Java example source code file (GraphicsUtilities.java)

This example Java source code file (GraphicsUtilities.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

awt, border, dimension, font, fontmetrics, geometry, graphics, graphicsutilities, gui, random, rectangle2d, swing, util

The GraphicsUtilities.java Java example source code

/*
 * Copyright (c) 2000, 2004, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

package sun.jvm.hotspot.ui;

import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.util.Random;
import javax.swing.*;
import javax.swing.border.*;

/** Useful utilities for drawing graphics */

public class GraphicsUtilities {
  /** Returns a plain-styled 12-point version of the given font, or
      null if the font could not be found */
  public static Font lookupFont(String fontName) {
    Font[] allFonts = GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
    Font font = null;
    for (int i = 0; i < allFonts.length; i++) {
      if (allFonts[i].getFontName().indexOf(fontName) != -1) {
        font = allFonts[i];
        break;
      }
    }
    if (font == null) {
      return null;
    }
    return font.deriveFont(Font.PLAIN, 12);
  }

  /** Compute the width and height of given string given the current
      font context in the Graphics object */
  public static Rectangle2D getStringBounds(String s, Graphics g) {
    FontMetrics fm = g.getFontMetrics();
    return fm.getStringBounds(s, 0, s.length(), g);
  }

  /** Compute just the width of the given string with the given
      FontMetrics. This is less accurate then getStringBounds(),
      above, since the graphics context is not taken into account. */
  public static int getStringWidth(String s, FontMetrics fm) {
    return fm.stringWidth(s);
  }

  public static void reshapeToAspectRatio(Component component,
                                          float aspectRatio,
                                          float fillRatio,
                                          Dimension containerDimension) {
    int x = containerDimension.width;
    int y = containerDimension.height;

    int desiredX;
    int desiredY;

    if (((float) x / (float) y) > aspectRatio) {
      desiredY = (int) (fillRatio * y);
      desiredX = (int) (desiredY * aspectRatio);
    } else {
      desiredX = (int) (fillRatio * x);
      desiredY = (int) (desiredX / aspectRatio);
    }
    component.setSize(desiredX, desiredY);
  }

  public static void constrainToSize(Component component, Dimension containerDimension) {
    Dimension d = component.getSize();
    int x = d.width;
    int y = d.height;
    boolean changed = false;

    if (x > containerDimension.width) {
      x = containerDimension.width;
      changed = true;
    }
    if (y > containerDimension.height) {
      y = containerDimension.height;
      changed = true;
    }

    if (changed) {
      component.setSize(x, y);
    }
  }

  public static void centerInContainer(Component c) {
    centerInContainer(c, c.getParent().getSize());
  }

  public static void centerInContainer(Component component,
                                       Dimension containerDimension) {
    Dimension sz = component.getSize();
    int x = ((containerDimension.width - sz.width) / 2);
    int y = ((containerDimension.height - sz.height) / 2);
    component.setLocation(x, y);
  }

  public static void moveToInContainer(Component component,
                                       float relativeX,
                                       float relativeY,
                                       int minX,
                                       int minY) {
    Dimension d = component.getParent().getSize();
    // Move the center of this component to the relative position in
    // the parent. Don't clip this component, however.
    Dimension sz = component.getSize();
    int xPos = Math.min(d.width - sz.width,
                        (int) ((d.width * relativeX) - (sz.width / 2)));
    int yPos = Math.min(d.height - sz.height,
                        (int) ((d.height * relativeY) - (sz.height / 2)));
    xPos = Math.max(xPos, minX);
    yPos = Math.max(yPos, minY);
    component.setLocation(xPos, yPos);
  }

  static Random random = new Random();

  public static void randomLocation(Component c) {
    randomLocation(c, c.getParent().getSize());
  }

  public static void randomLocation(Component component,
                                    Dimension containerDimension) {
    Dimension sz = component.getSize();
    int x = (int)((containerDimension.width - sz.width) * random.nextFloat());
    int y = (int)((containerDimension.height - sz.height) * random.nextFloat());
    component.setLocation(x, y);
  }


  public static Border newBorder(int size) {
    return BorderFactory.createEmptyBorder(size, size, size, size);
  }
}