We Keep Coding

I am not sure what is incorrect

I am creating a small Java Jpanel game in which I am supposed to have a rocket that moves up and down via arrows and fires via space.
The firing method should work like this: Space bar pressed, thing fires and moves across screen , and then when it hits a certain x, it disappears. Also, you can only fire once until the other bullet disappears.
I do not know what I am doing wrong. For one, as soon as my code starts you can see a bullet flying across the screen.
2nd, the bullet is not disappearing.
3rd, even though the other bullet is still visible, it allows me to fire again.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.File;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class SpaceGame extends JPanel implements ActionListener{
Timer t = new Timer(2, this);
private ImageIcon rocket,asteroid,bullet;
private JLabel rocketlabel,ast1,ast2,ast3,bulletLabel;
public static int y=90,dy=0,bulletX=110,bulletY,i=0,canFire;
//public sound sound;
static boolean bulletFired=false;;
static JFrame f = new JFrame();
SpaceGame(){
this.setBackground(Color.black);
rocket = new ImageIcon(getClass().getResource("rocketFinal.png"));
rocketlabel= new JLabel(rocket);
this.add(rocketlabel);
asteroid = new ImageIcon(getClass().getResource("asteroid.png"));
ast1=new JLabel(asteroid);
ast2=new JLabel(asteroid);
ast3=new JLabel(asteroid);
bullet = new ImageIcon(getClass().getResource("bulletReal.png"));
bulletLabel = new JLabel(bullet);
canFire=1;
bulletLabel.setVisible(false);
this.add(ast1);this.add(ast2);this.add(ast3);this.add(bulletLabel);
f.addKeyListener(new controller());
this.setLayout(null);
this.setVisible(true);
}
public class controller implements KeyListener{
#Override
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if(keyCode== KeyEvent.VK_UP) {
dy=-1;
}
if(keyCode== KeyEvent.VK_DOWN) {
dy=1;
}
if(keyCode== KeyEvent.VK_SPACE) {
if(canFire==0) {
System.out.println(String.valueOf(canFire));
bulletFired = true;
bulletY = y;
bulletX=110;
}canFire=1;
}
}
#Override
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
switch(key) {
case KeyEvent.VK_UP: dy=0; break;
case KeyEvent.VK_DOWN: dy=0; break;
}
}
#Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
rocketlabel.setBounds(45,y,rocket.getIconWidth(),80);
fireBullet();
paintStars(g);
t.start();
}
public void paintStars(Graphics g) {
g.setColor(Color.yellow);
for(int i=0; i<5;i++) {
Random rand = new Random();
int o = rand.nextInt(500);
int p = rand.nextInt(300);
g.fillOval(o, p, 3, 3);
}
}
public void actionPerformed(ActionEvent e) {
if(y==-20) y=249;
if(y==250)y=-20;
y+=dy;
if(bulletFired=true) {
bulletX++;
if(bulletX==455)bulletFired=false;bulletLabel.setVisible(false);System.out.println(String.valueOf(bulletX)); canFire=0;
}
repaint();
}
public void fireBullet(){
if(bulletFired=true) {
bulletLabel.setVisible(true);
bulletLabel.setBounds(bulletX,bulletY+25,bullet.getIconHeight(),bullet.getIconWidth());
}
}
public static void main(String[] args) {
String filepath = "SpaceGameMusic.wav";
musicStuff musicPlayer = new musicStuff();
musicPlayer.playMusic(filepath);
SpaceGame t = new SpaceGame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(t);
f.setSize(500,335);
f.setVisible(true);
f.setResizable(false);
}
}

