Is there any way to get only the initial press from the drag, because right now it keeps toggling between black and white when dragged over the same square. Also, I am trying to get from the command line the width and height of the rectangles that will make the grid, if the user screws up or nothing is input then they are set to 50 by default. I tried creating a method because I didn't really know how to put them in the main an then use it in the JPanel.
public class Clicky extends JFrame {
private static class Board extends JPanel {
public int BRICK_WIDTH = 50;
public int BRICK_HEIGHT = 50;
public Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
public double width = screenSize.getWidth();
public double height = screenSize.getHeight();
public double bWidth;
public double bHeight;
private int COLS = (int) (width / bWidth);
private int ROWS = (int) (height / bHeight);
private Color CO = Color.BLACK;
private boolean[][] isWhite = new boolean[COLS + 1][ROWS + 1];
public Board() {
System.out.println("WIdth:" + COLS + "Height:" + ROWS);
setBackground(Color.BLACK);
addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
mx = e.getX();
my = e.getY();
System.out.printf("X: %d Y: %d ", mx, my);
isWhite[(int) (mx / bWidth)][(int) (my
/ bHeight)] = !isWhite[(int) (mx / bWidth)][(int) (my / bHeight)];
repaint();
}
});
addMouseMotionListener(new MouseMotionListener() {
#Override
public void mouseDragged(MouseEvent e) {
mx = e.getX();
my = e.getY();
isWhite[(int) (mx / bWidth)][(int) (my
/ bHeight)] = !isWhite[(int) (mx / bWidth)][(int) (my / bHeight)];
int gridx = e.getX();
int gridy = e.getY();
System.out.println(gridx);
}
#Override
public void mouseMoved(MouseEvent e) {
}
});
}
#Override
protected void paintComponent(Graphics g,String[] args ) {
super.paintComponent(g);
drawBricks(g);
getValues(args);
}
private double x;
private double y;
public void getValues(String[] args){
try
{
bWidth = Integer.valueOf(args[0]);
}
catch (IndexOutOfBoundsException | NumberFormatException ex)
{
// If the argument was bad then use the default.
bWidth = BRICK_WIDTH;
}
try
{
bHeight = Integer.valueOf(args[1]);
}
catch (IndexOutOfBoundsException | NumberFormatException ex)
{
// If the argument was bad then use the default.
bHeight = BRICK_HEIGHT;
}
}
private void drawBricks(Graphics g) {
Graphics2D brick = (Graphics2D) g.create();
x = 0;
y = 0;
for (int j = 0; j <= ROWS; j++) {
for (int a = 0; a <= COLS; a++) {
if (isWhite[a][j]) {
brick.setColor(Color.WHITE);
} else {
brick.setColor(Color.BLACK);
}
Rectangle2D.Double rect = new Rectangle2D.Double(x, y, bWidth, bHeight);
brick.fill(rect);
brick.setColor(Color.gray);
brick.draw(rect);
x += bWidth;
}
repaint();
x = 0;
y += bHeight;
}
}
public int mx = -100;
public int my = -100;
}
public Clicky() {
setDefaultCloseOperation(EXIT_ON_CLOSE); // mai bine cu exit on close
setSize(800, 820);
add(new Board());
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new Clicky().setVisible(true);
}
});
}
}
There isn't an event you can listen for that will tell you when the drag event starts. You can write one yourself. You'll need to some kind of stateful variable that can be toggled on the first receipt of a mouse dragged event then used as a guard for subsequent mouse dragged events. You can reset the stateful variable on a mouse release event. See MouseEvent and MouseEventListener.
As for your other question - I'm not really sure what you're asking. Are you wondering how to get user-supplied data from the command line or trying to figure out how to make use of them once they are supplied?
For the former it's dead simple with command line arguments. For the latter, all you have to do is write a setter method that validates the input and overrides the default if caller-supplied values are valid.
Related
I am working on homework for class, and its late because I can't seem to understand the material despite all the research that I am doing. I am a beginner and do not know much in the way of java. Also, this is my first post so please be forgiving when you are reading this.
I am building on source code from my textbook, which I updated recently for past homework, but now I am trying to generate a class that draws multiple squares and moves those objects independently and at different speeds. They will all need to rebound off the walls as well. I followed the instructions and created two arrays that will hold the random x and y values between 1 and 10. However, I struggle with arrays and I am sure that I am not doing it correctly. So, I would love some feedback to see if I have it set up correctly.
