/*
* @(#)PropertyEditor.java 1.37 03/12/19
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package java.beans;
/**
* A PropertyEditor class provides support for GUIs that want to
* allow users to edit a property value of a given type.
* <p>
* PropertyEditor supports a variety of different kinds of ways of
* displaying and updating property values. Most PropertyEditors will
* only need to support a subset of the different options available in
* this API.
* <P>
* Simple PropertyEditors may only support the getAsText and setAsText
* methods and need not support (say) paintValue or getCustomEditor. More
* complex types may be unable to support getAsText and setAsText but will
* instead support paintValue and getCustomEditor.
* <p>
* Every propertyEditor must support one or more of the three simple
* display styles. Thus it can either (1) support isPaintable or (2)
* both return a non-null String[] from getTags() and return a non-null
* value from getAsText or (3) simply return a non-null String from
* getAsText().
* <p>
* Every property editor must support a call on setValue when the argument
* object is of the type for which this is the corresponding propertyEditor.
* In addition, each property editor must either support a custom editor,
* or support setAsText.
* <p>
* Each PropertyEditor should have a null constructor.
*/
public interface PropertyEditor {
/**
* Set (or change) the object that is to be edited. Primitive types such
* as "int" must be wrapped as the corresponding object type such as
* "java.lang.Integer".
*
* @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.
*/
void setValue(Object value);
/**
* Gets the property value.
*
* @return The value of the property. Primitive types such as "int" will
* be wrapped as the corresponding object type such as "java.lang.Integer".
*/
Object getValue();
//----------------------------------------------------------------------
/**
* Determines whether this property editor is paintable.
*
* @return True if the class will honor the paintValue method.
*/
boolean isPaintable();
/**
* 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.
* <p>
* The given Graphics object will have the default font, color, etc of
* the parent container. The PropertyEditor may change graphics attributes
* such as font and color and doesn't need to restore the old values.
*
* @param gfx Graphics object to paint into.
* @param box Rectangle within graphics object into which we should paint.
*/
void paintValue(java.awt.Graphics gfx, java.awt.Rectangle box);
//----------------------------------------------------------------------
/**
* Returns a fragment of Java code that can be used to set a property
* to match the editors current state. This method is intended
* for use when generating Java code to reflect changes made through the
* property editor.
* <p>
* The code fragment should be context free and must be a legal Java
* expression as specified by the JLS.
* <p>
* Specifically, if the expression represents a computation then all
* classes and static members should be fully qualified. This rule
* applies to constructors, static methods and non primitive arguments.
* <p>
* Caution should be used when evaluating the expression as it may throw
* exceptions. In particular, code generators must ensure that generated
* code will compile in the presence of an expression that can throw
* checked exceptions.
* <p>
* Example results are:
* <ul>
* <li>Primitive expresssion: <code>2</code>
* <li>Class constructor: <code>new java.awt.Color(127,127,34)</code>
* <li>Static field: <code>java.awt.Color.orange</code>
* <li>Static method: <code>javax.swing.Box.createRigidArea(new
* java.awt.Dimension(0, 5))</code>
* </ul>
*
* @return a fragment of Java code representing an initializer for the
* current value. It should not contain a semi-colon
* ('<code>;</code>') to end the expression.
*/
String getJavaInitializationString();
//----------------------------------------------------------------------
/**
* Gets the property value as text.
*
* @return The property value as a human editable string.
* <p> Returns null if the value can't be expressed as an editable string.
* <p> If a non-null value is returned, then the PropertyEditor should
* be prepared to parse that string back in setAsText().
*/
String getAsText();
/**
* Set 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.
*/
void setAsText(String text) throws java.lang.IllegalArgumentException;
//----------------------------------------------------------------------
/**
* If the property value must be one of a set of known tagged values,
* then this method should return an array of the tags. 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 and the use of getAsText
* to identify the current value.
*
* @return The tag values for this property. May be null if this
* property cannot be represented as a tagged value.
*
*/
String[] getTags();
//----------------------------------------------------------------------
/**
* A PropertyEditor may choose 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.
*/
java.awt.Component getCustomEditor();
/**
* Determines whether this property editor supports a custom editor.
*
* @return True if the propertyEditor can provide a custom editor.
*/
boolean supportsCustomEditor();
//----------------------------------------------------------------------
/**
* Register a listener for the PropertyChange event. When a
* PropertyEditor changes its value it should fire a PropertyChange
* event on all registered PropertyChangeListeners, specifying the
* null value for the property name and itself as the source.
*
* @param listener An object to be invoked when a PropertyChange
* event is fired.
*/
void addPropertyChangeListener(PropertyChangeListener listener);
/**
* Remove a listener for the PropertyChange event.
*
* @param listener The PropertyChange listener to be removed.
*/
void removePropertyChangeListener(PropertyChangeListener listener);
}
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