Follow-up to #150: delayed fade-out, minor style changes.

Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>

src/org/newdawn/slick/state/transition/DelayedFadeOutTransition.java

@@ -0,0 +1,81 @@
+package org.newdawn.slick.state.transition;
+
+import org.newdawn.slick.Color;
+import org.newdawn.slick.GameContainer;
+import org.newdawn.slick.Graphics;
+import org.newdawn.slick.state.GameState;
+import org.newdawn.slick.state.StateBasedGame;
+
+/**
+ * A transition to fade out to a given colour after a delay.
+ *
+ * @author kevin (base)
+ */
+public class DelayedFadeOutTransition implements Transition {
+	/** The color to fade to */
+	private final Color color;
+	/** The time it takes the fade to happen */
+	private final int fadeTime;
+	/** The time it takes before the fade starts */
+	private final int delay;
+	/** The elapsed time */
+	private int elapsedTime = 0;
+
+	/**
+	 * Create a new delayed fade out transition.
+	 */
+	public DelayedFadeOutTransition() { this(Color.black, 500, 0); }
+
+	/**
+	 * Create a new delayed fade out transition.
+	 * 
+	 * @param color The color we're going to fade out to
+	 */
+	public DelayedFadeOutTransition(Color color) { this(color, 500, 0); }
+
+	/**
+	 * Create a new delayed fade out transition
+	 * 
+	 * @param color The color we're going to fade out to
+	 * @param fadeTime The time it takes the fade to occur
+	 * @param delay The time before the fade starts (must be less than {@code fadeTime})
+	 */
+	public DelayedFadeOutTransition(Color color, int fadeTime, int delay) {
+		if (delay > fadeTime)
+			throw new IllegalArgumentException();
+
+		this.color = new Color(color);
+		this.color.a = 0;
+		this.fadeTime = fadeTime;
+		this.delay = delay;
+	}
+
+	@Override
+	public boolean isComplete() { return (color.a >= 1); }
+
+	@Override
+	public void postRender(StateBasedGame game, GameContainer container, Graphics g) {
+		Color old = g.getColor();
+		g.setColor(color);
+		g.fillRect(0, 0, container.getWidth() * 2, container.getHeight() * 2);
+		g.setColor(old);
+	}
+
+	@Override
+	public void update(StateBasedGame game, GameContainer container, int delta) {
+		if (elapsedTime < delay) {
+			elapsedTime += delta;
+			return;
+		}
+
+		color.a += delta * (1.0f / (fadeTime - delay));
+		if (color.a > 1)
+			color.a = 1;
+	}
+
+	@Override
+	public void preRender(StateBasedGame game, GameContainer container, Graphics g) {}
+
+	@Override
+	public void init(GameState firstState, GameState secondState) {}
+}