Snake game in Java Swing - My snake only grows - java

I'm trying to do the classic Snake game in Swing and I managed to make Snake move, but when it moves, it becomes infinitely long because it never erases its tail.
I have been using validate() and repaint() but nothing works.
Problem
This is my code:
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.Timer;
public class controls extends JPanel implements KeyListener, ActionListener { // Amb aquestes dues implementacions, fem que el programa pugui rebre per teclat
// Mida serp
private int[] longXserp = new int[750];
private int[] longYserp = new int[750];
// Longitut inicial de la serp
private int serplong = 3;
// Moviments que fem
private int moviments = 0;
// Controls
private boolean esquerra = false;
private boolean dreta = false;
private boolean amunt = false;
private boolean avall = false;
// Gràfics de moviment
private ImageIcon serpesquerra;
private ImageIcon serpdreta;
private ImageIcon serpamunt;
private ImageIcon serpavall;
private Timer timer;
private int velocitatserp = 100;
private ImageIcon serp;
public controls() {
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
timer = new Timer(velocitatserp, this);
timer.start();
}
public void paint(Graphics g) { // Mètode amb el que imprimim per pantalla. Ha d'anomenar-se "paint", o si no, no funcionarà
if(moviments == 0) {
longXserp[2] = 50;
longXserp[1] = 75;
longXserp[0] = 100;
longYserp[2] = 100;
longYserp[1] = 100;
longYserp[0] = 100;
}
serpdreta = new ImageIcon("src/grafics/serpdreta.png");
serpdreta.paintIcon(this, g, longXserp[0], longYserp[0]);
for(int a = 0; a < serplong; a++) {
if(a == 0 && esquerra) {
serpesquerra = new ImageIcon("src/grafics/serpesquerra.png");
serpesquerra.paintIcon(this, g, longXserp[a], longYserp[a]);
}
if(a == 0 && dreta) {
serpdreta = new ImageIcon("src/grafics/serpdreta.png");
serpdreta.paintIcon(this, g, longXserp[a], longYserp[a]);
}
if(a == 0 && amunt) {
serpamunt = new ImageIcon("src/grafics/serpamunt.png");
serpamunt.paintIcon(this, g, longXserp[a], longYserp[a]);
}
if(a == 0 && avall) {
serpavall = new ImageIcon("src/grafics/serpavall.png");
serpavall.paintIcon(this, g, longXserp[a], longYserp[a]);
}
if(a != 0) {
serp = new ImageIcon("src/grafics/serp.png");
serp.paintIcon(this, g, longXserp[a], longYserp[a]);
}
}
g.dispose();
}
#Override
public void keyPressed(KeyEvent ke) {
if(ke.getKeyCode() == KeyEvent.VK_RIGHT){ // Si polses la tecla X, la seva variable boolean es posa en true
moviments++;
dreta = true;
if(!esquerra) {
dreta = true;
}
else {
dreta = false;
esquerra = true;
}
amunt = false;
avall = false;
}
if(ke.getKeyCode() == KeyEvent.VK_LEFT){
moviments++;
esquerra = true;
if(!dreta) {
esquerra = true;
}
else {
esquerra = false;
dreta = true;
}
amunt = false;
avall = false;
}
if(ke.getKeyCode() == KeyEvent.VK_UP){
moviments++;
amunt = true;
if(!avall) {
amunt = true;
}
else {
amunt = false;
avall = true;
}
esquerra = false;
dreta = false;
}
if(ke.getKeyCode() == KeyEvent.VK_DOWN){
moviments++;
avall = true;
if(!amunt) {
avall = true;
}
else {
amunt = true;
avall = false;
}
esquerra = false;
dreta = false;
}
}
#Override
public void keyReleased(KeyEvent ke) {
// TODO Auto-generated method stub
}
#Override
public void keyTyped(KeyEvent ke) {
// TODO Auto-generated method stub
}
#Override
public void actionPerformed(ActionEvent ae) {
timer.start();
if(dreta) {
for(int d = serplong-1; d>=0; d--) {
longYserp[d+1] = longYserp[d];
}
for(int e = serplong; e>= 0; e--) {
if(e==0) {
longXserp[e] = longXserp[e] + 25;
}
else {
longXserp[e] = longXserp[e-1];
}
if(longXserp[e] > 850) {
longXserp[e] = 25;
}
}
repaint(); // Mètode per refrescar els gràfics tornant a cridar al mètode paint(). Es usa quan es realitzan canvis sobre els gràfics
}
if(esquerra) {
for(int d = serplong-1; d>=0; d--) {
longYserp[d+1] = longYserp[d];
}
for(int d = serplong; d>= 0; d--) {
if(d==0) {
longXserp[d] = longXserp[d] - 25;
}
else {
longXserp[d] = longXserp[d-1];
}
if(longXserp[d] < 25) {
longXserp[d] = 850;
}
}
repaint();
}
if(amunt) {
for(int d = serplong-1; d>=0; d--) {
longXserp[d+1] = longXserp[d];
}
for(int d = serplong; d>= 0; d--) {
if(d==0) {
longYserp[d] = longYserp[d] - 25;
}
else {
longYserp[d] = longYserp[d-1];
}
if(longYserp[d] < 75) {
longYserp[d] = 625;
}
}
repaint();
}
if(avall) {
for(int d = serplong-1; d>=0; d--) {
longXserp[d+1] = longXserp[d];
}
for(int d = serplong; d>= 0; d--) {
if(d==0) {
longYserp[d] = longYserp[d] + 25;
}
else {
longYserp[d] = longYserp[d-1];
}
if(longYserp[d] > 625) {
longYserp[d] = 75;
}
}
repaint();
}
}
}
I've been trying to figure out what's wrong for days. What is wrong with the above code?

public void paint(Graphics g) { ..
This should be:
public void paintComponent(Graphics g) {
super.paintComponent(g); ..
Note two important differences:
Override paintComponent for any class that is or extends JComponent.
Call the super method when custom painting to erase the previous drawings.
Other tips now I look more closely at the code:
serpdreta = new ImageIcon("src/grafics/serpdreta.png"); This type of resource loading should not be done in a paint method, which are expected to be completed in a minimal time. Instead load the image(s) when the class is constructed and store them as fields of the class, to then be used whenever needed.
But that path will likely fail when the app. is turned into a Jar. The src directory is typically not included.
Application resources will become embedded resources by the time of deployment, so it is wise to start accessing them as if they were, right now. An embedded-resource must be accessed by URL rather than file. See the info. page for embedded resource for how to form the URL.
If the app. needs to paint images, create an Image rather than an ImageIcon.
For better feedback when loading images, use ImageIO.read(..) rather than creating an ImageIcon as it will fail silently while ImageIO will provide useful information as to the cause of any problems.
For Swing, we typically use key bindings rather than the lower level KeyListener.

Related

Java 2D Game Programming : Missile shooting is too fast?

Hello I'm fairly new to programming and this is my first time posting here so any help would be appreciated so:
my problem is that I"m trying to create some kind of 2D shooter game in java but I don't know if my simple game loop is good because when i shoot a missile it shoots a one every 20 ms and it's too fast and shoots a ton of missiles at once so is there any way to adjust it ? Like to keep some delay between every missile and the other??
and please tell me if i have problems or bad programming in my code !!
this is my game panel where most of the game happens and where my loop and adding missiles method in
public class GamePanel extends JPanel implements KeyListener {
Measurments mesure = new Measurments();
int panel_width = mesure.getUniversalWidth();
int panel_height = mesure.getUniversalHeight();
Timer timer;
Random rand = new Random();
ArrayList<Enemy> enemies = new ArrayList<>();
ArrayList<Missile> missiles = new ArrayList<>();
Player player = new Player(0, 0);
boolean up = false;
boolean down = false;
boolean right = false;
boolean left = false;
boolean isShooting = false;
boolean isRunning = true;
public boolean gameRunning() {
return isRunning;
}
int count = 5;
int missilesCount = 6;
public GamePanel() {
timer = new Timer(20, new ActionListener() {
public void actionPerformed(ActionEvent e) {
StartGame();
repaint();
}
});
setSize(panel_width, panel_height);
addKeyListener(this);
timer.start();
for (int i = 0; i < count; i++) {
addEnemy(new Enemy(rand.nextInt(750), rand.nextInt(500)));
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
player.paint(g2d);
for (int i = 0; i < enemies.size(); i++) {
Enemy temp = enemies.get(i);
temp.paint(g2d);
}
for (int i = 0; i < missiles.size(); i++) {
Missile mis = missiles.get(i);
mis.paint(g2d);
mis.behave();
}
}
public void StartGame() {
if (isRunning) {
runGame();
setBackground(Color.YELLOW);
} else {
setBackground(Color.BLACK);
}
}
public void runGame() {
update();
};
public void update() {
player.checkBorders();
checkColls();
if (up) {
player.updateUp();
}
if (down) {
player.updateDown();
}
if (right) {
player.updateRight();
}
if (left) {
player.updateLeft();
}
if (isShooting) {
for (int i = 0; i < 5; i++) {
missiles.add(new Missile(player.getX() + 16, player.getY() + 16));
}
}
for (int i = 0; i < missiles.size(); i++) {
Missile temp = missiles.get(i);
if (temp.getX() == panel_width) {
RemoveMissile(temp);
}
}
}
public void addEnemy(Enemy e) {
enemies.add(e);
}
public void removeEnemy(Enemy e) {
enemies.remove(e);
}
public void addMissile(Missile e) {
missiles.add(e);
}
public void RemoveMissile(Missile e) {
missiles.add(e);
}
public void checkColls() {
for (int i = 0; i < enemies.size(); i++) {
Enemy tempEnm = enemies.get(i);
for (int e = 0; e < missiles.size(); e++) {
Missile tempMis = missiles.get(e);
if (tempMis.missileRect().intersects(tempEnm.enemyRect())) {
enemies.remove(tempEnm);
missiles.remove(tempMis);
}
}
}
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == e.VK_UP) {
up = true;
}
if (key == e.VK_DOWN) {
down = true;
}
if (key == e.VK_RIGHT) {
right = true;
}
if (key == e.VK_LEFT) {
left = true;
}
if (key == e.VK_ENTER) {
isRunning = true;
}
if (key == e.VK_SPACE) {
isShooting = true;
}
}
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if (key == e.VK_UP) {
up = false;
}
if (key == e.VK_DOWN) {
down = false;
}
if (key == e.VK_RIGHT) {
right = false;
}
if (key == e.VK_LEFT) {
left = false;
}
if (key == e.VK_SPACE) {
isShooting = false;
}
}
public void keyTyped(KeyEvent e) {
}
}
Thanks in advance !!
