Block


1   /*
2    * $Id: Block.java,v 1.41.2.18 2003/04/11 00:24:38 pietsch Exp $
3    * ============================================================================
4    *                    The Apache Software License, Version 1.1
5    * ============================================================================
6    * 
7    * Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
8    * 
9    * Redistribution and use in source and binary forms, with or without modifica-
10   * tion, are permitted provided that the following conditions are met:
11   * 
12   * 1. Redistributions of source code must retain the above copyright notice,
13   *    this list of conditions and the following disclaimer.
14   * 
15   * 2. Redistributions in binary form must reproduce the above copyright notice,
16   *    this list of conditions and the following disclaimer in the documentation
17   *    and/or other materials provided with the distribution.
18   * 
19   * 3. The end-user documentation included with the redistribution, if any, must
20   *    include the following acknowledgment: "This product includes software
21   *    developed by the Apache Software Foundation (http://www.apache.org/)."
22   *    Alternately, this acknowledgment may appear in the software itself, if
23   *    and wherever such third-party acknowledgments normally appear.
24   * 
25   * 4. The names "FOP" and "Apache Software Foundation" must not be used to
26   *    endorse or promote products derived from this software without prior
27   *    written permission. For written permission, please contact
28   *    apache@apache.org.
29   * 
30   * 5. Products derived from this software may not be called "Apache", nor may
31   *    "Apache" appear in their name, without prior written permission of the
32   *    Apache Software Foundation.
33   * 
34   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
35   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
36   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
37   * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
38   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
39   * DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
40   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
41   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
42   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
43   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44   * ============================================================================
45   * 
46   * This software consists of voluntary contributions made by many individuals
47   * on behalf of the Apache Software Foundation and was originally created by
48   * James Tauber <jtauber@jtauber.com>. For more information on the Apache
49   * Software Foundation, please see <http://www.apache.org/>.
50   */ 
51  package org.apache.fop.fo.flow;
52  
53  // FOP
54  import org.apache.fop.fo.*;
55  import org.apache.fop.layout.*;
56  import org.apache.fop.apps.FOPException;
57  
58  /*
59    Modified by Mark Lillywhite mark-fop@inomial.com. The changes
60    here are based on memory profiling and do not change functionality.
61    Essentially, the Block object had a pointer to a BlockArea object
62    that it created. The BlockArea was not referenced after the Block
63    was finished except to determine the size of the BlockArea, however
64    a reference to the BlockArea was maintained and this caused a lot of
65    GC problems, and was a major reason for FOP memory leaks. So,
66    the reference to BlockArea was made local, the required information
67    is now stored (instead of a reference to the complex BlockArea object)
68    and it appears that there are a lot of changes in this file, in fact
69    there are only a few sematic changes; mostly I just got rid of 
70    "this." from blockArea since BlockArea is now local.
71    */
72  
73  public class Block extends FObjMixed {
74  
75      public static class Maker extends FObj.Maker {
76          public FObj make(FObj parent, PropertyList propertyList,
77                           String   systemId, int line, int column)
78              throws FOPException {
79              return new Block(parent, propertyList, systemId, line, column);
80          }
81  
82      }
83  
84      public static FObj.Maker maker() {
85          return new Block.Maker();
86      }
87  
88      int align;
89      int alignLast;
90      int breakAfter;
91      int lineHeight;
92      int startIndent;
93      int endIndent;
94      int spaceBefore;
95      int spaceAfter;
96      int textIndent;
97      int keepWithNext;
98  
99      int areaHeight = 0;
100     int contentWidth = 0;
101     int infLoopThreshhold = 50;
102 
103     String   id;
104     int span;
105     boolean breakStatusBeforeChecked = false;
106 
107     // this may be helpful on other FOs too
108     boolean anythingLaidOut = false;
109     //Added to see how long it's been since nothing was laid out.
