world
Class World

java.lang.Object
  world.World

Direct Known Subclasses:

FallingWorld, FallingWorld, KeyMoveWorld, KeyMoveWorld, MousePointsWorld, MousePointsWorld, RotatingLinesWorld, RotatingLinesWorld, SnakeGame, WorldTest.MousePointsWorld

public abstract class World
extends java.lang.Object

A Class representing a World and the related methods for drawing the world and handling various events. In order to implement a functioning World you must extend this class, and implement an onDraw method. Other handler methods (tickRate, onTick, onMouse, onKey, onRelease, stopWhen, and lastScene) are optional, and can be overridden to add new functionality.

See the individual methods for detailed documentation.

Displaying Images/Scenes

Simple and generated images can be displayed in a Window using the static method display(Image).

     import world.World;
     import image.*;
 
     public class DisplayTest{
         public static void main(String[] args){
             World.display(new EmptyScene(200, 200)
                                .placeImage(new Overlay(new Star(50, 30, 10, "outline", "black"),
                                                        new Star(50, 30, 10, "solid", "green")),
                                            100, 100));
         }
     }
 

When run, the program opens a window that looks something like this:

Extending World

Below is a simple example of a World that adds a new point at each mouse click. The world contains a Scene and a new Circle is placed for each "button-down" event received.

   
        import image.*;
        import world.World;
        
        public class MousePointsWorld extends World{
            // Simple Main Program
            public static void main(String[] args){
                new MousePointsWorld( = new EmptyScene(200, 200))
                     .bigBang();
            }
            
            // The inner Scene
            Scene scene;
        
            // Create a new World
            MousePointsWorld(Scene scene){
                 this.scene = scene;
            }
            
            // Draw by returning the inner Scene
            public Scene onDraw(){ return this.scene; }
        
            // On a mouse click add a circle to the inner Scene
            public MouseWorld onMouse(int x, int y, String me){
                if(me.equals("button-down")){
                    return new MousePointsWorld(this.scene.placeImage(
                                     new Circle(20, "solid", "red")
                                           .overlay(new Circle(20, "outline", "black")), x, y));
                }
            }
        }
 

After a few mouse clicks, the window will look something like this:

Field Summary

static double	DEFAULT_TICK_RATE Default Tick rate for the world: ~33 frames per second
static java.lang.String	KEY_ARROW_DOWN Key arrow-down event String
static java.lang.String	KEY_ARROW_LEFT Key arrow-left event String
static java.lang.String	KEY_ARROW_RIGHT Key arrow-right event String
static java.lang.String	KEY_ARROW_UP Key arrow-up event String
static java.lang.String	MOUSE_DOWN Mouse down (button-down) event String
static java.lang.String	MOUSE_DRAG Mouse down & move (drag) event String
static java.lang.String	MOUSE_ENTER Mouse window enter (enter) event String
static java.lang.String	MOUSE_LEAVE Mouse window leave (leave) event String
static java.lang.String	MOUSE_MOVE Mouse motion (move) event String
static java.lang.String	MOUSE_UP Mouse up (button-up) event String

Constructor Summary

World()

Method Summary

World	bigBang() Kick off the interaction/animation.
static boolean	display(Image i) Opens a new Window and displays the given Image/Scene, returns true once the window is closed.
Scene	lastScene() Returns the Scene that should be displayed when the interaction/animation completes (stopWhen() returns true).
abstract Scene	onDraw() Return a visualization of this World as a Scene.
World	onKey(java.lang.String event) Produce a (possibly) new World when a key is pressed.
World	onMouse(int x, int y, java.lang.String event) Produce a (possibly) new World when a mouse event is triggered.
World	onRelease(java.lang.String event) Produce a (possibly) new World when a key is released.
World	onTick() Produce a (possibly) new World based on the Tick of the clock.
boolean	stopWhen() Determine if the World/interaction/animation should be stopped.
double	tickRate() Return the tick rate for this World in seconds.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_TICK_RATE