private long fired = 0L;
public void update() {
...
// firing missiles: only if the missile count is less than the max., and the elapsed
// time is more than a limit (100 ms)
if ( isShooting && missiles.size() < missilesCount &&
( System.currentTimeMilis() - this.fired ) > 100 ) {
missiles.add( new Missile( player.getX() + 16, player.getY() + 16 ) );
// time of last firing
this.fired = System.currentTimeMilis();
}
...
}
public void RemoveMissile(Missile e) {
// as Guest is asked in another answer, this method should remove, not add...
missiles.remove(e);
}

How to add a object into a JPanel

I am trying to add a ball into a JPanel, however, I am unsure how to do this Below is the code I currently have for adding the ball into the JPanel. I am trying to add multiple balls in a random location onto the screen. The first appears as expected but any more than that don't appear on the screen.
Ball class;
public class Ball extends Component {
public static double ballX = rand.nextInt(500) + 40;
public static double ballY = rand.nextInt(300) + 10;
public static Ball[] balls = new Ball[20];
public Ball() {
}
public void draw(Graphics g2) {
Color color = new Color(r, g, b);
g2.setColor(color);
g2.fillOval((int) ballX, (int) ballY, 30, 30);
}
}
Method trying to add a ball into the JPanel;
public class BallFrames extends JFrame {
/* creates static varibles privite for use withing class and public for
use out side of the class */
public static final JPanel controlPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
public static final JPanel ballPanel = new JPanel();
public static JButton button;
public static JPanel displayPanel = new JPanel(new BorderLayout());
private static int FRAME_WIDTH = 600;
private static int FRAME_HEIGHT = 600;
/**
* constructor called method to create the components
*/
public BallFrames() {
setSize(FRAME_WIDTH,FRAME_HEIGHT);
createComponents(); // creates all compononents
}
/*
* calls helper methods to create all of the componanats needed
*/
private void createComponents() {
ActionListener listener = new BallListener();
createPanel(); // creates a panel
createButtons(listener); // Creates a button
createSlider();
}
/**
* method to create panels
*/
public void createPanel() {
BallComponent component = new BallComponent(); // creates a new BallCompoenet
displayPanel.add(component, BorderLayout.CENTER);
displayPanel.add(controlPanel, BorderLayout.SOUTH); // adds thecontrol panel
add(displayPanel); // adds the dice to the JFrame
}
public static void addBall() throws InterruptedException {
Ball.balls[BallListener.balls] = new Ball();
System.out.println(BallListener.balls); // testing
ballPanel.add(Ball.balls[BallListener.balls]);
// ballPanel.add(ball);
Runnable r = new BallRunnable();
Thread t = new Thread(r);
t.start();
t.join();
ballPanel.repaint();
}
How I am drawing them;
public class BallComponent extends JComponent {
/**
* calls paintComponenet to render images on the screen
*
* #param g
*/
#Override
public void paintComponent(Graphics g) {
int delay = 1000;
super.paintComponent(g); // call to super
Graphics2D g2 = (Graphics2D) g; // recover the graphic
TimerListener listener = new TimerListener();
Timer t = new Timer(delay, listener);
if (BallListener.gameOn == true) {
for(int i = 0; i < BallListener.balls; i++){
Ball.balls[i].draw(g2);
}
BallFrames.displayPanel.repaint();
}
}
ActionListener for the buttons;
public class BallListener implements ActionListener {
public static boolean gameOn = false;
public static int balls = 0;
/**
* gets the which button has been pressed and responds appriately
*
* #param event based on the event it will preform selected actions
*/
#Override
public void actionPerformed(ActionEvent event) {
String action = event.getActionCommand();
switch (action) {
case "start":
gameOn = true;
{
try {
BallFrames.addBall();
} catch (InterruptedException ex) {
Logger.getLogger(BallListener.class.getName()).log(Level.SEVERE, null, ex);
}
balls++;
}
BallFrames.displayPanel.repaint();
break;
case "pause":
break;
}
}
Ball Runnable;
public class BallRunnable implements Runnable {
private static Random rand = new Random();
public static boolean goLeft = true;
public static boolean goRight = false;
public static boolean goUp = false;
public static boolean goDown = false;
public static boolean diagonalUp = false;
public static boolean diagonalDown = false;
public static double speed = 0.2f;
public BallRunnable() {
}
public void run() {
boundsCheckY1();
boundsCheckX1();
boundsCheckY2();
boundsCheckX2();
}
public void boundsCheckX1() {
int temp;
if (Ball.ballX < 1) {
temp = rand.nextInt(5) + 1;
if(temp == 1) {
goRight = true;
goLeft = false;
goUp = false;
goDown = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 2) {
goRight = true;
goUp = true;
goDown = false;
goLeft = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 3) {
goRight = true;
goUp = false;
goDown = true;
goLeft = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 4) {
goRight = true;
goUp = false;
goDown = false;
goLeft = false;
diagonalUp = true;
diagonalDown = false;
} else if (temp == 5) {
goRight = true;
goUp = false;
goDown = false;
goLeft = false;
diagonalUp = false;
diagonalDown = true;
}
}
}
public void boundsCheckY1(){
int temp;
if (Ball.ballY < 1) {
temp = rand.nextInt(5) + 1;
if(temp == 1) {
goRight = false;
goLeft = false;
goUp = false;
goDown = true;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 2) {
goRight = false;
goUp = false;
goDown = true;
goLeft = true;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 3) {
goRight = true;
goUp = false;
goDown = true;
goLeft = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 4) {
goRight = true;
goUp = false;
goDown = true;
goLeft = false;
diagonalUp = false;
diagonalDown = true;
} else if (temp == 5) {
goRight = false;
goUp = false;
goDown = true;
goLeft = true;
diagonalUp = false;
diagonalDown = true;
}
}
}
public void boundsCheckX2 () {
int temp;
if (Ball.ballX > 559) {
temp = rand.nextInt(5) + 1;
if(temp == 1) {
goRight = false;
goLeft = true;
goUp = false;
goDown = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 2) {
goRight = false;
goUp = true;
goDown = false;
goLeft = true;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 3) {
goRight = false;
goUp = false;
goDown = true;
goLeft = true;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 4) {
goRight = false;
goUp = false;
goDown = false;
goLeft = true;
diagonalUp = true;
diagonalDown = false;
} else if (temp == 5) {
goRight = false;
goUp = false;
goDown = false;
goLeft = true;
diagonalUp = false;
diagonalDown = true;
}
}
}
public void boundsCheckY2() {
int temp;
if (Ball.ballY > 470) {
temp = rand.nextInt(5) + 1;
if(temp == 1) {
goRight = false;
goLeft = false;
goUp = true;
goDown = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 2) {
goRight = false;
goUp = true;
goDown = false;
goLeft = true;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 3) {
goRight = true;
goUp = true;
goDown = false;
goLeft = false;
diagonalUp = false;
diagonalDown = false;
} else if (temp == 4) {
goRight = true;
goUp = true;
goDown = false;
goLeft = false;
diagonalUp = true;
diagonalDown = false;
} else if (temp == 5) {
goRight = false;
goUp = true;
goDown = false;
goLeft = true;
diagonalUp = true;
diagonalDown = false;
}
}
}
}
The viewer class;
public class BallViewer {
/**
* creates the main frame
*
* #param args
*/
public static void main(String[] args) throws InterruptedException {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
try {
for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (Exception e) {
// If Nimbus is not available, you can set the GUI to another look and feel.
