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 import java.io.IOException;
   9 import java.io.Reader;
  10 import java.io.StringReader;
  11 import java.util.Iterator;
  12
  13 import net.sourceforge.phpdt.internal.ui.PHPUIMessages;
  14 import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  15
  16 import org.eclipse.jface.text.DefaultInformationControl;
  17 import org.eclipse.jface.text.Region;
  18 import org.eclipse.jface.text.TextPresentation;
  19 import org.eclipse.swt.custom.StyleRange;
  20 import org.eclipse.swt.graphics.GC;
  21 import org.eclipse.swt.widgets.Display;
  22
  23 public class HTMLTextPresenter implements
  24                 DefaultInformationControl.IInformationPresenter {
  25
  26         private static final String LINE_DELIM = System.getProperty(
  27                         "line.separator", "\n"); //$NON-NLS-1$ //$NON-NLS-2$
  28
  29         private int fCounter;
  30
  31         private boolean fEnforceUpperLineLimit;
  32
  33         public HTMLTextPresenter(boolean enforceUpperLineLimit) {
  34                 super();
  35                 fEnforceUpperLineLimit = enforceUpperLineLimit;
  36         }
  37
  38         public HTMLTextPresenter() {
  39                 this(true);
  40         }
  41
  42         protected Reader createReader(String hoverInfo,
  43                         TextPresentation presentation) {
  44                 return new HTML2TextReader(new StringReader(hoverInfo), presentation);
  45         }
  46
  47         protected void adaptTextPresentation(TextPresentation presentation,
  48                         int offset, int insertLength) {
  49
  50                 int yoursStart = offset;
  51                 int yoursEnd = offset + insertLength - 1;
  52                 yoursEnd = Math.max(yoursStart, yoursEnd);
  53
  54                 Iterator e = presentation.getAllStyleRangeIterator();
  55                 while (e.hasNext()) {
  56
  57                         StyleRange range = (StyleRange) e.next();
  58
  59                         int myStart = range.start;
  60                         int myEnd = range.start + range.length - 1;
  61                         myEnd = Math.max(myStart, myEnd);
  62
  63                         if (myEnd < yoursStart)
  64                                 continue;
  65
  66                         if (myStart < yoursStart)
  67                                 range.length += insertLength;
  68                         else
  69                                 range.start += insertLength;
  70                 }
  71         }
  72
  73         private void append(StringBuffer buffer, String string,
  74                         TextPresentation presentation) {
  75
  76                 int length = string.length();
  77                 buffer.append(string);
  78
  79                 if (presentation != null)
  80                         adaptTextPresentation(presentation, fCounter, length);
  81
  82                 fCounter += length;
  83         }
  84
  85         private String getIndent(String line) {
  86                 int length = line.length();
  87
  88                 int i = 0;
  89                 while (i < length && Character.isWhitespace(line.charAt(i)))
  90                         ++i;
  91
  92                 return (i == length ? line : line.substring(0, i)) + " "; //$NON-NLS-1$
  93         }
  94
  95         /*
  96          * @see IHoverInformationPresenter#updatePresentation(Display display,
  97          *      String, TextPresentation, int, int)
  98          */
  99         public String updatePresentation(Display display, String hoverInfo,
 100                         TextPresentation presentation, int maxWidth, int maxHeight) {
 101
 102                 if (hoverInfo == null)
 103                         return null;
 104
 105                 GC gc = new GC(display);
 106                 try {
 107
 108                         StringBuffer buffer = new StringBuffer();
 109                         int maxNumberOfLines = Math.round(maxHeight
 110                                         / gc.getFontMetrics().getHeight());
 111
 112                         fCounter = 0;
 113                         LineBreakingReader reader = new LineBreakingReader(createReader(
 114                                         hoverInfo, presentation), gc, maxWidth);
 115
 116                         boolean lastLineFormatted = false;
 117                         String lastLineIndent = null;
 118
 119                         String line = reader.readLine();
 120                         boolean lineFormatted = reader.isFormattedLine();
 121                         boolean firstLineProcessed = false;
 122
 123                         while (line != null) {
 124
 125                                 if (fEnforceUpperLineLimit && maxNumberOfLines <= 0)
 126                                         break;
 127
 128                                 if (firstLineProcessed) {
 129                                         if (!lastLineFormatted)
 130                                                 append(buffer, LINE_DELIM, null);
 131                                         else {
 132                                                 append(buffer, LINE_DELIM, presentation);
 133                                                 if (lastLineIndent != null)
 134                                                         append(buffer, lastLineIndent, presentation);
 135                                         }
 136                                 }
 137
 138                                 append(buffer, line, null);
 139                                 firstLineProcessed = true;
 140
 141                                 lastLineFormatted = lineFormatted;
 142                                 if (!lineFormatted)
 143                                         lastLineIndent = null;
 144                                 else if (lastLineIndent == null)
 145                                         lastLineIndent = getIndent(line);
 146
 147                                 line = reader.readLine();
 148                                 lineFormatted = reader.isFormattedLine();
 149
 150                                 maxNumberOfLines--;
 151                         }
 152
 153                         if (line != null) {
 154                                 append(buffer, LINE_DELIM, lineFormatted ? presentation : null);
 155                                 append(buffer, PHPUIMessages
 156                                                 .getString("HTMLTextPresenter.ellipsis"), presentation); //$NON-NLS-1$
 157                         }
 158
 159                         return trim(buffer, presentation);
 160
 161                 } catch (IOException e) {
 162
 163                         PHPeclipsePlugin.log(e);
 164                         return null;
 165
 166                 } finally {
 167                         gc.dispose();
 168                 }
 169         }
 170
 171         private String trim(StringBuffer buffer, TextPresentation presentation) {
 172
 173                 int length = buffer.length();
 174
 175                 int end = length - 1;
 176                 while (end >= 0 && Character.isWhitespace(buffer.charAt(end)))
 177                         --end;
 178
 179                 if (end == -1)
 180                         return ""; //$NON-NLS-1$
 181
 182                 if (end < length - 1)
 183                         buffer.delete(end + 1, length);
 184                 else
 185                         end = length;
 186
 187                 int start = 0;
 188                 while (start < end && Character.isWhitespace(buffer.charAt(start)))
 189                         ++start;
 190
 191                 buffer.delete(0, start);
 192                 presentation.setResultWindow(new Region(start, buffer.length()));
 193                 return buffer.toString();
 194         }
 195 }