Border


1   package jimm.datavision.field;
2   import jimm.datavision.Section;
3   import jimm.datavision.Line;
4   import jimm.datavision.Point;
5   import jimm.datavision.Writeable;
6   import jimm.datavision.layout.LineDrawer;
7   import jimm.util.XMLWriter;
8   import java.awt.Color  ;
9   import java.util.Observer  ;
10  import java.util.Observable  ;
11  
12  /**
13   * A border is a visual decoration around a report field. Each of its four
14   * edges (top, left, bottom, and right) is a {@link BorderEdge} and may be
15   * <code>null</code>.
16   *
17   * @author Jim Menard, <a HREF="mailto:jimm@io.com">jimm@io.com</a>
18   */
19  public class Border
20      extends Observable  
21      implements Writeable, Cloneable  , Observer  
22  {
23  
24  protected static final int BORDER_LINE_SPACE_MULT = 3;
25  protected static final Color   DEFAULT_COLOR = Color.black;
26  
27  protected Field field;
28  protected BorderEdge top, left, bottom, right; // May be null
29  protected Color   color;
30  
31  /**
32   * Constructs a new border for the specified field.
33   *
34   * @param field a report field
35   */
36  public Border(Field field) {
37      this.field = field;
38  }
39  
40  /**
41   * Returns a clone of this border. All edges are cloned as well.
42   */
43  public Object   clone() {
44      Border b = new Border(field);
45      BorderEdge e;
46  
47      if ((e = getTop()) == null || e.getNumber() == 0)
48      b.setTop(null);
49      else
50      b.setTop((BorderEdge)e.clone());
51  
52      if ((e = getBottom()) == null || e.getNumber() == 0)
53      b.setBottom(null);
54      else
55      b.setBottom((BorderEdge)e.clone());
56  
57      if ((e = getLeft()) == null || e.getNumber() == 0)
58      b.setLeft(null);
59      else
60      b.setLeft((BorderEdge)e.clone());
61  
62      if ((e = getRight()) == null || e.getNumber() == 0)
63      b.setRight(null);
64      else
65      b.setRight((BorderEdge)e.clone());
66  
67      b.setColor(getColor());
68  
69      return b;
70  }
71  
72  /**
73   * For testing only. Checks color and edges but not field.
74   *
75   * @see jimm.datavision.test.ReportTest#testCloning
76   */
77  public boolean equals(Object   obj) {
78      if (obj == null || !(obj instanceof Border)) return false;
79      if (obj == this) return true;
80  
81      Border b = (Border)obj;
82      if (color == null && b.color != null) return false;
83      if (color != null && !color.equals(b.color)) return false;
84  
85      BorderEdge e, e2;
86      int n, n2;
87      e = top;
88      e2 = b.top;
89      n = e == null ? 0 : e.number;
90      n2 = e2 == null ? 0 : e2.number;
91      if (n != n2) return false;
92  
93      e = left;
94      e2 = b.left;
95      n = e == null ? 0 : e.number;
96      n2 = e2 == null ? 0 : e2.number;
97      if (n != n2) return false;
98  
99      e = bottom;
100     e2 = b.bottom;
101     n = e == null ? 0 : e.number;
102     n2 = e2 == null ? 0 : e2.number;
103     if (n != n2) return false;
104 
105     e = right;
106     e2 = b.right;
107     n = e == null ? 0 : e.number;
108     n2 = e2 == null ? 0 : e2.number;
109     if (n != n2) return false;
110 
111     return true;
112 }
113 
114 public int hashCode() {
115     int hc = 0;
116     if (color != null) hc += color.hashCode();
117     if (top != null) hc += top.hashCode();
118     if (left != null) hc += left.hashCode();
119     if (bottom != null) hc += bottom.hashCode();
120     if (right != null) hc += right.hashCode();
121     return hc;
122 }
123 
124 /**
125  * Used only when cloning a field, this sets our field. Otherwise, don't
126  * call this.