I have a the jpanel pulling up and drawing, and as long as there is 1 square it is working fine bouncing off the walls, but things change when I draw more than one. The do not move independently and they also share the same speed. Some even disappear from time to time. This has really thrown me off. I appreciate any help!
In short, I am trying to paint new squares that all travel in different directions and at different speeds. Per the instructions we are suppose create and use a two arrays that handle the x and y values.
Here is what I have so far:
public class DotsPanel extends JPanel
{
private int delay = 15;
private final int SIZE = 7, IMAGE_SIZE = 3; // radius of each dot
private Timer timer;
private int x, y, i;
private ArrayList<Point> pointList;
static int [] xarray = new int [1000];
static int [] yarray = new int [1000];
Random rand = new Random();
//-----------------------------------------------------------------
// Constructor: Sets up this panel to listen for mouse events.
//-----------------------------------------------------------------
public DotsPanel()
{
pointList = new ArrayList<Point>();
int [] xarray = new int [1000];
int [] yarray = new int [1000];
timer = new Timer(delay, new ReboundListener());
addMouseListener (new DotsListener());
addMouseMotionListener (new DotsListener());
setBackground(Color.gray);
setPreferredSize(new Dimension(700, 500));
for(int i = 0; i < xarray.length; i++)
{
xarray[i] = rand.nextInt(7);
yarray[i] = rand.nextInt(7);
}
timer.start();
}
//-----------------------------------------------------------------
// Draws all of the dots stored in the list.
//-----------------------------------------------------------------
public void paintComponent(Graphics page)
{
super.paintComponent(page);
page.setColor(Color.BLUE);
for (Point spot : pointList)
{
page.fillRect(spot.x-SIZE, spot.y-SIZE, 25, 25);
page.drawString("Count: " + pointList.size(), 5, 15);
}
}
//*****************************************************************
// Represents the listener for mouse events.
//*****************************************************************
private class DotsListener implements MouseListener, MouseMotionListener
{
//--------------------------------------------------------------
// Adds the current point to the list of points and redraws
// the panel whenever the mouse button is pressed.
//--------------------------------------------------------------
public void mousePressed(MouseEvent event)
{
pointList.add(event.getPoint());
repaint();
}
public void mouseDragged(MouseEvent event)
{
// initially I had two xarray and yarray in here just like in
// mouseClicked
// but it did not change anything when removed
}
//--------------------------------------------------------------
// Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void mouseClicked(MouseEvent event)
{
xarray[i] = rand.nextInt(7);
yarray[i] = rand.nextInt(7);
}
public void mouseReleased(MouseEvent event) {}
public void mouseEntered(MouseEvent event) {}
public void mouseExited(MouseEvent event) {}
public void mouseMoved(MouseEvent e) {}
}
private class ReboundListener implements ActionListener
{
//--------------------------------------------------------------
// Updates the position of the image and possibly the direction
// of movement whenever the timer fires an action event.
//--------------------------------------------------------------
public void actionPerformed(ActionEvent event)
{
for (Point spot : pointList)
{
spot.x += xarray[i];
spot.y += yarray[i];
if (spot.x <= 0 || spot.x >= 700)
xarray[i] = xarray[i] * -1;
if (spot.y <= 0 || spot.y >= 500)
yarray[i] = yarray[i] * -1;
repaint();
}
}
}
}
However, I struggle with arrays and I am sure that I am not doing it correctly.
I wouldn't use Arrays.
Instead, have a Ball object manage its own state. Then you can have different color, speed, size etc for each Ball. Then when the Timer fires you just calculate the new position and repaint the Ball.
