I have a class called vbPop (which is basically just a player) and it is just a rectangle right now, i wanted to ask how to load an image instead of just a rectangle?
This is the constructor:
public vbPop(Color c, int x, int y, int n) {
this.colour = c;
this.posX = x;
this.posY = y;
this.vakNummer = n;
}
and the code to draw is:
public void draw (Graphics g){
g.setColor(this.colour);
g.fillRect(posX, posY, width, height);
g.setColor(Color.BLACK);
g.drawRect(posX, posY, width, height);
}
You have to add a BufferedImage to your player object, e.g
try {
img = ImageIO.read(getClass().getResourceAsStream("/img.png"));
} catch(IOException e){
e.printStackTrace();
}
"/img.png" is a relativ path, in this case img.png is located in your source folder.
afterwards you can display your image in the draw() method so:
g.drawImage( img, posX, posY, width, heigth, null);
Related
So I've been working on a homework on abstraction for my programming class and fell into a problem. The goal for me right now is to be able to use abstraction, then later be able to draw with rectangles and ovals a simple city, like a rectangular building or a oval light on a light post.
The error I am receiving when I compile is: MyTestApp.Rectangle is not abstract and does not override abstract method drawEllipse(java.awt.Graphics) in MyTestApp.Shape. This Error shows up on the line "class Rectangle extends Shape{" right below the class Shape.
My question is what am I doing wrong with my abstraction? I've been messing with the constructors and draw() methods in classes Rectangle and Ellipse for a while now and still to no luck happen to find a solution.
Code is below:
import java.awt.*;
import javax.swing.*;
public class MyTestApp extends JPanel {
Rectangle rect;
Ellipse oval;
public static void main(String [] args) {
MyTestApp myTestApp = new MyTestApp ();
myTestApp.test();
}
public MyTestApp () { //creates the jframe
JFrame frame = new JFrame("MyClass Driver");
setBackground(new Color(200, 250, 200));
setPreferredSize(new Dimension(500, 400));
frame.add(this);
frame.pack();
frame.setVisible(true);
}
public void delay(int msecs) {
try {
Thread.sleep(msecs);
} catch (InterruptedException e) {
}
}
public void paint(Graphics g) {//paints the rectangle and ellipse
super.paint(g);
if (rect != null)
rect.drawRectangle(g);
if (oval != null)
oval.drawEllipse(g);
}
public void test() {//gives the x/y position, width/height, and fill/outline color for the rectangle and oval
delay(1000);
rect = new Rectangle(20, 30, 23, 75, Color.GREEN, Color.BLUE);
oval = new Ellipse(10, 10, 10 , 34, Color.RED, Color.MAGENTA);
repaint();
}
public abstract class Shape{//abstract class Shape that sets the x/y, width/height, and colors for the shapes
private int x, y, width, height;
private Color fillColor;
private Color outlineColor;
public Shape(int x, int y, int width, int height, Color fillColor, Color outlineColor) {
setXY(x, y);
setSize(width, height);
setFillColor(fillColor);
setOutlineColor(outlineColor);
}
public boolean setXY(int x, int y) {
this.x = x;
this.y = y;
return true;
}
public void setSize(int width, int height) {
if (width > 0)
this.width = width;
if (height > 0)
this.height = height;
}
public boolean setFillColor(Color fillColor){
if (fillColor == null) return false;
this.fillColor = fillColor;
return true;
}
public boolean setOutlineColor(Color outlineColor){
if (outlineColor == null) return false;
this.outlineColor = outlineColor;
return true;
}
public Color getFillColor() {
return fillColor;
}
public Color getOutlineColor() {
return outlineColor;
}
public abstract void drawRectangle(Graphics g);//do i need two?
public abstract void drawEllipse(Graphics g);//do i need both?
}
class Rectangle extends Shape{//!!!!!!!!!! where the error shows
public Rectangle(int x, int y, int width, int height, Color fillColor, Color outlineColor) {
super(x, y, width, height, fillColor, outlineColor);
}
public void drawRectangle(Graphics g){//draws the retangle
g.setColor(fillColor);
g.fillRect(x, y, width, height);
g.setColor(outlineColor);
g.drawRect(x, y, width, height);
}
}
class Ellipse extends Shape{
public Ellipse(int x, int y, int width, int height, Color fillColor, Color outlineColor) {
super(x, y, width, height, fillColor, outlineColor);
}
public void drawEllipse(Graphics g){//draws the ellipse
g.setColor(fillColor);
g.fillOval(x, y, width, height);
g.setColor(outlineColor);
g.drawOval(x, y, width, height);
}
}
}
Thanks for reading and helping!
