lots of methods to try to get a drop shadow

1 files changed, 555 insertions, 0 deletions

diff --git a/dropShadow/GraphicsUtilities.java b/dropShadow/GraphicsUtilities.java
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+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package dropShadow;
+
+import java.awt.image.BufferedImage;
+import java.awt.image.ColorModel;
+import java.awt.image.Raster;
+import java.awt.image.WritableRaster;
+import java.awt.GraphicsConfiguration;
+import java.awt.Transparency;
+import java.awt.Graphics;
+import java.awt.GraphicsEnvironment;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.io.IOException;
+import java.net.URL;
+import javax.imageio.ImageIO;
+
+/**
+ * <p>
+ * <code>GraphicsUtilities</code> contains a set of tools to perform common
+ * graphics operations easily. These operations are divided into several themes,
+ * listed below.</p>
+ * <h2>Compatible Images</h2>
+ * <p>
+ * Compatible images can, and should, be used to increase drawing performance.
+ * This class provides a number of methods to load compatible images directly
+ * from files or to convert existing images to compatibles images.</p>
+ * <h2>Creating Thumbnails</h2>
+ * <p>
+ * This class provides a number of methods to easily scale down images. Some of
+ * these methods offer a trade-off between speed and result quality and shouuld
+ * be used all the time. They also offer the advantage of producing compatible
+ * images, thus automatically resulting into better runtime performance.</p>
+ * <p>
+ * All these methodes are both faster than
+ * {@link java.awt.Image#getScaledInstance(int, int, int)} and produce
+ * better-looking results than the various <code>drawImage()</code> methods in
+ * {@link java.awt.Graphics}, which can be used for image scaling.</p>
+ * <h2>Image Manipulation</h2>
+ * <p>
+ * This class provides two methods to get and set pixels in a buffered image.
+ * These methods try to avoid unmanaging the image in order to keep good
+ * performance.</p>
+ *
+ * @author Romain Guy <romain.guy@mac.com>
+ */
+public class GraphicsUtilities {
+
+    private GraphicsUtilities() {
+    }
+
+    // Returns the graphics configuration for the primary screen
+    private static GraphicsConfiguration getGraphicsConfiguration() {
+        return GraphicsEnvironment.getLocalGraphicsEnvironment().
+                getDefaultScreenDevice().getDefaultConfiguration();
+    }
+
+    /**
+     * <p>
+     * Returns a new <code>BufferedImage</code> using the same color model as
+     * the image passed as a parameter. The returned image is only compatible
+     * with the image passed as a parameter. This does not mean the returned
+     * image is compatible with the hardware.</p>
+     *
+     * @param image the reference image from which the color model of the new
+     * image is obtained
+     * @return a new <code>BufferedImage</code>, compatible with the color model
+     * of <code>image</code>
+     */
+    public static BufferedImage createColorModelCompatibleImage(BufferedImage image) {
+        ColorModel cm = image.getColorModel();
+        return new BufferedImage(cm,
+                cm.createCompatibleWritableRaster(image.getWidth(),
+                        image.getHeight()),
+                cm.isAlphaPremultiplied(), null);
+    }
+
+    /**
+     * <p>
+     * Returns a new compatible image with the same width, height and
+     * transparency as the image specified as a parameter.</p>
+     *
+     * @see java.awt.Transparency
+     * @see #createCompatibleImage(int, int)
+     * @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
+     * @see #createCompatibleTranslucentImage(int, int)
+     * @see #loadCompatibleImage(java.net.URL)
+     * @see #toCompatibleImage(java.awt.image.BufferedImage)
+     * @param image the reference image from which the dimension and the
+     * transparency of the new image are obtained
+     * @return a new compatible <code>BufferedImage</code> with the same
+     * dimension and transparency as <code>image</code>
+     */
+    public static BufferedImage createCompatibleImage(BufferedImage image) {
+        return createCompatibleImage(image, image.getWidth(), image.getHeight());
+    }
+
+    /**
+     * <p>
+     * Returns a new compatible image of the specified width and height, and the
+     * same transparency setting as the image specified as a parameter.</p>
+     *
+     * @see java.awt.Transparency
+     * @see #createCompatibleImage(java.awt.image.BufferedImage)
+     * @see #createCompatibleImage(int, int)
+     * @see #createCompatibleTranslucentImage(int, int)
+     * @see #loadCompatibleImage(java.net.URL)
