001    package org.nakedobjects.applib.events;
002    
003    import java.util.EventObject;
004    
005    import org.nakedobjects.applib.Identifier;
006    import org.nakedobjects.applib.util.NameUtils;
007    
008    
009    /**
010     * Represents an interaction with a domain object or a particular feature (property, collection, action) of a
011     * domain object.
012     * 
013     * <p>
014     * Many of the interactions are checks for {@link VisibilityEvent visibility},
015     * {@link UsabilityEvent usability} and {@link ValidityEvent validity}.
016     */
017    public abstract class InteractionEvent extends EventObject {
018    
019        private static final long serialVersionUID = 1L;
020    
021        private final Identifier identifier;
022        private String reason;
023        private Class<?> advisorClass;
024    
025        public InteractionEvent(final Object source, final Identifier identifier) {
026            super(source);
027            this.identifier = identifier;
028        }
029    
030    
031        /**
032         * The domain object (pojo) against which the interaction occurred.
033         */
034        @Override
035        public Object getSource() {
036            return super.getSource();
037        }
038    
039        /**
040         * The {@link Identifier} of the feature of the object being interacted with.
041         * 
042         * <p>
043         * Will be consistent with the subclass of {@link InteractionEvent}. So for example a
044         * {@link PropertyModifyEvent} will have an {@link Identifier} that identifies the property being
045         * modified.
046         * 
047         * @return
048         */
049        public Identifier getIdentifier() {
050            return identifier;
051        }
052    
053        /**
054         * Convenience method that returns the {@link Identifier#getClassName() class name} of the
055         * {@link #getIdentifier() identifier}.
056         * 
057         * @see #getIdentifier
058         */
059        public String getClassName() {
060            return identifier.getClassName();
061        }
062    
063        /**
064         * As per {@link #getClassName()}, but {@link NameUtils#naturalName(String) naturalized}.
065         */
066        public String getClassNaturalName() {
067            return NameUtils.naturalName(getClassName());
068        }
069    
070        /**
071         * Convenience method that returns the {@link Identifier#getMemberName() member name} of the
072         * {@link #getIdentifier() identifier}.
073         * 
074         * @see #getIdentifier
075         */
076        public String getMemberName() {
077            return identifier.getMemberName();
078        }
079    
080        /**
081         * As per {@link #getMemberName()}, but naturalized.
082         */
083        public String getMemberNaturalName() {
084            return NameUtils.naturalName(getMemberName());
085        }
086    
087        /**
088         * Convenience method that returns the {@link Identifier#getClassName() class name} of the
089         * {@link #getIdentifier() identifier}.
090         */
091        public String[] getMemberParameterNames() {
092            return identifier.getMemberParameterNames();
093        }
094    
095        /**
096         * As per {@link #getMemberParameterName()}, but naturalized.
097         */
098        public String[] getMemberParameterNaturalNames() {
099            return NameUtils.naturalNames(getMemberParameterNames());
100        }
101    
102        /**
103         * The reason, if any, that this interaction may have been vetoed or otherwise disallowed.
104         * 
105         * <p>
106         * Intended to be {@link #setReason(String) set} as a result of consulting one of the facets.
107         * 
108         * @return
109         */
110        public String getReason() {
111            return reason;
112        }
113    
114        /**
115         * The class of the (first) advisor, if any, that provided the {@link #getReason() reason} that this
116         * interaction is {@link #isVeto() vetoed}.
117         * 
118         * @return
119         */
120        public Class<?> getAdvisorClass() {
121            return advisorClass;
122        }
123    
124        /**
125         * Specify the {@link #getReason() reason} that this interaction has been vetoed and the
126         * {@link #getAdvisorClass() class of the advisor} that did the veto.
127         */
128        public void advised(final String reason, final Class<?> advisorClass) {
129            this.reason = reason;
130            this.advisorClass = advisorClass;
131        }
132    
133        /**
134         * Whether this interaction has been vetoed (meaning that {@link #getReason()} and
135         * {@link #getAdvisorClass()} will both be non-<tt>null</tt> and the {@link #getReason() reason}
136         * non-empty.)
137         * 
138         * <p>
139         * The interpretation of this depends on the subclass:
140         * <ul>
141         * <li>for {@link VisibilityEvent}, a veto means that the feature (property, collection, action) is
142         * hidden</li>
143         * <li>for {@link UsabilityEvent}, a veto means that the feature is disabled</li>
144         * <li>for {@link ValidityEvent}, a veto means that the proposed modification (property value, object
145         * added/removed, action argument) is invalid</li>
146         * </ul>
147         */
148        public boolean isVeto() {
149            return getReason() != null && getReason().length() > 0;
150        }
151    
152    }