127  *
128  * @param f the new field
129  */
130 public void setField(Field f) { field = f; }
131 
132 protected void finalize() throws Throwable   {
133     if (top != null) top.deleteObserver(this);
134     if (left != null) left.deleteObserver(this);
135     if (bottom != null) bottom.deleteObserver(this);
136     if (right != null) right.deleteObserver(this);
137 }
138 
139 public void update(Observable   o, Object   arg) {
140     setChanged();
141     notifyObservers(arg);
142 }
143 
144 /**
145  * Returns the border's top edge. May return <code>null</code>.
146  *
147  * @return the top edge
148  */
149 public BorderEdge getTop() { return top; }
150 
151 /**
152  * Sets the top edge. <i>newTop</i> may be <code>null</code>.
153  *
154  * @param newTop the new edge
155  */
156 public void setTop(BorderEdge newTop) {
157     if (top != newTop) {
158     if (top != null) top.deleteObserver(this);
159     top = newTop;
160     if (top != null) top.addObserver(this);
161     setChanged();
162     notifyObservers();
163     }
164 }
165 
166 /**
167  * Returns the border's left edge. May return <code>null</code>.
168  *
169  * @return the left edge
170  */
171 public BorderEdge getLeft() { return left; }
172 
173 /**
174  * Sets the left edge. <i>newLeft</i> may be <code>null</code>.
175  *
176  * @param newLeft the new edge
177  */
178 public void setLeft(BorderEdge newLeft) {
179     if (left != newLeft) {
180     if (left != null) left.deleteObserver(this);
181     left = newLeft;
182     if (left != null) left.addObserver(this);
183     setChanged();
184     notifyObservers();
185     }
186 }
187 
188 /**
189  * Returns the border's bottom edge. May return <code>null</code>.
190  *
191  * @return the bottom edge
192  */
193 public BorderEdge getBottom() { return bottom; }
194 
195 /**
196  * Sets the bottom edge. <i>newBottom</i> may be <code>null</code>.
197  *
198  * @param newBottom the new edge
199  */
200 public void setBottom(BorderEdge newBottom) {
201     if (bottom != newBottom) {
202     if (bottom != null) bottom.deleteObserver(this);
203     bottom = newBottom;
204     if (bottom != null) bottom.addObserver(this);
205     setChanged();
206     notifyObservers();
207     }
208 }
209 
210 /**
211  * Returns the border's right edge. May return <code>null</code>.
212  *
213  * @return the right edge
214  */
215 public BorderEdge getRight() { return right; }
216 
217 /**
218  * Sets the right edge. <i>newRight</i> may be <code>null</code>.
219  *
220  * @param newRight the new edge
221  */
222 public void setRight(BorderEdge newRight) {
223     if (right != newRight) {
224     if (right != null) right.deleteObserver(this);
225     right = newRight;
226     if (right != null) right.addObserver(this);
227     setChanged();
228     notifyObservers();
229     }
230 }
231 
232 /**
233  * Retrieves the border color.
234  *
235  * @return the border color
236  */
237 public Color   getColor() { return color; }
238 
239 /**
240  * Sets the border color.
241  *
242  * @param c the new color
243  */
244 public void setColor(Color   c) {
245     if (color != c) {
246     color = c;
247     setChanged();
248     notifyObservers();
249     }
250 }
251 
252 /**
253  * For each edge, hand the lines that make up that edge to the specified
254  * line drawer's <code>drawLine</code> method.
