Java Draw Arrow drawDoubleHeadedArrow(final Graphics aG, final int aX1, final int aY, final int aX2)

Description

Draws a double headed arrow of 8x8.

License

Open Source License

Parameter

Parameter	Description
aG	the canvas to draw on;
aX1	the starting X position of the arrow;
aY	the starting Y position of the arrow;
aX2	the ending X position of the arrow.

Declaration

public static final void drawDoubleHeadedArrow(final Graphics aG, final int aX1, final int aY, final int aX2) 

Method Source Code

//package com.java2s;
/*/*from  w w  w.j  av a  2 s  . co m*/
 * OpenBench LogicSniffer / SUMP project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
 *
 * 
 * Copyright (C) 2010-2011 - J.W. Janssen, http://www.lxtreme.nl
 */

import java.awt.*;

public class Main {
    public static final int LEFT_FACING = 1;
    public static final int RIGHT_FACING = -1;

    /**
     * Draws a double headed arrow of 8x8.
     * 
     * @param aG
     *          the canvas to draw on;
     * @param aX1
     *          the starting X position of the arrow;
     * @param aY
     *          the starting Y position of the arrow;
     * @param aX2
     *          the ending X position of the arrow.
     */
    public static final void drawDoubleHeadedArrow(final Graphics aG, final int aX1, final int aY, final int aX2) {
        drawDoubleHeadedArrow(aG, aX1, aY, aX2, aY);
    }

    /**
     * Draws a double headed arrow of 8x8.
     * 
     * @param aG
     *          the canvas to draw on;
     * @param aX1
     *          the starting X position of the arrow;
     * @param aY1
     *          the starting Y position of the arrow;
     * @param aX2
     *          the ending X position of the arrow;
     * @param aY2
     *          the ending Y position of the arrow.
     */
    public static final void drawDoubleHeadedArrow(final Graphics aG, final int aX1, final int aY1, final int aX2,
            final int aY2) {
        drawDoubleHeadedArrow(aG, aX1, aY1, aX2, aY2, 8, 8);
    }

    /**
     * Draws a double headed arrow with arrow heads of a given width and height.
     * 
     * @param aG
     *          the canvas to draw on;
     * @param aX1
     *          the starting X position of the arrow;
     * @param aY1
     *          the starting Y position of the arrow;
     * @param aX2
     *          the ending X position of the arrow;
     * @param aY2
     *          the ending Y position of the arrow;
     * @param aArrowWidth
     *          the total width of the arrow head;
     * @param aArrowHeight
     *          the total height of the arrow head.
     */
    public static final void drawDoubleHeadedArrow(final Graphics aG, final int aX1, final int aY1, final int aX2,
            final int aY2, final int aArrowWidth, final int aArrowHeight) {
        final Graphics2D g2d = (Graphics2D) aG.create();

        final int lineWidth = Math.abs(aX2 - aX1);
        final int threshold = (2 * aArrowWidth) + 2;
        try {
            int x1 = aX1;
            int x2 = aX2;

            if (lineWidth > threshold) {
                drawArrowHead(g2d, aX1, aY1, LEFT_FACING, aArrowWidth, aArrowHeight);
                // why x2 needs to be shifted by one pixel is beyond me...
                drawArrowHead(g2d, aX2 + 1, aY2, RIGHT_FACING, aArrowWidth, aArrowHeight);

                x1 += aArrowWidth - 1;
                x2 -= aArrowWidth + 1;
            }

            g2d.drawLine(x1, aY1, x2, aY2);
        } finally {
            g2d.dispose();
        }
    }

    /**
     * Draws a single arrow head
     * 
     * @param aG
     *          the canvas to draw on;
     * @param aXpos
     *          the X position of the arrow head;
     * @param aYpos
     *          the (center) Y position of the arrow head;
     * @param aFactor
     *          +1 to have a left-facing arrow head, -1 to have a right-facing
     *          arrow head;
     * @param aArrowWidth
     *          the total width of the arrow head;
     * @param aArrowHeight
     *          the total height of the arrow head.
     */
    public static final void drawArrowHead(final Graphics2D aG, final int aXpos, final int aYpos, final int aFactor,
            final int aArrowWidth, final int aArrowHeight) {
        final double halfHeight = aArrowHeight / 2.0;
        final int x1 = aXpos + (aFactor * aArrowWidth);
        final int y1 = (int) Math.ceil(aYpos - halfHeight);
        final int y2 = (int) Math.floor(aYpos + halfHeight);

        final Polygon arrowHead = new Polygon();
        arrowHead.addPoint(aXpos, aYpos);
        arrowHead.addPoint(x1, y1);
        arrowHead.addPoint(x1, y2);

        aG.fill(arrowHead);
    }

    /**
     * Closes and disposes a given {@link Window}.
     * 
     * @param aWindow
     *          the window to close, if <code>null</code>, this method doesn't do
     *          anything.
     */
    public static void dispose(final Window aWindow) {
        if (aWindow == null) {
            return;
        }
        if (aWindow.isVisible()) {
            aWindow.setVisible(false);
        }
        aWindow.dispose();
    }
}

Related

1. drawArrow(Graphics2D g2d, int xCenter, int yCenter, int x, int y, float stroke)
2. drawArrowHead(final Graphics2D aG, final int aXpos, final int aYpos, final int aFactor, final int aArrowWidth, final int aArrowHeight)
3. drawArrowHead(Graphics g, double c1, double c2, double phi, int l, int grad, boolean fill)
4. drawArrowLine(Graphics g, int x1, int y1, int x2, int y2, int d, int h, boolean capOnly)
5. drawArrowLine(Graphics g, int x1, int y1, int x2, int y2, int dist, boolean arrowLeft, boolean arrowRight)
6. drawHorizontalArrow(Graphics g, Rectangle r, boolean direction)