net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/HTMLTextPresenter.java

   1 package net.sourceforge.phpdt.internal.ui.text;
   2
   3 /*
   4  * (c) Copyright IBM Corp. 2000, 2001.
   5  * All Rights Reserved.
   6  */
   7
   8
   9 import java.io.IOException;
  10 import java.io.Reader;
  11 import java.io.StringReader;
  12 import java.util.Iterator;
  13
  14 import net.sourceforge.phpdt.internal.ui.PHPUIMessages;
  15 import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  16
  17 import org.eclipse.jface.text.DefaultInformationControl;
  18 import org.eclipse.jface.text.Region;
  19 import org.eclipse.jface.text.TextPresentation;
  20 import org.eclipse.swt.custom.StyleRange;
  21 import org.eclipse.swt.graphics.GC;
  22 import org.eclipse.swt.widgets.Display;
  23
  24
  25
  26
  27 public class HTMLTextPresenter implements DefaultInformationControl.IInformationPresenter {
  28
  29         private static final String LINE_DELIM= System.getProperty("line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
  30
  31         private int fCounter;
  32         private boolean fEnforceUpperLineLimit;
  33
  34         public HTMLTextPresenter(boolean enforceUpperLineLimit) {
  35                 super();
  36                 fEnforceUpperLineLimit= enforceUpperLineLimit;
  37         }
  38
  39         public HTMLTextPresenter() {
  40                 this(true);
  41         }
  42
  43         protected Reader createReader(String hoverInfo, TextPresentation presentation) {
  44                 return new HTML2TextReader(new StringReader(hoverInfo), presentation);
  45         }
  46
  47         protected void adaptTextPresentation(TextPresentation presentation, int offset, int insertLength) {
  48
  49                 int yoursStart= offset;
  50                 int yoursEnd=   offset + insertLength -1;
  51                 yoursEnd= Math.max(yoursStart, yoursEnd);
  52
  53                 Iterator e= presentation.getAllStyleRangeIterator();
  54                 while (e.hasNext()) {
  55
  56                         StyleRange range= (StyleRange) e.next();
  57
  58                         int myStart= range.start;
  59                         int myEnd=   range.start + range.length -1;
  60                         myEnd= Math.max(myStart, myEnd);
  61
  62                         if (myEnd < yoursStart)
  63                                 continue;
  64
  65                         if (myStart < yoursStart)
  66                                 range.length += insertLength;
  67                         else
  68                                 range.start += insertLength;
  69                 }
  70         }
  71
  72         private void append(StringBuffer buffer, String string, TextPresentation presentation) {
  73
  74                 int length= string.length();
  75                 buffer.append(string);
  76
  77                 if (presentation != null)
  78                         adaptTextPresentation(presentation, fCounter, length);
  79
  80                 fCounter += length;
  81         }
  82
  83         private String getIndent(String line) {
  84                 int length= line.length();
  85
  86                 int i= 0;
  87                 while (i < length && Character.isWhitespace(line.charAt(i))) ++i;
  88
  89                 return (i == length ? line : line.substring(0, i)) + " "; //$NON-NLS-1$
  90         }
  91
  92         /*
  93          * @see IHoverInformationPresenter#updatePresentation(Display display, String, TextPresentation, int, int)
  94          */
  95         public String updatePresentation(Display display, String hoverInfo, TextPresentation presentation, int maxWidth, int maxHeight) {
  96
  97                 if (hoverInfo == null)
  98                         return null;
  99
 100                 GC gc= new GC(display);
 101                 try {
 102
 103                         StringBuffer buffer= new StringBuffer();
 104                         int maxNumberOfLines= Math.round(maxHeight / gc.getFontMetrics().getHeight());
 105
 106                         fCounter= 0;
 107                         LineBreakingReader reader= new LineBreakingReader(createReader(hoverInfo, presentation), gc, maxWidth);
 108
 109                         boolean lastLineFormatted= false;
 110                         String lastLineIndent= null;
 111
 112                         String line=reader.readLine();
 113                         boolean lineFormatted= reader.isFormattedLine();
 114                         boolean firstLineProcessed= false;
 115
 116                         while (line != null) {
 117
 118                                 if (fEnforceUpperLineLimit && maxNumberOfLines <= 0)
 119                                         break;
 120
 121                                 if (firstLineProcessed) {
 122                                         if (!lastLineFormatted)
 123                                                 append(buffer, LINE_DELIM, null);
 124                                         else {
 125                                                 append(buffer, LINE_DELIM, presentation);
 126                                                 if (lastLineIndent != null)
 127                                                         append(buffer, lastLineIndent, presentation);
 128                                         }
 129                                 }
 130
 131                                 append(buffer, line, null);
 132                                 firstLineProcessed= true;
 133
 134                                 lastLineFormatted= lineFormatted;
 135                                 if (!lineFormatted)
 136                                         lastLineIndent= null;
 137                                 else if (lastLineIndent == null)
 138                                         lastLineIndent= getIndent(line);
 139
 140                                 line= reader.readLine();
 141                                 lineFormatted= reader.isFormattedLine();
 142
 143                                 maxNumberOfLines--;
 144                         }
 145
 146                         if (line != null) {
 147                                 append(buffer, LINE_DELIM, lineFormatted ? presentation : null);
 148                                 append(buffer, PHPUIMessages.getString("HTMLTextPresenter.ellipsis"), presentation); //$NON-NLS-1$
 149                         }
 150
 151                         return trim(buffer, presentation);
 152
 153                 } catch (IOException e) {
 154
 155                         PHPeclipsePlugin.log(e);
 156                         return null;
 157
 158                 } finally {
 159                         gc.dispose();
 160                 }
 161         }
 162
 163         private String trim(StringBuffer buffer, TextPresentation presentation) {
 164
 165                 int length= buffer.length();
 166
 167                 int end= length -1;
 168                 while (end >= 0 && Character.isWhitespace(buffer.charAt(end)))
 169                         -- end;
 170
 171                 if (end == -1)
 172                         return ""; //$NON-NLS-1$
 173
 174                 if (end < length -1)
 175                         buffer.delete(end + 1, length);
 176                 else
 177                         end= length;
 178
 179                 int start= 0;
 180                 while (start < end && Character.isWhitespace(buffer.charAt(start)))
 181                         ++ start;
 182
 183                 buffer.delete(0, start);
 184                 presentation.setResultWindow(new Region(start, buffer.length()));
 185                 return buffer.toString();
 186         }
 187 }
 188