Both classes Rectangle and Ellipse need to override both of the abstract methods.
To work around this, you have 3 options:
Add the two methods
Make each class that extends Shape abstract
Have a single method that does the function of the classes that will extend Shape, and override that method in Rectangle and Ellipse, for example:
abstract class Shape {
// ...
void draw(Graphics g);
}
And
class Rectangle extends Shape {
void draw(Graphics g) {
// ...
}
}
Finally
class Ellipse extends Shape {
void draw(Graphics g) {
// ...
}
}
And you can switch in between them, like so:
Shape shape = new Ellipse();
shape.draw(/* ... */);
shape = new Rectangle();
shape.draw(/* ... */);
Again, just an example.
If you're trying to take advantage of polymorphic behavior, you need to ensure that the methods visible to outside classes (that need polymorphism) have the same signature. That means they need to have the same name, number and order of parameters, as well as the parameter types.
In your case, you might do better to have a generic draw() method, and rely on the subclasses (Rectangle, Ellipse) to implement the draw() method as what you had been thinking of as "drawEllipse" and "drawRectangle".
I want to convert the drawn circle into x,y coordinates and store in an array or string. I have to use this array to store an image file from my frame.
private final DrawingPanel panel = new DrawingPanel();
private static int[] generateRandomValues(int maxX, int maxY,
int minSize, int maxSize) {
Random random = new Random();
int[] values = new int[3];
values[0] = random.nextInt(maxX);
values[1] = random.nextInt(maxY);
values[2] = Math.min(random.nextInt(maxSize) + minSize, maxSize);
return values;
}
static class Circle {
int x, y, width, height;
public Circle(int x, int y, int width, int height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public void draw(Graphics g) {
g.drawOval(x, y, width, height);
}
}
static class DrawingPanel extends JPanel {
List<Circle> circles = new ArrayList<>();
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Circle circle : circles) {
circle.draw(g);
}
}
public void addCircle(Circle circle) {
circles.add(circle);
repaint();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
}
in my main function i have written the following code:
DrawingPanel drawPane = new DrawingPanel();
int[] circleValues = generateRandomValues(300, 300, 50, 150);
int x = circleValues[0];
int y = circleValues[1];
int width = circleValues[2];
int height = width;
Circle circle = new Circle(x, y, width, height);
drawPane.addCircle(circle);
I have to store the array in image format later
what does that mean? An Array of points is not an image.
If you want to know what is painted on the screen, then you can:
create a BufferedImage of your panel. See Screen Image for an easy way to do this.
Then you can iterate through the BufferedImage one pixel at a time. If the Color of the pixel is not equal to the color of the background of the panel, then that means you painted something there. So you save the x/y value of that pixel in your ArrayList.
I am working on a game.I want to add images to the applet but they do not appear there until I resize or minimize the applet.I do not know whether my image observer is wrong or not.
The images are in right path.Their in build and class folder with correct spelling. What is wrong with my code?
any help would be much appreciated.
