https://openjdk.java.net/ 
/*
 * Copyright (c) 1997, 2006, 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.plaf.basic;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Color;

import javax.swing.*;
import javax.swing.plaf.UIResource;


JButton object that draws a scaled Arrow in one of the cardinal directions.


Warning:
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 JavaBeansTM
has been added to the java.beans package. Please see XMLEncoder. 
Author:David Kloba
/**
 * JButton object that draws a scaled Arrow in one of the cardinal directions.
 * <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 David Kloba
 */
public class BasicArrowButton extends JButton implements SwingConstants
{
        
The direction of the arrow. One of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST. 
/**
         * The direction of the arrow. One of
         * {@code SwingConstants.NORTH}, {@code SwingConstants.SOUTH},
         * {@code SwingConstants.EAST} or {@code SwingConstants.WEST}.
         */
        protected int direction;

        private Color shadow;
        private Color darkShadow;
        private Color highlight;

        
Creates a BasicArrowButton whose arrow is drawn in the specified direction and with the specified colors. 
Params:
  • direction – the direction of the arrow; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST
  • background – the background color of the button
  • shadow – the color of the shadow
  • darkShadow – the color of the dark shadow
  • highlight – the color of the highlight
Since:1.4
/**
         * Creates a {@code BasicArrowButton} whose arrow
         * is drawn in the specified direction and with the specified
         * colors.
         *
         * @param direction the direction of the arrow; one of
         *        {@code SwingConstants.NORTH}, {@code SwingConstants.SOUTH},
         *        {@code SwingConstants.EAST} or {@code SwingConstants.WEST}
         * @param background the background color of the button
         * @param shadow the color of the shadow
         * @param darkShadow the color of the dark shadow
         * @param highlight the color of the highlight
         * @since 1.4
         */
        public BasicArrowButton(int direction, Color background, Color shadow,
                         Color darkShadow, Color highlight) {
            super();
            setRequestFocusEnabled(false);
            setDirection(direction);
            setBackground(background);
            this.shadow = shadow;
            this.darkShadow = darkShadow;
            this.highlight = highlight;
        }

        
Creates a BasicArrowButton whose arrow is drawn in the specified direction. 
Params:
  • direction – the direction of the arrow; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST
/**
         * Creates a {@code BasicArrowButton} whose arrow
         * is drawn in the specified direction.
         *
         * @param direction the direction of the arrow; one of
         *        {@code SwingConstants.NORTH}, {@code SwingConstants.SOUTH},
         *        {@code SwingConstants.EAST} or {@code SwingConstants.WEST}
         */
        public BasicArrowButton(int direction) {
            this(direction, UIManager.getColor("control"), UIManager.getColor("controlShadow"),
                 UIManager.getColor("controlDkShadow"), UIManager.getColor("controlLtHighlight"));
        }

        
Returns the direction of the arrow.

/**
         * Returns the direction of the arrow.
         */
        public int getDirection() {
            return direction;
        }

        
Sets the direction of the arrow.

Params:
  • direction – the direction of the arrow; one of of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST
/**
         * Sets the direction of the arrow.
         *
         * @param direction the direction of the arrow; one of
         *        of {@code SwingConstants.NORTH},
         *        {@code SwingConstants.SOUTH},
         *        {@code SwingConstants.EAST} or {@code SwingConstants.WEST}
         */
        public void setDirection(int direction) {
            this.direction = direction;
        }

        public void paint(Graphics g) {
            Color origColor;
            boolean isPressed, isEnabled;
            int w, h, size;

            w = getSize().width;
            h = getSize().height;
            origColor = g.getColor();
            isPressed = getModel().isPressed();
            isEnabled = isEnabled();

            g.setColor(getBackground());
            g.fillRect(1, 1, w-2, h-2);

            /// Draw the proper Border
            if (getBorder() != null && !(getBorder() instanceof UIResource)) {
                paintBorder(g);
            } else if (isPressed) {
                g.setColor(shadow);
                g.drawRect(0, 0, w-1, h-1);
            } else {
                // Using the background color set above
                g.drawLine(0, 0, 0, h-1);
                g.drawLine(1, 0, w-2, 0);

                g.setColor(highlight);    // inner 3D border
                g.drawLine(1, 1, 1, h-3);
                g.drawLine(2, 1, w-3, 1);

                g.setColor(shadow);       // inner 3D border
                g.drawLine(1, h-2, w-2, h-2);
                g.drawLine(w-2, 1, w-2, h-3);

                g.setColor(darkShadow);     // black drop shadow  __|
                g.drawLine(0, h-1, w-1, h-1);
                g.drawLine(w-1, h-1, w-1, 0);
            }