Here is an example to get you started:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;
public class BallAnimation4
{
private static void createAndShowUI()
{
BallPanel panel = new BallPanel();
JFrame frame = new JFrame("BallAnimation4");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( panel );
frame.setSize(800, 600);
frame.setLocationRelativeTo( null );
//frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible( true );
panel.addBalls(5);
panel.startAnimation();
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
class BallPanel extends JPanel implements ActionListener
{
private ArrayList<Ball> balls = new ArrayList<Ball>();
public BallPanel()
{
setLayout( null );
setBackground( Color.BLACK );
}
public void addBalls(int ballCount)
{
Random random = new Random();
for (int i = 0; i < ballCount; i++)
{
Ball ball = new Ball();
ball.setRandomColor(true);
ball.setLocation(random.nextInt(getWidth()), random.nextInt(getHeight()));
ball.setMoveRate(32, 32, 1, 1, true);
// ball.setMoveRate(16, 16, 1, 1, true);
ball.setSize(32, 32);
balls.add( ball );
}
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
for (Ball ball: balls)
{
ball.draw(g);
}
}
public void startAnimation()
{
Timer timer = new Timer(75, this);
timer.start();
}
public void actionPerformed(ActionEvent e)
{
move();
repaint();
}
private void move()
{
for (Ball ball : balls)
{
ball.move(this);
}
}
class Ball
{
public Color color = Color.BLACK;
public int x = 0;
public int y = 0;
public int width = 1;
public int height = 1;
private int moveX = 1;
private int moveY = 1;
private int directionX = 1;
private int directionY = 1;
private int xScale = moveX;
private int yScale = moveY;
private boolean randomMove = false;
private boolean randomColor = false;
private Random myRand = null;
public Ball()
{
myRand = new Random();
setRandomColor(randomColor);
}
public void move(JPanel parent)
{
int iRight = parent.getSize().width;
int iBottom = parent.getSize().height;
x += 5 + (xScale * directionX);
y += 5 + (yScale * directionY);
if (x <= 0)
{
x = 0;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (x >= iRight - width)
{
x = iRight - width;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (y <= 0)
{
y = 0;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
if (y >= iBottom - height)
{
y = iBottom - height;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
}
public void draw(Graphics g)
{
g.setColor(color);
g.fillOval(x, y, width, height);
}
public void setColor(Color c)
{
color = c;
}
public void setLocation(int x, int y)
{
this.x = x;
this.y = y;
}
public void setMoveRate(int xMove, int yMove, int xDir, int yDir, boolean randMove)
{
this.moveX = xMove;
this.moveY = yMove;
directionX = xDir;
directionY = yDir;
randomMove = randMove;
}
public void setRandomColor(boolean randomColor)
{
this.randomColor = randomColor;
switch (myRand.nextInt(3))
{
case 0: color = Color.BLUE;
break;
case 1: color = Color.GREEN;
break;
case 2: color = Color.RED;
break;
default: color = Color.BLACK;
break;
}
}
public void setSize(int width, int height)
{
this.width = width;
this.height = height;
}
}
}
Since your Arrays only contain the Point you want to paint you don't have any information about the speed each point should be moved at. The best you could do is create a random amount each point should be moved each time its location is changed. This would give erratic movement as each time you move a point the distance would be random.
If you want more constant speed then you would need to create a second Array to contain the distance each point should move every time.
This starts to get messy creating a new Array every time you want a new property to be unique for the object you want to paint. That is why the approach to create a custom Object with multiple properties is easier to manage.
So I have two classes here:
PhotoComponent class:
(This class is to handle a specific image as a JComponent. When "flipped" I want to draw pen strokes instead of having an image. So I replace the image with a rectangle, attempting to draw pen strokes over it.)
