J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 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). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package javax.swing.text.html; |
| 26 | |
| 27 | import java.util.Enumeration; |
| 28 | import java.awt.*; |
| 29 | import javax.swing.SizeRequirements; |
| 30 | import javax.swing.border.*; |
| 31 | import javax.swing.event.DocumentEvent; |
| 32 | import javax.swing.text.*; |
| 33 | |
| 34 | /** |
| 35 | * A view implementation to display a block (as a box) |
| 36 | * with CSS specifications. |
| 37 | * |
| 38 | * @author Timothy Prinzing |
| 39 | */ |
| 40 | public class BlockView extends BoxView { |
| 41 | |
| 42 | /** |
| 43 | * Creates a new view that represents an |
| 44 | * html box. This can be used for a number |
| 45 | * of elements. |
| 46 | * |
| 47 | * @param elem the element to create a view for |
| 48 | * @param axis either View.X_AXIS or View.Y_AXIS |
| 49 | */ |
| 50 | public BlockView(Element elem, int axis) { |
| 51 | super(elem, axis); |
| 52 | } |
| 53 | |
| 54 | /** |
| 55 | * Establishes the parent view for this view. This is |
| 56 | * guaranteed to be called before any other methods if the |
| 57 | * parent view is functioning properly. |
| 58 | * <p> |
| 59 | * This is implemented |
| 60 | * to forward to the superclass as well as call the |
| 61 | * {@link #setPropertiesFromAttributes()} |
| 62 | * method to set the paragraph properties from the css |
| 63 | * attributes. The call is made at this time to ensure |
| 64 | * the ability to resolve upward through the parents |
| 65 | * view attributes. |
| 66 | * |
| 67 | * @param parent the new parent, or null if the view is |
| 68 | * being removed from a parent it was previously added |
| 69 | * to |
| 70 | */ |
| 71 | public void setParent(View parent) { |
| 72 | super.setParent(parent); |
| 73 | if (parent != null) { |
| 74 | setPropertiesFromAttributes(); |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | /** |
| 79 | * Calculate the requirements of the block along the major |
| 80 | * axis (i.e. the axis along with it tiles). This is implemented |
| 81 | * to provide the superclass behavior and then adjust it if the |
| 82 | * CSS width or height attribute is specified and applicable to |
| 83 | * the axis. |
| 84 | */ |
| 85 | protected SizeRequirements calculateMajorAxisRequirements(int axis, SizeRequirements r) { |
| 86 | if (r == null) { |
| 87 | r = new SizeRequirements(); |
| 88 | } |
| 89 | if (! spanSetFromAttributes(axis, r, cssWidth, cssHeight)) { |
| 90 | r = super.calculateMajorAxisRequirements(axis, r); |
| 91 | } |
| 92 | else { |
| 93 | // Offset by the margins so that pref/min/max return the |
| 94 | // right value. |
| 95 | SizeRequirements parentR = super.calculateMajorAxisRequirements( |
| 96 | axis, null); |
| 97 | int margin = (axis == X_AXIS) ? getLeftInset() + getRightInset() : |
| 98 | getTopInset() + getBottomInset(); |
| 99 | r.minimum -= margin; |
| 100 | r.preferred -= margin; |
| 101 | r.maximum -= margin; |
| 102 | constrainSize(axis, r, parentR); |
| 103 | } |
| 104 | return r; |
| 105 | } |
| 106 | |
| 107 | /** |
| 108 | * Calculate the requirements of the block along the minor |
| 109 | * axis (i.e. the axis orthoginal to the axis along with it tiles). |
| 110 | * This is implemented |
| 111 | * to provide the superclass behavior and then adjust it if the |
| 112 | * CSS width or height attribute is specified and applicable to |
| 113 | * the axis. |
| 114 | */ |
| 115 | protected SizeRequirements calculateMinorAxisRequirements(int axis, SizeRequirements r) { |
| 116 | if (r == null) { |
| 117 | r = new SizeRequirements(); |
| 118 | } |
| 119 | |
| 120 | if (! spanSetFromAttributes(axis, r, cssWidth, cssHeight)) { |
| 121 | |
| 122 | /* |
| 123 | * The requirements were not directly specified by attributes, so |
| 124 | * compute the aggregate of the requirements of the children. The |