For one, as soon as my code starts you can see a bullet flying across the screen.
The paintComponent() method is for painting only. You can't control when Swing will determine a component needs to be repainted.
So, for example:
t.start();
should NOT be in the painting method. As soon as the frame is made visible the panel will be painted and the Timer will be started.
You application code should control when the Timer is started.
Other issues:
you should not be using static variables. The variable should simply be instances of your class.
the paintStars() method should not generate random locations. Again. a painting method should only paint the current state of the class. So if you want to change the location of the stars you should have a method like randomizeStars(). In this method you would update an ArrayList of Point objects. Each Point instance would represent the location of a star. Then the paintStars() method would simply iterate through the ArrayList and paint each star.
you should not be using a KeyListener. A KeyListener only works if a component has focus. You can't guarantee that your component will lose focus. Instead you should be using Key Bindings. Key bindings allow you to handle a KeyEvent even if the component doesn't have focus. See Motion Using the Keyboard for more information and a working example.
you can only fire once until the other bullet disappears
Your canFire variable should be a boolean variable so it only has true/false values. Again you have a method that sets the state. Your game logic will then check the state before firing the bullet again.
if(y==-20) y=249;
if(y==250)y=-20;
Don't hardcode values. The number should be based on the size of your panel. So you use methods like getWidth() and getHeight() to determine the current size of the panel.

The problem was quite simply that I had forgotten to use == in my if(boolean) statements.

Set JButton to the location of another JButton

I'm trying to move a JButton to the location of another one but the button I want to move moves to a wrong point. My idea is that this happens because I use multiple JPanels. I tried: getLocationOnScreen, getBounds and getLocation, but none of them worked, how to solve it? When an user selects a card on the table or from a player by clicking this card the the target is set, the sender is set by clicking a card from the top panel. playerCardSpotTargetand playerCardSpotSender are both of type Card. When I try to move the for example eight of diamonds this card moves to a point behind the eight and nine of clubs.
Code:
This events belong to the blue cards on the table and the cards for the players(I have to change the name of the event, I know).
private void PlayerOneMouseClicked(java.awt.event.MouseEvent evt){
playerCardSpotTarget=(Card)evt.getSource();
if(playerCardSpotTarget.isBorderPainted()){
playerCardSpotTarget.setBorderPainted(false);
}
else{
playerCardSpotTarget.setBorderPainted(true);
}
}
This event belongs to the cards in the top panel.
private void MouseClicked(java.awt.event.MouseEvent evt) {
playerCardSpotSender=(Card)evt.getSource();
System.out.println(playerCardSpotSender.suit+" "+playerCardSpotSender.kind);
if (playerCardSpotTarget != null && playerCardSpotTarget.isBorderPainted()) {
playerCardSpotSender.setLocation(playerCardSpotTarget.getLocation());
System.out.println(playerCardSpotTarget.getLocationOnScreen());
System.out.println(playerCardSpotSender.getLocationOnScreen());
}
}
Layout for the center panel in the JFrame (BorderLayout.CENTER)
JPanel centerPanelNorth;
JPanel centerPanelCenter;
JPanel centerPanelEast;
JPanel centerPanelSouth;
JPanel centerPanelWest;
JLabel tablePicture;
JPanel centerPanel;
centerPanel=new JPanel(new BorderLayout());
tablePicture = new JLabel(new ImageIcon(this.getClass().getResource(Constants.POKERTABLE_ICON)));
centerPanelNorth=new JPanel();
centerPanelEast=new JPanel();
centerPanelSouth=new JPanel();
centerPanelWest=new JPanel();
centerPanelCenter=new JPanel();
centerPanel.add(centerPanelCenter,BorderLayout.CENTER);
centerPanelCenter.add(tablePicture);
//add
tablePicture.add(boardCard1);
tablePicture.add(boardCard2);
tablePicture.add(boardCard3);
tablePicture.setLayout(new GridBagLayout());
//PLAYER NORTH
centerPanel.add(centerPanelNorth,BorderLayout.NORTH);
centerPanelNorth.add(playerOneCardOne);
centerPanelNorth.add(playerOneCardTwo);
//PLAYER EAST
centerPanel.add(centerPanelEast,BorderLayout.EAST);
centerPanelEast.setLayout(new BoxLayout(centerPanelEast,BoxLayout.X_AXIS));
centerPanelEast.add(playerTwoCardOne);
centerPanelEast.add(playerTwoCardTwo);
//PLAYER SOUTH
centerPanel.add(centerPanelSouth,BorderLayout.SOUTH);
centerPanelSouth.add(playerThreeCardOne);
centerPanelSouth.add(playerThreeCardTwo);
//PLAYER WEST
centerPanel.add(centerPanelWest,BorderLayout.WEST);
centerPanelWest.setLayout(new BoxLayout(centerPanelWest,BoxLayout.X_AXIS));
centerPanelWest.add(playerFourCardOne);
centerPanelWest.add(playerFourCardTwo);
Card.java
public class Card extends JButton{
int suit;
int kind;
boolean known;
String iconPath;
Integer boardPosition;
}

