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34
35 package swingwt.awt;
36
37
38
39
40 public class BorderLayout implements LayoutManager2 {
41
42 private int hgap;
43 private int vgap;
44 private Component north;
45 private Component west;
46 private Component east;
47 private Component south;
48 private Component center;
49 private Component firstLine;
50 private Component lastLine;
51 private Component firstItem;
52 private Component lastItem;
53
54 public static final String  NORTH = "North";
55 public static final String SOUTH = "South";
56 public static final String EAST = "East";
57 public static final String WEST = "West";
58 public static final String CENTER = "Center";
59 public static final String BEFORE_FIRST_LINE = "First";
60 public static final String AFTER_LAST_LINE = "Last";
61 public static final String BEFORE_LINE_BEGINS = "Before";
62 public static final String AFTER_LINE_ENDS = "After";
63 public static final String PAGE_START = BEFORE_FIRST_LINE;
64 public static final String PAGE_END = AFTER_LAST_LINE;
65 public static final String LINE_START = BEFORE_LINE_BEGINS;
66 public static final String LINE_END = AFTER_LINE_ENDS;
67
68 public BorderLayout() {
69 this(0, 0);
70 }
71
72 public BorderLayout(int hgap, int vgap) {
73 this.hgap = hgap;
74 this.vgap = vgap;
75 }
76
77 public int getHgap() {
78 return hgap;
79 }
80
81 public void setHgap(int hgap) {
82 this.hgap = hgap;
83 }
84
85 public int getVgap() {
86 return vgap;
87 }
88
89 public void setVgap(int vgap) {
90 this.vgap = vgap;
91 }
92
93 public void addLayoutComponent(Component comp, Object constraints) {
94 if ((constraints == null) || (constraints instanceof String )) {
95 addLayoutComponent((String ) constraints, comp);
96 } else {
97 throw new IllegalArgumentException ("constraint must be a string");
98 }
99 }
100
101 public void addLayoutComponent(String name, Component comp) {
102
103 if (name == null) {
104 name = "Center";
105 }
106 if ("Center".equals(name)) {
107 center = comp;
108 }
109 else if ("North".equals(name)) {
110 north = comp;
111 }
112 else if ("South".equals(name)) {
113 south = comp;
114 }
115 else if ("East".equals(name)) {
116 east = comp;
117 }
118 else if ("West".equals(name)) {
119 west = comp;
120 }
121 else if (BEFORE_FIRST_LINE.equals(name)) {
122 firstLine = comp;
123 }
124 else if (AFTER_LAST_LINE.equals(name)) {
125 lastLine = comp;
126 }
127 else if (BEFORE_LINE_BEGINS.equals(name)) {
128 firstItem = comp;
129 }
130 else if (AFTER_LINE_ENDS.equals(name)) {
131 lastItem = comp;
132 }
133 else {
134 throw new IllegalArgumentException (
135 "unknown constraint: " + name);
136 }
137
138 }
139
140 public void removeLayoutComponent(Component comp) {
141
142 if (comp == center) {
143 center = null;
144 }
145 else if (comp == north) {
146 north = null;
147 }
148 else if (comp == south) {
149 south = null;
150 }
151 else if (comp == east) {
152 east = null;
153 }
154 else if (comp == west) {
155 west = null;
156 }
157 if (comp == firstLine) {
158 firstLine = null;
159 }
160 else if (comp == lastLine) {
161 lastLine = null;
162 }
163 else if (comp == firstItem) {
164 firstItem = null;
165 }
166 else if (comp == lastItem) {
167 lastItem = null;
168 }
169
170 }
171
172 public Dimension minimumLayoutSize(Container target) {
173
174 Dimension dim = new Dimension(0, 0);
175
176 boolean ltr = target.getComponentOrientation().isLeftToRight();
177 Component c = null;
178
179 if ((c = getChild(EAST, ltr)) != null) {
180 Dimension d = c.getMinimumSize();
181 dim.width += d.width + hgap;
182 dim.height = Math.max(d.height, dim.height);
183 }
184 if ((c = getChild(WEST, ltr)) != null) {
185 Dimension d = c.getMinimumSize();
186 dim.width += d.width + hgap;
187 dim.height = Math.max(d.height, dim.height);
188 }
189 if ((c = getChild(CENTER, ltr)) != null) {
190 Dimension d = c.getMinimumSize();
191 dim.width += d.width;
192 dim.height = Math.max(d.height, dim.height);
193 }
194 if ((c = getChild(NORTH, ltr)) != null) {
195 Dimension d = c.getMinimumSize();
196 dim.width = Math.max(d.width, dim.width);