110     int noLayoutCount = 0;
111 
112     public Block(FObj parent, PropertyList propertyList,
113                  String   systemId, int line, int column)
114         throws FOPException {
115         super(parent, propertyList, systemId, line, column);
116         this.span = this.properties.get("span").getEnum();
117     }
118 
119     public String   getName() {
120         return "fo:block";
121     }
122 
123     public int layout(Area area) throws FOPException {
124         if (!breakStatusBeforeChecked) {
125             breakStatusBeforeChecked = true;
126             // no break if first in area tree, or leading in context
127             // area
128             int breakBeforeStatus = propMgr.checkBreakBefore(area);
129             if (breakBeforeStatus != Status.OK) {
130                 return breakBeforeStatus;
131             }
132         }
133 
134         BlockArea blockArea;
135 
136         if (!anythingLaidOut) {
137             noLayoutCount++;
138         }
139         if (noLayoutCount > infLoopThreshhold) {
140             throw new FOPException(
141                 "No meaningful layout in block after many attempts.  "+
142                 "Infinite loop is assumed.  Processing halted.",
143                 systemId, line, column);
144         }
145 
146         // log.error(" b:LAY[" + marker + "] ");
147 
148         if (this.marker == BREAK_AFTER) {
149             return Status.OK;
150         }
151 
152         if (this.marker == START) {
153             noLayoutCount=0; // Reset the "loop counter".
154 
155             // Common Accessibility Properties
156             AccessibilityProps mAccProps = propMgr.getAccessibilityProps();
157 
158             // Common Aural Properties
159             AuralProps mAurProps = propMgr.getAuralProps();
160 
161             // Common Border, Padding, and Background Properties
162             BorderAndPadding bap = propMgr.getBorderAndPadding();
163             BackgroundProps bProps = propMgr.getBackgroundProps();
164 
165             // Common Font Properties
166             //this.fontState = propMgr.getFontState(area.getFontInfo());
167 
168             // Common Hyphenation Properties
169             HyphenationProps mHyphProps = propMgr.getHyphenationProps();
170 
171             // Common Margin Properties-Block
172             MarginProps mProps = propMgr.getMarginProps();
173 
174             // Common Relative Position Properties
175             RelativePositionProps mRelProps = propMgr.getRelativePositionProps();
176 
177             this.align = this.properties.get("text-align").getEnum();
178             this.alignLast = this.properties.get("text-align-last").getEnum();
179             this.breakAfter = this.properties.get("break-after").getEnum();
180             this.lineHeight =
181                 this.properties.get("line-height").getLength().mvalue();
182             this.startIndent =
183                 this.properties.get("start-indent").getLength().mvalue();
184             this.endIndent =
185                 this.properties.get("end-indent").getLength().mvalue();
186             this.spaceBefore =
187                 this.properties.get("space-before.optimum").getLength().mvalue();
188             this.spaceAfter =
189                 this.properties.get("space-after.optimum").getLength().mvalue();
190             this.textIndent =
191                 this.properties.get("text-indent").getLength().mvalue();
192             this.keepWithNext =
193                 this.properties.get("keep-with-next").getEnum();
194 
195             this.id = this.properties.get("id").getString();
196 
197             if (area instanceof BlockArea) {
198                 area.end();
199             }
200 
201             if (area.getIDReferences() != null) {
202                 try {
203                     area.getIDReferences().createID(id);
204                 }
205                 catch(FOPException e) {
206                     if (!e.isLocationSet()) {
207                         e.setLocation(systemId, line, column);
208                     }
209                     throw e;
210                 }
211             }
212 
213             this.marker = 0;
214         }
215 
216         if ((spaceBefore != 0) && (this.marker == 0)) {
217             area.addDisplaySpace(spaceBefore);
218         }
219 
220         if (anythingLaidOut) {
221             this.textIndent = 0;
222         }
223 
224         if (marker == 0 && area.getIDReferences() != null) {
