java/11 : java.desktop/java/beans/PropertyEditorSupport.java

PropertyEditorSupport
https://openjdk.java.net/
GPLv2 + Classpath Exception
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package java.beans;

import java.beans.*;

This is a support class to help build property editors.

It can be used either as a base class or as a delegate.
Since: 1.1/**
 * This is a support class to help build property editors.
 * <p>
 * It can be used either as a base class or as a delegate.
 *
 * @since 1.1
 */

public class PropertyEditorSupport implements PropertyEditor {

    Constructs a PropertyEditorSupport object. 
Since: 1.5/**
     * Constructs a {@code PropertyEditorSupport} object.
     *
     * @since 1.5
     */
    public PropertyEditorSupport() {
        setSource(this);
    }

    Constructs a PropertyEditorSupport object. 
Params: source – the source used for event firing
Since: 1.5/**
     * Constructs a {@code PropertyEditorSupport} 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 PropertyEditorSupport is returned. 
Returns: the source object or this instance
Since: 1.5/**
     * 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} is returned.
     *
     * @return the source object or this instance
     * @since 1.5
     */
    public Object getSource() {
        return source;
    }

    Sets the source bean.

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.
Params: source – source object to be used for events
Since: 1.5/**
     * 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.
Params: 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./**
     * 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.
Returns: The value of the property./**
     * 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.
Returns:  True if the class will honor the paintValue method./**
     * 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.

If the PropertyEditor doesn't honor paint requests (see isPaintable)
this method should be a silent noop.
Params: gfx –  Graphics object to paint into.
box –  Rectangle within graphics object into which we should paint./**
     * 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.

Example results are "2", "new Color(127,127,34)", "Color.orange", etc.
Returns: A fragment of Java code representing an initializer for the
         current value./**
     * 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.
Returns: The property value as a string suitable for presentation
      to a human to edit.
   Returns null if the value can't be expressed as a string.
   If a non-null value is returned, then the PropertyEditor should
      be prepared to parse that string back in setAsText()./**
     * 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 if 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() {
        return (this.value != null)
                ? this.value.toString()
                : null;
    }

    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.
Params: text –  The string to be parsed./**
     * 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.
Returns: The tag values for this property.  May be null if this
  property cannot be represented as a tagged value./**
     * 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.

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 ...
Returns: A java.awt.Component that will allow a human to directly
     edit the current property value.  May be null if this is
     not supported./**
     * 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.
Returns:  True if the propertyEditor can provide a custom editor./**
     * Determines whether the propertyEditor can provide a custom editor.
     *
     * @return  True if the propertyEditor can provide a custom editor.
     */
    public boolean supportsCustomEditor() {
        return false;
    }

    //----------------------------------------------------------------------

    Adds a listener for the value change. When the property editor changes its value it should fire a PropertyChangeEvent on all registered PropertyChangeListeners, specifying the null value for the property name. If the source property is set, it should be used as the source of the event.  The same listener object may be added more than once, and will be called as many times as it is added. If listener is null, no exception is thrown and no action is taken. 
Params: listener –  the PropertyChangeListener to add/**
     * Adds a listener for the value change.
     * When the property editor changes its value
     * it should fire a {@link PropertyChangeEvent}
     * on all registered {@link PropertyChangeListener}s,
     * specifying the {@code null} value for the property name.
     * If the source property is set,
     * it should be used as the source of the event.
     * <p>
     * The same listener object may be added more than once,
     * and will be called as many times as it is added.
     * If {@code listener} is {@code null},
     * no exception is thrown and no action is taken.
     *
     * @param listener  the {@link PropertyChangeListener} to add
     */
    public synchronized void addPropertyChangeListener(
                                PropertyChangeListener listener) {
        if (listeners == null) {
            listeners = new java.util.Vector<>();
        }
        listeners.addElement(listener);
    }

    Removes a listener for the value change.
 If the same listener was added more than once, it will be notified one less time after being removed. If listener is null, or was never added, no exception is thrown and no action is taken. 
Params: listener –  the PropertyChangeListener to remove/**
     * Removes a listener for the value change.
     * <p>
     * If the same listener was added more than once,
     * it will be notified one less time after being removed.
     * If {@code listener} is {@code null}, or was never added,
     * no exception is thrown and no action is taken.
     *
     * @param listener  the {@link PropertyChangeListener} to remove
     */
    public synchronized void removePropertyChangeListener(
                                PropertyChangeListener listener) {
        if (listeners == null) {
            return;
        }
        listeners.removeElement(listener);
    }

    Report that we have been modified to any interested listeners.
/**
     * Report that we have been modified to any interested listeners.
     */
    public void firePropertyChange() {
        java.util.Vector<PropertyChangeListener> targets;
        synchronized (this) {
            if (listeners == null) {
                return;
            }
            targets = unsafeClone(listeners);
        }
        // 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 = targets.elementAt(i);
            target.propertyChange(evt);
        }
    }

    @SuppressWarnings("unchecked")
    private <T> java.util.Vector<T> unsafeClone(java.util.Vector<T> v) {
        return (java.util.Vector<T>)v.clone();
    }

    //----------------------------------------------------------------------

    private Object value;
    private Object source;
    private java.util.Vector<PropertyChangeListener> listeners;
}
Params:	source – source object to be used for events
Since:	1.5
/

java/ 11/ java.desktop/java/beans/PropertyEditorSupport.java
