Add cropped thumbnail

Author: glibas

src/main/java/com/assertthat/selenium_shutterbug/core/Snapshot.java

@@ -77,7 +77,37 @@ public T withThumbnail(String path, String name, double scale) {
         FileUtil.writeImage(thumbnailImage, EXTENSION, thumbnailFile);
         return self();
     }
-
+    
+    /**
+     * Generate cropped thumbnail of the original screenshot.
+     * Will save different thumbnails depends on when it was called in the chain.
+     *
+     * @param path to save thumbnail image to
+     * @param name of the resulting image
+     * @param scale to apply
+     * @return instance of type Snapshot
+     */
+    public T withCroppedThumbnail(String path, String name, double scale,  double cropWidth, double cropHeight) {
+        File thumbnailFile = new File(path.toString(), name);
+        if(!Files.exists(Paths.get(path))) {
+            thumbnailFile.mkdirs();
+        }
+        thumbnailImage=ImageProcessor.cropAndScale(image,scale, cropWidth, cropHeight);
+        FileUtil.writeImage(thumbnailImage, EXTENSION, thumbnailFile);
+        return self();
+    }
+    
+    /**
+     * Generate cropped thumbnail of the original screenshot.
+     * Will save different thumbnails depends on when it was called in the chain.
+     *
+     * @param scale to apply
+     * @return instance of type Snapshot
+     */
+    public T withCroppedThumbnail(double scale, double cropWidth, double cropHeight) {
+        return withCroppedThumbnail(Paths.get(location.toString(), "./thumbnails").toString(), "thumb_" + fileName, scale,cropWidth,cropHeight);
+    }
+    
     /**
      * Generate a thumbnail of the original screenshot.
      * Will save different thumbnails depends on when it was called in the chain.

src/main/java/com/assertthat/selenium_shutterbug/utils/image/ImageProcessor.java

@@ -191,15 +191,19 @@ public static boolean imagesAreEqualsWithDiff(BufferedImage image1, BufferedImag
     }
 
     public static BufferedImage scale(BufferedImage source, double ratio) {
-        int w = (int) (source.getWidth() * ratio);
-        int h = (int) (source.getHeight() * ratio);
+        return cropAndScale(source, ratio, 1.0,1.0);
+    }
+    
+    public static BufferedImage cropAndScale(BufferedImage source,double ratio, double cropWidth, double cropHeight) {
+        int w = source.getWidth();
+        int h = source.getHeight();
         BufferedImage scaledImage = getCompatibleImage(w, h, source);
         Graphics2D resultGraphics = scaledImage.createGraphics();
         resultGraphics.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                 RenderingHints.VALUE_INTERPOLATION_BICUBIC);
         resultGraphics.drawImage(source, 0, 0, w, h, null);
         resultGraphics.dispose();
-        return scaledImage;
+        return scaledImage.getSubimage(0, 0, (int)(w*cropWidth),(int)(h*cropHeight));
     }
 
     private static BufferedImage getCompatibleImage(int w, int h, BufferedImage source) {