public class game extends JApplet implements KeyListener, Runnable {
ScreenDir sd;
Image ball;
Image flower;
public void init() {
sd = new ScreenDir(this);
ball = getImage(getCodeBase(), "ball.jpg");
ballb = new Ball(50, 50, 30, 40, Color.red, ball, sd);
sd.add(ball);
flower = getImage(getCodeBase(), "flower.gif");
//class Flower is just defined like class Ball
flowerf = new Flower(60, 100, 30, 30, Color.green, flower, sd);
sd.add(flower);
}
public void paint(Graphics g) {
sd.draw(g);
}
//These are for moving the ball
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyPressed(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
}
#Override
public void run() {
while (true) {
repaint();
try {
Thread.sleep(15);
} catch (InterruptedException ex) {}}}
public class ScreenDir {
ArrayList<Object> olist;
JApplet parent;
public ScreenDir(JApplet parent) {
this.parent = parent;
olist = new ArrayList<>();
}
public void add(Object o) {
olist.add(o);
}
Image Img;
Graphics oG;
Img = parent.createImage(parent.getWidth(), parent.getHeight());
oG = offImg.getGraphics();
for(int i = 0;i<olist.size ();i++){
olist.get(i).draw(offG);
}
g.drawImage (Img,0, 0, parent);
}
public class Ball extends Object {
ScreenDir sd;
public ball(int x, int y, int w, int h, Color c, Image pi, ScreenDir sd) {
{
this.sd = sd;
}
public void draw(Graphics g) {
g.drawImage(pi, x, y, w, h, null);
}
public abstract class Object {
int x, y, w, h;
Color c;
Image pi;
public Object(int x, int y, int w, int h, Color c, Image pi) {
this.x = x;
this.y = y;
this.w = w;
this.h = h;
this.c = c;
this.pi = pi;
}
public abstract void draw(Graphics g) {
}
Applets load images asynchronously, so it is likely the images are not fully loaded before the applet goes to paint. But every Java component worth mentioning implements an ImageObserver that means it will get updates on image loading. So to fix the problem, change this:
g.drawImage(pi, x, y, w, h, null);
To this:
g.drawImage(pi, x, y, w, h, this);
Update
I mistakenly thought the drawImage method was part of the JApplet (which is an ImageObserver). You might simply change the method declaration & painting line to:
public void draw(Graphics g, ImageObserver io) {
g.drawImage(pi, x, y, w, h, io);
}
Then to call it, change:
sd.draw(g);
To:
sd.draw(g, this);
I made these methods:
public Player(double x, double y){
this.x = x;
this.y = y;
ImageLoader loader = new ImageLoader();
SpriteSheet ss = new SpriteSheet(loader.loadImage("/Pics/TheSpriteSheet.png"));
this.image = ss.grabImage(1, 1, 32, 32);
}
public void tick(){
this.x++;
}
public void render(Graphics g){
g.drawImage(image, (int) x, (int) y, null);
}
Then I put it in my tick method in my main class which gets called every nanosecond or so.
public void tick(){
playerClass.tick();
}
It looks like you are only updating the space ship's x position but you are not redrawing the screen. Therefore, the x position is increased but you won't see it on your screen!
You might use something like spaceShip.repaint();
I'm trying to use the ShadowRenderer from swingx to create a shadow for a panel. Here is what i did so far:
Creating the shadow renderer one time in the panel constructor.
public CustomPanel() {
super();
renderer = new ShadowRenderer(20, 0.5f, Color.RED);
}
Each time the panel is resized, i recalculate the new shadow.
#Override
public void setBounds(int x, int y, int width, int height) {
super.setBounds(x, y, width, height);
shadow = renderer.createShadow(GraphicsUtilities.createCompatibleTranslucentImage(width, height));
}
And then i override the paintComponent method of my panel to draw the generated image:
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g.create();
g2.drawImage(shadow, 0, 0, null);
//super.paintComponent(g);
}
But the shadow image is never shown. Why? I read this and i except my code to draw a kind of "shadowed" image generated by the shadow renderer.
Here's a shortened example of DropShadowDemo
JXPanel panel = new JXPanel() {
int shadowSize = 40;
ShadowRenderer renderer = new ShadowRenderer(shadowSize/ 2, 0.5f, Color.RED);
BufferedImage imageA =
XTestUtils.loadDefaultImage("moon.jpg");
BufferedImage shadow;
#Override
public void setBounds(int x, int y, int width, int height) {
super.setBounds(x, y, width, height);
// not really needed here - the base image size is fixed
shadow = renderer.createShadow(imageA);
}
#Override
protected void paintComponent(Graphics g) {
int x = (getWidth() - imageA.getWidth()) / 2;
int y = (getHeight() - imageA.getHeight()) / 2;
Graphics2D g2 = (Graphics2D) g;
Composite c = g2.getComposite();
g2.setComposite(AlphaComposite.SrcOver.derive(renderer.getOpacity()));
g.drawImage(shadow, x - shadowSize / 2, y - shadowSize / 2, null);
g2.setComposite(c);
g.drawImage(imageA, x, y, null);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(imageA.getWidth() + shadowSize, imageA.getHeight()+ shadowSize);
}
};
panel.setOpaque(false);