taxeditor-editor/src/main/java/eu/etaxonomy/taxeditor/editor/LineWrapSupport.java

   1 /**
   2 * Copyright (C) 2007 EDIT
   3 * European Distributed Institute of Taxonomy
   4 * http://www.e-taxonomy.eu
   5 *
   6 * The contents of this file are subject to the Mozilla Public License Version 1.1
   7 * See LICENSE.TXT at the top of this package for the full license terms.
   8 */
   9
  10 package eu.etaxonomy.taxeditor.editor;
  11
  12 import org.apache.log4j.Logger;
  13 import org.eclipse.jface.text.TextViewer;
  14 import org.eclipse.swt.custom.StyledText;
  15 import org.eclipse.swt.events.ModifyEvent;
  16 import org.eclipse.swt.events.ModifyListener;
  17 import org.eclipse.ui.forms.IManagedForm;
  18 import org.eclipse.ui.forms.widgets.ScrolledForm;
  19
  20 /**
  21  * Checks whether the ScrolledForm a TextViewer is on needs to be
  22  *  redrawn because of a new line break or the removal of an existing
  23  *  one ...
  24  *  <p>
  25  *  ... in theory, anyway. Until I figure out how to detect a word wrap,
  26  *   the ScrolledForm is redrawn with every modify event.
  27  *
  28  * @author p.ciardelli
  29  * @created 19.05.2008
  30  * @version 1.0
  31  */
  32 public class LineWrapSupport {
  33         private static final Logger logger = Logger
  34                         .getLogger(LineWrapSupport.class);
  35
  36         ModifyListener listener = new LineWrapListener();
  37         int lineCount;
  38
  39         private StyledText textWidget;
  40         private ScrolledForm scrolledForm;
  41
  42 //      private TextViewer viewer;
  43
  44         /**
  45          * @return the viewer
  46          */
  47 //      public TextViewer getViewer() {
  48 //              return viewer;
  49 //      }
  50
  51         public LineWrapSupport(TextViewer viewer, IManagedForm form) {
  52
  53                 if (viewer == null) {
  54                         throw new IllegalArgumentException(
  55                                         "The provided TextViewer object is null.");
  56                 }
  57
  58 //              this.viewer = viewer;
  59
  60                 textWidget = viewer.getTextWidget();
  61                 textWidget.addModifyListener(listener);
  62
  63                 this.lineCount = textWidget.getLinePixel(textWidget.getLineCount());
  64                 this.scrolledForm = form.getForm();
  65
  66                 logger.trace(this.getClass().getSimpleName() + " created");
  67         }
  68
  69         /**
  70          * Redraws the scrolledForm if a line wrap is detected.
  71          */
  72         private void checkLineCount() {
  73
  74                 boolean lineWrapDetected = true;
  75                 if (lineWrapDetected ) {
  76                         scrolledForm.getBody().layout();
  77                 }
  78         }
  79
  80         /**
  81          * Calls <code>checkLineCount()</code> on a modify event.
  82          *
  83          * @author p.ciardelli
  84          * @created 21.05.2008
  85          * @version 1.0
  86          */
  87         class LineWrapListener implements ModifyListener {
  88
  89                 public void modifyText(ModifyEvent e) {
  90                         checkLineCount();
  91                 }
  92         }
  93 }