+     * @see #toCompatibleImage(java.awt.image.BufferedImage)
+     * @param width the width of the new image
+     * @param height the height of the new image
+     * @param image the reference image from which the transparency of the new
+     * image is obtained
+     * @return a new compatible <code>BufferedImage</code> with the same
+     * transparency as <code>image</code> and the specified dimension
+     */
+    public static BufferedImage createCompatibleImage(BufferedImage image,
+            int width, int height) {
+        return getGraphicsConfiguration().createCompatibleImage(width, height,
+                image.getTransparency());
+    }
+
+    /**
+     * <p>
+     * Returns a new opaque compatible image of the specified width and
+     * height.</p>
+     *
+     * @see #createCompatibleImage(java.awt.image.BufferedImage)
+     * @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
+     * @see #createCompatibleTranslucentImage(int, int)
+     * @see #loadCompatibleImage(java.net.URL)
+     * @see #toCompatibleImage(java.awt.image.BufferedImage)
+     * @param width the width of the new image
+     * @param height the height of the new image
+     * @return a new opaque compatible <code>BufferedImage</code> of the
+     * specified width and height
+     */
+    public static BufferedImage createCompatibleImage(int width, int height) {
+        return getGraphicsConfiguration().createCompatibleImage(width, height);
+    }
+
+    /**
+     * <p>
+     * Returns a new translucent compatible image of the specified width and
+     * height.</p>
+     *
+     * @see #createCompatibleImage(java.awt.image.BufferedImage)
+     * @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
+     * @see #createCompatibleImage(int, int)
+     * @see #loadCompatibleImage(java.net.URL)
+     * @see #toCompatibleImage(java.awt.image.BufferedImage)
+     * @param width the width of the new image
+     * @param height the height of the new image
+     * @return a new translucent compatible <code>BufferedImage</code> of the
+     * specified width and height
+     */
+    public static BufferedImage createCompatibleTranslucentImage(int width,
+            int height) {
+        return getGraphicsConfiguration().createCompatibleImage(width, height,
+                Transparency.TRANSLUCENT);
+    }
+
+    /**
+     * <p>
+     * Returns a new compatible image from a URL. The image is loaded from the
+     * specified location and then turned, if necessary into a compatible
+     * image.</p>
+     *
+     * @see #createCompatibleImage(java.awt.image.BufferedImage)
+     * @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
+     * @see #createCompatibleImage(int, int)
+     * @see #createCompatibleTranslucentImage(int, int)
+     * @see #toCompatibleImage(java.awt.image.BufferedImage)
+     * @param resource the URL of the picture to load as a compatible image
+     * @return a new translucent compatible <code>BufferedImage</code> of the
+     * specified width and height
+     * @throws java.io.IOException if the image cannot be read or loaded
+     */
+    public static BufferedImage loadCompatibleImage(URL resource)
+            throws IOException {
+        BufferedImage image = ImageIO.read(resource);
+        return toCompatibleImage(image);
+    }
+
+    /**
+     * <p>
+     * Return a new compatible image that contains a copy of the specified
+     * image. This method ensures an image is compatible with the hardware, and
+     * therefore optimized for fast blitting operations.</p>
+     *
+     * @see #createCompatibleImage(java.awt.image.BufferedImage)
+     * @see #createCompatibleImage(java.awt.image.BufferedImage, int, int)
+     * @see #createCompatibleImage(int, int)
+     * @see #createCompatibleTranslucentImage(int, int)
+     * @see #loadCompatibleImage(java.net.URL)
+     * @param image the image to copy into a new compatible image
+     * @return a new compatible copy, with the same width and height and
+     * transparency and content, of <code>image</code>
+     */
+    public static BufferedImage toCompatibleImage(BufferedImage image) {
+        if (image.getColorModel().equals(
+                getGraphicsConfiguration().getColorModel())) {
+            return image;
+        }
+
+        BufferedImage compatibleImage
+                = getGraphicsConfiguration().createCompatibleImage(
+                        image.getWidth(), image.getHeight(),
+                        image.getTransparency());
+        Graphics g = compatibleImage.getGraphics();
+        g.drawImage(image, 0, 0, null);
+        g.dispose();
+
+        return compatibleImage;
+    }
+
+    /**
+     * <p>