}
// new BallFrames().setVisible(true);
JFrame frame = new BallFrames(); // creates new JFrame
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Multi-Treaded Balls");// Sets the Title
frame.setVisible(true); // Makes the frame visible
frame.setResizable(false);
}
});
}
}
the timer listener;
public class TimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent event) {
String action = event.getActionCommand();
try {
movement();
} catch (InterruptedException ex) {
Logger.getLogger(TimerListener.class.getName()).log(Level.SEVERE, null, ex);
}
}
public void movement() throws InterruptedException {
if(goLeft == true) {
Ball.ballX -= speed;
}
if(goRight == true) {
Ball.ballX += speed;
}
if(goUp == true) {
Ball.ballY -= speed;
}
if(goDown == true) {
Ball.ballY += speed;
}
if(diagonalUp == true) {
Ball.ballY += speed / 2;
}
if(diagonalDown == true) {
Ball.ballY -= speed / 2;
}
}
}
I want to be able to add more than one ball on the screen at a given time, which also moves around like the first ball.
Your definition of the ball class is behaving as expected:
public class Ball extends Component {
public static double ballX = rand.nextInt(500) + 40;
public static double ballY = rand.nextInt(300) + 10;
public static Ball[] balls = new Ball[20];
public Ball() {
}
public void draw(Graphics g2) {
Color color = new Color(r, g, b);
g2.setColor(color);
g2.fillOval((int) ballX, (int) ballY, 30, 30);
}
}
All of the static fields are shared between all instances of the class. That's what static means. All Balls have the same ballX and ballY coordinates.
What you are looking for is non-static fields that belong to each individual instance. You also have to initialize these fields every time you make a new ball. static fields only get initialized once when the class is loaded. There are a couple more changes that I would recommend:
If your x- and y-coordinates belong only to the one ball, it is better to make them private.
Extend JComponent instead of Component, since you are clearly using swing here.
Implement paintComponent instead of draw. It will make your drawing code require less maintenance if nothing else.
Here is a version of the class that should work a bit better:
public class Ball extends JComponent
{
private double ballX;
private double ballY;
public static Ball[] balls = new Ball[20];
public Ball()
{
ballX = rand.nextInt(500) + 40;
ballY = rand.nextInt(300) + 10;
}
public void paintComponent(Graphics g2)
{
Color color = new Color(r, g, b);
g2.setColor(color);
g2.fillOval((int) ballX, (int) ballY, 30, 30);
}
}
Painting code is for painting only.
You should NEVER create/start a Timer in a painting method. Get rid of all that code.
You should never invoke repaint(), this will cause an infinite loop.
Also, get rid of all you animation code. Your first task is to paint multiple balls on the panel. Once you get this working, then you worry about trying to do animation.
There is no need to extend JComponent, since you class is NOT a component. That is you never add the component to a panel. All you do is paint the object in another class.
So your BallComponent class (which is a component) needs to have an ArrayList which keeps track of the ball objects you want to paint. So you need a method to add a ball object to this ArrayList. Then the paintComponent() method simply iterates through the list and paints all the balls.
Check out the DrawOnComponent example found in Custom Painting Approaches.

Why is my simple java2d Space Invaders game lagging?

I'm currently making a space invaders-esque game for my software engineering course. I've already got everything working that satisfies the requirements, so this isn't a 'solve my homework' kind of question. My problem is that the game will lag (at what seems like random times & intervals) to the point where it becomes too frustrating to play. Some things I think might be causing this - though I'm not positive - are as follows:
Problem with timer event every 10 ms (I doubt this because of the very limited resources required for this game).
Problem with collision detection (checking for collision with every visible enemy every 10 ms seems like it would take up a large chunk of resources)
Problem with repainting? This seems unlikely to me however...
#SuppressWarnings("serial")
public class SIpanel extends JPanel {
private SIpanel panel;
private Timer timer;
private int score, invaderPace, pulseRate, mysteryCount, distanceToEdge;
private ArrayList<SIthing> cast;
private ArrayList<SIinvader> invaders, dead;
private ArrayList<SImissile> missileBase, missileInvader;
private SIinvader[] bottomRow;
private SIbase base;
private Dimension panelDimension;
private SImystery mysteryShip;
private boolean gameOver, left, right, mysteryDirection, space, waveDirection;
private boolean runningTimer;
private Music sound;
private void pulse() {
pace();
processInputs();
if (gameOver) gameOver();
repaint();
}
private void pace() {
// IF invaders still live
if (!invaders.isEmpty()) {
invaderPace++;
// Switch back manager
if (distanceToEdge <= 10) {
switchBack();
pulseRate = (pulseRate >= 16) ? (int) (pulseRate*(0.8)) : pulseRate;
waveDirection = !waveDirection;
distanceToEdge = calculateDistanceToEdge();
}
// Move invaders left/right
else if (invaderPace >= pulseRate) {
invaderPace = 0;
distanceToEdge = calculateDistanceToEdge();
moveAI();
invadersFire();
if (!dead.isEmpty()) removeDead();
if (mysteryCount < 1) tryInitMysteryShip();
}
// All invaders are kill, create new wave
} else if (missileBase.isEmpty() && missileInvader.isEmpty() && !cast.contains(mysteryShip)) {
// System.out.println("New Wave!");
newWave();
}
// Every pace
if (!missileBase.isEmpty()) moveMissileBase();
// Every two paces
if (invaderPace % 2 == 0) {
if (!missileInvader.isEmpty()) moveMissileInvader();
if (mysteryCount > 0) moveMysteryShip();
}
}
private void processInputs() {
if (left) move(left);
if (right) move(!right);
if (space) fireMissile(base, true);
}
protected void fireMissile(SIship ship, boolean isBase) {
if(isBase && missileBase.isEmpty()) {
base.playSound();
SImissile m = new SImissile(ship.getX()+(ship.getWidth()/2), ship.getY()-(ship.getHeight()/4));
missileBase.add(m);
cast.add(m);
} else if (!isBase && missileInvader.size()<3) {
base.playSound();
SImissile m = new SImissile(ship.getX()+(ship.getWidth()/2), ship.getY()+(ship.getHeight()/4));
missileInvader.add(m);
cast.add(m);
}
}
private void newWave() {
pulseRate = 50;
int defaultY=60, defaultX=120, defaultWidth=30, defaultHeight=24;
for(int i=0; i<5; i++) {
for(int j=0; j<10; j++) {
if (i<1) invaders.add(new SItop((j*defaultWidth)+defaultX, (i*defaultHeight)+defaultY, defaultWidth, defaultHeight));
else if (i<3) invaders.add(new SImiddle((j*defaultWidth)+defaultX, (i*defaultHeight)+defaultY, defaultWidth, defaultHeight));
else if (i<5) invaders.add(new SIbottom((j*defaultWidth)+defaultX, (i*defaultHeight)+defaultY, defaultWidth, defaultHeight));
}
}
for (SIinvader s: invaders) {
cast.add(s);
}
if (!cast.contains(base)) {
cast.add(base);
}
bottomRow = getBottomRow();
}
private void tryInitMysteryShip() {
Random rand = new Random();
int x=rand.nextInt(1000);
if (x<=3) {
mysteryCount = 1;
if (rand.nextBoolean()) {
mysteryDirection = true;
}
if (mysteryDirection) {
mysteryShip = new SImystery(0, 60, 36, 18);
} else {
mysteryShip = new SImystery(480, 60, 36, 18);
}
cast.add(mysteryShip);
}
}
private void moveMysteryShip() {
int distance = 0;
if (mysteryDirection) {
mysteryShip.moveRight(5);
distance = getWidth() - mysteryShip.getX();
} else {
mysteryShip.moveLeft(5);
distance = 30+mysteryShip.getX()-mysteryShip.getWidth();
}
if (distance <= 5) {
dead.add(mysteryShip);
mysteryShip = null;
mysteryCount = 0;
}
}
private void removeDead() {
#SuppressWarnings("unchecked")
ArrayList<SIinvader> temp = (ArrayList<SIinvader>) dead.clone();
dead.clear();
for (SIinvader s : temp) {
invaders.remove(s);
cast.remove(s);
}
bottomRow = getBottomRow();
}
private void invadersFire() {
int[] p = new int[bottomRow.length];
for (int i=0; i<p.length; i++) {
for (int j=0; j<p.length; j++) {
p[j] = j;
}
Random rand = new Random();
int a=rand.nextInt(101);
if (a>=20) {
int b=rand.nextInt(p.length);
fireMissile(bottomRow[b], false);
}
}
}
private int calculateDistanceToEdge() {
int distance = 0;
SIinvader[] outliers = getOutliers();
if (waveDirection) {
distance = getWidth() - outliers[0].getX()-outliers[0].getWidth();
} else {
distance = outliers[1].getX();
}
return distance;
}
private SIinvader[] getOutliers() {
SIinvader leftMost = invaders.get(0), rightMost = invaders.get(0);
for (SIinvader s : invaders) {
if (s.getX() < leftMost.getX()) {
leftMost = s;
}
if (s.getX() > rightMost.getX()) {
rightMost = s;
}
}
return new SIinvader[] { rightMost, leftMost };
}
private SIinvader[] getBottomRow() {
SIinvader[] x = new SIinvader[(invaders.size()>10)?10:invaders.size()];
for (int i=0; i<x.length; i++) {
x[i] = invaders.get(i);
for (SIinvader s:invaders) {
if (s.getX() == x[i].getX()) {
if (s.getY() > x[i].getY()) {
x[i] = s;
}
}
}
}
return x;
}
private void move(boolean b) {
int defaultX = 5;
if (b) base.moveLeft(defaultX);
else base.moveRight(defaultX);
}
private void moveAI() {
for(SIinvader s : invaders) {
s.changeImage();
int defaultX = 5;
if (waveDirection) s.moveRight(defaultX);
else s.moveLeft(defaultX);
}
}
private void moveMissileBase() {
if (invaders.isEmpty()) return;
int movement = -5, bound = 0;
SImissile missile = missileBase.get(0);
missile.moveDown(movement);
SIinvader lowestInvader = getLowestInvader();
if (missile.getY() < (lowestInvader.getY() + lowestInvader.getHeight())) {
for (SIinvader s:bottomRow) {
if (checkCollision(missile, s)) {
s.setHit();
dead.add(s);
cast.remove(missile);
missileBase.clear();
score += s.value;
return;
}
}
if (mysteryCount > 0) {
if (checkCollision(missile, mysteryShip)) {
mysteryShip.setHit();
dead.add(mysteryShip);
cast.remove(missile);
missileBase.clear();
score += mysteryShip.value;
return;
}
}
if (missile.getY() < bound) {
missileBase.remove(missile);
cast.remove(missile);
}
}
}