public class PhotoComponent extends JComponent {
private Image pic;
private boolean flipped;
private int contentAreaWidth;
private int contentAreaHeight;
p
#Override
public void paintComponent(Graphics g) {
//Does all the drawing and contains whatever state information is associated with the photo
//create an action event to auto call repaint
//call repaint anytime flip was changed to true or false
System.out.println("Draw: " + draw + ", Pic: " + pic);
if (draw && pic != null) {
super.paintComponent(g);
System.out.println("width using this: " + this.getWidth() + ", actual width of JPanel: " + contentAreaWidth);
System.out.println("height using this: " + this.getHeight() + ", actual height of JPanel: " + contentAreaHeight);
g2 = (Graphics2D) g;
int x = (contentAreaWidth - pic.getWidth(null)) / 2;
int y = (contentAreaHeight - pic.getHeight(null)) / 2;
if (!flipped) {
g2.drawImage(pic, x, y, null);
} else if (flipped) {
g2.setColor(Color.WHITE);
g2.fillRect(x,y,pic.getWidth(null), pic.getHeight(null));
g2.drawRect(x, y, pic.getWidth(null), pic.getHeight(null));
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if (drawingMode) {
g2.setPaint(Color.RED);
if (drawOval) {
penStrokes.put(ovalX, ovalY);
if (penStrokes != null) {
for (Integer xCoor : penStrokes.keySet()) {
g2.setPaint(Color.RED);
int brushSize = 5;
g2.fillOval((xCoor - (brushSize / 2)), (penStrokes.get(xCoor) - (brushSize / 2)), brushSize, brushSize);
//System.out.println("SIZE OF HASHTABLE: " + penStrokes.size());
}
}
System.out.println("Filling an oval!" + ovalX + ", " + ovalY);
}
} else if (textMode) {
g2.setPaint(Color.YELLOW);
if (drawRect) {
rectDimensions.add(rectX);
rectDimensions.add(rectY);
rectDimensions.add(rectWidth);
rectDimensions.add(rectHeight);
for (int i = 0; i < rectDimensions.size(); i+=4) {
g2.fillRect(rectDimensions.get(i), rectDimensions.get(i+1), rectDimensions.get(i+2), rectDimensions.get(i+3));
g2.drawRect(rectDimensions.get(i), rectDimensions.get(i+1), rectDimensions.get(i+2), rectDimensions.get(i+3));
}
}
}
System.out.println("This is being called again!");
}
}
}
public void setRectangle(int x, int y, int width, int height) {
drawRect = true;
rectX = x;
rectY = y;
rectWidth = width;
rectHeight = height;
}
public void removeRectangle() {
drawRect = false;
}
public int[] setOval(int currentX, int currentY) {
drawOval = true;
int[] toReturn = {ovalX, ovalY};
ovalX =
NOTE THE DRAWLINE() METHOD ABOVE. I am drawing at the given points, repainting, and setting the old variables to be the current variables.
Main class:
private static PhotoComponent img;
private static JFrame frame;
private static JPanel contentArea;
//Mouse Coordinates for PenStrokes
private static int oldX, oldY;
//Mouse Coordinates for Sticky Notes
private static Point clickPoint;
public static void main (String[] args) {
frame = new JFrame("PhotoManip");
img = null;
contentArea = null;
oldX = 0;
oldY = 0;
setupMenubar(frame);
setupJFrame(frame);
}
private static void addPhotoComponent(File file) {
}
if (img.getTextMode()) {
img.removeRectangle();
clickPoint = null;
}
}
});
img.addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
if (img.getDrawingMode()) {
if (withinRange(e.getX(), e.getY())) {
int[] toUpdate = img.setOval(e.getX(), e.getY());
oldX = toUpdate[0];
oldY = toUpdate[1];
img.repaint();
}
}
if (img.getTextMode()) {
if (withinRange(e.getX(), e.getY())) {
Point dragPoint = e.getPoint();
h, height);
img.repaint();
}
}
}
});
if (img!=null) {
contentArea.add(img);
}
}
private static boolean withinRange(int x, int y) {
if (x > img.getX() && x < img.getX() + img.getWidth()) {
if (y > img.getY() && y < img.getY() + img.getHeight()) {
return true;
}
}
return false;
}
private static void flipImage() {
if (!img.isFlipped()) {
img.setFlipped(true);
} else if (img.isFlipped()) {
img.setFlipped(false);
}
}
drawLine() is called above in this main class, when a mousedrag occurs. Problem is that the strokes don't appear to show.
I know that the program is calling g2.fillOval() because I am printing out a verification statement afterwards.
Additionally, I have created print statements for when the mouse is pressed and dragged and they are getting the correct coordinates?
Why don't red strokes appear? I'm confused. Is it the way my code is structured?
