * please keep this performance consideration in mind.

 * <p>

 *

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @author Philip Milne

 * @see JTable

 */

public class DefaultTableCellRenderer extends JLabel

    implements TableCellRenderer, Serializable

{

   /**

    * An empty <code>Border</code>. This field might not be used. To change the

    * <code>Border</code> used by this renderer override the

    * <code>getTableCellRendererComponent</code> method and set the border

    * of the returned component directly.

    */

    private static final Border SAFE_NO_FOCUS_BORDER = new EmptyBorder(1, 1, 1, 1);

    private static final Border DEFAULT_NO_FOCUS_BORDER = new EmptyBorder(1, 1, 1, 1);

    protected static Border noFocusBorder = DEFAULT_NO_FOCUS_BORDER;

    // We need a place to store the color the JLabel should be returned

    // to after its foreground and background colors have been set

    // to the selection background color.

    // These ivars will be made protected when their names are finalized.

    private Color unselectedForeground;

    private Color unselectedBackground;

    /**

     * Creates a default table cell renderer.

     */

    public DefaultTableCellRenderer() {

        super();

        setOpaque(true);

        setBorder(getNoFocusBorder());

        setName("Table.cellRenderer");

    }

    private Border getNoFocusBorder() {

        Border border = DefaultLookup.getBorder(this, ui, "Table.cellNoFocusBorder");

        if (System.getSecurityManager() != null) {

            if (border != null) return border;

            return SAFE_NO_FOCUS_BORDER;

        } else if (border != null) {

            if (noFocusBorder == null || noFocusBorder == DEFAULT_NO_FOCUS_BORDER) {

                return border;

            }

        }

        return noFocusBorder;

    }

    /**

     * Overrides <code>JComponent.setForeground</code> to assign

     * the unselected-foreground color to the specified color.

     *

     * @param c set the foreground color to this value

     */

    public void setForeground(Color c) {

        super.setForeground(c);

        unselectedForeground = c;

    }

    /**

     * Overrides <code>JComponent.setBackground</code> to assign

     * the unselected-background color to the specified color.

     *

     * @param c set the background color to this value

     */

    public void setBackground(Color c) {

        super.setBackground(c);

        unselectedBackground = c;

    }

    /**

     * Notification from the <code>UIManager</code> that the look and feel

     * [L&F] has changed.

     * Replaces the current UI object with the latest version from the

     * <code>UIManager</code>.

     *

     * @see JComponent#updateUI

     */

    public void updateUI() {

        super.updateUI();

        setForeground(null);

        setBackground(null);

    }

    // implements javax.swing.table.TableCellRenderer

    /**

     *

     * Returns the default table cell renderer.

     * <p>

     * During a printing operation, this method will be called with

     * <code>isSelected</code> and <code>hasFocus</code> values of

     * <code>false</code> to prevent selection and focus from appearing

     * in the printed output. To do other customization based on whether

     * or not the table is being printed, check the return value from

     * {@link javax.swing.JComponent#isPaintingForPrint()}.

     *

     * @param table  the <code>JTable</code>

     * @param value  the value to assign to the cell at

     *                  <code>[row, column]</code>

     * @param isSelected true if cell is selected

     * @param hasFocus true if cell has focus

     * @param row  the row of the cell to render

     * @param column the column of the cell to render

     * @return the default table cell renderer

     * @see javax.swing.JComponent#isPaintingForPrint()

     */

    public Component getTableCellRendererComponent(JTable table, Object value,

                          boolean isSelected, boolean hasFocus, int row, int column) {

        if (table == null) {

            return this;

        }

        Color fg = null;

        Color bg = null;

        JTable.DropLocation dropLocation = table.getDropLocation();

        if (dropLocation != null

                && !dropLocation.isInsertRow()

                && !dropLocation.isInsertColumn()

                && dropLocation.getRow() == row

                && dropLocation.getColumn() == column) {

            fg = DefaultLookup.getColor(this, ui, "Table.dropCellForeground");

            bg = DefaultLookup.getColor(this, ui, "Table.dropCellBackground");

            isSelected = true;

        }

        if (isSelected) {

            super.setForeground(fg == null ? table.getSelectionForeground()

