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Diffstat (limited to 'libjava/classpath/javax/swing/border/EmptyBorder.java')
| -rw-r--r-- | libjava/classpath/javax/swing/border/EmptyBorder.java | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/libjava/classpath/javax/swing/border/EmptyBorder.java b/libjava/classpath/javax/swing/border/EmptyBorder.java new file mode 100644 index 000000000..da6651163 --- /dev/null +++ b/libjava/classpath/javax/swing/border/EmptyBorder.java @@ -0,0 +1,223 @@ +/* EmptyBorder.java -- + Copyright (C) 2003 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath 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, or (at your option) +any later version. + +GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package javax.swing.border; + +import java.awt.Component; +import java.awt.Graphics; +import java.awt.Insets; + + +/** + * A border for leaving a specifiable number of pixels empty around + * the enclosed component. An EmptyBorder requires some space on each + * edge, but does not perform any drawing. + * + * <p><img src="EmptyBorder-1.png" width="290" height="200" + * alt="[An illustration of EmptyBorder]" /> + * + * @author Sascha Brawer (brawer@dandelis.ch) + */ +public class EmptyBorder extends AbstractBorder +{ + /** + * Determined using the <code>serialver</code> tool + * of Apple/Sun JDK 1.3.1 on MacOS X 10.1.5. + */ + static final long serialVersionUID = -8116076291731988694L; + + + /** + * The number of pixels required at the left edge. + */ + protected int left; + + + /** + * The number of pixels required at the right edge. + */ + protected int right; + + + /** + * The number of pixels required at the top edge. + */ + protected int top; + + + /** + * The number of pixels required at the bottom edge. + */ + protected int bottom; + + + /** + * Constructs an empty border given the number of pixels required + * on each side. + * + * @param top the number of pixels that the border will need + * for its top edge. + * + * @param left the number of pixels that the border will need + * for its left edge. + * + * @param bottom the number of pixels that the border will need + * for its bottom edge. + * + * @param right the number of pixels that the border will need + * for its right edge. + */ + public EmptyBorder(int top, int left, int bottom, int right) + { + this.top = top; + this.left = left; + this.bottom = bottom; + this.right = right; + } + + + /** + * Constructs an empty border given the number of pixels required + * on each side, passed in an Insets object. + * + * @param borderInsets the Insets for the new border. + */ + public EmptyBorder(Insets borderInsets) + { + this(borderInsets.top, borderInsets.left, + borderInsets.bottom, borderInsets.right); + } + + + /** + * Performs nothing because an EmptyBorder does not paint any + * pixels. While the inherited implementation provided by + * {@link AbstractBorder#paintBorder} is a no-op as well, + * it is overwritten in order to match the API of the Sun + * reference implementation. + * + * @param c the component whose border is to be painted. + * @param g the graphics for painting. + * @param x the horizontal position for painting the border. + * @param y the vertical position for painting the border. + * @param width the width of the available area for painting the border. + * @param height the height of the available area for painting the border. + */ + public void paintBorder(Component c, Graphics g, + int x, int y, int width, int height) + { + // Nothing to do here. + } + + + /** + * Measures the width of this border. + * + * @param c the component whose border is to be measured. + * + * @return an Insets object whose <code>left</code>, <code>right</code>, + * <code>top</code> and <code>bottom</code> fields indicate the + * width of the border at the respective edge. + * + * @see #getBorderInsets(java.awt.Component, java.awt.Insets) + */ + public Insets getBorderInsets(Component c) + { + return getBorderInsets(c, null); + } + + + /** + * Measures the width of this border, storing the results into a + * pre-existing Insets object. + * + * @param insets an Insets object for holding the result values. + * After invoking this method, the <code>left</code>, + * <code>right</code>, <code>top</code> and + * <code>bottom</code> fields indicate the width of the + * border at the respective edge. + * + * @return the same object that was passed for <code>insets</code>. + * + * @see #getBorderInsets() + */ + public Insets getBorderInsets(Component c, Insets insets) + { + if (insets == null) + insets = new Insets(0, 0, 0, 0); + + insets.left = left; + insets.right = right; + insets.top = top; + insets.bottom = bottom; + return insets; + } + + + /** + * Measures the width of this border. + * + * @return an Insets object whose <code>left</code>, <code>right</code>, + * <code>top</code> and <code>bottom</code> fields indicate the + * width of the border at the respective edge. + * + * @see #getBorderInsets(java.awt.Component, java.awt.Insets) + */ + public Insets getBorderInsets() + { + return getBorderInsets(null, null); + } + + + /** + * Determines whether this border fills every pixel in its area + * when painting. Since an empty border does not paint any pixels + * whatsoever, the result is <code>false</code>. + * + * @return <code>false</code>. + */ + public boolean isBorderOpaque() + { + /* The inherited implementation of AbstractBorder.isBorderOpaque() + * would also return false. It is not clear why this is overriden + * in the Sun implementation, at least not from just reading the + * JavaDoc. + */ + return false; + } +} |