PrintVisitor.java example

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openflexo-master
/*
 * (c) Copyright 2010-2011 AgileBirds
 *
 * This file is part of OpenFlexo.
 *
 * OpenFlexo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * OpenFlexo is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenFlexo. If not, see <http://www.gnu.org/licenses/>.
 *
 */
package cb.parser;

import java.io.PrintStream;
import java.util.Collection;
import java.util.Iterator;
import java.util.Stack;

import cb.petal.BooleanLiteral;
import cb.petal.DescendingVisitor;
import cb.petal.FloatLiteral;
import cb.petal.IntegerLiteral;
import cb.petal.List;
import cb.petal.Location;
import cb.petal.PetalFile;
import cb.petal.PetalNode;
import cb.petal.PetalObject;
import cb.petal.StringLiteral;
import cb.petal.Tag;
import cb.petal.Tagged;
import cb.petal.Tuple;
import cb.petal.Value;

/**
 * Print petal file exactly like Rose would with some limitations concerning indendattion, i.e., if you don't mind white space, input and
 * output files are identical.
 * 
 * @version $Id: PrintVisitor.java,v 1.3 2011/09/12 11:47:21 gpolet Exp $
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
public class PrintVisitor extends DescendingVisitor {
	private PrintStream out;
	private int level = 0;
	private int column = 0, row = 1;
	private Stack align_stack = new Stack();

	public PrintVisitor(PrintStream out) {
		this.out = out;
	}

	@Override
	public void visit(PetalFile obj) {
		println();
		obj.getPetal().accept(this);
		println();
		println();
		obj.getDesign().accept(this);
		println();
	}

	@Override
	public void visitObject(PetalObject obj) {
		StringBuffer buf = new StringBuffer("(object " + obj.getName());

		for (Iterator i = obj.getParameterList().iterator(); i.hasNext();) {
			buf.append(" \"" + i.next() + "\"");
		}

		if (obj instanceof Tagged) {
			int label = ((Tagged) obj).getTag();

			if (label > 0) {
				buf.append(" @" + label);
			}
		}

		print(buf);

		if (obj.getNames().size() > 0) {
			println();
		}

		level++;
		setAlignment(obj.getLongestName().length());

		for (Iterator i = obj.getNames().iterator(), j = obj.getPropertyList().iterator(); i.hasNext();) {
			indent();
			print(i.next());
			align();

			((PetalNode) j.next()).accept(this);

			if (i.hasNext()) {
				println();
			}
		}

		print(")");

		level--;
		restoreAlignment();
	}

	/* Property names are aligned to a 4 column boundary
	 * Property values are aligned to a 8 column boundary
	 * 8 spaces are replaced by one tab.
	 */

	private int align_at = -1;

	private void setAlignment(int max) {
		align_stack.push(new Integer(align_at));

		int indent = level * 4;
		int min_dist; // min distance between first char of name and first char of property

		if (indent % 8 == 0) {
			min_dist = 16;
		} else {
			// name aligned on 4
			min_dist = 12;
		}

		align_at = indent + min_dist;
	}

	private void restoreAlignment() {
		Integer i = (Integer) align_stack.pop();
		align_at = i.intValue();
	}

	/**
	 * Insert spaces up to next 8 column boundary
	 */
	private void align() {
		int fill;

		if (column < align_at) {
			fill = align_at - column;
			// System.err.println("< : " + align_at + ":" + column + ":" + fill);
		} else {
			fill = 8 - column % 8;
			// System.err.println(">= : " + align_at + ":" + column + ":" + fill);
		}

		int spaces = 4 - fill % 4;
		for (int i = 0; i < spaces; i++) {
			out.print(' ');
		}

		column += spaces;
		fill -= spaces;

		if (fill > 0) {
			int tabs = fill / 8;

			if (fill % 8 > 0) {
				tabs++;
			}

			for (int i = 0; i < tabs; i++) {
				out.print('\t');
			}
		}

		// for(int i=0; i < fill; i++)
		// out.print(' ');

		column += fill;
	}

	/**
	 * Initial indentation of line depend on current nesting level to 4 column boundary.
	 */
	private void indent() {
		int tabs = level / 2; // 4 spaces (INDENT) == 1 tab
		int spaces = level % 2;

		for (int i = 0; i < tabs; i++) {
			out.print('\t');
		}

		for (int i = 0; i < spaces; i++) {
			out.print("    ");
		}

		column += level * 4;
	}

	private void println() {
		out.print("\r\n");
		row++;
		column = 0;
	}

	private void print(java.lang.Object o) {
		String s = o.toString();
		column += s.length();

		out.print(s);
	}

	@Override
	public void visit(StringLiteral obj) {
		if (obj.isMultiLine()) {
			println();

			Collection c = obj.getLines();

			for (Iterator i = c.iterator(); i.hasNext();) {
				print("|" + i.next());
				println();
			}

			indent();
		} else {
			print(obj);
		}
	}

	@Override
	public void visit(BooleanLiteral obj) {
		print(obj);
	}

	@Override
	public void visit(FloatLiteral obj) {
		print(obj);
	}

	@Override
	public void visit(IntegerLiteral obj) {
		print(obj);
	}

	@Override
	public void visit(Tag ref) {
		print(ref);
	}

	@Override
	public void visit(Location loc) {
		print(loc);
	}

	@Override
	public void visit(List list) {
		print("(list ");

		if (list.getName() != null) {
			print(list.getName());
		}

		java.util.List c = list.getElements();

		if (c.size() > 0) {
			level++;

			for (Iterator i = c.iterator(); i.hasNext();) {
				println();
				indent();
				((PetalNode) i.next()).accept(this);
			}

			level--;
		}

		print(")");
	}

	@Override
	public void visit(Value value) {
		print("(value " + value.getValueName());

		StringLiteral val = value.getValue();

		if (val.isMultiLine()) {
			val.accept(this);

			print(")");
		} else {
			print(" " + val + ")");
		}
	}

	@Override
	public void visit(Tuple tuple) {
		print(tuple);
	}

	public static void main(String[] args) {
		PetalFile tree = PetalParser.parse(args);
		tree.accept(new PrintVisitor(System.out));
	}
}