225             area.getIDReferences().configureID(id, area);
226         }
227 
228         int spaceLeft = area.spaceLeft();
229         blockArea =
230             new BlockArea(propMgr.getFontState(area.getFontInfo()),
231                           area.getAllocationWidth(), area.spaceLeft(),
232                           startIndent, endIndent, textIndent, align,
233                           alignLast, lineHeight);
234         blockArea.setGeneratedBy(this);
235         this.areasGenerated++;
236         if (this.areasGenerated == 1)
237             blockArea.isFirst(true);
238         // markers
239 //         if (this.hasMarkers())
240 //             blockArea.addMarkers(this.getMarkers());
241 
242         blockArea.setParent(area);    // BasicLink needs it
243         blockArea.setPage(area.getPage());
244         blockArea.setBackground(propMgr.getBackgroundProps());
245         blockArea.setBorderAndPadding(propMgr.getBorderAndPadding());
246         blockArea.setHyphenation(propMgr.getHyphenationProps());
247         blockArea.start();
248 
249         blockArea.setAbsoluteHeight(area.getAbsoluteHeight());
250         blockArea.setIDReferences(area.getIDReferences());
251 
252         blockArea.setTableCellXOffset(area.getTableCellXOffset());
253 
254         int numChildren = this.children.size();
255         for (int i = this.marker; i < numChildren; i++) {
256             FONode fo = (FONode)children.get(i);
257             int status = fo.layout(blockArea);
258             if (Status.isIncomplete(status)) {
259                 this.marker = i;
260                 if (status == Status.AREA_FULL_NONE) {
261                     if (i == 0) {
262                         // Nothing was laid out.
263                         anythingLaidOut = false;
264                         return status;
265                     } else {
266                         // A previous child has already been laid out.
267                         area.addChild(blockArea);
268                         area.setMaxHeight(area.getMaxHeight() - spaceLeft
269                                           + blockArea.getMaxHeight());
270                         area.increaseHeight(blockArea.getHeight());
271                         anythingLaidOut = true;
272                         return Status.AREA_FULL_SOME;
273                     }
274                 }
275                 // Something has been laid out.
276                 area.addChild(blockArea);
277                 area.setMaxHeight(area.getMaxHeight() - spaceLeft
278                                   + blockArea.getMaxHeight());
279                 area.increaseHeight(blockArea.getHeight());
280                 anythingLaidOut = true;
281                 return status;
282             }
283             anythingLaidOut = true;
284         }
285 
286         blockArea.end();
287         blockArea.isLast(true);
288         area.addChild(blockArea);
289         area.setMaxHeight(area.getMaxHeight() - spaceLeft
290                           + blockArea.getMaxHeight());
291         area.increaseHeight(blockArea.getHeight());
292 
293         if (spaceAfter != 0) {
294             area.addDisplaySpace(spaceAfter);
295         }
296 
297         if (area instanceof BlockArea) {
298             area.start();
299         }
300         areaHeight= blockArea.getHeight();
301         contentWidth= blockArea.getContentWidth();
302 
303         // no break if last in area tree, or trailing in context
304         // area
305         int breakAfterStatus = propMgr.checkBreakAfter(area);
306         if (breakAfterStatus != Status.OK) {
307             this.marker = BREAK_AFTER;
308             blockArea = null;
309             return breakAfterStatus;
310         }
311         if (keepWithNext != 0) {
312             return Status.KEEP_WITH_NEXT;
313         }
314         return Status.OK;
315     }
316 
317     public int getAreaHeight() {
318         return areaHeight;
319     }
320 
321 
322     /**
323      * Return the content width of the boxes generated by this FO.
324      */
325     public int getContentWidth() {
326         return contentWidth;    // getAllocationWidth()??
327     }
328 
329 
330     public int getSpan() {
331         return this.span;
332     }
333 
334     public void resetMarker() {
335         anythingLaidOut = false;
336         super.resetMarker();
337     }
338 
339 }
340
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