public void addLineStyleListener( LineStyleListener lineStyler ) {
  styledText.addLineStyleListener( lineStyler );
}
 

private void buildPreview(Composite container) {
	GridData gridData = new GridData();
	gridData.horizontalAlignment = SWT.RIGHT;
	gridData.verticalAlignment = SWT.TOP;
	gridData.grabExcessVerticalSpace = true;
	gridData.horizontalSpan = 1;
	gridData.verticalSpan = 5;

	Composite composite = new Composite(container, SWT.NONE);
	composite.setLayout(new GridLayout(1, false));
	composite.setLayoutData(gridData);

	// create overview
	Table table = new Table(composite, SWT.BORDER);
	table.setLayoutData(new GridData(SWT.RIGHT, SWT.FILL, true, true, 1, 1));

	TableColumn intersection = new TableColumn(table, SWT.CENTER);
	TableColumn mergeConflicts = new TableColumn(table, SWT.CENTER);
	TableColumn unionWithoutConflicts = new TableColumn(table, SWT.CENTER);
	intersection.setText("Intersection");
	mergeConflicts.setText("Merge conflicts");
	unionWithoutConflicts.setText("Union without conflicts");
	intersection.setWidth(80);
	mergeConflicts.setWidth(100);
	unionWithoutConflicts.setWidth(140);
	table.setHeaderVisible(true);

	previewStats = new TableItem(table, SWT.NONE);

	Label label = new Label(composite, SWT.NONE);
	label.setLayoutData(new GridData(SWT.RIGHT, SWT.FILL, true, true, 1, 1));
	label.setText("Preview: ");

	preview = new StyledText(composite, SWT.MULTI | SWT.WRAP | SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
	preview.setLayoutData(new GridData(GridData.FILL_BOTH));
	preview.setEditable(false);
	preview.setEnabled(false);
	preview.setBlockSelection(true);

	// highlight current conflict
	initializeConflictIterator();
	preview.addLineStyleListener(new LineStyleListener() {
		public void lineGetStyle(LineStyleEvent event) {
			if (currentConflictedField == null
					|| currentConflictedResource.getConflictForField(currentConflictedField) == null)
				return;

			String currentConflict = currentConflictedResource.getConflictForField(currentConflictedField);
			StyleRange styleRange = new StyleRange();
			styleRange.start = preview.getText().indexOf(currentConflict);
			styleRange.length = currentConflict.length();
			styleRange.background = getParentShell().getDisplay().getSystemColor(SWT.COLOR_YELLOW);
			event.styles = new StyleRange[] { styleRange };
		}
	});

	GridData textGrid = new GridData(500, 500);
	textGrid.horizontalSpan = 2;
	preview.setLayoutData(textGrid);

	updatePreview();
}
 

public void addLineStyleListener( LineStyleListener lineStyler ) {
  styledText.addLineStyleListener( lineStyler );
}