private SIinvader getLowestInvader() {
SIinvader lowest = bottomRow[0];
for (SIinvader invader : bottomRow) {
if (invader.getY() > lowest.getY()) {
lowest = invader;
}
}
return lowest;
}
private void moveMissileInvader() {
int movement = 5, bound = (int) panelDimension.getHeight();
for (SImissile missile : missileInvader) {
missile.moveDown(movement);
if(missile.getY() >= base.getY()) {
if (checkCollision(missile, base)) {
base.setHit();
gameOver = true;;
missileInvader.remove(missile);
cast.remove(missile);
return;
} else if (missile.getY() >= bound-25) {
missileInvader.remove(missile);
cast.remove(missile);
return;
}
}
}
}
private boolean checkCollision(SIthing missile, SIthing ship) {
Rectangle2D rect1 = new Rectangle2D.Double(
missile.getX(),
missile.getY(),
missile.getWidth(),
missile.getHeight()
);
Rectangle2D rect2 = new Rectangle2D.Double(
ship.getX(),
ship.getY(),
ship.getWidth(),
ship.getHeight()
);
return rect1.intersects(rect2);
}
private void switchBack() {
int defaultY = 12;
for (SIinvader s : invaders) {
if (s.getY() > getHeight()) {
gameOver = true;
return;
}
s.moveDown(defaultY);
}
}
private void gameOver() {
pause(true);
SI.setGameOverLabelVisibile(true);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.GREEN);
Font font = new Font("Arial", 0, 20);
setFont(font);
String score = "Score: "+this.score;
Rectangle2D rect = font.getStringBounds(score, g2.getFontRenderContext());
int screenWidth = 0;
try { screenWidth = (int) panelDimension.getWidth(); }
catch (NullPointerException e) {}
g2.setColor(Color.GREEN);
g2.drawString(score, (int) (screenWidth - (10 + rect.getWidth())), 20);
for(SIthing a:cast) {
a.paint(g);
}
}
public SIpanel() {
super();
setBackground(Color.BLACK);
cast = new ArrayList<SIthing>();
missileBase = new ArrayList<SImissile>();
score = invaderPace = mysteryCount = pulseRate = 0;
sound = new Music("AmbientMusic.wav");
panel = this;
addKeyListener(new KeyAdapter() {
#Override
public void keyPressed(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_LEFT : left = true; break;
case KeyEvent.VK_RIGHT : right = true; break;
case KeyEvent.VK_SPACE : space = true; break;
}
}
#Override
public void keyReleased(KeyEvent e) {
switch (e.getKeyCode()) {
case KeyEvent.VK_LEFT : left = false; break;
case KeyEvent.VK_RIGHT : right = false; break;
case KeyEvent.VK_SPACE : space = false; break;
}
}
});
setFocusable(true);
timer = new Timer(10, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
pulse();
}
});
}
public void reset() {
SI.setGameOverLabelVisibile(false);
score = invaderPace = mysteryCount = 0;
pulseRate = 50;
cast = new ArrayList<SIthing>();
invaders = new ArrayList<SIinvader>();
dead = new ArrayList<SIinvader>();
missileBase = new ArrayList<SImissile>();
missileInvader = new ArrayList<SImissile>();
base = new SIbase(230, 370, 26, 20);
waveDirection = true;
gameOver = false;
sound.stop();
sound.loop();
panelDimension = SI.getFrameDimensions();
bottomRow = getBottomRow();
newWave();
timer.start();
runningTimer=true;
}
public SIpanel getPanel() {
return this.panel;
}
public void pause(boolean paused) {
if (paused) timer.stop();
else timer.start();
}
}
I believe that collision detection may be the reason for lagging and you should simply investigate it by trying to increase and decrease count of enemies or missiles drastically to see if that makes a difference.
Consider garbage collector your enemy. In your checkCollision method you are instantiating two (very simple) objects. It may not seem like a lot, but consider that your might be creating them for each collision check, and that at 60fps it adds up until it may reach critical mass when GC says "stop the world" and you see noticeable lag.
If that is the case, possible solution to that would be to not instantiate any objects in a method called so frequently. You may create Rectangle2D once, and then update its position, instead of creating a new one each time, so you will avoid unnecessary memory allocation.

How could I possibly create two of the same thing in java

Okay, so my question is, in swing, how could i make two of the same thing while they both have the same attributes but yet can act independently, for example, i am working on a city builder, when the uses presses a button to add a oil power station, the power station will get added to the world, however, there is only one. how could i make it so that the player could make a seamless amount of the same building but yet they all act independently, e.g when i go to add a second of the same building the first one won't follow the mouse.
heres my current code to help explain my issue:
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
public class Game extends JFrame{
public Image map;
public Image utilButton;
public Image resButton;
public Image oilPlantBox;
public Image apartmentBlockABox;
//Building Img
public Image oilPowerStation;
public Image apartmentBlockA;
//Util selects
boolean showUtil = false;
boolean UtilSelect = false;
//Residential selects
boolean showRes = false;
boolean resSelect = false;
//Oil Power Station
boolean showOPPBox = true;
boolean checkOilPowerPlant = false;
boolean drawOilPlant = false;
boolean setPowerStation = false;
boolean placeOilPowerPlant = true;
int OilPowerStationxX = 0;
int OilPowerStationY = 0;
//Apartment Block A
boolean showABA = true;
boolean checkApartmentBlockA = false;
boolean drawApartmentBlockA = false;
boolean setApartmentBlockA = false;
boolean placeApartmentBlockA = true;
int apartmentBlockAX = 0;
int apartmentBlockAY = 0;
int x;
int y;
public int power = 0;
int jobs = 0;
public Game(){
//Load Images:
ImageIcon mapI = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/map.jpg");
map = mapI.getImage();
ImageIcon utilButtonI = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/UTIL.jpg");
utilButton = utilButtonI.getImage();
ImageIcon resButtonI = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/RES.jpg");
resButton = resButtonI.getImage();
ImageIcon oPB = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/oilPlantBox.png");
oilPlantBox = oPB.getImage();
ImageIcon aBAB = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/apartmentABlock.jpg");
apartmentBlockABox = aBAB.getImage();
//Building Images
//Oil Power Station
ImageIcon oilPlantI = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/oilPlant.jpg");
oilPowerStation = oilPlantI.getImage();
//Apartment Block A
ImageIcon apartmentBlockI = new ImageIcon("C:/Programs/Eclipse/eclipse/CityCenterBeta/bin/apartment block.jpg");
apartmentBlockA = apartmentBlockI.getImage();
//Set up game
addKeyListener(new AL());
addMouseListener(new Mouse());
init();
}
private Image dbImage;
private Graphics dbg;
public static void main(String[] args) {
new Game();
}
//When the program runs, thins are initialised here
public void init(){
windowManager();
}
public void paintComponent(Graphics g){
g.drawImage(map,0,0,null);
g.drawImage(utilButton,20,100,null);
g.drawImage(resButton,20,200,null);
if(showUtil == true){
if(showOPPBox == true){
g.drawImage(oilPlantBox,190,130,null);
}
}
if(showRes == true){
if(showABA == true){
g.drawImage(apartmentBlockABox,190,130,null);
}
}
if(drawOilPlant == true){
g.drawImage(oilPowerStation,OilPowerStationxX,OilPowerStationY,null);
if(checkOilPowerPlant == true){
setPowerStation = true;
}
if(drawApartmentBlockA == true){
g.drawImage(apartmentBlockA,apartmentBlockAX,apartmentBlockAY,null);
if(checkApartmentBlockA == true){
setApartmentBlockA = true;
}
}
}
repaint();
}
public void paint(Graphics g){
dbImage = createImage(getWidth(), getHeight());
dbg = dbImage.getGraphics();
paintComponent(dbg);
g.drawImage(dbImage,0,0,this);
}
public void windowManager(){
JFrame f = new JFrame();
setTitle("City Center");
setVisible(true);
setResizable(false);
setBackground(Color.BLACK);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setExtendedState(f.MAXIMIZED_BOTH);
setUndecorated(true);
}
public class AL extends KeyAdapter{
public void keyPressed(KeyEvent e){
int keyCode = e.getKeyCode();
if(keyCode == e.VK_ENTER){
if(setPowerStation == true)
placeOilPowerPlant = false;
checkOilPowerPlant = false;
setPowerStation = false;
showUtil = false;
UtilSelect = false;
showOPPBox = false;
oilPlantAtt();
System.out.println(jobs + " Job Openings");
System.out.println(power + "MW");
}
if(setApartmentBlockA == true){
placeApartmentBlockA = false;
checkApartmentBlockA = false;
setApartmentBlockA = false;
showRes = false;
resSelect = false;
showABA = false;
apartmentBlockAtt();
}
}
public void keyReleased(KeyEvent e){
}
}
public class Mouse extends MouseAdapter {
public void mousePressed(MouseEvent e) {
x = e.getX();
y = e.getY();
//Pressed Utilies button
if((x > 20) && (x < 120) && (y > 100) && (y < 200) && (showUtil == false)) {
showUtil = true;
UtilSelect = true;
showRes = false;
resSelect = false;
}
//Pressed Residential Button
if((x > 20) && (x < 120) && (y > 200) && (y < 300) && (showRes == false)){
showRes = true;
resSelect = true;
showUtil = false;
UtilSelect = false;
}
if((x > 190) && (x < 265) && (y > 130) && (y < 192)){
if(resSelect == true){
drawApartmentBlockA = true;
if(placeApartmentBlockA == true){
checkApartmentBlockA = true;
}
}
if(UtilSelect == true){
drawOilPlant = true;
if(placeOilPoerPlant == true){
checkOilPowerPlant = true;
}
}
}
if(setPowerStation == true){
OilPowerStationxX = x;
OilPowerStationY = y;
}else{
OilPowerStationxX = OilPowerStationxX;
OilPowerStationY = OilPowerStationY;
}
if(setApartmentBlockA == true){
apartmentBlockAX = x;
apartmentBlockAY = y;
}else{
apartmentBlockAX = apartmentBlockAX;
apartmentBlockAY = apartmentBlockAY;
}
}
}
public void oilPlantAtt(){
jobs = jobs + 150;
power = power + 1000;
}
public void apartmentBlockAtt(){
boolean work = false;
if(power > 0){
work = true;
}
if(work == true){
jobs = jobs - 300;
power = power - 100;
}
}
You actually need to create 2 different instances with the similar properties or try this snippet:
Object building = new Object();
building.isLockedInPlace = false;
And use building.isLockedInPlace to say if you have one down.
