/*
* @(#)PropertyEditorSupport.java 1.22 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.beans;
import java.beans.*;
/**
* This is a support class to help build property editors.
* <p>
* It can be used either as a base class or as a delagatee.
*/
public class PropertyEditorSupport implements PropertyEditor {
/**
* Constructs a <code>PropertyEditorSupport</code> object.
*
* @since 1.5
*/
public PropertyEditorSupport() {
setSource(this);
}
/**
* Constructs a <code>PropertyEditorSupport</code> object.
*
* @param source the source used for event firing
* @since 1.5
*/
public PropertyEditorSupport(Object source) {
if (source == null) {
throw new NullPointerException();
}
setSource(source);
}
/**
* Returns the bean that is used as the
* source of events. If the source has not
* been explicitly set then this instance of
* <code>PropertyEditorSupport</code> is returned.
*
* @return the source object or this instance
* @since 1.5
*/
public Object getSource() {
return source;
}
/**
* Sets the source bean.
* <p>
* The source bean is used as the source of events
* for the property changes. This source should be used for information
* purposes only and should not be modified by the PropertyEditor.
*
* @param source source object to be used for events
* @since 1.5
*/
public void setSource(Object source) {
this.source = source;
}
/**
* Set (or change) the object that is to be edited.
*
* @param value The new target object to be edited. Note that this
* object should not be modified by the PropertyEditor, rather
* the PropertyEditor should create a new object to hold any
* modified value.
*/
public void setValue(Object value) {
this.value = value;
firePropertyChange();
}
/**
* Gets the value of the property.
*
* @return The value of the property.
*/
public Object getValue() {
return value;
}
//----------------------------------------------------------------------
/**
* Determines whether the class will honor the paintValue method.
*
* @return True if the class will honor the paintValue method.
*/
public boolean isPaintable() {
return false;
}
/**
* Paint a representation of the value into a given area of screen
* real estate. Note that the propertyEditor is responsible for doing
* its own clipping so that it fits into the given rectangle.
* <p>
* If the PropertyEditor doesn't honor paint requests (see isPaintable)
* this method should be a silent noop.
*
* @param gfx Graphics object to paint into.
* @param box Rectangle within graphics object into which we should paint.
*/
public void paintValue(java.awt.Graphics gfx, java.awt.Rectangle box) {
}
//----------------------------------------------------------------------
/**
* This method is intended for use when generating Java code to set
* the value of the property. It should return a fragment of Java code
* that can be used to initialize a variable with the current property
* value.
* <p>
* Example results are "2", "new Color(127,127,34)", "Color.orange", etc.
*
* @return A fragment of Java code representing an initializer for the
* current value.
*/
public String getJavaInitializationString() {
return "???";
}
//----------------------------------------------------------------------
/**
* Gets the property value as a string suitable for presentation
* to a human to edit.
*
* @return The property value as a string suitable for presentation
* to a human to edit.
* <p> Returns "null" is the value can't be expressed as a string.
* <p> If a non-null value is returned, then the PropertyEditor should
* be prepared to parse that string back in setAsText().
*/
public String getAsText() {
if (value instanceof String) {
return (String)value;
}
return ("" + value);
}
/**
* Sets the property value by parsing a given String. May raise
* java.lang.IllegalArgumentException if either the String is
* badly formatted or if this kind of property can't be expressed
* as text.
*
* @param text The string to be parsed.
*/
public void setAsText(String text) throws java.lang.IllegalArgumentException {
if (value instanceof String) {
setValue(text);
return;
}
throw new java.lang.IllegalArgumentException(text);
}
//----------------------------------------------------------------------
/**
* If the property value must be one of a set of known tagged values,
* then this method should return an array of the tag values. This can
* be used to represent (for example) enum values. If a PropertyEditor
* supports tags, then it should support the use of setAsText with
* a tag value as a way of setting the value.
*
* @return The tag values for this property. May be null if this
* property cannot be represented as a tagged value.
*
*/
public String[] getTags() {
return null;
}
//----------------------------------------------------------------------
/**
* A PropertyEditor may chose to make available a full custom Component
* that edits its property value. It is the responsibility of the
* PropertyEditor to hook itself up to its editor Component itself and
* to report property value changes by firing a PropertyChange event.
* <P>
* The higher-level code that calls getCustomEditor may either embed
* the Component in some larger property sheet, or it may put it in
* its own individual dialog, or ...
*
* @return A java.awt.Component that will allow a human to directly
* edit the current property value. May be null if this is
* not supported.
*/
public java.awt.Component getCustomEditor() {
return null;
}
/**
* Determines whether the propertyEditor can provide a custom editor.
*
* @return True if the propertyEditor can provide a custom editor.
*/
public boolean supportsCustomEditor() {
return false;
}
//----------------------------------------------------------------------
/**
* Register a listener for the PropertyChange event. The class will
* fire a PropertyChange value whenever the value is updated.
*
* @param listener An object to be invoked when a PropertyChange
* event is fired.
*/
public synchronized void addPropertyChangeListener(
PropertyChangeListener listener) {
if (listeners == null) {
listeners = new java.util.Vector();
}
listeners.addElement(listener);
}
/**
* Remove a listener for the PropertyChange event.
*
* @param listener The PropertyChange listener to be removed.
*/
public synchronized void removePropertyChangeListener(
PropertyChangeListener listener) {
if (listeners == null) {
return;
}
listeners.removeElement(listener);
}
/**
* Report that we have been modified to any interested listeners.
*/
public void firePropertyChange() {
java.util.Vector targets;
synchronized (this) {
if (listeners == null) {
return;
}
targets = (java.util.Vector) listeners.clone();
}
// Tell our listeners that "everything" has changed.
PropertyChangeEvent evt = new PropertyChangeEvent(source, null, null, null);
for (int i = 0; i < targets.size(); i++) {
PropertyChangeListener target = (PropertyChangeListener)targets.elementAt(i);
target.propertyChange(evt);
}
}
//----------------------------------------------------------------------
private Object value;
private Object source;
private java.util.Vector listeners;
}
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