197 dim.height += d.height + vgap;
198 }
199 if ((c = getChild(SOUTH, ltr)) != null) {
200 Dimension d = c.getMinimumSize();
201 dim.width = Math.max(d.width, dim.width);
202 dim.height += d.height + vgap;
203 }
204
205 Insets insets = target.getInsets();
206 dim.width += insets.left + insets.right;
207 dim.height += insets.top + insets.bottom;
208
209 return dim;
210
211 }
212
213 public Dimension preferredLayoutSize(Container target) {
214
215 Dimension dim = new Dimension(0, 0);
216
217 boolean ltr = target.getComponentOrientation().isLeftToRight();
218 Component c = null;
219
220 if ((c = getChild(EAST, ltr)) != null) {
221 Dimension d = c.getPreferredSize();
222 dim.width += d.width + hgap;
223 dim.height = Math.max(d.height, dim.height);
224 }
225 if ((c = getChild(WEST, ltr)) != null) {
226 Dimension d = c.getPreferredSize();
227 dim.width += d.width + hgap;
228 dim.height = Math.max(d.height, dim.height);
229 }
230 if ((c = getChild(CENTER, ltr)) != null) {
231 Dimension d = c.getPreferredSize();
232 dim.width += d.width;
233 dim.height = Math.max(d.height, dim.height);
234 }
235 if ((c = getChild(NORTH, ltr)) != null) {
236 Dimension d = c.getPreferredSize();
237 dim.width = Math.max(d.width, dim.width);
238 dim.height += d.height + vgap;
239 }
240 if ((c = getChild(SOUTH, ltr)) != null) {
241 Dimension d = c.getPreferredSize();
242 dim.width = Math.max(d.width, dim.width);
243 dim.height += d.height + vgap;
244 }
245
246 Insets insets = target.getInsets();
247 dim.width += insets.left + insets.right;
248 dim.height += insets.top + insets.bottom;
249
250 return dim;
251
252 }
253
254 public Dimension maximumLayoutSize(Container target) {
255 return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
256 }
257
258 public float getLayoutAlignmentX(Container parent) {
259 return (float) 0.5;
260 }
261
262 public float getLayoutAlignmentY(Container parent) {
263 return (float) 0.5;
264 }
265
266 public void invalidateLayout(Container target) {
267 }
268
269 public void layoutContainer(Container target) {
270 Insets insets = target.getInsets();
271 int top = insets.top;
272 int bottom = target.getHeight() - insets.bottom;
273 int left = insets.left;
274 int right = target.getWidth() - insets.right;
275
276 boolean ltr = target.getComponentOrientation().isLeftToRight();
277 Component c = null;
278
279 if ((c = getChild(NORTH, ltr)) != null) {
280 c.setSize(right - left, c.getHeight());
281 Dimension d = c.getPreferredSize();
282 c.setBounds(left, top, right - left, d.height);
283 top += d.height + vgap;
284 }
285 if ((c = getChild(SOUTH, ltr)) != null) {
286 c.setSize(right - left, c.getHeight());
287 Dimension d = c.getPreferredSize();
288 c.setBounds(left, bottom - d.height, right - left, d.height);
289 bottom -= d.height + vgap;
290 }
291 if ((c = getChild(EAST, ltr)) != null) {
292 c.setSize(c.getWidth(), bottom - top);
293 Dimension d = c.getPreferredSize();
294 c.setBounds(right - d.width, top, d.width, bottom - top);
295 right -= d.width + hgap;
296 }
297 if ((c = getChild(WEST, ltr)) != null) {
298 c.setSize(c.getWidth(), bottom - top);
299 Dimension d = c.getPreferredSize();
300 c.setBounds(left, top, d.width, bottom - top);
301 left += d.width + hgap;
302 }
303 if ((c = getChild(CENTER, ltr)) != null) {
304 c.setBounds(left, top, right - left, bottom - top);
305 }
306 }
307
308 private Component getChild(String key, boolean ltr) {
309 Component result = null;
310
311 if (key == NORTH) {
312 result = (firstLine != null) ? firstLine : north;
313 } else if (key == SOUTH) {
314 result = (lastLine != null) ? lastLine : south;
315 } else if (key == WEST) {
316 result = ltr ? firstItem : lastItem;
317 if (result == null) {
318 result = west;
319 }
320 } else if (key == EAST) {
321 result = ltr ? lastItem : firstItem;
322 if (result == null) {
323 result = east;
324 }
325 } else if (key == CENTER) {
326 result = center;
327 }
328 if (result != null && !result.isVisible()) {
329 result = null;
330 }
331 return result;
332 }
333
334 }
335 |
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