The crux of your problem is that you are trying to draw something outside the paintComponent method, which is never supported. Whatever you draw will get overwritten by the next call of paintComponent, which will happen almost instantly. We can solve this by storing the co-ordinates of the oval and drawing it within paintComponent instead of trying to draw on a graphics object outside of the paintComponent method. See code below:
First we are going to add the following variables to your PhotoComponent class:
private boolean drawOval = false;
private int ovalX = 0;
private int ovalY = 0;
Then we will add methods for controlling them:
public int[] setOval(int currentX, int currentY) {
drawOval = true;
int[] toReturn = {ovalX, ovalY};
ovalX = currentX;
ovalY = currentY;
return toReturn;
}
public void removeOval() {
drawOval = false;
}
After that we can change the paintComponent method to have it draw the oval based on those variables:
#Override
public void paintComponent(Graphics g) {
//Does all the drawing and contains whatever state information is associated with the photo
//create an action event to auto call repaint
//call repaint anytime flip was changed to true or false
super.paintComponent(g);
g2 = (Graphics2D) g;
int x = (contentAreaWidth - pic.getWidth(null)) / 2;
int y = (contentAreaHeight - pic.getHeight(null)) / 2;
if (!flipped) {
g2.drawImage(pic, x, y, null);
} else if (flipped) {
g2.setColor(Color.WHITE);
g2.fillRect(x, y, pic.getWidth(null), pic.getHeight(null));
g2.drawRect(x, y, pic.getWidth(null), pic.getHeight(null));
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(Color.RED);
}
//took the code you already used for drawing the oval and moved it here
if (drawOval) {
g2.setPaint(Color.RED);
int brushSize = 5;
g2.fillOval((ovalX - (brushSize / 2)), (ovalY - (brushSize / 2)), brushSize, brushSize);
}
}
Finally change the addPhotoComponent method to update those variables instead of trying to draw the oval directly:
private static void addPhotoComponent(File file) {
Image image = null;
try {
image = ImageIO.read(file);
} catch (IOException e2) {
System.out.println("ERROR: Couldn't get image.");
}
img = new PhotoComponent(image, contentArea);
img.revalidate();
img.addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() == 2) {
// your code here
System.out.println("You flipped the photo!!!");
flipImage();
img.repaint();
}
}
#Override
public void mousePressed(MouseEvent e) {
img.setOval(e.getX(), e.getY());
}
#Override
public void mouseReleased(MouseEvent e) {
img.removeOval();
}
});
img.addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
int[] toUpdate = img.setOval(e.getX(), e.getY());
oldX = toUpdate[0];
oldY = toUpdate[1];
}
});
if (img != null) {
contentArea.add(img);
}
}
I am new to graphics in java and I am currently working on a game. Essentially, there are rising bubbles, and the user has to pop them by moving the mouse over them.
I have already made the bubbles but now for the collision detection, I need to be able to find the x and coordinates as well as the diameter of the circle. How can I return the instance variables for each bubble (from the Bubbles object array). You can see my code below. If you find coding errors, please let me know.
Game Class:
public class Game extends JPanel{
public static final int WINDOW_WIDTH = 600;
public static final int WINDOW_HEIGHT = 400;
private boolean insideCircle = false;
private static boolean ifPaused = false;
private static JPanel mainPanel;
private static JLabel statusbar;
private static int clicks = 0;
//Creates a Bubbles object Array
Bubbles[] BubblesArray = new Bubbles[5];
public Game() {
//initializes bubble objects
for (int i = 0; i < BubblesArray.length; i++)
BubblesArray[i] = new Bubbles();
}
public void paint(Graphics graphics) {
//makes background white
graphics.setColor(Color.WHITE);
graphics.fillRect(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
//paints square objects to the screen
for (Bubbles aBubblesArray : BubblesArray) {
aBubblesArray.paint(graphics);
}
}
public void update() {
//calls the Square class update method on the square objects
for (Bubbles aBubblesArray : BubblesArray) aBubblesArray.update();
}
public static void main(String[] args) throws InterruptedException {
statusbar = new JLabel("Default");
Game game = new Game();
game.addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
statusbar.setText(String.format("Your mouse is at %d, %d", e.getX(), e.getY()));
}
public void mouseExited(MouseEvent e){
ifPaused = true;
}
public void mouseEntered(MouseEvent e){
ifPaused = false;
}
});
JFrame frame = new JFrame();
