GNU Classpath (0.20) | |
Frames | No Frames |
1: /* AbstractBorder.java -- 2: Copyright (C) 2003 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package javax.swing.border; 40: 41: import java.awt.Component; 42: import java.awt.Graphics; 43: import java.awt.Insets; 44: import java.awt.Rectangle; 45: import java.io.Serializable; 46: 47: 48: /** 49: * An invisible zero-width border, serving as a base class for 50: * implementing more interesting borders. 51: * 52: * @author Sascha Brawer (brawer@dandelis.ch) 53: * @author Ronald Veldema (rveldema@cs.vu.nl) 54: */ 55: public abstract class AbstractBorder implements Border, Serializable 56: { 57: static final long serialVersionUID = -545885975315191844L; 58: 59: /** 60: * Constructs a new AbstractBorder. 61: */ 62: public AbstractBorder() 63: { 64: // Nothing to do here. 65: } 66: 67: /** 68: * Performs nothing, because the default implementation provided by 69: * this class is an invisible, zero-width border. Subclasses will 70: * likely want to override this method, but they are not required 71: * for doing so. 72: * 73: * @param c the component whose border is to be painted. 74: * @param g the graphics for painting. 75: * @param x the horizontal position for painting the border. 76: * @param y the vertical position for painting the border. 77: * @param width the width of the available area for painting the border. 78: * @param height the height of the available area for painting the border. 79: */ 80: public void paintBorder(Component c, Graphics g, int x, int y, int width, 81: int height) 82: { 83: // A previous version of Classpath had emitted a warning when 84: // this method was called. The warning was removed because it is 85: // perfectly legal for a subclass to not override the paintBorder 86: // method. An example would be EmptyBorder. 87: } 88: 89: /** 90: * Measures the width of this border. 91: * 92: * @param c the component whose border is to be measured. 93: * 94: * @return an Insets object whose <code>left</code>, <code>right</code>, 95: * <code>top</code> and <code>bottom</code> fields indicate the 96: * width of the border at the respective edge, which is zero 97: * for the default implementation provided by AbstractButton. 98: * 99: * @see #getBorderInsets(java.awt.Component, java.awt.Insets) 100: */ 101: public Insets getBorderInsets(Component c) 102: { 103: return new Insets(0, 0, 0, 0); 104: } 105: 106: /** 107: * Determines the insets of this border. The implementation provided 108: * by AbstractButton sets the <code>left</code>, <code>right</code>, 109: * <code>top</code> and <code>bottom</code> fields of the passed 110: * <code>insets</code> parameter to zero. 111: * 112: * @param c the component whose border is to be measured 113: * 114: * @return the same object that was passed for <code>insets</code> 115: * 116: * @see #getBorderInsets(Component) 117: */ 118: public Insets getBorderInsets(Component c, Insets insets) 119: { 120: insets.left = insets.right = insets.top = insets.bottom = 0; 121: return insets; 122: } 123: 124: /** 125: * Determines whether or not this border is opaque. An opaque border 126: * fills every pixel in its area when painting. Partially 127: * translucent borders must return <code>false</code>, or ugly 128: * artifacts can appear on screen. The default implementation 129: * provided by AbstractBorder always returns <code>false</code>. 130: * 131: * @return <code>false</code>. 132: */ 133: public boolean isBorderOpaque() 134: { 135: return false; 136: } 137: 138: /** 139: * Returns a rectangle that covers the specified area minus this 140: * border. Components that wish to determine an area into which 141: * they can safely draw without intersecting with a border might 142: * want to use this helper method. 143: * 144: * @param c the component in the center of this border. 145: * @param x the horizontal position of the border. 146: * @param y the vertical position of the border. 147: * @param width the width of the available area for the border. 148: * @param height the height of the available area for the border. 149: */ 150: public Rectangle getInteriorRectangle(Component c, int x, int y, int width, 151: int height) 152: { 153: return getInteriorRectangle (c, this, x, y, width, height); 154: } 155: 156: /** 157: * Returns a rectangle that covers the specified area minus a 158: * border. Components that wish to determine an area into which 159: * they can safely draw without intersecting with a border might 160: * want to use this helper method. 161: * 162: * @param c the component in the center of this border. 163: * @param x the horizontal position of the border. 164: * @param y the vertical position of the border. 165: * @param width the width of the available area for the border. 166: * @param height the height of the available area for the border. 167: */ 168: public static Rectangle getInteriorRectangle(Component c, Border b, int x, 169: int y, int width, int height) 170: { 171: Insets borderInsets; 172: 173: if (b != null) 174: { 175: borderInsets = b.getBorderInsets (c); 176: x += borderInsets.left; 177: y += borderInsets.top; 178: width -= borderInsets.left + borderInsets.right; 179: height -= borderInsets.top + borderInsets.bottom; 180: } 181: 182: return new Rectangle (x, y, width, height); 183: } 184: }
GNU Classpath (0.20) |