VectorGraphicsEncoder.java

/**
 * Copyright 2015-2017 Knowm Inc. (http://knowm.org) and contributors.
 * Copyright 2011-2015 Xeiam LLC (http://xeiam.com) and contributors.
 *
 * Licensed 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.knowm.xchart;

import java.io.FileOutputStream;
import java.io.IOException;

import org.knowm.xchart.internal.chartpart.Chart;

import de.erichseifert.vectorgraphics2d.EPSGraphics2D;
import de.erichseifert.vectorgraphics2d.PDFGraphics2D;
import de.erichseifert.vectorgraphics2d.ProcessingPipeline;
import de.erichseifert.vectorgraphics2d.SVGGraphics2D;

/**
 * A helper class with static methods for saving Charts as vectors
 *
 * @author timmolter
 */
public final class VectorGraphicsEncoder {

  /**
   * Constructor - Private constructor to prevent instantiation
   */
  private VectorGraphicsEncoder() {

  }

  public enum VectorGraphicsFormat {
    EPS, PDF, SVG
  }

  public static void saveVectorGraphic(Chart chart, String fileName, VectorGraphicsFormat vectorGraphicsFormat) throws IOException {

    ProcessingPipeline g = null;

    switch (vectorGraphicsFormat) {
      case EPS:
        g = new EPSGraphics2D(0.0, 0.0, chart.getWidth(), chart.getHeight());
        break;
      case PDF:
        g = new PDFGraphics2D(0.0, 0.0, chart.getWidth(), chart.getHeight());
        break;
      case SVG:
        g = new SVGGraphics2D(0.0, 0.0, chart.getWidth(), chart.getHeight());
        break;

      default:
        break;
    }

    chart.paint(g, chart.getWidth(), chart.getHeight());

    // Write the vector graphic output to a file
    FileOutputStream file = new FileOutputStream(addFileExtension(fileName, vectorGraphicsFormat));

    try {
      file.write(g.getBytes());
    } finally {
      file.close();
    }
  }

  /**
   * Only adds the extension of the VectorGraphicsFormat to the filename if the filename doesn't already have it.
   *
   * @param fileName
   * @param vectorGraphicsFormat
   * @return filename (if extension already exists), otherwise;: filename + "." + extension
   */
  public static String addFileExtension(String fileName, VectorGraphicsFormat vectorGraphicsFormat) {

    String fileNameWithFileExtension = fileName;
    final String newFileExtension = "." + vectorGraphicsFormat.toString().toLowerCase();
    if (fileName.length() <= newFileExtension.length() || !fileName.substring(fileName.length() - newFileExtension.length(), fileName.length()).equalsIgnoreCase(newFileExtension)) {
      fileNameWithFileExtension = fileName + newFileExtension;
    }
    return fileNameWithFileExtension;
  }
}