EditFieldLayout


1   package jimm.datavision.gui;
2   import java.util.ArrayList  ;
3   import java.util.Iterator  ;
4   import java.awt.*;
5   import javax.swing.*;
6   import javax.swing.border.Border  ;
7   import java.awt.GridBagLayout  ;
8   import java.awt.GridBagConstraints  ;
9   
10  /**
11   * Lays out a bunch of label/edit widget pairs. Optionally creates
12   * the edit widget for you. This is not a layout manager <i>per se</i>.
13   * Calling any of the <code>add</code>* methods creates label/edit
14   * widget pairs. Calling <code>getPanel</code> returns a panel containing
15   * the labels and edit widgets, arranged for your pleasure.
16   *
17   * @author Jim Menard, <a HREF="mailto:jimm@io.com">jimm@io.com</a>
18   */
19  public class EditFieldLayout {
20  
21  /* ================================================================ */
22  /** Represents a label/component pair. */
23  static class Row {
24  protected JLabel label;
25  protected Component component;
26  Row(JLabel l, Component c) {
27      label = l;
28      component = c;
29  }
30  }
31  /* ================================================================ */
32  
33  protected ArrayList   rows;
34  protected Border   border;
35  protected JPanel panel;
36  
37  public EditFieldLayout() {
38      rows = new ArrayList  ();
39  }
40  
41  /**
42   * Adds the label/component pair to the layout and returns the component.
43   * If <var>label</var> does not end with a colon, one will be added.
44   * <var>label</var> may be <code>null</code>, in which case no label is
45   * displayed.
46   * <p>
47   * All the other <code>add*</code> methods call this one.
48   *
49   * @param label a possibly <code>null</code> label string
50   * @param c a GUI component
51   * @return the component
52   */
53  public Component add(String   label, Component c) {
54      if (label == null || label.length() == 0)
55      label = "";
56      else if (!label.endsWith(":"))
57      label += ":";
58  
59      rows.add(new Row(new JLabel(label), c));
60      return c;
61  }
62  
63  /**
64   * Creates a text field and adds it and the label.
65   *
66   * @param label a possibly <code>null</code> label string
67   * @return the new text field
68   */
69  public JTextField addTextField(String   label) {
70      return (JTextField)add(label, new JTextField());
71  }
72  
73  /**
74   * Creates a text field and adds it and the label.
75   *
76   * @param label a possibly <code>null</code> label string
77   * @param columns the text field's size
78   * @return the new text field
79   */
80  public JTextField addTextField(String   label, int columns) {
81      return (JTextField)add(label, new JTextField(columns));
82  }
83  
84  /**
85   * Creates a text field and adds it and the label.
86   *
87   * @param label a possibly <code>null</code> label string
88   * @param text the text field's initial text
89   * @return the new text field
90   */
91  public JTextField addTextField(String   label, String   text) {
92      return (JTextField)add(label, new JTextField(text == null ? "" : text));
93  }
94  
95  /**
96   * Creates a text field and adds it and the label.
97   *
98   * @param label a possibly <code>null</code> label string
99   * @param text the text field's initial text
100  * @param columns the text field's size
101  * @return the new text field
102  */
103 public JTextField addTextField(String   label, String   text, int columns) {
104     return (JTextField)add(label, new JTextField(text == null ? "" : text,
105                          columns));
106 }
107 
108 /**
109  * Creates a text area and adds it and the label.
110  *
111  * @param label a possibly <code>null</code> label string
112  * @return the new text area
113  */
114 public JTextArea addTextArea(String   label) {
115     JTextArea area = new JTextArea();
116     area.setBorder(BorderFactory.createLoweredBevelBorder());
117     add(label, area);
118     return area;
119 }
120 
121 /**
122  * Creates a text area and adds it and the label.
123  *
124  * @param label a possibly <code>null</code> label string
125  * @param rows the text field's height
126  * @param cols the text field's width
127  * @return the new text area
128  */
129 public JTextArea addTextArea(String   label, int rows, int cols) {
130     JTextArea area = new JTextArea(rows, cols);
131     area.setBorder(BorderFactory.createLoweredBevelBorder());
132     add(label, area);
133     return area;
134 }
135 
136 /**
137  * Creates a text area and adds it and the label.
138  *
139  * @param label a possibly <code>null</code> label string
140  * @param text the text field's initial text
141  * @return the new text area
142  */
143 public JTextArea addTextArea(String   label, String   text) {
144     JTextArea area = new JTextArea(text == null ? "" : text);
145     area.setBorder(BorderFactory.createLoweredBevelBorder());
146     add(label, area);
147     return area;
148 }
149 
150 /**
151  * Creates a text area and adds it and the label.
152  *
153  * @param label a possibly <code>null</code> label string
154  * @param text the text field's initial text
155  * @param rows the text field's height
156  * @param cols the text field's width
157  * @return the new text area
158  */
159 public JTextArea addTextArea(String   label, String   text, int rows, int cols) {
160     JTextArea area = new JTextArea(text == null ? "" : text, rows, cols);
161     JScrollPane scroller = new JScrollPane(area);
162     add(label, scroller);
163     return area;
164 }
165 
166 /**
167  * Creates a check box and adds it and the label.
168  *
169  * @param label a possibly <code>null</code> label string
170  * @return the new check box
171  */
172 public JCheckBox addCheckBox(String   label) {
173     return addCheckBox(label, 0);
174 }
175 
176 /**
177  * Creates a check box and adds it and the label.
