001 package users;
002
003 import sale.*;
004
005 /**
006 * A special capability guarding an action object.
007 *
008 * <p>The ActionCapability is itself an Action again, so that you can write code like
009 * this:</p>
010 *
011 * <pre>
012 * public class S extends SalesPoint {
013 *
014 * ...
015 *
016 * public MenuSheet getDefaultMenuSheet() {
017 *
018 * MenuSheet ms = new MenuSheet();
019 *
020 * <b> ms.addItem ("Capability Test",
021 * (Action) {@link SalesPoint#getUser getUser}().{@link User#getCapability getCapability}("CapTest"));
022 * </b>
023 * return ms;
024 * }
025 *
026 * ...
027 *
028 * }
029 *
030 * </pre>
031 *
032 * <p>Assuming that the CapTest capability is represented by an ActionCapability wrapping
033 * some other Action.</p>
034 *
035 * @see SalesPoint
036 * @see MenuSheet
037 * @see UserManager
038 * @see User
039 *
040 * @author Steffen Zschaler
041 * @version 2.0 05/05/1999
042 * @since v2.0
043 */
044 public class ActionCapability extends AbstractCapability implements Action {
045
046 /**
047 * Is this capability granted?
048 *
049 * @serial
050 */
051 private boolean m_fGranted;
052
053 /**
054 * The action guarded.
055 *
056 * @serial
057 */
058 private Action m_aToDo;
059
060 /**
061 * A message to be presented on denial.
062 *
063 * @serial
064 */
065 private String m_sOnDeny;
066
067 /**
068 * Create a granted capability.
069 *
070 * @param sName the name of the capability.
071 * @param aToDo the Action to be guarded.
072 */
073 public ActionCapability(String sName, Action aToDo) {
074 this(sName, null, aToDo, true);
075 }
076
077 /**
078 * Create a new ActionCapability.
079 *
080 * @param sName the name of the capability.
081 * @param sOnDeny a message to be popped up on denial.
082 * @param aToDo the Action to be guarded.
083 * @param fGranted true if this capability is to grant rights.
084 */
085 public ActionCapability(String sName, String sOnDeny, Action aToDo, boolean fGranted) {
086 super(sName);
087
088 m_sOnDeny = sOnDeny;
089 m_aToDo = aToDo;
090 m_fGranted = fGranted;
091 }
092
093 // Capability interface methods
094
095 /**
096 * Get the ActionCapability that is the inverse to this one. I.e. if this capability grants the right to
097 * execute a given action, the returned capability will deny this right and vice versa.
098 *
099 * @return the ActionCapability that is the inverse to this one.
100 *
101 * @override Never
102 */
103 public Capability getToggled() {
104 return new ActionCapability(getName(), m_sOnDeny, m_aToDo, !m_fGranted);
105 }
106
107 /**
108 * Return true if this capability is granting rights.
109 *
110 * @return true if this capability is granting rights.
111 *
112 * @override Never
113 */
114 public boolean isGranted() {
115 return m_fGranted;
116 }
117
118 // Action interface method
119
120 /**
121 * If the capability is granting rights, perform the guarded action; otherwise,
122 * print a message to the user that he/she is not granted the right to
123 * perform this action.
124 *
125 * @param p the process in which to perform the action
126 * @param sp the SalesPoint on which to perform the action.
127 *
128 * @override Never
129 */
130 public void doAction(SaleProcess p, SalesPoint sp) throws Throwable {
131 // This is not the proper way, normally the two cases should be different subclasses
132 // of Capability, but for the sake of useability I put it like this.
133 if (m_fGranted) {
134 if (m_aToDo != null) {
135 m_aToDo.doAction(p, sp);
136 }
137 } else {
138 if (m_sOnDeny != null) {
139
140 // use the JOptionPane to make it easy to pop up a message box.
141 // Should actually be using a p.popupFormSheet (new MsgForm (...)) instead
142 javax.swing.JOptionPane.showMessageDialog(null, m_sOnDeny, "Error",
143 javax.swing.JOptionPane.ERROR_MESSAGE);
144 }
145 }
146 }
147 }