Java Slick Icon

Slick Icon and User Keyboard Input

This section I'll show you how to create your own icon for your application and react to user keyboard input. For icon, the image can't be
too big, so go ahead and create any "16 x 16 pixel" images. Lets look at the example

Example

/* This is a slick demo * It gets the user input, then react to the user input */ package slickkeyinput; import org.newdawn.slick.*; /** * * @author jj */ public class UserInput extends BasicGame { //Create a null image object Image backGround = null; Image saber = null; //Holds the location of the light saber float x = 50; float y = 50; public UserInput() { //The title of the window super("Get User Input"); } //The start screen of the game @Override public void init(GameContainer container) throws SlickException { //Loads the background image backGround = new Image("slickkeyinput/images/eclipse2.png"); //Loads the saber image saber = new Image("slickkeyinput/images/lightsaber.png"); } //Each time the software updates, we will go here @Override public void update(GameContainer container, int delta) throws SlickException { //Get the user input Input input = container.getInput(); //Rotate the image if the user pushes A on the keyboard if(input.isKeyDown(Input.KEY_A)) { saber.rotate(-0.2f); } //Rotate the image if the user pushes D on the keyboard if(input.isKeyDown(Input.KEY_D)) { saber.rotate(5.2f); //If the angle is greater than 135 of equal to 135 set the rotation back to 100 if(saber.getRotation()>=135.0) { saber.setRotation(100.0f); } } //If the right arrow key is pressed move the image to the right by 0.5f if(input.isKeyDown(Input.KEY_RIGHT)) { x+=0.5f; } //If the left arrow key is pressed move the image to the left by 0.5f if(input.isKeyDown(Input.KEY_LEFT)) { x-=0.5f; } //If the down key is pressed move the image down by 0.5f if(input.isKeyDown(Input.KEY_DOWN)) { y+=0.5f; } //If the up key is pressed move the image up by 0.5f if(input.isKeyDown(input.KEY_UP)) { y-=0.5f; } } //Each time the software render we go here @Override public void render(GameContainer container, Graphics g) throws SlickException { //Draw the background image at location (0,0) with width 800 and height 500 backGround.draw(0,0, 800, 500); //Draw the battery image saber.draw(x, y, 200, 200); } public static void main(String[] args) throws SlickException { //Create a container object AppGameContainer app = new AppGameContainer(new UserInput()); //Set the size of the window app.setDisplayMode(800, 500, false); //Hide the fps app.setShowFPS(false); //Set the icon of the screen app.setIcon("slickkeyinput/images/test.png"); //Start the window app.start(); } }

Click to Download Example

The example will load two images, one image will use as the background and the other one will be able to control by the user.

Image backGround = null;

We will use this as our background image.

Image saber = null;

This is a saber image, the user have control to rotate, move left and right or up and down.

Lets break down the code,

float x = 50;
float y = 50;

It holds the start location of the saber image, we update the x and y values each time the image changes its location on the x and y axis.

This time we will be using the update method whenever the image changes its location. We have to update the image to its new location
in addition to that we have to "re-render" the image again. Whenever we want to get keyboard input from user we have to use the follow method.

Input getUserInput = container.getInput();

container is just an object we created in our parameter using " GameContainer ".

The rest are just a series of " if-statement condition " to react to a key-press or a key push.

Now, for creating your own icon, all we need is to call the " setIcon() ", method inside our main method.

(Note: 0.5f, f stands for floating point, this implies the value 0.5f is a floating point number)