+     * Returns a thumbnail of a source image. <code>newSize</code> defines the
+     * length of the longest dimension of the thumbnail. The other dimension is
+     * then computed according to the dimensions ratio of the original
+     * picture.</p>
+     * <p>
+     * This method favors speed over quality. When the new size is less than
+     * half the longest dimension of the source image,
+     * {@link #createThumbnail(BufferedImage, int)} or
+     * {@link #createThumbnail(BufferedImage, int, int)} should be used instead
+     * to ensure the quality of the result without sacrificing too much
+     * performance.</p>
+     *
+     * @see #createThumbnailFast(java.awt.image.BufferedImage, int, int)
+     * @see #createThumbnail(java.awt.image.BufferedImage, int)
+     * @see #createThumbnail(java.awt.image.BufferedImage, int, int)
+     * @param image the source image
+     * @param newSize the length of the largest dimension of the thumbnail
+     * @return a new compatible <code>BufferedImage</code> containing a
+     * thumbnail of <code>image</code>
+     * @throws IllegalArgumentException if <code>newSize</code> is larger than
+     * the largest dimension of <code>image</code> or &lt;= 0
+     */
+    public static BufferedImage createThumbnailFast(BufferedImage image,
+            int newSize) {
+        float ratio;
+        int width = image.getWidth();
+        int height = image.getHeight();
+
+        if (width > height) {
+            if (newSize >= width) {
+                throw new IllegalArgumentException("newSize must be lower than"
+                        + " the image width");
+            } else if (newSize <= 0) {
+                throw new IllegalArgumentException("newSize must"
+                        + " be greater than 0");
+            }
+
+            ratio = (float) width / (float) height;
+            width = newSize;
+            height = (int) (newSize / ratio);
+        } else {
+            if (newSize >= height) {
+                throw new IllegalArgumentException("newSize must be lower than"
+                        + " the image height");
+            } else if (newSize <= 0) {
+                throw new IllegalArgumentException("newSize must"
+                        + " be greater than 0");
+            }
+
+            ratio = (float) height / (float) width;
+            height = newSize;
+            width = (int) (newSize / ratio);
+        }
+
+        BufferedImage temp = createCompatibleImage(image, width, height);
+        Graphics2D g2 = temp.createGraphics();
+        g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+                RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+        g2.drawImage(image, 0, 0, temp.getWidth(), temp.getHeight(), null);
+        g2.dispose();
+
+        return temp;
+    }
+
+    /**
+     * <p>
+     * Returns a thumbnail of a source image.</p>
+     * <p>
+     * This method favors speed over quality. When the new size is less than
+     * half the longest dimension of the source image,
+     * {@link #createThumbnail(BufferedImage, int)} or
+     * {@link #createThumbnail(BufferedImage, int, int)} should be used instead
+     * to ensure the quality of the result without sacrificing too much
+     * performance.</p>
+     *
+     * @see #createThumbnailFast(java.awt.image.BufferedImage, int)
+     * @see #createThumbnail(java.awt.image.BufferedImage, int)
+     * @see #createThumbnail(java.awt.image.BufferedImage, int, int)
+     * @param image the source image
+     * @param newWidth the width of the thumbnail
+     * @param newHeight the height of the thumbnail
+     * @return a new compatible <code>BufferedImage</code> containing a
+     * thumbnail of <code>image</code>
+     * @throws IllegalArgumentException if <code>newWidth</code> is larger than
+     * the width of <code>image</code> or if code>newHeight</code> is larger
+     * than the height of <code>image</code> or if one of the dimensions is
+     * &lt;= 0
+     */
+    public static BufferedImage createThumbnailFast(BufferedImage image,
+            int newWidth, int newHeight) {
+        if (newWidth >= image.getWidth()
+                || newHeight >= image.getHeight()) {
+            throw new IllegalArgumentException("newWidth and newHeight cannot"
+                    + " be greater than the image"
+                    + " dimensions");
+        } else if (newWidth <= 0 || newHeight <= 0) {
+            throw new IllegalArgumentException("newWidth and newHeight must"
+                    + " be greater than 0");
+        }
+
+        BufferedImage temp = createCompatibleImage(image, newWidth, newHeight);
+        Graphics2D g2 = temp.createGraphics();