| 125 | * children that have a percentage value specified will be treated |
| 126 | * as completely stretchable since that child is not limited in any |
| 127 | * way. |
| 128 | */ |
| 129 | /* |
| 130 | int min = 0; |
| 131 | long pref = 0; |
| 132 | int max = 0; |
| 133 | int n = getViewCount(); |
| 134 | for (int i = 0; i < n; i++) { |
| 135 | View v = getView(i); |
| 136 | min = Math.max((int) v.getMinimumSpan(axis), min); |
| 137 | pref = Math.max((int) v.getPreferredSpan(axis), pref); |
| 138 | if ( |
| 139 | max = Math.max((int) v.getMaximumSpan(axis), max); |
| 140 | |
| 141 | } |
| 142 | r.preferred = (int) pref; |
| 143 | r.minimum = min; |
| 144 | r.maximum = max; |
| 145 | */ |
| 146 | r = super.calculateMinorAxisRequirements(axis, r); |
| 147 | } |
| 148 | else { |
| 149 | // Offset by the margins so that pref/min/max return the |
| 150 | // right value. |
| 151 | SizeRequirements parentR = super.calculateMinorAxisRequirements( |
| 152 | axis, null); |
| 153 | int margin = (axis == X_AXIS) ? getLeftInset() + getRightInset() : |
| 154 | getTopInset() + getBottomInset(); |
| 155 | r.minimum -= margin; |
| 156 | r.preferred -= margin; |
| 157 | r.maximum -= margin; |
| 158 | constrainSize(axis, r, parentR); |
| 159 | } |
| 160 | |
| 161 | /* |
| 162 | * Set the alignment based upon the CSS properties if it is |
| 163 | * specified. For X_AXIS this would be text-align, for |
| 164 | * Y_AXIS this would be vertical-align. |
| 165 | */ |
| 166 | if (axis == X_AXIS) { |
| 167 | Object o = getAttributes().getAttribute(CSS.Attribute.TEXT_ALIGN); |
| 168 | if (o != null) { |
| 169 | String align = o.toString(); |
| 170 | if (align.equals("center")) { |
| 171 | r.alignment = 0.5f; |
| 172 | } else if (align.equals("right")) { |
| 173 | r.alignment = 1.0f; |
| 174 | } else { |
| 175 | r.alignment = 0.0f; |
| 176 | } |
| 177 | } |
| 178 | } |
| 179 | // Y_AXIS TBD |
| 180 | return r; |
| 181 | } |
| 182 | |
| 183 | boolean isPercentage(int axis, AttributeSet a) { |
| 184 | if (axis == X_AXIS) { |
| 185 | if (cssWidth != null) { |
| 186 | return cssWidth.isPercentage(); |
| 187 | } |
| 188 | } else { |
| 189 | if (cssHeight != null) { |
| 190 | return cssHeight.isPercentage(); |
| 191 | } |
| 192 | } |
| 193 | return false; |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * Adjust the given requirements to the CSS width or height if |
| 198 | * it is specified along the applicable axis. Return true if the |
| 199 | * size is exactly specified, false if the span is not specified |
| 200 | * in an attribute or the size specified is a percentage. |
| 201 | */ |
| 202 | static boolean spanSetFromAttributes(int axis, SizeRequirements r, |
| 203 | CSS.LengthValue cssWidth, |
| 204 | CSS.LengthValue cssHeight) { |
| 205 | if (axis == X_AXIS) { |
| 206 | if ((cssWidth != null) && (! cssWidth.isPercentage())) { |
| 207 | r.minimum = r.preferred = r.maximum = (int) cssWidth.getValue(); |
| 208 | return true; |
| 209 | } |
| 210 | } else { |
| 211 | if ((cssHeight != null) && (! cssHeight.isPercentage())) { |
| 212 | r.minimum = r.preferred = r.maximum = (int) cssHeight.getValue(); |
| 213 | return true; |
| 214 | } |
| 215 | } |
| 216 | return false; |
| 217 | } |
| 218 | |
| 219 | /** |
| 220 | * Performs layout for the minor axis of the box (i.e. the |
| 221 | * axis orthoginal to the axis that it represents). The results |
| 222 | * of the layout (the offset and span for each children) are |
| 223 | * placed in the given arrays which represent the allocations to |
| 224 | * the children along the minor axis. |
| 225 | * |
| 226 | * @param targetSpan the total span given to the view, which |
| 227 | * whould be used to layout the childre. |
| 228 | * @param axis the axis being layed out |
| 229 | * @param offsets the offsets from the origin of the view for |
| 230 | * each of the child views; this is a return value and is |
| 231 | * filled in by the implementation of this method |
