1: /* java.beans.PropertyEditorSupport 2: Copyright (C) 1998, 2004 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 java.beans; 40: 41: 42: /** 43: * PropertyEditorSupport helps with PropertyEditors, 44: * implementing base functionality that they usually must 45: * have but which is a pain to implement. You may extend 46: * from this class or use it as a standalone.<P> 47: * 48: * This class does not do any painting or actual editing. 49: * For that, you must use or extend it. See the 50: * PropertyEditor class for better descriptions of what 51: * the various methods do. 52: * 53: * @author John Keiser 54: * @author Robert Schuster 55: * @since 1.1 56: * @status updated to 1.5 57: */ 58: public class PropertyEditorSupport implements PropertyEditor 59: { 60: Object eventSource; 61: Object value; 62: PropertyChangeSupport pSupport; 63: 64: /** Call this constructor when you are deriving from 65: * PropertyEditorSupport. 66: * 67: * Using this constructor the event source is this PropertyEditorSupport 68: * instance itself. 69: * 70: * @since 1.5 71: * @specnote this was <code>protected</code> prior to 1.5 72: */ 73: public PropertyEditorSupport() 74: { 75: eventSource = this; 76: pSupport = new PropertyChangeSupport(this); 77: } 78: 79: /** Call this constructor when you are using 80: * PropertyEditorSupport as a helper object. 81: * 82: * This constructor throws a NullPointerException when <code>source</code> is <code>null</code>, 83: * for compatibility reasons with J2SDK 1.5.0 . 84: * 85: * @param source The source to use when firing 86: * property change events. 87: * @since 1.5 88: * @specnote this was <code>protected</code> prior to 1.5 89: */ 90: public PropertyEditorSupport(Object source) 91: { 92: // note: constructor rejects source being null for the sake of compatibility 93: // with official 1.5.0 implementation 94: if (source == null) 95: throw new NullPointerException("Event source must not be null."); 96: 97: eventSource = source; 98: pSupport = new PropertyChangeSupport(eventSource); 99: } 100: 101: /** Sets the current value of the property and a property change 102: * event is fired to all registered PropertyChangeListener instances. 103: * 104: * @param newValue The new value for the property. 105: */ 106: public void setValue(Object newValue) 107: { 108: value = newValue; 109: 110: // specification in java.beans.PropertyChangeEvent says 111: // that without a property name (first argument) the 112: // new and the old value should always be null 113: pSupport.firePropertyChange(null, null, null); 114: } 115: 116: /** Gets the current value of the property. 117: * 118: * @return the current value of the property. 119: */ 120: public Object getValue() 121: { 122: return value; 123: } 124: 125: /** Gets whether this object is paintable or not. 126: * 127: * @return <CODE>false</CODE> 128: */ 129: public boolean isPaintable() 130: { 131: return false; 132: } 133: 134: /** Paints this object. This class does nothing in 135: * this method. 136: */ 137: public void paintValue(java.awt.Graphics g, java.awt.Rectangle r) 138: { 139: } 140: 141: /** Gets the Java initialization String for the current 142: * value of the Object. This class returns gibberish or 143: * null (though the spec does not say which).<P> 144: * <STRONG>Implementation Note:</STRONG> This class 145: * returns the string "@$#^" to make sure the code will 146: * be broken, so that you will know to override it when 147: * you create your own property editor. 148: * 149: * @return the Java initialization string. 150: */ 151: public String getJavaInitializationString() 152: { 153: return "@$#^"; 154: } 155: 156: /** Gets the value as text. 157: * In this class, you cannot count on getAsText() doing 158: * anything useful, although in this implementation I 159: * do toString(). 160: * 161: * @return the value as text. 162: */ 163: public String getAsText() 164: { 165: return value != null ? value.toString() : "null"; 166: } 167: 168: /** Sets the value as text. 169: * In this class, you cannot count on setAsText() doing 170: * anything useful across implementations. 171: * <STRONG>Implementation Note:</STRONG> In this 172: * implementation it checks if the String is "null", and 173: * if it is, sets the value to null, otherwise it throws 174: * an IllegalArgumentException. 175: * 176: * @param s the text to convert to a new value. 177: * @exception IllegalArgumentException if the text is 178: * malformed. 179: */ 180: public void setAsText(String s) throws IllegalArgumentException 181: { 182: if (s.equals("null")) 183: setValue(null); 184: else 185: throw new IllegalArgumentException(); 186: } 187: 188: /** Returns a list of possible choices for the value. 189: * 190: * @return <CODE>null</CODE> 191: */ 192: public String[] getTags() 193: { 194: return null; 195: } 196: 197: /** Returns a custom component to edit the value. 198: * 199: * @return <CODE>null</CODE> in this class. 200: */ 201: public java.awt.Component getCustomEditor() 202: { 203: return null; 204: } 205: 206: /** Finds out whether this property editor supports a 207: * custom component to edit its value. 208: * 209: * @return <CODE>false</CODE> in this class. 210: */ 211: public boolean supportsCustomEditor() 212: { 213: return false; 214: } 215: 216: /** Adds a property change listener to this property editor. 217: * 218: * @param l the listener to add. 219: */ 220: public void addPropertyChangeListener(PropertyChangeListener l) 221: { 222: pSupport.addPropertyChangeListener(l); 223: } 224: 225: /** Removes a property change listener from this property editor. 226: * 227: * @param l the listener to remove. 228: */ 229: public void removePropertyChangeListener(PropertyChangeListener l) 230: { 231: pSupport.removePropertyChangeListener(l); 232: } 233: 234: /** Notifies people that we've changed, although we don't 235: * tell them just how. 236: */ 237: public void firePropertyChange() 238: { 239: pSupport.firePropertyChange(null, null, null); 240: } 241: 242: /** Returns the bean that is used as the source of events. 243: * 244: * @return The event source object 245: * @since 1.5 246: */ 247: public Object getSource() 248: { 249: return eventSource; 250: } 251: 252: /** Sets the bean that is used as the source of events 253: * when property changes occur. 254: * 255: * The event source bean is for informational purposes only 256: * and should not be changed by the <code>PropertyEditor</code>. 257: * 258: * @param source 259: * @since 1.5 260: */ 261: public void setSource(Object source) 262: { 263: eventSource = source; 264: } 265: }