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.swt.widgets.Composite;
  18 import org.eclipse.ui.forms.IManagedForm;
  19 import org.eclipse.ui.forms.widgets.ScrolledForm;
  20
  21 /**
  22  * Checks whether the ScrolledForm a TextViewer is on needs to be
  23  *  redrawn because of a new line break or the removal of an existing
  24  *  one ...
  25  *  <p>
  26  *  ... in theory, anyway. Until I figure out how to detect a word wrap,
  27  *   the ScrolledForm is redrawn with every modify event.
  28  *
  29  * @author p.ciardelli
  30  * @created 19.05.2008
  31  * @version 1.0
  32  */
  33 public class LineWrapSupport {
  34         private static final Logger logger = Logger
  35                         .getLogger(LineWrapSupport.class);
  36
  37         ModifyListener listener = new LineWrapListener();
  38         int lineCount;
  39
  40         private StyledText textWidget;
  41         private ScrolledForm scrolledForm;
  42
  43         private TextViewer viewer;
  44
  45         public LineWrapSupport(TextViewer viewer, IManagedForm form) {
  46
  47                 if (viewer == null) {
  48                         throw new IllegalArgumentException(
  49                                         "The provided TextViewer object is null.");
  50                 }
  51
  52                 this.viewer = viewer;
  53
  54                 textWidget = viewer.getTextWidget();
  55                 textWidget.addModifyListener(listener);
  56
  57                 this.lineCount = textWidget.getLinePixel(textWidget.getLineCount());
  58                 this.scrolledForm = form.getForm();
  59         }
  60
  61         /**
  62          * Redraws the scrolledForm if a line wrap is detected.
  63          */
  64         private void checkLineCount() {
  65
  66                 boolean lineWrapDetected = true;
  67                 if (lineWrapDetected ) {
  68                         scrolledForm.getBody().layout();
  69                 }
  70         }
  71
  72         /**
  73          * Calls <code>checkLineCount()</code> on a modify event.
  74          *
  75          * @author p.ciardelli
  76          * @created 21.05.2008
  77          * @version 1.0
  78          */
  79         class LineWrapListener implements ModifyListener {
  80
  81                 public void modifyText(ModifyEvent e) {
  82                         checkLineCount();
  83                 }
  84         }
  85 }