To have multiple, you will have to use Object.clone();.
Hope it works and happy coding!
Based on your problem description and your provided code, it appears that you are new to object-oriented programming (OOP), which Java revolves around. If you haven't done so already, I'd recommend looking through the core Java tutorials again, regarding objects and their use.
As it stands, you have included everything in one file: the attributes of your power plant, of your apartment block, etc. What your program should look like is the following:
A Game class (which you have already) that contains either one or a collection of City objects.
A City class which contains a collection of Building objects.
A Building class could be abstract or an interface, which your ApartmentBlock and PowerPlant classes would extend or implement.
This structure is extensible and allows you to easily add more buildings and building types. You can also better enforce data encapsulation (which you aren't doing at all here), as each concrete building class (like your ApartmentBlock and PowerPlant) would also be the only ones who cared about what image they were displaying, and other data building specific information that only they really need to know.

How to implement draggable tab using Java Swing?

How do I implement a draggable tab using Java Swing? Instead of the static JTabbedPane I would like to drag-and-drop a tab to different position to rearrange the tabs.
EDIT: The Java Tutorials - Drag and Drop and Data Transfer.
Curses! Beaten to the punch by a Google search. Unfortunately it's true there is no easy way to create draggable tab panes (or any other components) in Swing. So whilst the example above is complete this one I've just written is a bit simpler. So it will hopefully demonstrate the more advanced techniques involved a bit clearer. The steps are:
Detect that a drag has occurred
Draw the dragged tab to an offscreen buffer
Track the mouse position whilst dragging occurs
Draw the tab in the buffer on top of the component.
The above example will give you what you want but if you want to really understand the techniques applied here it might be a better exercise to round off the edges of this example and add the extra features demonstrated above to it.
Or maybe I'm just disappointed because I spent time writing this solution when one already existed :p
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.image.BufferedImage;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTabbedPane;
public class DraggableTabbedPane extends JTabbedPane {
private boolean dragging = false;
private Image tabImage = null;
private Point currentMouseLocation = null;
private int draggedTabIndex = 0;
public DraggableTabbedPane() {
super();
addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
if(!dragging) {
// Gets the tab index based on the mouse position
int tabNumber = getUI().tabForCoordinate(DraggableTabbedPane.this, e.getX(), e.getY());
if(tabNumber >= 0) {
draggedTabIndex = tabNumber;
Rectangle bounds = getUI().getTabBounds(DraggableTabbedPane.this, tabNumber);
// Paint the tabbed pane to a buffer
Image totalImage = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics totalGraphics = totalImage.getGraphics();
totalGraphics.setClip(bounds);
// Don't be double buffered when painting to a static image.
setDoubleBuffered(false);
paintComponent(totalGraphics);
// Paint just the dragged tab to the buffer
tabImage = new BufferedImage(bounds.width, bounds.height, BufferedImage.TYPE_INT_ARGB);
Graphics graphics = tabImage.getGraphics();
graphics.drawImage(totalImage, 0, 0, bounds.width, bounds.height, bounds.x, bounds.y, bounds.x + bounds.width, bounds.y+bounds.height, DraggableTabbedPane.this);
dragging = true;
repaint();
}
} else {
currentMouseLocation = e.getPoint();
// Need to repaint
repaint();
}
super.mouseDragged(e);
}
});
addMouseListener(new MouseAdapter() {
public void mouseReleased(MouseEvent e) {
if(dragging) {
int tabNumber = getUI().tabForCoordinate(DraggableTabbedPane.this, e.getX(), 10);
if(tabNumber >= 0) {
Component comp = getComponentAt(draggedTabIndex);
String title = getTitleAt(draggedTabIndex);
removeTabAt(draggedTabIndex);
insertTab(title, null, comp, null, tabNumber);
}
}
dragging = false;
tabImage = null;
}
});
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
// Are we dragging?
if(dragging && currentMouseLocation != null && tabImage != null) {
// Draw the dragged tab
g.drawImage(tabImage, currentMouseLocation.x, currentMouseLocation.y, this);
}
}
public static void main(String[] args) {
JFrame test = new JFrame("Tab test");
test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
test.setSize(400, 400);
DraggableTabbedPane tabs = new DraggableTabbedPane();
tabs.addTab("One", new JButton("One"));
tabs.addTab("Two", new JButton("Two"));
tabs.addTab("Three", new JButton("Three"));
tabs.addTab("Four", new JButton("Four"));
test.add(tabs);
test.setVisible(true);
}
}
I liked Terai Atsuhiro san's DnDTabbedPane, but I wanted more from it. The original Terai implementation transfered tabs within the TabbedPane, but it would be nicer if I could drag from one TabbedPane to another.
Inspired by #Tom's effort, I decided to modify the code myself.
There are some details I added. For example, the ghost tab now slides along the tabbed pane instead of moving together with the mouse.
setAcceptor(TabAcceptor a_acceptor) should let the consumer code decide whether to let one tab transfer from one tabbed pane to another. The default acceptor always returns true.
/** Modified DnDTabbedPane.java
* http://java-swing-tips.blogspot.com/2008/04/drag-and-drop-tabs-in-jtabbedpane.html
* originally written by Terai Atsuhiro.
* so that tabs can be transfered from one pane to another.
* eed3si9n.
