JSegue

A Java library of animated image-to-image transitions useful for slide shows, photo montages, UI transitions and the like.

Features

• 24 animations for transitioning one image to another including cross-dissolve, wipe, scroll, zoom, and checkerboard effects. May be used to generate realtime animations or to render frames offline (in batch).
• May substitute a Paint for either source or destination image for effects like fade-to-black.
• Configurable animation duration, frames-per-second and alpha blending.
• Simple to use and integrate; lightweight library with no transitive dependencies (approx. 40KB in size).

Animated Segues

Animated Segue	Name	Description
	AlphaDissolveEffect	Cross-dissolve from source to destination by increasing the source transparency while reducing the destination's.
	PixelDissolveEffect	Cross-dissolve from source to destination by randomly replacing source pixels with destination pixels.
	CheckerboardEffect	Destination image appears over the source in a 8x8 matrix.
	BlindsEffect	Destination appears in "louvered" horizontal stripes.
	ScrollLeftEffect	Scroll from right to left.
	ScrollRightEffect	Scroll from left to right.
	ScrollUpEffect	Scroll from bottom to top.
	ScrollDownEffect	Scroll from top to bottom.
	WipeLeftEffect	Slides the destination image over the source from right to left.
	WipeRightEffect	Slides the destination image over the source from left to right.
	WipeUpEffect	Slides the destination image over the source from bottom to top.
	WipeDownEffect	Slides the destination image over the source from top to bottom.
	ZoomOutEffect	The destination image expands over the source in a rectangle aperture.
	ZoomInEffect	The source image collapses over the destination in a rectangle aperture.
	IrisOpenEffect	The destination image expands over the source in a circular aperture.
	IrisCloseEffect	The source image collapses over the destination in a circular aperture.
	BarnDoorOpenEffect	The source image is split horizontally and each side slides out left/right to expose the destination.
	BarnDoorCloseEffect	The destination image slides in the from the left/right obscuring the source image.
	ShrinkToBottomEffect	The source image shrinks downward exposing the destination.
	ShrinkToTopEffect	The source image shrinks upward exposing the destination.
	ShrinkToCenterEffect	The source image shrinks from the center of the screen exposing the destination.
	StretchFromBottomEffect	The destination image grows from the bottom obscuring the source underneath it.
	StretchFromTopEffect	The destination image grows from the top obscuring the source underneath it.
	StretchFromCenterEffect	The destination image grows from the center of the screen obscuring the source underneath it.
	PlainEffect	A no-op transition that simply renders the source image.

Getting Started

1. Install the library:

JSegue is published to Maven Central; include the library in your Maven project's POM, like:

<dependency>
  <groupId>com.defano.jsegue</groupId>
  <artifactId>jsegue</artifactId>
  <version>0.0.3</version>
</dependency>

... or your Gradle build script:

repositories {
  mavenCentral()
}

dependencies {
  compile 'com.defano.jsegue:jsegue:0.0.3'
}

2. Make your class react to animation changes:

As your animation runs, JSegue will notify you that a new animation frame is ready to be displayed. Typically you'll place this image into some component visible to the user:

public class MyClass implements SegueAnimationObserver {

  private JLabel myDisplay;

  ...

  @Override
  void onFrameRendered(AnimatedSegue segue, BufferedImage image) {
    myDisplay.setIcon(new ImageIcon(image));
  }  

}

3. Build an animation:

  BufferedImage mySource = ... ;
  BufferedImage myDestination = ... ;

  // Create a cross-dissolve segue
  AnimatedSegue mySegue = SegueBuilder.of(BlindsEffect.class)
    .withSource(mySource)
    .withDestination(myDestination)
    .withDuration(1500, TimeUnit.MILLISECONDS)      // Animation lasts 1.5 seconds
    .withMaxFramesPerSecond(30)                     // No more than 30fps
    .withAnimationObserver(this)                    // Make this class an observer
    .alphaBlend(true)                               // Overlay images; see FAQs
    .build()

  // Kick it off...
  mySegue.start();

Frequently Asked Questions

How do I fade-to-black or animate the appearance of a single image?

Use the Paint form of the withSource() and withDestination() methods in the builder.

For example, to fade an image to black:

SegueBuilder.of(AlphaDissolveEffect.class)
  .withSource(myImage)
  .withDestination(Color.BLACK)
  ...
  .build();

Or, to make an image appear using a zoom effect:

SegueBuilder.of(ZoomInEffect.class)
  .withSource(new Color(0, 0, 0, 0))     // Transparent color
  .withDestination(myImage)
  ...
  .build();

What does the overlay option do?

First, it has no effect if both images contain no areas of translucency. Otherwise, when true, the source and destination images will be alpha composited together. When false, the destination image is generally treated as fully opaque; the bounds of the destination will obscure the the other as the animation progresses. The exact impact of this property differs across segue animations and has no affect at all on some.

Which looks best is a matter of preference (as well as the composition of the source and destination images). Note that the animations shown in the table above were created with overlay on.

Do my source and destination images have to be the same size?

Kinda. The AnimatedSegue objects expect the source and destination images to be the same size. So if you create these objects yourself (or invoke the render() method directly), you'll need assure both source and destination images are the same size.

However, if you create a segue using SegueBuilder, the builder will automatically resize the image(s) to the largest dimensions.

Can I chain animations together or have more than two images participate in a segue?

Yes, but... This library does not manage segue sequences for you. But you can achieve this effect by registering yourself as an observer of animation completion. At the completion of each segue you can immediate start the next one in your sequence.

SegueBuilder.of(ZoomInEffect.class)
  .withSource(new Color(0, 0, 0, 0))    // Fully transparent
  .withDestination(myImage)
  .withCompletionObserver(segue -> startNextSegueInSequence())
  ...
  .build();