+        g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+                RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+        g2.drawImage(image, 0, 0, temp.getWidth(), temp.getHeight(), null);
+        g2.dispose();
+
+        return temp;
+    }
+
+    /**
+     * <p>
+     * Returns a thumbnail of a source image. <code>newSize</code> defines the
+     * length of the longest dimension of the thumbnail. The other dimension is
+     * then computed according to the dimensions ratio of the original
+     * picture.</p>
+     * <p>
+     * This method offers a good trade-off between speed and quality. The result
+     * looks better than
+     * {@link #createThumbnailFast(java.awt.image.BufferedImage, int)} when the
+     * new size is less than half the longest dimension of the source image, yet
+     * the rendering speed is almost similar.</p>
+     *
+     * @see #createThumbnailFast(java.awt.image.BufferedImage, int, int)
+     * @see #createThumbnailFast(java.awt.image.BufferedImage, int)
+     * @see #createThumbnail(java.awt.image.BufferedImage, int, int)
+     * @param image the source image
+     * @param newSize the length of the largest dimension of the thumbnail
+     * @return a new compatible <code>BufferedImage</code> containing a
+     * thumbnail of <code>image</code>
+     * @throws IllegalArgumentException if <code>newSize</code> is larger than
+     * the largest dimension of <code>image</code> or &lt;= 0
+     */
+    public static BufferedImage createThumbnail(BufferedImage image,
+            int newSize) {
+        int width = image.getWidth();
+        int height = image.getHeight();
+
+        boolean isWidthGreater = width > height;
+
+        if (isWidthGreater) {
+            if (newSize >= width) {
+                throw new IllegalArgumentException("newSize must be lower than"
+                        + " the image width");
+            }
+        } else if (newSize >= height) {
+            throw new IllegalArgumentException("newSize must be lower than"
+                    + " the image height");
+        }
+
+        if (newSize <= 0) {
+            throw new IllegalArgumentException("newSize must"
+                    + " be greater than 0");
+        }
+
+        float ratioWH = (float) width / (float) height;
+        float ratioHW = (float) height / (float) width;
+
+        BufferedImage thumb = image;
+
+        do {
+            if (isWidthGreater) {
+                width /= 2;
+                if (width < newSize) {
+                    width = newSize;
+                }
+                height = (int) (width / ratioWH);
+            } else {
+                height /= 2;
+                if (height < newSize) {
+                    height = newSize;
+                }
+                width = (int) (height / ratioHW);
+            }
+
+            BufferedImage temp = createCompatibleImage(image, width, height);
+            Graphics2D g2 = temp.createGraphics();
+            g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+                    RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+            g2.drawImage(thumb, 0, 0, temp.getWidth(), temp.getHeight(), null);
+            g2.dispose();
+
+            thumb = temp;
+        } while (newSize != (isWidthGreater ? width : height));
+
+        return thumb;
+    }
+
+    /**
+     * <p>
+     * Returns a thumbnail of a source image.</p>
+     * <p>
+     * This method offers a good trade-off between speed and quality. The result
+     * looks better than
+     * {@link #createThumbnailFast(java.awt.image.BufferedImage, int)} when the
+     * new size is less than half the longest dimension of the source image, yet
+     * the rendering speed is almost similar.</p>
+     *
+     * @see #createThumbnailFast(java.awt.image.BufferedImage, int)
+     * @see #createThumbnailFast(java.awt.image.BufferedImage, int, int)
+     * @see #createThumbnail(java.awt.image.BufferedImage, int)
+     * @param image the source image
+     * @param newWidth the width of the thumbnail
+     * @param newHeight the height of the thumbnail
+     * @return a new compatible <code>BufferedImage</code> containing a
+     * thumbnail of <code>image</code>
+     * @throws IllegalArgumentException if <code>newWidth</code> is larger than
+     * the width of <code>image</code> or if code>newHeight</code> is larger
+     * than the height of
+     * <code>image or if one the dimensions is not &gt; 0</code>
+     */
+    public static BufferedImage createThumbnail(BufferedImage image,
+            int newWidth, int newHeight) {
+        int width = image.getWidth();
+        int height = image.getHeight();
+
