001    /*
002     * Copyright 2002-2004 the original author or authors.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License"); you may not
005     * use this file except in compliance with the License. You may obtain a copy of
006     * the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
012     * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
013     * License for the specific language governing permissions and limitations under
014     * the License.
015     */
016    package org.springframework.richclient.form.binding.support;
017    
018    import java.beans.PropertyChangeEvent;
019    import java.beans.PropertyChangeListener;
020    
021    import org.springframework.binding.form.FormModel;
022    
023    /**
024     * A helper implementation for binding to custom controls.  
025     * 
026     * @author Oliver Hutchison
027     */
028    public abstract class CustomBinding extends AbstractBinding {
029    
030        private final ValueModelChangeHandler valueModelChangeHandler;
031    
032        /** Possible forced read-only. */
033        private boolean readOnly = false;
034    
035        protected CustomBinding(FormModel formModel, String formPropertyPath, Class requiredSourceClass) {
036            super(formModel, formPropertyPath, requiredSourceClass);
037            valueModelChangeHandler = new ValueModelChangeHandler();
038            getValueModel().addValueChangeListener(valueModelChangeHandler);
039        }
040    
041        /**
042         * Called when the underlying property's value model value changes. 
043         */
044        protected abstract void valueModelChanged(Object newValue);
045        
046        /**
047         * Should be called when the bound component's value changes. 
048         */
049        protected final void controlValueChanged(Object newValue) {
050            getValueModel().setValueSilently(newValue, valueModelChangeHandler);
051        }
052    
053        private class ValueModelChangeHandler implements PropertyChangeListener {
054            public void propertyChange(PropertyChangeEvent evt) {
055                if (logger.isDebugEnabled()) {
056                    logger.debug("Notifying binding of value model value changed");
057                }
058                valueModelChanged(getValue());
059            }
060        }
061    
062        /**
063         * Force this binding to be readonly, whatever the metaInfo.
064         *
065         * @param readOnly <code>true</code> if only read-access should be allowed.
066         */
067        public void setReadOnly(boolean readOnly)
068        {
069            this.readOnly = readOnly;
070            readOnlyChanged();
071        }
072    
073        /**
074         * We were using an override to check the setter's visibility on the backing object.
075         */
076        @Override
077        protected boolean isReadOnly()
078        {
079            return this.readOnly || super.isReadOnly();
080        }
081    }