                                           : fg);

            super.setBackground(bg == null ? table.getSelectionBackground()

                                           : bg);

        } else {

            Color background = unselectedBackground != null

                                    ? unselectedBackground

                                    : table.getBackground();

            if (background == null || background instanceof javax.swing.plaf.UIResource) {

                Color alternateColor = DefaultLookup.getColor(this, ui, "Table.alternateRowColor");

                if (alternateColor != null && row % 2 != 0) {

                    background = alternateColor;

                }

            }

            super.setForeground(unselectedForeground != null

                                    ? unselectedForeground

                                    : table.getForeground());

            super.setBackground(background);

        }

        setFont(table.getFont());

        if (hasFocus) {

            Border border = null;

            if (isSelected) {

                border = DefaultLookup.getBorder(this, ui, "Table.focusSelectedCellHighlightBorder");

            }

            if (border == null) {

                border = DefaultLookup.getBorder(this, ui, "Table.focusCellHighlightBorder");

            }

            setBorder(border);

            if (!isSelected && table.isCellEditable(row, column)) {

                Color col;

                col = DefaultLookup.getColor(this, ui, "Table.focusCellForeground");

                if (col != null) {

                    super.setForeground(col);

                }

                col = DefaultLookup.getColor(this, ui, "Table.focusCellBackground");

                if (col != null) {

                    super.setBackground(col);

                }

            }

        } else {

            setBorder(getNoFocusBorder());

        }

        setValue(value);

        return this;

    }

    /*

     * The following methods are overridden as a performance measure to

     * to prune code-paths are often called in the case of renders

     * but which we know are unnecessary.  Great care should be taken

     * when writing your own renderer to weigh the benefits and

     * drawbacks of overriding methods like these.

     */

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    public boolean isOpaque() {

        Color back = getBackground();

        Component p = getParent();

        if (p != null) {

            p = p.getParent();

        }

        // p should now be the JTable.

        boolean colorMatch = (back != null) && (p != null) &&

            back.equals(p.getBackground()) &&

                        p.isOpaque();

        return !colorMatch && super.isOpaque();

    }

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     *

     * @since 1.5

     */

    public void invalidate() {}

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    public void validate() {}

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    public void revalidate() {}

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    public void repaint(long tm, int x, int y, int width, int height) {}

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    public void repaint(Rectangle r) { }

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     *

     * @since 1.5

     */

    public void repaint() {

    }

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) {

        // Strings get interned...

        if (propertyName=="text"

                || propertyName == "labelFor"

                || propertyName == "displayedMnemonic"

                || ((propertyName == "font" || propertyName == "foreground")

                    && oldValue != newValue

                    && getClientProperty(javax.swing.plaf.basic.BasicHTML.propertyKey) != null)) {

            super.firePropertyChange(propertyName, oldValue, newValue);

        }

    }

    /**

     * Overridden for performance reasons.

     * See the <a href="#override">Implementation Note</a>

     * for more information.

     */

    public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) { }

    /**

     * Sets the <code>String</code> object for the cell being rendered to

     * <code>value</code>.

     *

     * @param value  the string value for this cell; if value is

     *          <code>null</code> it sets the text value to an empty string

     * @see JLabel#setText

     *

     */

    protected void setValue(Object value) {

        setText((value == null) ? "" : value.toString());

    }

    /**

     * A subclass of <code>DefaultTableCellRenderer</code> that

     * implements <code>UIResource</code>.

     * <code>DefaultTableCellRenderer</code> doesn't implement

     * <code>UIResource</code>

     * directly so that applications can safely override the

     * <code>cellRenderer</code> property with

     * <code>DefaultTableCellRenderer</code> subclasses.

     * <p>

     * <strong>Warning:</strong>

     * Serialized objects of this class will not be compatible with

     * future Swing releases. The current serialization support is

     * appropriate for short term storage or RMI between applications running

     * the same version of Swing.  As of 1.4, support for long term storage

     * of all JavaBeans<sup><font size="-2">TM</font></sup>

     * has been added to the <code>java.beans</code> package.

     * Please see {@link java.beans.XMLEncoder}.

     */

    public static class UIResource extends DefaultTableCellRenderer

        implements javax.swing.plaf.UIResource

    {

    }

}