frame.add(game);
frame.add(statusbar, BorderLayout.SOUTH);
frame.setVisible(true);
frame.setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Bubble Burst");
frame.setResizable(false);
frame.setLocationRelativeTo(null);
while (true) {
if (!ifPaused){
game.update();
game.repaint();
Thread.sleep(5);
}
}
}
}
Bubbles Class:
public class Bubbles{
private int circleXLocation;
private int circleSize;
private int circleYLocation = Game.WINDOW_WIDTH + circleSize;
private int fallSpeed = 1;
private int color = (int) (4 * Math.random() + 1);
Random rand = new Random();
private int whereMouseX;
private int whereMouseY;
public int generateRandomXLocation(){
return circleXLocation = (int) (Game.WINDOW_WIDTH * Math.random() - circleSize);
}
public int generateRandomCircleSize(){
return circleSize = (int) (50 * Math.random() + 30);
}
public int generateRandomFallSpeed(){
return fallSpeed = (int) (5 * Math.random() + 1);
}
public void paint(Graphics g){
if (color == 1) g.setColor(new Color(0x87CEEB));
if (color == 2) g.setColor(new Color(0x87CEFF));
if (color == 3) g.setColor(new Color(0x7EC0EE));
if (color == 4) g.setColor(new Color(0x6CA6CD));
g.fillOval (circleXLocation, circleYLocation, circleSize, circleSize);
}
public Bubbles(){
generateRandomXLocation();
generateRandomCircleSize();
generateRandomFallSpeed();
}
public void update(){
if (circleYLocation <= - circleSize){
generateRandomXLocation();
generateRandomFallSpeed();
generateRandomCircleSize();
circleYLocation = Game.WINDOW_HEIGHT + circleSize;
}
if (circleYLocation > - circleSize){
circleYLocation -= fallSpeed;
}
}
public int getX(){
return circleXLocation;
}
public int getY(){
return circleYLocation;
}
public int getCircleSize(){
return circleSize;
}
}
Set your bubbles to include x and y values in it's constructor.
Public Bubble(float x, float y, int circleSize){
// initialize variables here
}
Then check to see if they are colliding with your current mouse location, something like...
if(e.getX() == this.getX() && e.getY() == this.getY()){
// do something
}
Loop through each Bubble in the array and access the public get methods you have created in the Bubble class:
Example:
for (Bubble b : BubblesArray)
{
int x = b.getX();
int y = b.getY();
}
Well my problem is that I'm making the stars move with a thread, they move verticaly and it works good but i do a random X for the star and sometimes it intersecs other stars like this :
This is my code for the JPanel:
class Backgroundmoving
public class Backgroundmoving extends JPanel {
ArrayList<starmoving> star;
public Backgroundmoving() {
this.setSize(650, 501);
star = new ArrayList<>();
for (int i = 0; i < 20; i++)
this.addStar();
}
public void addStar() {
int x, y;
x = (int) (Math.random() * 625);
y = (int) (Math.random() * 476);
starmoving e = new starmoving(x, y);
star.add(e);
Thread t = new Thread(e);
t.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
draw(g);
}
public void draw(Graphics g) {
g.drawImage(new ImageIcon("background.png").getImage(), 0, 0, 650, 501, null);
for (int i = 0; i < star.size(); i++) {
star.get(i).draw(g);
}
repaint();
}
public static void main(String[] args) {
// TODO code application logic here
JFrame gui = new JFrame();
gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
gui.setSize(650, 510);
gui.setResizable(false);
gui.add(new Backgroundmoving());
gui.setVisible(true);
}
}
class starmoving
public class starmoving implements Runnable {
int x;
int y;
int yVel;
public starmoving(int x, int y) {
this.x = x;
this.y = y;
yVel = 1;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
private void move() {
y += yVel;
if (y > 476) {
y = 0;
x = (int) (Math.random() * 625);
}
}
private boolean isOffScreen() {
if (y <= 476)
return false;
return true;
}
public void draw(Graphics g) {
g.drawImage(new ImageIcon("star.png").getImage(), x, y, 12, 12, null);
}
#Override
public void run() {
while (true) {
move();
try {
Thread.sleep(7);
} catch (InterruptedException ex) {
System.out.println(ex.getMessage());
}
}
}
}
i don't want stars intersecting, was thinking in a if before the random X but how can i know if other star is in that X ?
You have an ArrayList that contains all your "StarMoving" objects. So you need to iterate through that list to make sure that none of the object intersect.
On top of that you have other problems.
Use proper Java class names. Java classes SHOULD start with an upper case character. (ie. "starmoving" is wrong)
Don't use multiple Threads for the animation. You current code starts 20 Threads. You should have a single Thread and then iterate through your ArrayList to move all the stars.
