How to use

setSelection

method

in

org.eclipse.jface.text.TextViewer

public void setSelection(ISelection sel) {
  txtViewer.setSelection(sel);
}

public void setSelection(ISelection selection, boolean reveal) {
  if (fViewerInFocus != null) {
    if (reveal && !isSelectionInsideVisibleRegion(fViewerInFocus, selection))
      resetVisibleRegion();
    fViewerInFocus.setSelection(selection, reveal);
  }
}

  @Override
  public void run() {
    SelectionProcessor processor= new SelectionProcessor(TextViewer.this);
    try {
      /* Use the selection instead of the event's coordinates. Is this dangerous? */
      ISelection selection= getSelection();
      int length= e.text.length();
      if (length == 0 && e.character == '\0') {
        // backspace in StyledText block selection mode...
        TextEdit edit= processor.backspace(selection);
        edit.apply(fDocument, TextEdit.UPDATE_REGIONS);
        ISelection empty= processor.makeEmpty(selection, true);
        setSelection(empty);
      } else {
        int lines= processor.getCoveredLines(selection);
        String delim= fDocument.getLegalLineDelimiters()[0];
        StringBuffer text= new StringBuffer(lines * length + (lines - 1) * delim.length());
        text.append(e.text);
        for (int i= 0; i < lines - 1; i++) {
          text.append(delim);
          text.append(e.text);
        }
        processor.doReplace(selection, text.toString());
      }
    } catch (BadLocationException x) {
      if (TRACE_ERRORS)
        System.out.println(JFaceTextMessages.getString("TextViewer.error.bad_location.verifyText")); //$NON-NLS-1$
    }
  }
});

  edit.apply(fDocument, TextEdit.UPDATE_REGIONS);
  ISelection empty= processor.makeEmpty(selection, true);
  setSelection(empty);
} else {
  int lines= processor.getCoveredLines(selection);

  int startColumn= fSelection.getOffset() - startLineOffset + cp.fStartColumn;
  int endColumn= selectionEnd - endLineOffset + cp.fEndColumn;
  setSelection(new BlockTextSelection(document, startLine, startColumn, endLine, endColumn, tabs));
} catch (BadLocationException e) {

  int startColumn= fSelection.getOffset() - startLineOffset + cp.fStartColumn;
  int endColumn= selectionEnd - endLineOffset + cp.fEndColumn;
  setSelection(new BlockTextSelection(document, startLine, startColumn, endLine, endColumn, tabs));
} catch (BadLocationException e) {

if (fTextWidget.getBlockSelection())
  setSelection(new BlockTextSelection(doc, 0, 0, doc.getNumberOfLines() - 1, 1000, fTextWidget.getTabs()));
else
  setSelectedRange(0, doc.getLength());

if (fTextWidget.getBlockSelection())
  setSelection(new BlockTextSelection(doc, 0, 0, doc.getNumberOfLines() - 1, 1000, fTextWidget.getTabs()));
else
  setSelectedRange(0, doc.getLength());