Image.java

/**
 * Copyright (C) 2013 Christian Kohlschütter (ckkohl79@gmail.com)
 *
 * 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 de.l3s.boilerpipe.document;

/**
 * Represents an Image resource that is contained in the document.
 * 
 * Any of the attributes may be null, except for "src".
 *  
 * @author Christian Kohlschuetter
 */
public class Image extends Media implements Comparable<Image> {
	private final String src;
	private final String width;
	private final String height;
	private final String alt;
	private final int area;

	public Image(final String src, final String width, final String height, final String alt) {
		this.src = src;
		if(src == null) {
			throw new NullPointerException("src attribute must not be null");
		}
		this.width = nullTrim(width);
		this.height = nullTrim(height);
		this.alt = nullTrim(alt);
		
		if(width != null && height != null) {
			int a;
			try {
				a = Integer.parseInt(width) * Integer.parseInt(height);
			} catch(NumberFormatException e) {
				a = -1;
			}
			this.area = a;
		} else {
			this.area = -1;
		}
	}
	
	/**
	 * gets the src attribut from the image tag in the html source. 
	 * it's not everytime an absolute path!
	 * 
	 * @return gets the src attribut from the image 
	 */
	public String getSrc() {
		return src;
	}

	public String getWidth() {
		return width;
	}

	public String getHeight() {
		return height;
	}

	public String getAlt() {
		return alt;
	}
	
	private static String nullTrim(String s) {
		if(s == null) {
			return null;
		}
		s = s.trim();
		if(s.length() == 0) {
			return null;
		}
		return s;
	}
	
	/**
	 * Returns the image's area (specified by width * height), or -1 if width/height weren't both specified or could not be parsed.
	 * 
	 * @return the image's area
	 */
	public int getArea() {
		return area;
	}
	
	public String toString() {
		return src+"\twidth="+width+"\theight="+height+"\talt="+alt+"\tarea="+area;
	}

	public int compareTo(Image o) {
		if(o == this) {
			return 0;
		}
		if(area > o.area) {
			return -1;
		} else if(area == o.area) {
			return src.compareTo(o.src);
		} else {
			return 1;
		}
	}
}