Don't read the image in the draw() method. Currently you code is reading the image every 7ms. This is not very efficient. The image should be read once and then stored as a property of your class.
I'm trying to create a custom extension of BasicSliderUI. I'm just trying to make the thumb a circle (note I'm in the Windows L&F). I've created a very simple implementation that just calls g.drawOval, but whenever I drag it, it leaves a "trail" behind. Any ideas why this is?
thanks,
Jeff
You need to call repaint on the whole thing, you cant just draw the oval on top of it. Swing will by default only repaint what needs to be repainted, which usually isn't the whole control. When are you drawing the circle?
If you want to get rid of "trail" when you drag you should write your custom TrackListener and control trumb position related to mouse move.
Look at my implementation:
public class LightSliderUI extends BasicSliderUI{
private final Color rangeColor = Color.BLUE;
private final BasicStroke stroke = new BasicStroke(2f);
private transient boolean upperDragging;
public LightSliderUI(JSlider b) {
super(b);
}
public static ComponentUI createUI(JComponent c) {
return new LightSliderUI((JSlider)c);
}
#Override
protected void calculateThumbSize() {
super.calculateThumbSize();
thumbRect.setSize(thumbRect.width, thumbRect.height);
}
/** Creates a listener to handle track events in the specified slider.*/
#Override
protected TrackListener createTrackListener(JSlider slider) {
return new RangeTrackListener();
}
#Override
protected void calculateThumbLocation() {
// Call superclass method for lower thumb location.
super.calculateThumbLocation();
// Adjust upper value to snap to ticks if necessary.
if (slider.getSnapToTicks()) {
int upperValue = slider.getValue() + slider.getExtent();
int snappedValue = upperValue;
int majorTickSpacing = slider.getMajorTickSpacing();
int minorTickSpacing = slider.getMinorTickSpacing();
int tickSpacing = 0;
if (minorTickSpacing > 0) {
tickSpacing = minorTickSpacing;
} else if (majorTickSpacing > 0) {
tickSpacing = majorTickSpacing;
}
if (tickSpacing != 0) {
// If it's not on a tick, change the value
if ((upperValue - slider.getMinimum()) % tickSpacing != 0) {
float temp = (float)(upperValue - slider.getMinimum()) / (float)tickSpacing;
int whichTick = Math.round(temp);
snappedValue = slider.getMinimum() + (whichTick * tickSpacing);
}
if (snappedValue != upperValue) {
slider.setExtent(snappedValue - slider.getValue());
}
}
}
// Calculate upper thumb location. The thumb is centered over its
// value on the track.
if (slider.getOrientation() == JSlider.HORIZONTAL) {
int upperPosition = xPositionForValue(slider.getValue() + slider.getExtent());
thumbRect.x = upperPosition - (thumbRect.width / 2);
thumbRect.y = trackRect.y;
} else {
int upperPosition = yPositionForValue(slider.getValue() + slider.getExtent());
thumbRect.x = trackRect.x;
thumbRect.y = upperPosition - (thumbRect.height / 2);
}
slider.repaint();
}
/** Returns the size of a thumb.
