pdfbox-trunk/pdfbox/src/main/java/org/apache/pdfbox/pdmodel/graphics/pattern/PDAbstractPattern.java
/*
 * 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.pdmodel.graphics.pattern;

import java.awt.geom.AffineTransform;
import java.io.IOException;

import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSFloat;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.pdmodel.ResourceCache;
import org.apache.pdfbox.pdmodel.common.COSObjectable;
import org.apache.pdfbox.util.Matrix;

/**
 * This class wraps a pattern dictionary. Patterns can be found in resource dictionaries.
 */
public abstract class PDAbstractPattern implements COSObjectable
{
    /** Tiling pattern type. */
    public static final int TYPE_TILING_PATTERN = 1;

    /** Shading pattern type. */
    public static final int TYPE_SHADING_PATTERN = 2;

    /**
     * Create the correct PD Model pattern based on the COS base pattern.
     * @param dictionary the COS pattern dictionary
     * @param resourceCache the resource cache, may be null, useful for tiling patterns.
     * @return the newly created pattern object
     * @throws IOException If we are unable to create the PDPattern object.
     */
    public static PDAbstractPattern create(COSDictionary dictionary, ResourceCache resourceCache) throws IOException
    {
        PDAbstractPattern pattern;
        int patternType = dictionary.getInt(COSName.PATTERN_TYPE, 0);
        switch (patternType)
        {
            case TYPE_TILING_PATTERN:
                pattern = new PDTilingPattern(dictionary, resourceCache);
                break;
            case TYPE_SHADING_PATTERN:
                pattern = new PDShadingPattern(dictionary);
                break;
            default:
                throw new IOException("Error: Unknown pattern type " + patternType);
        }
        return pattern;
    }

    private final COSDictionary patternDictionary;

    /**
     * Creates a new Pattern dictionary.
     */
    public PDAbstractPattern()
    {
        patternDictionary = new COSDictionary();
        patternDictionary.setName(COSName.TYPE, COSName.PATTERN.getName());
    }

    /**
     * Creates a new Pattern dictionary from the given COS dictionary.
     * @param dictionary The COSDictionary for this pattern.
     */
    public PDAbstractPattern(COSDictionary dictionary)
    {
        patternDictionary = dictionary;
    }

    /**
     * This will get the underlying dictionary.
     * @return The dictionary for this pattern.
     */
    @Override
    public COSDictionary getCOSObject()
    {
        return patternDictionary;
    }

    /**
     * This will set the paint type.
     * @param paintType The new paint type.
     */
    public void setPaintType(int paintType)
    {
        patternDictionary.setInt(COSName.PAINT_TYPE, paintType);
    }

    /**
     * This will return the paint type.
     * @return The type of object that this is.
     */
    public String getType()
    {
        return COSName.PATTERN.getName();
    }

    /**
     * This will set the pattern type.
     * @param patternType The new pattern type.
     */
    public void setPatternType(int patternType)
    {
        patternDictionary.setInt(COSName.PATTERN_TYPE, patternType);
    }

    /**
     * This will return the pattern type.
     * @return The pattern type
     */
    public abstract int getPatternType();

    /**
     * Returns the pattern matrix, or the identity matrix is none is available.
     * 
     * @return the pattern matrix
     */
    public Matrix getMatrix()
    {
        return Matrix.createMatrix(getCOSObject().getDictionaryObject(COSName.MATRIX));
    }

    /**
     * Sets the optional Matrix entry for the Pattern.
     * @param transform the transformation matrix
     */
    public void setMatrix(AffineTransform transform)
    {
        COSArray matrix = new COSArray();
        double[] values = new double[6];
        transform.getMatrix(values);
        for (double v : values)
        {
            matrix.add(new COSFloat((float)v));
        }
        getCOSObject().setItem(COSName.MATRIX, matrix);
    }

}