*/
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.awt.geom.*;
import java.awt.image.*;
import javax.swing.*;
public class DnDTabbedPane extends JTabbedPane {
public static final long serialVersionUID = 1L;
private static final int LINEWIDTH = 3;
private static final String NAME = "TabTransferData";
private final DataFlavor FLAVOR = new DataFlavor(
DataFlavor.javaJVMLocalObjectMimeType, NAME);
private static GhostGlassPane s_glassPane = new GhostGlassPane();
private boolean m_isDrawRect = false;
private final Rectangle2D m_lineRect = new Rectangle2D.Double();
private final Color m_lineColor = new Color(0, 100, 255);
private TabAcceptor m_acceptor = null;
public DnDTabbedPane() {
super();
final DragSourceListener dsl = new DragSourceListener() {
public void dragEnter(DragSourceDragEvent e) {
e.getDragSourceContext().setCursor(DragSource.DefaultMoveDrop);
}
public void dragExit(DragSourceEvent e) {
e.getDragSourceContext()
.setCursor(DragSource.DefaultMoveNoDrop);
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
s_glassPane.setPoint(new Point(-1000, -1000));
s_glassPane.repaint();
}
public void dragOver(DragSourceDragEvent e) {
//e.getLocation()
//This method returns a Point indicating the cursor location in screen coordinates at the moment
TabTransferData data = getTabTransferData(e);
if (data == null) {
e.getDragSourceContext().setCursor(
DragSource.DefaultMoveNoDrop);
return;
} // if
/*
Point tabPt = e.getLocation();
SwingUtilities.convertPointFromScreen(tabPt, DnDTabbedPane.this);
if (DnDTabbedPane.this.contains(tabPt)) {
int targetIdx = getTargetTabIndex(tabPt);
int sourceIndex = data.getTabIndex();
if (getTabAreaBound().contains(tabPt)
&& (targetIdx >= 0)
&& (targetIdx != sourceIndex)
&& (targetIdx != sourceIndex + 1)) {
e.getDragSourceContext().setCursor(
DragSource.DefaultMoveDrop);
return;
} // if
e.getDragSourceContext().setCursor(
DragSource.DefaultMoveNoDrop);
return;
} // if
*/
e.getDragSourceContext().setCursor(
DragSource.DefaultMoveDrop);
}
public void dragDropEnd(DragSourceDropEvent e) {
m_isDrawRect = false;
m_lineRect.setRect(0, 0, 0, 0);
// m_dragTabIndex = -1;
if (hasGhost()) {
s_glassPane.setVisible(false);
s_glassPane.setImage(null);
}
}
public void dropActionChanged(DragSourceDragEvent e) {
}
};
final DragGestureListener dgl = new DragGestureListener() {
public void dragGestureRecognized(DragGestureEvent e) {
// System.out.println("dragGestureRecognized");
Point tabPt = e.getDragOrigin();
int dragTabIndex = indexAtLocation(tabPt.x, tabPt.y);
if (dragTabIndex < 0) {
return;
} // if
initGlassPane(e.getComponent(), e.getDragOrigin(), dragTabIndex);
try {
e.startDrag(DragSource.DefaultMoveDrop,
new TabTransferable(DnDTabbedPane.this, dragTabIndex), dsl);
} catch (InvalidDnDOperationException idoe) {
idoe.printStackTrace();
}
}
};
//dropTarget =
new DropTarget(this, DnDConstants.ACTION_COPY_OR_MOVE,
new CDropTargetListener(), true);
new DragSource().createDefaultDragGestureRecognizer(this,
DnDConstants.ACTION_COPY_OR_MOVE, dgl);
m_acceptor = new TabAcceptor() {
public boolean isDropAcceptable(DnDTabbedPane a_component, int a_index) {
return true;
}
};
}
public TabAcceptor getAcceptor() {
return m_acceptor;
}
public void setAcceptor(TabAcceptor a_value) {
m_acceptor = a_value;
}
private TabTransferData getTabTransferData(DropTargetDropEvent a_event) {
try {
TabTransferData data = (TabTransferData) a_event.getTransferable().getTransferData(FLAVOR);
return data;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private TabTransferData getTabTransferData(DropTargetDragEvent a_event) {
try {
TabTransferData data = (TabTransferData) a_event.getTransferable().getTransferData(FLAVOR);
return data;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private TabTransferData getTabTransferData(DragSourceDragEvent a_event) {
try {
TabTransferData data = (TabTransferData) a_event.getDragSourceContext()
.getTransferable().getTransferData(FLAVOR);
return data;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
class TabTransferable implements Transferable {
private TabTransferData m_data = null;
public TabTransferable(DnDTabbedPane a_tabbedPane, int a_tabIndex) {
m_data = new TabTransferData(DnDTabbedPane.this, a_tabIndex);
}
public Object getTransferData(DataFlavor flavor) {
return m_data;
// return DnDTabbedPane.this;
}
public DataFlavor[] getTransferDataFlavors() {
DataFlavor[] f = new DataFlavor[1];
f[0] = FLAVOR;
return f;
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.getHumanPresentableName().equals(NAME);
}
}
class TabTransferData {
private DnDTabbedPane m_tabbedPane = null;
private int m_tabIndex = -1;
public TabTransferData() {
}
public TabTransferData(DnDTabbedPane a_tabbedPane, int a_tabIndex) {
m_tabbedPane = a_tabbedPane;
m_tabIndex = a_tabIndex;
}
public DnDTabbedPane getTabbedPane() {
return m_tabbedPane;
}
public void setTabbedPane(DnDTabbedPane pane) {
m_tabbedPane = pane;
}
public int getTabIndex() {
return m_tabIndex;
}
public void setTabIndex(int index) {
m_tabIndex = index;
}
}
private Point buildGhostLocation(Point a_location) {
Point retval = new Point(a_location);
switch (getTabPlacement()) {
case JTabbedPane.TOP: {
retval.y = 1;
retval.x -= s_glassPane.getGhostWidth() / 2;
} break;
case JTabbedPane.BOTTOM: {
retval.y = getHeight() - 1 - s_glassPane.getGhostHeight();
retval.x -= s_glassPane.getGhostWidth() / 2;
} break;
case JTabbedPane.LEFT: {
retval.x = 1;
retval.y -= s_glassPane.getGhostHeight() / 2;
} break;
case JTabbedPane.RIGHT: {
retval.x = getWidth() - 1 - s_glassPane.getGhostWidth();
retval.y -= s_glassPane.getGhostHeight() / 2;
} break;
} // switch
retval = SwingUtilities.convertPoint(DnDTabbedPane.this,
retval, s_glassPane);
return retval;
}
class CDropTargetListener implements DropTargetListener {
public void dragEnter(DropTargetDragEvent e) {
// System.out.println("DropTarget.dragEnter: " + DnDTabbedPane.this);
if (isDragAcceptable(e)) {
e.acceptDrag(e.getDropAction());
} else {
e.rejectDrag();
} // if
}
public void dragExit(DropTargetEvent e) {
// System.out.println("DropTarget.dragExit: " + DnDTabbedPane.this);
m_isDrawRect = false;
}
public void dropActionChanged(DropTargetDragEvent e) {
}
public void dragOver(final DropTargetDragEvent e) {
TabTransferData data = getTabTransferData(e);
if (getTabPlacement() == JTabbedPane.TOP
|| getTabPlacement() == JTabbedPane.BOTTOM) {
initTargetLeftRightLine(getTargetTabIndex(e.getLocation()), data);
} else {
initTargetTopBottomLine(getTargetTabIndex(e.getLocation()), data);
} // if-else
repaint();
if (hasGhost()) {
s_glassPane.setPoint(buildGhostLocation(e.getLocation()));
s_glassPane.repaint();
}
}
public void drop(DropTargetDropEvent a_event) {
// System.out.println("DropTarget.drop: " + DnDTabbedPane.this);
if (isDropAcceptable(a_event)) {
convertTab(getTabTransferData(a_event),
getTargetTabIndex(a_event.getLocation()));
a_event.dropComplete(true);
} else {
a_event.dropComplete(false);
} // if-else
m_isDrawRect = false;
repaint();
}
public boolean isDragAcceptable(DropTargetDragEvent e) {
Transferable t = e.getTransferable();
if (t == null) {
return false;
} // if
DataFlavor[] flavor = e.getCurrentDataFlavors();
if (!t.isDataFlavorSupported(flavor[0])) {
return false;
} // if
TabTransferData data = getTabTransferData(e);
if (DnDTabbedPane.this == data.getTabbedPane()
&& data.getTabIndex() >= 0) {
return true;
} // if
if (DnDTabbedPane.this != data.getTabbedPane()) {
if (m_acceptor != null) {
return m_acceptor.isDropAcceptable(data.getTabbedPane(), data.getTabIndex());
} // if
} // if
return false;
}
public boolean isDropAcceptable(DropTargetDropEvent e) {
Transferable t = e.getTransferable();
if (t == null) {
return false;
} // if
DataFlavor[] flavor = e.getCurrentDataFlavors();
if (!t.isDataFlavorSupported(flavor[0])) {
return false;
} // if
TabTransferData data = getTabTransferData(e);
if (DnDTabbedPane.this == data.getTabbedPane()
&& data.getTabIndex() >= 0) {
return true;
} // if
if (DnDTabbedPane.this != data.getTabbedPane()) {
if (m_acceptor != null) {
return m_acceptor.isDropAcceptable(data.getTabbedPane(), data.getTabIndex());
} // if
} // if
return false;
}
}
private boolean m_hasGhost = true;
public void setPaintGhost(boolean flag) {
m_hasGhost = flag;
}
public boolean hasGhost() {
return m_hasGhost;
}
/**
* returns potential index for drop.
* #param a_point point given in the drop site component's coordinate
* #return returns potential index for drop.
