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3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
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24   */
25  package javax.swing;
26  
27  
28  import java.awt.event.*;
29  import java.awt.*;
30  import javax.swing.event.*;
31  
32  /**
33   * State model for buttons.
34   * <p>
35   * This model is used for regular buttons, as well as check boxes
36   * and radio buttons, which are special kinds of buttons. In practice,
37   * a button's UI takes the responsibility of calling methods on its
38   * model to manage the state, as detailed below:
39   * <p>
40   * In simple terms, pressing and releasing the mouse over a regular
41   * button triggers the button and causes and <code>ActionEvent</code>
42   * to be fired. The same behavior can be produced via a keyboard key
43   * defined by the look and feel of the button (typically the SPACE BAR).
44   * Pressing and releasing this key while the button has
45   * focus will give the same results. For check boxes and radio buttons, the
46   * mouse or keyboard equivalent sequence just described causes the button
47   * to become selected.
48   * <p>
49   * In details, the state model for buttons works as follows
50   * when used with the mouse:
51   * <br>
52   * Pressing the mouse on top of a button makes the model both
53   * armed and pressed. As long as the mouse remains down,
54   * the model remains pressed, even if the mouse moves
55   * outside the button. On the contrary, the model is only
56   * armed while the mouse remains pressed within the bounds of
57   * the button (it can move in or out of the button, but the model
58   * is only armed during the portion of time spent within the button).
59   * A button is triggered, and an <code>ActionEvent</code> is fired,
60   * when the mouse is released while the model is armed
61   * - meaning when it is released over top of the button after the mouse
62   * has previously been pressed on that button (and not already released).
63   * Upon mouse release, the model becomes unarmed and unpressed.
64   * <p>
65   * In details, the state model for buttons works as follows
66   * when used with the keyboard:
67   * <br>
68   * Pressing the look and feel defined keyboard key while the button
69   * has focus makes the model both armed and pressed. As long as this key
70   * remains down, the model remains in this state. Releasing the key sets
71   * the model to unarmed and unpressed, triggers the button, and causes an
72   * <code>ActionEvent</code> to be fired.
73   *
74   * @author Jeff Dinkins
75   */
76  public interface ButtonModel extends ItemSelectable {
77  
78      /**
79       * Indicates partial commitment towards triggering the
80       * button.
81       *
82       * @return <code>true</code> if the button is armed,
83       *         and ready to be triggered
84       * @see #setArmed
85       */
86      boolean isArmed();
87  
88      /**
89       * Indicates if the button has been selected. Only needed for
90       * certain types of buttons - such as radio buttons and check boxes.
91       *
92       * @return <code>true</code> if the button is selected
93       */
94      boolean isSelected();
95  
96      /**
97       * Indicates if the button can be selected or triggered by
98       * an input device, such as a mouse pointer.
99       *
100      * @return <code>true</code> if the button is enabled
101      */
102     boolean isEnabled();
103 
104     /**
105      * Indicates if the button is pressed.
106      *
107      * @return <code>true</code> if the button is pressed
108      */
109     boolean isPressed();
110 
111     /**
112      * Indicates that the mouse is over the button.
113      *
114      * @return <code>true</code> if the mouse is over the button
115      */
116     boolean isRollover();
117 
118     /**
119      * Marks the button as armed or unarmed.
120      *
121      * @param b whether or not the button should be armed
122      */
123     public void setArmed(boolean b);
124 
125     /**
126      * Selects or deselects the button.
127      *
128      * @param b <code>true</code> selects the button,
129      *          <code>false</code> deselects the button
130      */
131     public void setSelected(boolean b);
132 
133     /**
134      * Enables or disables the button.
135      *
136      * @param b whether or not the button should be enabled
137      * @see #isEnabled
138      */
139     public void setEnabled(boolean b);
140 
141     /**
142      * Sets the button to pressed or unpressed.
143      *
144      * @param b whether or not the button should be pressed
145      * @see #isPressed
146      */
147     public void setPressed(boolean b);
148 
149     /**
150      * Sets or clears the button's rollover state
151      *
152      * @param b whether or not the button is in the rollover state
153      * @see #isRollover
154      */
155     public void setRollover(boolean b);
156 
157     /**
158      * Sets the keyboard mnemonic (shortcut key or
159      * accelerator key) for the button.
160      *
161      * @param key an int specifying the accelerator key
162      */
163     public void setMnemonic(int key);
164 
165     /**
166      * Gets the keyboard mnemonic for the button.
167      *
168      * @return an int specifying the accelerator key
169      * @see #setMnemonic
170      */
171     public int  getMnemonic();
172 
173     /**
174      * Sets the action command string that gets sent as part of the
175      * <code>ActionEvent</code> when the button is triggered.
176      *
177      * @param s the <code>String</code> that identifies the generated event
178      * @see #getActionCommand
179      * @see java.awt.event.ActionEvent#getActionCommand
180      */
181     public void setActionCommand(String s);
182 
183     /**
184      * Returns the action command string for the button.
185      *
186      * @return the <code>String</code> that identifies the generated event
187      * @see #setActionCommand
188      */
189     public String getActionCommand();
190 
191     /**
192      * Identifies the group the button belongs to --
193      * needed for radio buttons, which are mutually
194      * exclusive within their group.
195      *
196      * @param group the <code>ButtonGroup</code> the button belongs to
197      */
198     public void setGroup(ButtonGroup group);
199 
200     /**
201      * Adds an <code>ActionListener</code> to the model.
202      *
203      * @param l the listener to add
204      */
205     void addActionListener(ActionListener l);
206 
207     /**
208      * Removes an <code>ActionListener</code> from the model.
209      *
210      * @param l the listener to remove
211      */
212     void removeActionListener(ActionListener l);
213 
214     /**
215      * Adds an <code>ItemListener</code> to the model.
216      *
217      * @param l the listener to add
218      */
219     void addItemListener(ItemListener l);
220 
221     /**
222      * Removes an <code>ItemListener</code> from the model.
223      *
224      * @param l the listener to remove
225      */
226     void removeItemListener(ItemListener l);
227 
228     /**
229      * Adds a <code>ChangeListener</code> to the model.
230      *
231      * @param l the listener to add
232      */
233     void addChangeListener(ChangeListener l);
234 
235     /**
236      * Removes a <code>ChangeListener</code> from the model.
237      *
238      * @param l the listener to remove
239      */
240     void removeChangeListener(ChangeListener l);
241 
242 }