Animating the button movement isn't actually the hardest problem, the hardest problem is trying to move the data about in away in which you can manage it and how to connect the source component with the target...
To start with, you need a means by which you can move a component across container boundaries. While there are probably a few ways to do this, the simplest is to probably use the glass pane of the frame
public class AnimationPane extends JPanel {
public AnimationPane() {
setOpaque(false);
setLayout(null);
}
}
This is nothing special, it's just a JPanel which is transparent and has no layout manager, normally, not recommended, but in the case, we're going to take control..
Now, we need some way to animate the movement...
public enum Animator {
INSTANCE;
private List<IAnimatable> animatables;
private Timer timer;
private Animator() {
animatables = new ArrayList<>(25);
timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
IAnimatable[] anins = animatables.toArray(new IAnimatable[animatables.size()]);
for (IAnimatable animatable : anins) {
animatable.update();
}
}
});
timer.start();
}
public void addAnimatable(IAnimatable animatable) {
animatables.add(animatable);
}
public void removeAnimatable(IAnimatable animatable) {
animatables.remove(animatable);
}
}
public interface IAnimatable {
public void update();
}
public interface IMoveAnimatable extends IAnimatable{
public JComponent getSourceComponent();
public IImportable getImportable();
}
So the Animator is the core "engine", it's basically a Swing Timer which simply calls update on any IAnimatables it might be managing. The intention with this approach is you can have a number of animations running, but it won't degrade the system (greatly) as you only have a single update/timer point.
Now, normally I'd just use something like the Timing Framework or the Trident Framework or even the Universal Tween Engine
The IAnimatable interfaces just define the basic contracts that provide functionality for the animation.
We need to define some kind of contract the defines objects which can take part in the animation process and receive information, or the "target"
public interface IImportable {
public JComponent getView();
public void importValue(String value);
}
public abstract class AbstractImportable extends JPanel implements IImportable {
#Override
public JComponent getView() {
return this;
}
}
Now it occurs to me that we could tap into the pre-existing Transferable API, which would allow you to also implement drag-n-drop (and even copy/cut and paste), this would be used to define a lookup mechanism where you match a given data type with potential targets based on the DataFlavor ... but I'll leave you to investigate how that might work...
The core mechanism basically removes the source component from it's current container, adds it to the AnimationPane, moves the source component across the AnimationPane and then imports the data into the target...
The problem is, you need to translate the location of component from it's current context to the AnimationPane.
A components location is relative to it's parents context. It's relatively easy to do with SwingUtilities.convertPoint(Component, Point, Component)
We calculate the origin point of the source component and the target point, relative to the AnimationPane. We then, on each call to update, calculate the progress of the animation. Instead of using a "delta" movement, we calculate the different between the time we started and a predefined duration (1 second in this case), this generally produces a more flexible animation
public class DefaultAnimatable implements IMoveAnimatable {
public static final double PLAY_TIME = 1000d;
private Long startTime;
private JComponent sourceComponent;
private IImportable importable;
private JComponent animationSurface;
private Point originPoint, destinationPoint;
private String value;
public DefaultAnimatable(JComponent animationSurface, JComponent sourceComponent, IImportable importable, String value) {
this.sourceComponent = sourceComponent;
this.importable = importable;