| 232 | * @param spans the span of each child view; this is a return |
| 233 | * value and is filled in by the implementation of this method |
| 234 | */ |
| 235 | protected void layoutMinorAxis(int targetSpan, int axis, int[] offsets, int[] spans) { |
| 236 | int n = getViewCount(); |
| 237 | Object key = (axis == X_AXIS) ? CSS.Attribute.WIDTH : CSS.Attribute.HEIGHT; |
| 238 | for (int i = 0; i < n; i++) { |
| 239 | View v = getView(i); |
| 240 | int min = (int) v.getMinimumSpan(axis); |
| 241 | int max; |
| 242 | |
| 243 | // check for percentage span |
| 244 | AttributeSet a = v.getAttributes(); |
| 245 | CSS.LengthValue lv = (CSS.LengthValue) a.getAttribute(key); |
| 246 | if ((lv != null) && lv.isPercentage()) { |
| 247 | // bound the span to the percentage specified |
| 248 | min = Math.max((int) lv.getValue(targetSpan), min); |
| 249 | max = min; |
| 250 | } else { |
| 251 | max = (int)v.getMaximumSpan(axis); |
| 252 | } |
| 253 | |
| 254 | // assign the offset and span for the child |
| 255 | if (max < targetSpan) { |
| 256 | // can't make the child this wide, align it |
| 257 | float align = v.getAlignment(axis); |
| 258 | offsets[i] = (int) ((targetSpan - max) * align); |
| 259 | spans[i] = max; |
| 260 | } else { |
| 261 | // make it the target width, or as small as it can get. |
| 262 | offsets[i] = 0; |
| 263 | spans[i] = Math.max(min, targetSpan); |
| 264 | } |
| 265 | } |
| 266 | } |
| 267 | |
| 268 | |
| 269 | /** |
| 270 | * Renders using the given rendering surface and area on that |
| 271 | * surface. This is implemented to delegate to the css box |
| 272 | * painter to paint the border and background prior to the |
| 273 | * interior. |
| 274 | * |
| 275 | * @param g the rendering surface to use |
| 276 | * @param allocation the allocated region to render into |
| 277 | * @see View#paint |
| 278 | */ |
| 279 | public void paint(Graphics g, Shape allocation) { |
| 280 | Rectangle a = (Rectangle) allocation; |
| 281 | painter.paint(g, a.x, a.y, a.width, a.height, this); |
| 282 | super.paint(g, a); |
| 283 | } |
| 284 | |
| 285 | /** |
| 286 | * Fetches the attributes to use when rendering. This is |
| 287 | * implemented to multiplex the attributes specified in the |
| 288 | * model with a StyleSheet. |
| 289 | */ |
| 290 | public AttributeSet getAttributes() { |
| 291 | if (attr == null) { |
| 292 | StyleSheet sheet = getStyleSheet(); |
| 293 | attr = sheet.getViewAttributes(this); |
| 294 | } |
| 295 | return attr; |
| 296 | } |
| 297 | |
| 298 | /** |
| 299 | * Gets the resize weight. |
| 300 | * |
| 301 | * @param axis may be either X_AXIS or Y_AXIS |
| 302 | * @return the weight |
| 303 | * @exception IllegalArgumentException for an invalid axis |
| 304 | */ |
| 305 | public int getResizeWeight(int axis) { |
| 306 | switch (axis) { |
| 307 | case View.X_AXIS: |
| 308 | return 1; |
| 309 | case View.Y_AXIS: |
| 310 | return 0; |
| 311 | default: |
| 312 | throw new IllegalArgumentException("Invalid axis: " + axis); |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | /** |
| 317 | * Gets the alignment. |
| 318 | * |
| 319 | * @param axis may be either X_AXIS or Y_AXIS |
| 320 | * @return the alignment |
| 321 | */ |
| 322 | public float getAlignment(int axis) { |
| 323 | switch (axis) { |
| 324 | case View.X_AXIS: |
| 325 | return 0; |
| 326 | case View.Y_AXIS: |
| 327 | if (getViewCount() == 0) { |
| 328 | return 0; |
| 329 | } |
| 330 | float span = getPreferredSpan(View.Y_AXIS); |
| 331 | View v = getView(0); |
| 332 | float above = v.getPreferredSpan(View.Y_AXIS); |
| 333 | float a = (((int)span) != 0) ? (above * v.getAlignment(View.Y_AXIS)) / span: 0; |
| 334 | return a; |
| 335 | default: |
| 336 | throw new IllegalArgumentException("Invalid axis: " + axis); |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | public void changedUpdate(DocumentEvent changes, Shape a, ViewFactory f) { |
| 341 | super.changedUpdate(changes, a, f); |
