/* * Copyright (c) 1998, 2010, 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.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * 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. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ 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    {    } }