HW example

App.java

import hiddenwood.concurrent.*;
import hiddenwood.display.*;
import hiddenwood.gl.*;
import hiddenwood.http.*;

class App {
	private static final String URL =
		"http://www.random.org/integers/?num=1&min=1&max=100000&col=1&base=10&format=plain&rnd=new";

	public static void main(String[] args) {
		Display.newBuilder().
			width(1024).height(768).
			onSuccess(App::onDisplayBuilt).
			build();
	}

	public static void onDisplayBuilt(Display display) {
		// download a random number from the interwebs
		// parse the data into an integer
		// test wether or not this is a prime number (in the "background", so ui is not blocked)
		// print the result
		Future<HttpResponse> response =
			Http.
				get(URL).
				map(response -> response.data.toString()).
				map(Integer::parseInt).
				map(App::isPrime, Dispatchers.BACKGROUND).
				onSuccess(b -> System.out::println);

		// create a display list
		DisplayList displayList = DisplayList.newBuilder().
			backgroundColor(0x000000).
			display(display).
			build();

		// create a solid plane 512x512px (not that you would have to do it this way)
		Canvas canvas = new Canvas(512.0f, 512.0f, gl -> { gl.clearColor(1.0f, 0.0f, 1.0f, 1.0f); });

		// center the canvas pivot and move to center of display
		canvas.
			centerPivot().
			moveTo(512.0f, 384.0f);

		// add to root of display list
		displayList.root().addChild(canvas);

		// rotate the canvas each frame
		display.onEnterFrame.attach(d -> { canvas.rotateBy(0.001f); });
	}

	public static boolean isPrime(final int value) {
		for(int i = 2; i < value; ++i) {
			if(value % i == 0) return false;
		}

		return true;
	}
}