public static double DEFAULT_TICK_RATE

Default Tick rate for the world: ~33 frames per second

MOUSE_DOWN

public static java.lang.String MOUSE_DOWN

Mouse down (button-down) event String

MOUSE_UP

public static java.lang.String MOUSE_UP

Mouse up (button-up) event String

MOUSE_ENTER

public static java.lang.String MOUSE_ENTER

Mouse window enter (enter) event String

MOUSE_LEAVE

public static java.lang.String MOUSE_LEAVE

Mouse window leave (leave) event String

MOUSE_MOVE

public static java.lang.String MOUSE_MOVE

Mouse motion (move) event String

MOUSE_DRAG

public static java.lang.String MOUSE_DRAG

Mouse down & move (drag) event String

KEY_ARROW_UP

public static java.lang.String KEY_ARROW_UP

Key arrow-up event String

KEY_ARROW_DOWN

public static java.lang.String KEY_ARROW_DOWN

Key arrow-down event String

KEY_ARROW_LEFT

public static java.lang.String KEY_ARROW_LEFT

Key arrow-left event String

KEY_ARROW_RIGHT

public static java.lang.String KEY_ARROW_RIGHT

Key arrow-right event String

Constructor Detail

World

public World()

Method Detail

onDraw

public abstract Scene onDraw()

Return a visualization of this World as a Scene. See EmptyScene, Scene.placeImage(Image, int, int), and Scene.addLine(int, int, int, int, String) for documentation on constructing Scenes

tickRate

public double tickRate()

Return the tick rate for this World in seconds. For example, 0.5 means two ticks per second. The rate is only accessed when bigBang() is initially called and the window is created.

onTick

public World onTick()

Produce a (possibly) new World based on the Tick of the clock. This method is called to get the next world on each clock tick.

onMouse

public World onMouse(int x,
                     int y,
                     java.lang.String event)

Produce a (possibly) new World when a mouse event is triggered. x and y are the location of the event in the window, and event is a String that describes what kind of event occurred.

Possible Mouse Events

"button-down" :	The user presses a mouse button in the World window
"button-up" :	The user releases a mouse button in the World window
"move" :	The user moves the mouse in the World window
"drag" :	The user holds a mouse button and moves the mouse in the World window
"enter" :	The user moves the mouse in-to the World window
"leave" :	The user moves the mouse out-of the World window

onKey

public World onKey(java.lang.String event)

Produce a (possibly) new World when a key is pressed. The given event is a String that describes what key was pressed.

Special Keys

"up" :	The user presses the up-arrow key
"down" :	The user presses the down-arrow key
"left" :	The user presses the left-arrow key
"right" :	The user presses the right-arrow key

Other keys generate a single character String that represents the key pressed. For example, Pressing the B key on the keyboard generates "b" as an event. If the shift key is held while pressing B then "B" is generated.

onRelease

public World onRelease(java.lang.String event)

Produce a (possibly) new World when a key is released. The given event is a String that describes which key was released.

Special Keys

"up" :	The user presses the up-arrow key
"down" :	The user presses the down-arrow key
"left" :	The user presses the left-arrow key
"right" :	The user presses the right-arrow key

Other keys generate a single character String that represents the key released. For example, Pressing then releasing the B key on the keyboard generates "b" as an onKey event and again as an onRelease event. If the shift key is held while pressing/releasing B then "B" is generated.

stopWhen

public boolean stopWhen()

Determine if the World/interaction/animation should be stopped. Returning a value of true discontinues all events (mouse, key, ticks) and causes lastScene() to be used to draw the final Scene.

lastScene

public Scene lastScene()

Returns the Scene that should be displayed when the interaction/animation completes (stopWhen() returns true).

bigBang

public World bigBang()

Kick off the interaction/animation. This method returns the final state of the world after the user closes the World window.

display

public static boolean display(Image i)

Opens a new Window and displays the given Image/Scene, returns true once the window is closed.