*/
private int getTargetTabIndex(Point a_point) {
boolean isTopOrBottom = getTabPlacement() == JTabbedPane.TOP
|| getTabPlacement() == JTabbedPane.BOTTOM;
// if the pane is empty, the target index is always zero.
if (getTabCount() == 0) {
return 0;
} // if
for (int i = 0; i < getTabCount(); i++) {
Rectangle r = getBoundsAt(i);
if (isTopOrBottom) {
r.setRect(r.x - r.width / 2, r.y, r.width, r.height);
} else {
r.setRect(r.x, r.y - r.height / 2, r.width, r.height);
} // if-else
if (r.contains(a_point)) {
return i;
} // if
} // for
Rectangle r = getBoundsAt(getTabCount() - 1);
if (isTopOrBottom) {
int x = r.x + r.width / 2;
r.setRect(x, r.y, getWidth() - x, r.height);
} else {
int y = r.y + r.height / 2;
r.setRect(r.x, y, r.width, getHeight() - y);
} // if-else
return r.contains(a_point) ? getTabCount() : -1;
}
private void convertTab(TabTransferData a_data, int a_targetIndex) {
DnDTabbedPane source = a_data.getTabbedPane();
int sourceIndex = a_data.getTabIndex();
if (sourceIndex < 0) {
return;
} // if
Component cmp = source.getComponentAt(sourceIndex);
String str = source.getTitleAt(sourceIndex);
if (this != source) {
source.remove(sourceIndex);
if (a_targetIndex == getTabCount()) {
addTab(str, cmp);
} else {
if (a_targetIndex < 0) {
a_targetIndex = 0;
} // if
insertTab(str, null, cmp, null, a_targetIndex);
} // if
setSelectedComponent(cmp);
// System.out.println("press="+sourceIndex+" next="+a_targetIndex);
return;
} // if
if (a_targetIndex < 0 || sourceIndex == a_targetIndex) {
//System.out.println("press="+prev+" next="+next);
return;
} // if
if (a_targetIndex == getTabCount()) {
//System.out.println("last: press="+prev+" next="+next);
source.remove(sourceIndex);
addTab(str, cmp);
setSelectedIndex(getTabCount() - 1);
} else if (sourceIndex > a_targetIndex) {
//System.out.println(" >: press="+prev+" next="+next);
source.remove(sourceIndex);
insertTab(str, null, cmp, null, a_targetIndex);
setSelectedIndex(a_targetIndex);
} else {
//System.out.println(" <: press="+prev+" next="+next);
source.remove(sourceIndex);
insertTab(str, null, cmp, null, a_targetIndex - 1);
setSelectedIndex(a_targetIndex - 1);
}
}
private void initTargetLeftRightLine(int next, TabTransferData a_data) {
if (next < 0) {
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
return;
} // if
if ((a_data.getTabbedPane() == this)
&& (a_data.getTabIndex() == next
|| next - a_data.getTabIndex() == 1)) {
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
} else if (getTabCount() == 0) {
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
return;
} else if (next == 0) {
Rectangle rect = getBoundsAt(0);
m_lineRect.setRect(-LINEWIDTH / 2, rect.y, LINEWIDTH, rect.height);
m_isDrawRect = true;
} else if (next == getTabCount()) {
Rectangle rect = getBoundsAt(getTabCount() - 1);
m_lineRect.setRect(rect.x + rect.width - LINEWIDTH / 2, rect.y,
LINEWIDTH, rect.height);
m_isDrawRect = true;
} else {
Rectangle rect = getBoundsAt(next - 1);
m_lineRect.setRect(rect.x + rect.width - LINEWIDTH / 2, rect.y,
LINEWIDTH, rect.height);
m_isDrawRect = true;
}
}
private void initTargetTopBottomLine(int next, TabTransferData a_data) {
if (next < 0) {
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
return;
} // if
if ((a_data.getTabbedPane() == this)
&& (a_data.getTabIndex() == next
|| next - a_data.getTabIndex() == 1)) {
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
} else if (getTabCount() == 0) {
m_lineRect.setRect(0, 0, 0, 0);
m_isDrawRect = false;
return;
} else if (next == getTabCount()) {
Rectangle rect = getBoundsAt(getTabCount() - 1);
m_lineRect.setRect(rect.x, rect.y + rect.height - LINEWIDTH / 2,
rect.width, LINEWIDTH);
m_isDrawRect = true;
} else if (next == 0) {
Rectangle rect = getBoundsAt(0);
m_lineRect.setRect(rect.x, -LINEWIDTH / 2, rect.width, LINEWIDTH);
m_isDrawRect = true;
} else {
Rectangle rect = getBoundsAt(next - 1);
m_lineRect.setRect(rect.x, rect.y + rect.height - LINEWIDTH / 2,
rect.width, LINEWIDTH);
m_isDrawRect = true;
}
}
private void initGlassPane(Component c, Point tabPt, int a_tabIndex) {
//Point p = (Point) pt.clone();
getRootPane().setGlassPane(s_glassPane);
if (hasGhost()) {
Rectangle rect = getBoundsAt(a_tabIndex);
BufferedImage image = new BufferedImage(c.getWidth(),
c.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
c.paint(g);
image = image.getSubimage(rect.x, rect.y, rect.width, rect.height);
s_glassPane.setImage(image);
} // if
s_glassPane.setPoint(buildGhostLocation(tabPt));
s_glassPane.setVisible(true);
}
private Rectangle getTabAreaBound() {
Rectangle lastTab = getUI().getTabBounds(this, getTabCount() - 1);
return new Rectangle(0, 0, getWidth(), lastTab.y + lastTab.height);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (m_isDrawRect) {
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(m_lineColor);
g2.fill(m_lineRect);
} // if
}
public interface TabAcceptor {
boolean isDropAcceptable(DnDTabbedPane a_component, int a_index);
}
}
class GhostGlassPane extends JPanel {
public static final long serialVersionUID = 1L;
private final AlphaComposite m_composite;
private Point m_location = new Point(0, 0);
private BufferedImage m_draggingGhost = null;
public GhostGlassPane() {
setOpaque(false);
m_composite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.7f);
}
public void setImage(BufferedImage draggingGhost) {
m_draggingGhost = draggingGhost;
}
public void setPoint(Point a_location) {
m_location.x = a_location.x;
m_location.y = a_location.y;
}
public int getGhostWidth() {
if (m_draggingGhost == null) {
return 0;
} // if
return m_draggingGhost.getWidth(this);
}
public int getGhostHeight() {
if (m_draggingGhost == null) {
return 0;
} // if
return m_draggingGhost.getHeight(this);
}
public void paintComponent(Graphics g) {
if (m_draggingGhost == null) {
return;
} // if
Graphics2D g2 = (Graphics2D) g;
g2.setComposite(m_composite);
g2.drawImage(m_draggingGhost, (int) m_location.getX(), (int) m_location.getY(), null);
}
}
Found this code out there on the tubes:
class DnDTabbedPane extends JTabbedPane {
private static final int LINEWIDTH = 3;
private static final String NAME = "test";
private final GhostGlassPane glassPane = new GhostGlassPane();
private final Rectangle2D lineRect = new Rectangle2D.Double();
private final Color lineColor = new Color(0, 100, 255);
//private final DragSource dragSource = new DragSource();
//private final DropTarget dropTarget;
private int dragTabIndex = -1;
public DnDTabbedPane() {
super();
final DragSourceListener dsl = new DragSourceListener() {
public void dragEnter(DragSourceDragEvent e) {
e.getDragSourceContext().setCursor(DragSource.DefaultMoveDrop);
}
public void dragExit(DragSourceEvent e) {
e.getDragSourceContext().setCursor(DragSource.DefaultMoveNoDrop);
lineRect.setRect(0,0,0,0);
glassPane.setPoint(new Point(-1000,-1000));
glassPane.repaint();
}
public void dragOver(DragSourceDragEvent e) {
//e.getLocation()
//This method returns a Point indicating the cursor location in screen coordinates at the moment
Point tabPt = e.getLocation();
SwingUtilities.convertPointFromScreen(tabPt, DnDTabbedPane.this);
Point glassPt = e.getLocation();
SwingUtilities.convertPointFromScreen(glassPt, glassPane);
int targetIdx = getTargetTabIndex(glassPt);
if(getTabAreaBound().contains(tabPt) && targetIdx>=0 &&
targetIdx!=dragTabIndex && targetIdx!=dragTabIndex+1) {
e.getDragSourceContext().setCursor(DragSource.DefaultMoveDrop);
}else{
e.getDragSourceContext().setCursor(DragSource.DefaultMoveNoDrop);
}
}
public void dragDropEnd(DragSourceDropEvent e) {
lineRect.setRect(0,0,0,0);
dragTabIndex = -1;
if(hasGhost()) {
glassPane.setVisible(false);
glassPane.setImage(null);
}
}
public void dropActionChanged(DragSourceDragEvent e) {}
};
final Transferable t = new Transferable() {
private final DataFlavor FLAVOR = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType, NAME);
public Object getTransferData(DataFlavor flavor) {
return DnDTabbedPane.this;
}
public DataFlavor[] getTransferDataFlavors() {
DataFlavor[] f = new DataFlavor[1];
f[0] = this.FLAVOR;
return f;
}
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.getHumanPresentableName().equals(NAME);
