TextLinesBuilder.java

package folioxml.text;

import folioxml.core.InvalidMarkupException;
import folioxml.core.TokenUtils;
import folioxml.xml.Node;
import folioxml.xml.NodeList;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Created by nathanael on 6/18/15.
 */
public class TextLinesBuilder {

    private Pattern tabsAtTheSides = Pattern.compile("(\\A\\s*?\\t+|\\t+\\s*\\Z)");

    private Pattern tabsInTheMiddle = Pattern.compile("\\A\\s*[^\\t\\r\\n]+\\t+\\s*[^\\t \\r\\n]");

    private Pattern listAlignment = Pattern.compile("\\A\\s*?(•|[A-Z]|[ivx]{1,5}[\\.\\)]|[0-9]{1,2}[\\.\\)]?)\\t+[^\\t\\n]*\\Z");


    public TextLinesBuilder() {
    }


    public List<StringBuilder> generateLines(NodeList nl) {
        List<StringBuilder> lines = new ArrayList<StringBuilder>();
        for (Node n : nl.list()) {
            line_new(lines);
            add_lines(n, lines);
        }
        return lines;
    }

    public TabUsage analyzeTabUsage(List<StringBuilder> lines) throws InvalidMarkupException {
        TabUsage result = TabUsage.None;
        for (StringBuilder l : lines) {

            Matcher m = listAlignment.matcher(l);
            if (m.find()) return TabUsage.ListAlignment; //Numbered list indentation;

            m = tabsInTheMiddle.matcher(l);
            if (m.find()) return TabUsage.Tabulation; //Tabulation is a quick exit, no escalation from there

            m = tabsAtTheSides.matcher(l);
            if (m.find()) {
                result = TabUsage.Indentation; //Escalate to indentation.
            } else if (l.indexOf("\t") > -1) {
                throw new InvalidMarkupException("Tab analysis missed a code path for line '" + l.toString() + "'");

            }
        }
        return result;
    }

    public TabUsage analyzeTabUsage(NodeList nl) throws InvalidMarkupException {
        List<StringBuilder> lines = generateLines(nl);
        return analyzeTabUsage(lines);
    }

    public enum TabUsage {
        Indentation,
        ListAlignment,
        Tabulation,
        None
    }


    private void add_lines(Node n, List<StringBuilder> lines) {
        if (n.matches("p|br|table|td|th|note|div|record")) line_new(lines);

        if (n.isTag() && n.children != null) {
            for (Node c : n.children.list()) {
                add_lines(c, lines);
            }
        } else if (n.isTextOrEntity()) {
            String s = n.markup;
            if (n.isEntity()) s = TokenUtils.entityDecodeString(s);
            last_line(lines).append(s);
        }

        if (n.matches("p|br|table|td|th|note|div|record")) line_new(lines);

    }

    private StringBuilder last_line(List<StringBuilder> lines) {
        if (lines.size() == 0) {
            lines.add(new StringBuilder());
        }
        return lines.get(lines.size() - 1);
    }

    private void line_new(List<StringBuilder> lines) {
        if (lines.size() == 0 || lines.get(lines.size() - 1).length() > 0) {
            lines.add(new StringBuilder());
        }
    }
}