Widow and Orphan content support added

package com.itext.OrphanWidow;

import com.itextpdf.kernel.colors.Color;
import com.itextpdf.kernel.colors.ColorConstants;
import com.itextpdf.kernel.geom.PageSize;
import com.itextpdf.kernel.geom.Rectangle;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.ColumnDocumentRenderer;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.property.ParagraphOrphansControl;
import com.itextpdf.layout.property.ParagraphWidowsControl;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * This example demonstrates how to enable orphans and widows processing in
 * layout
 */
public class OrphanWidowExample {

	public static final String DEST = "src/main/resources/orphanwidow/output.pdf";

	public static void main(String args[]) throws IOException {
		File file = new File(DEST);
		file.getParentFile().mkdirs();

		new OrphanWidowExample().manipulatePdf(DEST);
	}

	public void manipulatePdf(String dest) throws FileNotFoundException {
		PdfDocument pdfDoc = new PdfDocument(new PdfWriter(dest));
		Document doc = new Document(pdfDoc);

        // The document is laid out in columns here in order to improve the
        // visualization of how orphans and widows work.
        // Columns' heights and widths are defined so that several orphans and widows
        // cases occur.
		Rectangle[] columns = generateColumns();
		doc.setRenderer(new ColumnDocumentRenderer(doc, true, columns));

       // Paragraphs alternate background colors to ease the visual distinction between different paragraphs.
		Color[] colors = new Color[] { ColorConstants.LIGHT_GRAY, ColorConstants.GRAY };

		List<String> content = createParagraphContents();
		for (int i = 0; i < content.size(); i++) {
			Paragraph para = new Paragraph(content.get(i)).setBackgroundColor(colors[i % 2]);

       // Set orphan control property on a paragraph
       // that at least 2 lines must remain on the area before the break,
       // when paragraph has to be split because of an area break, otherwise the entire paragraph should be pushed to the next area.
			int minOrphansNum = 2;
			para.setOrphansControl(new ParagraphOrphansControl(minOrphansNum));

       // Set widow control property on a paragraph. If custom handling of widow violation is needed, create a ParagraphWidowsControl extension
       // and override #handleViolatedWidows(ParagraphRenderer, String) accordingly.
			int minWidowsNum = 2;
			int maxLinesToMove = 1;
			boolean overflowParagraphOnViolation = true;
			para.setWidowsControl(
					new ParagraphWidowsControl(minWidowsNum, maxLinesToMove, overflowParagraphOnViolation));

			doc.add(para);
		}

		doc.close();
	}

	private static Rectangle[] generateColumns() {
		float margin = 40;
		float height = PageSize.A4.getHeight() * 0.43f;
		float width = (PageSize.A4.getWidth() - (2 * margin) - (margin / 2)) / 2;
		float bottom = (PageSize.A4.getHeight() - height) / 2;
		Rectangle rectLeft = new Rectangle(margin, bottom, width, height);
		Rectangle rectRight = new Rectangle(margin + width + (margin / 2), bottom, width, height);
		return new Rectangle[] { rectLeft, rectRight };
	}

	private static List<String> createParagraphContents() {

     // Substrings of different lengths of the following string are used in order to
     // create several orphans and widows cases.
		String content = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. "
				+ "Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. "
				+ "Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis "
				+ "enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut,"
				+ " imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt."
				+ " Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, "
				+ "porttitor eu, consequat vitae, eleifend ac, enim. Aliquam lorem ante, dapibus in, viverra quis, "
				+ "feugiat a, tellus. Phasellus viverra nulla ut metus varius laoreet. Quisque rutrum. Aenean "
				+ "imperdiet. Etiam ultricies nisi vel augue. Curabitur ullamcorper ultricies nisi. Nam eget dui. Etiam"
				+ " rhoncus. Maecenas tempus, tellus eget condimentum rhoncus, sem quam semper libero, sit amet "
				+ "adipiscing sem neque sed ipsum. Nam quam nunc, blandit vel, luctus pulvinar, hendrerit id, lorem. "
				+ "Maecenas nec odio et ante tincidunt tempus. Donec vitae sapien ut libero venenatis faucibus. "
				+ "Nullam quis ante. Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed fringilla mauris "
				+ "sit amet nibh. Donec sodales sagittis magna. Donec sodales sagittis magna. Donec sodales sagittis "
				+ "magna. Donec sodales sagittis magna. Donec sodales sagittis magna.";
		int[] substringLengths = new int[] { 361, 339, 1421, 208, 1245, 1251, 1122, 1270, 1276, 1230, 1420, 1180, 1190,
				807 };

		List<String> items = new ArrayList<String>(substringLengths.length);
		for (int i = 0; i < substringLengths.length; i++) {
			items.add(content.substring(0, substringLengths[i]));
		}

		return items;
	}
}