| 342 | int pos = changes.getOffset(); |
| 343 | if (pos <= getStartOffset() && (pos + changes.getLength()) >= |
| 344 | getEndOffset()) { |
| 345 | setPropertiesFromAttributes(); |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | /** |
| 350 | * Determines the preferred span for this view along an |
| 351 | * axis. |
| 352 | * |
| 353 | * @param axis may be either <code>View.X_AXIS</code> |
| 354 | * or <code>View.Y_AXIS</code> |
| 355 | * @return the span the view would like to be rendered into >= 0; |
| 356 | * typically the view is told to render into the span |
| 357 | * that is returned, although there is no guarantee; |
| 358 | * the parent may choose to resize or break the view |
| 359 | * @exception IllegalArgumentException for an invalid axis type |
| 360 | */ |
| 361 | public float getPreferredSpan(int axis) { |
| 362 | return super.getPreferredSpan(axis); |
| 363 | } |
| 364 | |
| 365 | /** |
| 366 | * Determines the minimum span for this view along an |
| 367 | * axis. |
| 368 | * |
| 369 | * @param axis may be either <code>View.X_AXIS</code> |
| 370 | * or <code>View.Y_AXIS</code> |
| 371 | * @return the span the view would like to be rendered into >= 0; |
| 372 | * typically the view is told to render into the span |
| 373 | * that is returned, although there is no guarantee; |
| 374 | * the parent may choose to resize or break the view |
| 375 | * @exception IllegalArgumentException for an invalid axis type |
| 376 | */ |
| 377 | public float getMinimumSpan(int axis) { |
| 378 | return super.getMinimumSpan(axis); |
| 379 | } |
| 380 | |
| 381 | /** |
| 382 | * Determines the maximum span for this view along an |
| 383 | * axis. |
| 384 | * |
| 385 | * @param axis may be either <code>View.X_AXIS</code> |
| 386 | * or <code>View.Y_AXIS</code> |
| 387 | * @return the span the view would like to be rendered into >= 0; |
| 388 | * typically the view is told to render into the span |
| 389 | * that is returned, although there is no guarantee; |
| 390 | * the parent may choose to resize or break the view |
| 391 | * @exception IllegalArgumentException for an invalid axis type |
| 392 | */ |
| 393 | public float getMaximumSpan(int axis) { |
| 394 | return super.getMaximumSpan(axis); |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * Update any cached values that come from attributes. |
| 399 | */ |
| 400 | protected void setPropertiesFromAttributes() { |
| 401 | |
| 402 | // update attributes |
| 403 | StyleSheet sheet = getStyleSheet(); |
| 404 | attr = sheet.getViewAttributes(this); |
| 405 | |
| 406 | // Reset the painter |
| 407 | painter = sheet.getBoxPainter(attr); |
| 408 | if (attr != null) { |
| 409 | setInsets((short) painter.getInset(TOP, this), |
| 410 | (short) painter.getInset(LEFT, this), |
| 411 | (short) painter.getInset(BOTTOM, this), |
| 412 | (short) painter.getInset(RIGHT, this)); |
| 413 | } |
| 414 | |
| 415 | // Get the width/height |
| 416 | cssWidth = (CSS.LengthValue) attr.getAttribute(CSS.Attribute.WIDTH); |
| 417 | cssHeight = (CSS.LengthValue) attr.getAttribute(CSS.Attribute.HEIGHT); |
| 418 | } |
| 419 | |
| 420 | protected StyleSheet getStyleSheet() { |
| 421 | HTMLDocument doc = (HTMLDocument) getDocument(); |
| 422 | return doc.getStyleSheet(); |
| 423 | } |
| 424 | |
| 425 | /** |
| 426 | * Constrains <code>want</code> to fit in the minimum size specified |
| 427 | * by <code>min</code>. |
| 428 | */ |
| 429 | private void constrainSize(int axis, SizeRequirements want, |
| 430 | SizeRequirements min) { |
| 431 | if (min.minimum > want.minimum) { |
| 432 | want.minimum = want.preferred = min.minimum; |
| 433 | want.maximum = Math.max(want.maximum, min.maximum); |
| 434 | } |
| 435 | } |
| 436 | |
| 437 | private AttributeSet attr; |
| 438 | private StyleSheet.BoxPainter painter; |
| 439 | |
| 440 | private CSS.LengthValue cssWidth; |
| 441 | private CSS.LengthValue cssHeight; |
| 442 | |
| 443 | } |