}
};
final DragGestureListener dgl = new DragGestureListener() {
public void dragGestureRecognized(DragGestureEvent e) {
Point tabPt = e.getDragOrigin();
dragTabIndex = indexAtLocation(tabPt.x, tabPt.y);
if(dragTabIndex<0) return;
initGlassPane(e.getComponent(), e.getDragOrigin());
try{
e.startDrag(DragSource.DefaultMoveDrop, t, dsl);
}catch(InvalidDnDOperationException idoe) {
idoe.printStackTrace();
}
}
};
//dropTarget =
new DropTarget(glassPane, DnDConstants.ACTION_COPY_OR_MOVE, new CDropTargetListener(), true);
new DragSource().createDefaultDragGestureRecognizer(this, DnDConstants.ACTION_COPY_OR_MOVE, dgl);
}
class CDropTargetListener implements DropTargetListener{
public void dragEnter(DropTargetDragEvent e) {
if(isDragAcceptable(e)) e.acceptDrag(e.getDropAction());
else e.rejectDrag();
}
public void dragExit(DropTargetEvent e) {}
public void dropActionChanged(DropTargetDragEvent e) {}
public void dragOver(final DropTargetDragEvent e) {
if(getTabPlacement()==JTabbedPane.TOP || getTabPlacement()==JTabbedPane.BOTTOM) {
initTargetLeftRightLine(getTargetTabIndex(e.getLocation()));
}else{
initTargetTopBottomLine(getTargetTabIndex(e.getLocation()));
}
repaint();
if(hasGhost()) {
glassPane.setPoint(e.getLocation());
glassPane.repaint();
}
}
public void drop(DropTargetDropEvent e) {
if(isDropAcceptable(e)) {
convertTab(dragTabIndex, getTargetTabIndex(e.getLocation()));
e.dropComplete(true);
}else{
e.dropComplete(false);
}
repaint();
}
public boolean isDragAcceptable(DropTargetDragEvent e) {
Transferable t = e.getTransferable();
if(t==null) return false;
DataFlavor[] f = e.getCurrentDataFlavors();
if(t.isDataFlavorSupported(f[0]) && dragTabIndex>=0) {
return true;
}
return false;
}
public boolean isDropAcceptable(DropTargetDropEvent e) {
Transferable t = e.getTransferable();
if(t==null) return false;
DataFlavor[] f = t.getTransferDataFlavors();
if(t.isDataFlavorSupported(f[0]) && dragTabIndex>=0) {
return true;
}
return false;
}
}
private boolean hasGhost = true;
public void setPaintGhost(boolean flag) {
hasGhost = flag;
}
public boolean hasGhost() {
return hasGhost;
}
private int getTargetTabIndex(Point glassPt) {
Point tabPt = SwingUtilities.convertPoint(glassPane, glassPt, DnDTabbedPane.this);
boolean isTB = getTabPlacement()==JTabbedPane.TOP || getTabPlacement()==JTabbedPane.BOTTOM;
for(int i=0;i<getTabCount();i++) {
Rectangle r = getBoundsAt(i);
if(isTB) r.setRect(r.x-r.width/2, r.y, r.width, r.height);
else r.setRect(r.x, r.y-r.height/2, r.width, r.height);
if(r.contains(tabPt)) return i;
}
Rectangle r = getBoundsAt(getTabCount()-1);
if(isTB) r.setRect(r.x+r.width/2, r.y, r.width, r.height);
else r.setRect(r.x, r.y+r.height/2, r.width, r.height);
return r.contains(tabPt)?getTabCount():-1;
}
private void convertTab(int prev, int next) {
if(next<0 || prev==next) {
//System.out.println("press="+prev+" next="+next);
return;
}
Component cmp = getComponentAt(prev);
String str = getTitleAt(prev);
if(next==getTabCount()) {
//System.out.println("last: press="+prev+" next="+next);
remove(prev);
addTab(str, cmp);
setSelectedIndex(getTabCount()-1);
}else if(prev>next) {
//System.out.println(" >: press="+prev+" next="+next);
remove(prev);
insertTab(str, null, cmp, null, next);
setSelectedIndex(next);
}else{
//System.out.println(" <: press="+prev+" next="+next);
remove(prev);
insertTab(str, null, cmp, null, next-1);
setSelectedIndex(next-1);
}
}
private void initTargetLeftRightLine(int next) {
if(next<0 || dragTabIndex==next || next-dragTabIndex==1) {
lineRect.setRect(0,0,0,0);
}else if(next==getTabCount()) {
Rectangle rect = getBoundsAt(getTabCount()-1);
lineRect.setRect(rect.x+rect.width-LINEWIDTH/2,rect.y,LINEWIDTH,rect.height);
}else if(next==0) {
Rectangle rect = getBoundsAt(0);
lineRect.setRect(-LINEWIDTH/2,rect.y,LINEWIDTH,rect.height);
}else{
Rectangle rect = getBoundsAt(next-1);
lineRect.setRect(rect.x+rect.width-LINEWIDTH/2,rect.y,LINEWIDTH,rect.height);
}
}
private void initTargetTopBottomLine(int next) {
if(next<0 || dragTabIndex==next || next-dragTabIndex==1) {
lineRect.setRect(0,0,0,0);
}else if(next==getTabCount()) {
Rectangle rect = getBoundsAt(getTabCount()-1);
lineRect.setRect(rect.x,rect.y+rect.height-LINEWIDTH/2,rect.width,LINEWIDTH);
}else if(next==0) {
Rectangle rect = getBoundsAt(0);
lineRect.setRect(rect.x,-LINEWIDTH/2,rect.width,LINEWIDTH);
}else{
Rectangle rect = getBoundsAt(next-1);
lineRect.setRect(rect.x,rect.y+rect.height-LINEWIDTH/2,rect.width,LINEWIDTH);
}
}
private void initGlassPane(Component c, Point tabPt) {
//Point p = (Point) pt.clone();
getRootPane().setGlassPane(glassPane);
if(hasGhost()) {
Rectangle rect = getBoundsAt(dragTabIndex);
BufferedImage image = new BufferedImage(c.getWidth(), c.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics g = image.getGraphics();
c.paint(g);
image = image.getSubimage(rect.x,rect.y,rect.width,rect.height);
glassPane.setImage(image);
}
Point glassPt = SwingUtilities.convertPoint(c, tabPt, glassPane);
glassPane.setPoint(glassPt);
glassPane.setVisible(true);
}
private Rectangle getTabAreaBound() {
Rectangle lastTab = getUI().getTabBounds(this, getTabCount()-1);
return new Rectangle(0,0,getWidth(),lastTab.y+lastTab.height);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
if(dragTabIndex>=0) {
Graphics2D g2 = (Graphics2D)g;
g2.setPaint(lineColor);
g2.fill(lineRect);
}
}
}
class GhostGlassPane extends JPanel {
private final AlphaComposite composite;
private Point location = new Point(0, 0);
private BufferedImage draggingGhost = null;
public GhostGlassPane() {
setOpaque(false);
composite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f);
}
public void setImage(BufferedImage draggingGhost) {
this.draggingGhost = draggingGhost;
}
public void setPoint(Point location) {
this.location = location;
}
public void paintComponent(Graphics g) {
if(draggingGhost == null) return;
Graphics2D g2 = (Graphics2D) g;
g2.setComposite(composite);
double xx = location.getX() - (draggingGhost.getWidth(this) /2d);
double yy = location.getY() - (draggingGhost.getHeight(this)/2d);
g2.drawImage(draggingGhost, (int)xx, (int)yy , null);
}
}
#Tony: It looks like Euguenes solution just overlooks preserving TabComponents during a swap.
The convertTab method just needs to remember the TabComponent and set it to the new tabs it makes.
Try using this:
private void convertTab(TabTransferData a_data, int a_targetIndex) {
DnDTabbedPane source = a_data.getTabbedPane();
System.out.println("this=source? " + (this == source));
int sourceIndex = a_data.getTabIndex();
if (sourceIndex < 0) {
return;
} // if
//Save the tab's component, title, and TabComponent.
Component cmp = source.getComponentAt(sourceIndex);
String str = source.getTitleAt(sourceIndex);
Component tcmp = source.getTabComponentAt(sourceIndex);
if (this != source) {
source.remove(sourceIndex);
if (a_targetIndex == getTabCount()) {
addTab(str, cmp);
setTabComponentAt(getTabCount()-1, tcmp);
} else {
if (a_targetIndex < 0) {
a_targetIndex = 0;
} // if
insertTab(str, null, cmp, null, a_targetIndex);
setTabComponentAt(a_targetIndex, tcmp);
} // if
setSelectedComponent(cmp);
return;
} // if
if (a_targetIndex < 0 || sourceIndex == a_targetIndex) {
return;
} // if
if (a_targetIndex == getTabCount()) {
source.remove(sourceIndex);
addTab(str, cmp);
setTabComponentAt(getTabCount() - 1, tcmp);
setSelectedIndex(getTabCount() - 1);
} else if (sourceIndex > a_targetIndex) {
source.remove(sourceIndex);
insertTab(str, null, cmp, null, a_targetIndex);
setTabComponentAt(a_targetIndex, tcmp);
setSelectedIndex(a_targetIndex);
} else {
source.remove(sourceIndex);
insertTab(str, null, cmp, null, a_targetIndex - 1);
setTabComponentAt(a_targetIndex - 1, tcmp);
setSelectedIndex(a_targetIndex - 1);
}
}
Add this to isDragAcceptable to avoid Exceptions:
boolean transferDataFlavorFound = false;
for (DataFlavor transferDataFlavor : t.getTransferDataFlavors()) {
if (FLAVOR.equals(transferDataFlavor)) {
transferDataFlavorFound = true;
break;
}
}
if (transferDataFlavorFound == false) {
return false;
}

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