+        if (newWidth >= width || newHeight >= height) {
+            throw new IllegalArgumentException("newWidth and newHeight cannot"
+                    + " be greater than the image"
+                    + " dimensions");
+        } else if (newWidth <= 0 || newHeight <= 0) {
+            throw new IllegalArgumentException("newWidth and newHeight must"
+                    + " be greater than 0");
+        }
+
+        BufferedImage thumb = image;
+
+        do {
+            if (width > newWidth) {
+                width /= 2;
+                if (width < newWidth) {
+                    width = newWidth;
+                }
+            }
+
+            if (height > newHeight) {
+                height /= 2;
+                if (height < newHeight) {
+                    height = newHeight;
+                }
+            }
+
+            BufferedImage temp = createCompatibleImage(image, width, height);
+            Graphics2D g2 = temp.createGraphics();
+            g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+                    RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+            g2.drawImage(thumb, 0, 0, temp.getWidth(), temp.getHeight(), null);
+            g2.dispose();
+
+            thumb = temp;
+        } while (width != newWidth || height != newHeight);
+
+        return thumb;
+    }
+
+    /**
+     * <p>
+     * Returns an array of pixels, stored as integers, from a
+     * <code>BufferedImage</code>. The pixels are grabbed from a rectangular
+     * area defined by a location and two dimensions. Calling this method on an
+     * image of type different from <code>BufferedImage.TYPE_INT_ARGB</code> and
+     * <code>BufferedImage.TYPE_INT_RGB</code> will unmanage the image.</p>
+     *
+     * @param img the source image
+     * @param x the x location at which to start grabbing pixels
+     * @param y the y location at which to start grabbing pixels
+     * @param w the width of the rectangle of pixels to grab
+     * @param h the height of the rectangle of pixels to grab
+     * @param pixels a pre-allocated array of pixels of size w*h; can be null
+     * @return <code>pixels</code> if non-null, a new array of integers
+     * otherwise
+     * @throws IllegalArgumentException is <code>pixels</code> is non-null and
+     * of length &lt; w*h
+     */
+    public static int[] getPixels(BufferedImage img,
+            int x, int y, int w, int h, int[] pixels) {
+        if (w == 0 || h == 0) {
+            return new int[0];
+        }
+
+        if (pixels == null) {
+            pixels = new int[w * h];
+        } else if (pixels.length < w * h) {
+            throw new IllegalArgumentException("pixels array must have a length"
+                    + " >= w*h");
+        }
+
+        int imageType = img.getType();
+        if (imageType == BufferedImage.TYPE_INT_ARGB
+                || imageType == BufferedImage.TYPE_INT_RGB) {
+            Raster raster = img.getRaster();
+            return (int[]) raster.getDataElements(x, y, w, h, pixels);
+        }
+
+        // Unmanages the image
+        return img.getRGB(x, y, w, h, pixels, 0, w);
+    }
+
+    /**
+     * <p>
+     * Writes a rectangular area of pixels in the destination
+     * <code>BufferedImage</code>. Calling this method on an image of type
+     * different from <code>BufferedImage.TYPE_INT_ARGB</code> and
+     * <code>BufferedImage.TYPE_INT_RGB</code> will unmanage the image.</p>
+     *
+     * @param img the destination image
+     * @param x the x location at which to start storing pixels
+     * @param y the y location at which to start storing pixels
+     * @param w the width of the rectangle of pixels to store
+     * @param h the height of the rectangle of pixels to store
+     * @param pixels an array of pixels, stored as integers
+     * @throws IllegalArgumentException is <code>pixels</code> is non-null and
+     * of length &lt; w*h
+     */
+    public static void setPixels(BufferedImage img,
+            int x, int y, int w, int h, int[] pixels) {
+        if (pixels == null || w == 0 || h == 0) {
+            return;
+        } else if (pixels.length < w * h) {
+            throw new IllegalArgumentException("pixels array must have a length"
+                    + " >= w*h");
+        }
+
+        int imageType = img.getType();
+        if (imageType == BufferedImage.TYPE_INT_ARGB
+                || imageType == BufferedImage.TYPE_INT_RGB) {
+            WritableRaster raster = img.getRaster();
+            raster.setDataElements(x, y, w, h, pixels);
+        } else {
+            // Unmanages the image
+            img.setRGB(x, y, w, h, pixels, 0, w);
+        }
+    }
+}