178  *
179  * @param label a possibly <code>null</code> label string
180  * @param key the mnemonic key (a <code>KeyEvent</code> constant)
181  * @return the new check box
182  */
183 public JCheckBox addCheckBox(String   label, int key) {
184     JCheckBox checkBox = new JCheckBox(label);
185     checkBox.setMnemonic(key);
186     return (JCheckBox)add(null, checkBox);
187 }
188 
189 /**
190  * Creates a combo box and adds it and the label.
191  *
192  * @param label a possibly <code>null</code> label string
193  * @param items an array of objects
194  * @return the new combo box
195  */
196 public JComboBox addComboBox(String   label, Object  [] items) {
197     return addComboBox(label, items, false);
198 }
199 
200 /**
201  * Creates a combo box and adds it and the label.
202  *
203  * @param label a possibly <code>null</code> label string
204  * @param items an array of objects
205  * @param editable if <code>true</code>, the combo box will allow custom
206  * value entry by the user
207  * @return the new combo box
208  */
209 public JComboBox addComboBox(String   label, Object  [] items, boolean editable) {
210     JComboBox comboBox = new JComboBox(items);
211     comboBox.setEditable(editable);
212     return (JComboBox)add(label, comboBox);
213 }
214 
215 /**
216  * Creates two labels and adds them.
217  *
218  * @param label a possibly <code>null</code> label string
219  * @param text text for the right-hand label
220  * @return the new right-hand label
221  */
222 public JLabel addLabel(String   label, String   text) {
223     return (JLabel)add(label, new JLabel(text == null ? "" : text));
224 }
225 
226 /**
227  * Creates a password field and adds it and the label.
228  *
229  * @param label a possibly <code>null</code> label string
230  * @return the new password field
231  */
232 public JPasswordField addPasswordField(String   label) {
233     return (JPasswordField)add(label, new JPasswordField());
234 }
235 
236 /**
237  * Creates a password field and adds it and the label.
238  *
239  * @param label a possibly <code>null</code> label string
240  * @param columns the password field's size
241  * @return the new password field
242  */
243 public JPasswordField addPasswordField(String   label, int columns) {
244     return (JPasswordField)add(label, new JPasswordField(columns));
245 }
246 
247 /**
248  * Creates a password field and adds it and the label.
249  *
250  * @param label a possibly <code>null</code> label string
251  * @param password the initial password text
252  * @return the new password field
253  */
254 public JPasswordField addPasswordField(String   label, String   password) {
255     return (JPasswordField)add(label, new JPasswordField(password == null
256                              ? "" : password));
257 }
258 
259 /**
260  * Creates a password field and adds it and the label.
261  *
262  * @param label a possibly <code>null</code> label string
263  * @param password the initial password text
264  * @param columns the password field's size
265  * @return the new password field
266  */
267 public JPasswordField addPasswordField(String   label, String   password,
268                        int columns)
269 {
270     return (JPasswordField)add(label, new JPasswordField(password == null
271                              ? "" : password,
272                              columns));
273 }
274 
275 /**
276  * Creates a button and adds it to the right-hand side, under the fields.
277  *
278  * @param label a button label
279  * @return the new button
280  */
281 public JButton addButton(String   label) {
282     return (JButton)add(null, new JButton(label));
283 }
284 
285 /**
286  * Creates an empty row.
287  */
288 public void skipRow() {
289     rows.add(null);
290 }
291 
292 /**
293  * Creates an empty border the same size on all sides.
294  *
295  * @param allSides the width of the border
296  */
297 public void setBorder(int allSides) {
298     setBorder(allSides, allSides, allSides, allSides);
299 }
300 
301 /**
302  * Creates an empty border on all sides.
303  *
304  * @param top top border size
305  * @param left left border size
306  * @param bottom bottom border size
307  * @param right right border size
308  */
309 public void setBorder(int top, int left, int bottom, int right) {
310     border = BorderFactory.createEmptyBorder(top, left, bottom, right);
311 }
312 
313 /**
314  * Returns the panel containing all the labels and edit widgets. Lazily
315  * instantiates the panel.
316  *
317  * @return the panel containing all the labels and edit widgets
318  */
319 public JPanel getPanel() {
320     if (panel == null)
321     buildPanel();
322     return panel;
323 }
324 
325 /**
326  * Builds the panel.
327  */
328 protected void buildPanel() {
329     GridBagLayout   bag = new GridBagLayout  ();
330     GridBagConstraints   c = new GridBagConstraints  ();
331     c.insets = new Insets(6, 6, 6, 6);
332     panel = new JPanel();
333     panel.setLayout(bag);
334     if (border != null)
335     panel.setBorder(border);
336 
337     c.gridy = 0;
338     for (Iterator   iter = rows.iterator(); iter.hasNext(); ++c.gridy) {
339     Row row = (Row)iter.next();
340     if (row == null)
341         continue;
342 
343     if (row.label != null) {
344         c.gridx = 0;
345         c.anchor = GridBagConstraints.NORTHEAST;
346         bag.setConstraints(row.label, c);
347         panel.add(row.label);
348     }
349 
350     if (row.component != null) {
351         c.gridx = 1;
352         c.anchor = GridBagConstraints.NORTHWEST;
353         bag.setConstraints(row.component, c);
354         panel.add(row.component);
355     }
356     }
357 }
358 
359 }
360
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