* Parent method not use size from LaF
* #return size of trumb */
#Override
protected Dimension getThumbSize() {
return Dimensions.getSliderThumbSize();
}
private Shape createThumbShape(int width, int height) {
Ellipse2D shape = new Ellipse2D.Double(0, 0, width, height);
return shape;
}
#Override
public void paintTrack(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
Stroke old = g2d.getStroke();
g2d.setStroke(stroke);
g2d.setPaint(Colors.TEXT_STEEL);
Color oldColor = Colors.TEXT_STEEL;
Rectangle trackBounds = trackRect;
if (slider.getOrientation() == SwingConstants.HORIZONTAL) {
g2d.drawLine(trackRect.x, trackRect.y + trackRect.height / 2,
trackRect.x + trackRect.width, trackRect.y + trackRect.height / 2);
int lowerX = thumbRect.width / 2;
int upperX = thumbRect.x + (thumbRect.width / 2);
int cy = (trackBounds.height / 2) - 2;
g2d.translate(trackBounds.x, trackBounds.y + cy);
g2d.setColor(rangeColor);
g2d.drawLine(lowerX - trackBounds.x, 2, upperX - trackBounds.x, 2);
g2d.translate(-trackBounds.x, -(trackBounds.y + cy));
g2d.setColor(oldColor);
}
g2d.setStroke(old);
}
/** Overrides superclass method to do nothing. Thumb painting is handled
* within the <code>paint()</code> method.*/
#Override
public void paintThumb(Graphics g) {
Rectangle knobBounds = thumbRect;
int w = knobBounds.width;
int h = knobBounds.height;
Graphics2D g2d = (Graphics2D) g.create();
Shape thumbShape = createThumbShape(w - 1, h - 1);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.translate(knobBounds.x, knobBounds.y);
g2d.setColor(Color.WHITE);
g2d.fill(thumbShape);
g2d.setColor(Colors.BIOLIN_BLUE_TINT);
g2d.draw(thumbShape);
g2d.dispose();
}
/** Listener to handle model change events. This calculates the thumb
* locations and repaints the slider if the value change is not caused by dragging a thumb.*/
public class ChangeHandler implements ChangeListener {
#Override
public void stateChanged(ChangeEvent arg0) {
calculateThumbLocation();
slider.repaint();
}
}
public static void main(String[] args) {
JFrame frame = new JFrame();
JSlider slider = new JSlider(0, 100);
slider.setPaintTicks(true);
slider.setUI(new LightSliderUI(slider));
frame.add(slider);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
/** Listener to handle mouse movements in the slider track.*/
public class RangeTrackListener extends TrackListener {
#Override
public void mouseClicked(MouseEvent e) {
if (!slider.isEnabled()) {
return;
}
currentMouseX -= thumbRect.width / 2; // Because we want the mouse location correspond to middle of the "thumb", not left side of it.
moveUpperThumb();
}
public void mousePressed(MouseEvent e) {
if (!slider.isEnabled()) {
return;
}
currentMouseX = e.getX();
currentMouseY = e.getY();
if (slider.isRequestFocusEnabled()) {
slider.requestFocus();
}
boolean upperPressed = false;
if (slider.getMinimum() == slider.getValue()) {
if (thumbRect.contains(currentMouseX, currentMouseY)) {
upperPressed = true;
}
} else {
if (thumbRect.contains(currentMouseX, currentMouseY)) {
upperPressed = true;
}
}
if (upperPressed) {
switch (slider.getOrientation()) {
case JSlider.VERTICAL:
offset = currentMouseY - thumbRect.y;
break;
case JSlider.HORIZONTAL:
offset = currentMouseX - thumbRect.x;
break;
}
//upperThumbSelected = true;
upperDragging = true;
return;
}
upperDragging = false;
}
#Override
public void mouseReleased(MouseEvent e) {
upperDragging = false;
slider.setValueIsAdjusting(false);
super.mouseReleased(e);
}
#Override
public void mouseDragged(MouseEvent e) {
if (!slider.isEnabled()) {
return;
}
currentMouseX = e.getX();
currentMouseY = e.getY();
if (upperDragging) {
slider.setValueIsAdjusting(true);
moveUpperThumb();
}
}
#Override
public boolean shouldScroll(int direction) {
return false;
}
/** Moves the location of the upper thumb, and sets its corresponding value in the slider.*/
public void moveUpperThumb() {
int thumbMiddle = 0;
switch (slider.getOrientation()) {
case JSlider.HORIZONTAL:
int halfThumbWidth = thumbRect.width / 2;
int thumbLeft = currentMouseX - offset;
int trackLeft = trackRect.x;
int trackRight = trackRect.x + (trackRect.width - 1);
int hMax = xPositionForValue(slider.getMaximum() -
slider.getExtent());
if (drawInverted()) {
trackLeft = hMax;
}
else {
trackRight = hMax;
}
thumbLeft = Math.max(thumbLeft, trackLeft - halfThumbWidth);
thumbLeft = Math.min(thumbLeft, trackRight - halfThumbWidth);
setThumbLocation(thumbLeft, thumbRect.y);//setThumbLocation
thumbMiddle = thumbLeft + halfThumbWidth;
slider.setValue(valueForXPosition(thumbMiddle));
break;
default:
return;
}
}
}
}