255  *
256  * @param ld a line drawer
257  */
258 public void eachLine(LineDrawer ld, Object   arg) {
259     Rectangle rect = field.getBounds();
260     Section section = field.getSection();
261     BorderEdge edge;
262     Line line;
263 
264     edge = top;
265     if (edge != null && edge.getThickness() > 0 && edge.getNumber() > 0) {
266     line = new Line(null, section, edge.getThickness(),
267             null, true, new Point(rect.x, rect.y),
268             new Point(rect.x + rect.width, rect.y));
269     for (int i = 0; i < edge.getNumber(); ++i) {
270         ld.drawLine(line, arg);
271         line.getPoint(0).y += BORDER_LINE_SPACE_MULT;
272         line.getPoint(1).y += BORDER_LINE_SPACE_MULT;
273     }
274     }
275 
276     edge = bottom;
277     if (edge != null && edge.getThickness() > 0 && edge.getNumber() > 0) {
278     line = new Line(null, section, edge.getThickness(),
279             null, true, new Point(rect.x, rect.y + rect.height),
280             new Point(rect.x + rect.width, rect.y + rect.height));
281     for (int i = 0; i < edge.getNumber(); ++i) {
282         ld.drawLine(line, arg);
283         line.getPoint(0).y -= BORDER_LINE_SPACE_MULT;
284         line.getPoint(1).y -= BORDER_LINE_SPACE_MULT;
285     }
286     }
287 
288     edge = left;
289     if (edge != null && edge.getThickness() > 0 && edge.getNumber() > 0) {
290     line = new Line(null, section, edge.getThickness(),
291             null, true, new Point(rect.x, rect.y),
292             new Point(rect.x, rect.y + rect.height));
293     for (int i = 0; i < edge.getNumber(); ++i) {
294         ld.drawLine(line, arg);
295         line.getPoint(0).x += BORDER_LINE_SPACE_MULT;
296         line.getPoint(1).x += BORDER_LINE_SPACE_MULT;
297     }
298     }
299 
300     edge = right;
301     if (edge != null && edge.getThickness() > 0 && edge.getNumber() > 0) {
302     line = new Line(null, section, edge.getThickness(),
303             null, true, new Point(rect.x + rect.width, rect.y),
304             new Point(rect.x + rect.width, rect.y + rect.height));
305     for (int i = 0; i < edge.getNumber(); ++i) {
306         ld.drawLine(line, arg);
307         line.getPoint(0).x -= BORDER_LINE_SPACE_MULT;
308         line.getPoint(1).x -= BORDER_LINE_SPACE_MULT;
309     }
310     }
311 }
312         
313 /**
314  * Returns <code>true</code> if this border's edges are all
315  * <code>null</code> or have zero count or width.
316  *
317  * @return <code>true</code> if this border's edges are all
318  * <code>null</code> or have zero count or width
319  */
320 public boolean isEmpty() {
321     return isEmptyEdge(top) && isEmptyEdge(bottom) && isEmptyEdge(left)
322     && isEmptyEdge(right);
323 }
324 
325 /**
326  * Returns <code>true</code> if <var>edge</var> is <code>null</code> or has
327  * zero count or width.
328  *
329  * @return <code>true</code> if <var>edge</var> is <code>null</code> or has
330  * zero count or width
331  */
332 protected boolean isEmptyEdge(BorderEdge edge) {
333     return edge == null || edge.getNumber() == 0 || edge.getThickness() == 0;
334 }
335 
336 /**
337  * Writes this border as an XML tag. Asks each edge to write itself as well.
338  * If {@link #isEmpty} returns <code>true</code>, returns without writing
339  * anything.
340  *
341  * @param out a writer that knows how to write XML
342  */
343 public void writeXML(XMLWriter out) {
344     if (isEmpty())
345     return;
346 
347     out.startElement("border");
348     if (color != null && !color.equals(DEFAULT_COLOR))
349     out.attr("color", color);
350 
351     if (top != null && top.getNumber() != 0) top.writeXML(out, "top");
352     if (bottom != null && bottom.getNumber() != 0)
353     bottom.writeXML(out, "bottom");
354     if (left != null && left.getNumber() != 0) left.writeXML(out, "left");
355     if (right != null && right.getNumber() != 0) right.writeXML(out, "right");
356 
357     out.endElement();
358 }
359 
360 }
361 
362
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