            // If there's no room to draw arrow, bail
            if(h < 5 || w < 5)      {
                g.setColor(origColor);
                return;
            }

            if (isPressed) {
                g.translate(1, 1);
            }

            // Draw the arrow
            size = Math.min((h - 4) / 3, (w - 4) / 3);
            size = Math.max(size, 2);
            paintTriangle(g, (w - size) / 2, (h - size) / 2,
                                size, direction, isEnabled);

            // Reset the Graphics back to it's original settings
            if (isPressed) {
                g.translate(-1, -1);
            }
            g.setColor(origColor);

        }

        
Returns the preferred size of the BasicArrowButton. 
Returns:the preferred size
/**
         * Returns the preferred size of the {@code BasicArrowButton}.
         *
         * @return the preferred size
         */
        public Dimension getPreferredSize() {
            return new Dimension(16, 16);
        }

        
Returns the minimum size of the BasicArrowButton. 
Returns:the minimum size
/**
         * Returns the minimum size of the {@code BasicArrowButton}.
         *
         * @return the minimum size
         */
        public Dimension getMinimumSize() {
            return new Dimension(5, 5);
        }

        
Returns the maximum size of the BasicArrowButton. 
Returns:the maximum size
/**
         * Returns the maximum size of the {@code BasicArrowButton}.
         *
         * @return the maximum size
         */
        public Dimension getMaximumSize() {
            return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
        }

        
Returns whether the arrow button should get the focus. BasicArrowButtons are used as a child component of composite components such as JScrollBar and JComboBox. Since the composite component typically gets the focus, this method is overriden to return false. 
Returns:false
/**
         * Returns whether the arrow button should get the focus.
         * {@code BasicArrowButton}s are used as a child component of
         * composite components such as {@code JScrollBar} and
         * {@code JComboBox}. Since the composite component typically gets the
         * focus, this method is overriden to return {@code false}.
         *
         * @return {@code false}
         */
        public boolean isFocusTraversable() {
          return false;
        }

        
Paints a triangle.

Params:
  • g – the Graphics to draw to
  • x – the x coordinate
  • y – the y coordinate
  • size – the size of the triangle to draw
  • direction – the direction in which to draw the arrow; one of SwingConstants.NORTH, SwingConstants.SOUTH, SwingConstants.EAST or SwingConstants.WEST
  • isEnabled – whether or not the arrow is drawn enabled
/**
         * Paints a triangle.
         *
         * @param g the {@code Graphics} to draw to
         * @param x the x coordinate
         * @param y the y coordinate
         * @param size the size of the triangle to draw
         * @param direction the direction in which to draw the arrow;
         *        one of {@code SwingConstants.NORTH},
         *        {@code SwingConstants.SOUTH}, {@code SwingConstants.EAST} or
         *        {@code SwingConstants.WEST}
         * @param isEnabled whether or not the arrow is drawn enabled
         */
        public void paintTriangle(Graphics g, int x, int y, int size,
                                        int direction, boolean isEnabled) {
            Color oldColor = g.getColor();
            int mid, i, j;

            j = 0;
            size = Math.max(size, 2);
            mid = (size / 2) - 1;

            g.translate(x, y);
            if(isEnabled)
                g.setColor(darkShadow);
            else
                g.setColor(shadow);

            switch(direction)       {
            case NORTH:
                for(i = 0; i < size; i++)      {
                    g.drawLine(mid-i, i, mid+i, i);
                }
                if(!isEnabled)  {
                    g.setColor(highlight);
                    g.drawLine(mid-i+2, i, mid+i, i);
                }
                break;
            case SOUTH:
                if(!isEnabled)  {
                    g.translate(1, 1);
                    g.setColor(highlight);
                    for(i = size-1; i >= 0; i--)   {
                        g.drawLine(mid-i, j, mid+i, j);
                        j++;
                    }
                    g.translate(-1, -1);
                    g.setColor(shadow);
                }

                j = 0;
                for(i = size-1; i >= 0; i--)   {
                    g.drawLine(mid-i, j, mid+i, j);
                    j++;
                }
                break;
            case WEST:
                for(i = 0; i < size; i++)      {
                    g.drawLine(i, mid-i, i, mid+i);
                }
                if(!isEnabled)  {
                    g.setColor(highlight);
                    g.drawLine(i, mid-i+2, i, mid+i);
                }
                break;
            case EAST:
                if(!isEnabled)  {
                    g.translate(1, 1);
                    g.setColor(highlight);
                    for(i = size-1; i >= 0; i--)   {
                        g.drawLine(j, mid-i, j, mid+i);
                        j++;
                    }
                    g.translate(-1, -1);
                    g.setColor(shadow);
                }

                j = 0;
                for(i = size-1; i >= 0; i--)   {
                    g.drawLine(j, mid-i, j, mid+i);
                    j++;
                }
                break;
            }
            g.translate(-x, -y);
            g.setColor(oldColor);
        }

}