/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.pdfbox.util.operator.pagedrawer;

import java.awt.geom.GeneralPath;
import java.awt.geom.Point2D;
import java.util.List;

import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSNumber;
import org.apache.pdfbox.pdfviewer.PageDrawer;
import org.apache.pdfbox.util.PDFOperator;
import org.apache.pdfbox.util.operator.OperatorProcessor;

/**
 * Implementation of content stream operator for page drawer.
 *
 * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
 * 
 */
public class AppendRectangleToPath extends OperatorProcessor
{


    /**
     * process : re : append rectangle to path.
     * @param operator The operator that is being executed.
     * @param arguments List
     */
    public void process(PDFOperator operator, List<COSBase> arguments)
    {
        PageDrawer drawer = (PageDrawer)context;

        COSNumber x = (COSNumber)arguments.get( 0 );
        COSNumber y = (COSNumber)arguments.get( 1 );
        COSNumber w = (COSNumber)arguments.get( 2 );
        COSNumber h = (COSNumber)arguments.get( 3 );

        double x1 = x.doubleValue();
        double y1 = y.doubleValue();
        // create a pair of coordinates for the transformation 
        double x2 = w.doubleValue()+x1;
        double y2 = h.doubleValue()+y1;

        Point2D startCoords = drawer.transformedPoint(x1,y1);
        Point2D endCoords = drawer.transformedPoint(x2,y2);

        float width = (float)(endCoords.getX()-startCoords.getX());
        float height = (float)(endCoords.getY()-startCoords.getY());
        float xStart = (float)startCoords.getX();
        float yStart = (float)startCoords.getY();

        // To ensure that the path is created in the right direction,
        // we have to create it by combining single lines instead of
        // creating a simple rectangle
        GeneralPath path = drawer.getLinePath();
        path.moveTo(xStart, yStart);
        path.lineTo(xStart+width, yStart);
        path.lineTo(xStart+width, yStart+height);
        path.lineTo(xStart, yStart+height);
        // close the subpath instead of adding the last line
        // so that a possible set line cap style isn't taken into account
        // at the "beginning" of the rectangle
        path.closePath();
    }
}
