gif-builder

A java dsl for building gifs using gifencoder.

DSL

The dsl starts with static methods from GifMethods. Start with a GifSpec.Builder.

gif("image.gif");

Various options can be added including loop and the defaults for delay and disposal method. Delay is in milliseconds although this will be converted to deciseconds (standard for GIF).

Note: interlace and transparency is not supported by gifencoder and so are not supported here.

gif("image.gif")
    .defaultDelay(100)
    .defaultDisposalMethod(RESTORE_TO_BACKGROUND);

Once defaults are set images can be added. This uses the ImageSpec.

gif("image.gif")
    .defaultDelay(100)
    .defaultDisposalMethod(RESTORE_TO_BACKGROUND)
    .addImages(image(image1))
    .addImages(image(image2));

Images are BufferedImages.

An ImageSpec can contain other options for the gif sequence: delay, disposalMethod, leftPosition, topPosition.

Once the images are added to the GifSpec the specification can be built.

gif("image.gif")
    .defaultDelay(100)
    .defaultDisposalMethod(RESTORE_TO_BACKGROUND)
    .addImages(image(image1))
    .addImages(image(image2))
    .build();

The image can then be created.

gif("image.gif")
    .defaultDelay(100)
    .defaultDisposalMethod(RESTORE_TO_BACKGROUND)
    .addImages(image(image1))
    .addImages(image(image2))
    .build()
    .create();

Conventions

• GIF size will match largest image
• If image is smaller than size it will be centered with a background
• Background of smaller image is guessed from pixel 1,1

Example

Animate a moving square

public class Main {

  private static int count = 1;

  public static void main(String... args) throws IOException {
    gif("gif.gif")
        .addImages(image(incrementImage()))
        .addImages(image(incrementImage()))
        .addImages(image(incrementImage()))
        .addImages(image(incrementImage()))
        .addImages(image(incrementImage()))
        .build()
        .create();
  }

  public static BufferedImage incrementImage() throws IOException {
    var image = new BufferedImage(600, 600, BufferedImage.TYPE_3BYTE_BGR);
    var graphics = image.getGraphics();
    graphics.setColor(Color.WHITE);
    graphics.drawRect(10 * count, 10 * count, 50, 50);
    graphics.dispose();
    ImageIO.write(image, "png", new File("image" + count + ".png"));
    count++;
    return image;
  }
}

Versions

0.2.0

Parent directories are now created before writing the gif file.

0.1.0

Initial implementation