this.animationSurface = animationSurface;
this.value = value;
}
public String getValue() {
return value;
}
public JComponent getAnimationSurface() {
return animationSurface;
}
#Override
public JComponent getSourceComponent() {
return sourceComponent;
}
#Override
public IImportable getImportable() {
return importable;
}
#Override
public void update() {
if (startTime == null) {
System.out.println("Start");
IImportable importable = getImportable();
JComponent target = importable.getView();
originPoint = SwingUtilities.convertPoint(getSourceComponent().getParent(), getSourceComponent().getLocation(), getAnimationSurface());
destinationPoint = SwingUtilities.convertPoint(target.getParent(), target.getLocation(), getAnimationSurface());
destinationPoint.x = destinationPoint.x + ((target.getWidth() - getSourceComponent().getWidth()) / 2);
destinationPoint.y = destinationPoint.y + ((target.getHeight() - getSourceComponent().getHeight()) / 2);
Container parent = getSourceComponent().getParent();
getAnimationSurface().add(getSourceComponent());
getSourceComponent().setLocation(originPoint);
parent.invalidate();
parent.validate();
parent.repaint();
startTime = System.currentTimeMillis();
}
long duration = System.currentTimeMillis() - startTime;
double progress = Math.min(duration / PLAY_TIME, 1d);
Point location = new Point();
location.x = progress(originPoint.x, destinationPoint.x, progress);
location.y = progress(originPoint.y, destinationPoint.y, progress);
getSourceComponent().setLocation(location);
getAnimationSurface().repaint();
if (progress == 1d) {
getAnimationSurface().remove(getSourceComponent());
Animator.INSTANCE.removeAnimatable(this);
animationCompleted();
}
}
public int progress(int startValue, int endValue, double fraction) {
int value = 0;
int distance = endValue - startValue;
value = (int) Math.round((double) distance * fraction);
value += startValue;
return value;
}
protected void animationCompleted() {
getImportable().importValue(getValue());
}
}
Okay, now this produces a linear animation, which is pretty boring, now if you have plenty of time, you could create an easement like this or just use one of the animation frameworks...
Now, we need to put it together...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
public class AnimationTest {
public static void main(String[] args) {
new AnimationTest();
}
public AnimationTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
AnimationPane animationPane = new AnimationPane();
LeftPane leftPane = new LeftPane(animationPane);
RightPane rightPane = new RightPane();
leftPane.setImportabale(rightPane);
rightPane.setImportabale(leftPane);
JFrame frame = new JFrame("Testing");
frame.setLayout(new GridLayout(1, 2));
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(leftPane, BorderLayout.WEST);
frame.add(rightPane, BorderLayout.WEST);
frame.setGlassPane(animationPane);
animationPane.setVisible(true);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class RightPane extends AbstractImportable {
private IImportable source;
private JButton imported;
private String importedValue;
public RightPane() {
setLayout(new GridBagLayout());
setBorder(new LineBorder(Color.DARK_GRAY));
}
public void setImportabale(IImportable source) {
this.source = source;
}
#Override
public void importValue(String value) {
if (imported != null) {
// May re-animate the movement back...
remove(imported);
}
importedValue = value;
imported = new JButton(">> " + value + "<<");
add(imported);
revalidate();
repaint();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
public class LeftPane extends AbstractImportable {
private IImportable importable;
public LeftPane(AnimationPane animationPane) {
setLayout(new GridBagLayout());
JButton btn = new JButton("Lefty");
btn.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
DefaultAnimatable animatable = new DefaultAnimatable(animationPane, btn, importable, "Lefty");
Animator.INSTANCE.addAnimatable(animatable);
}
});
add(btn);
setBorder(new LineBorder(Color.DARK_GRAY));
}
public void setImportabale(IImportable target) {
this.importable = target;
}
#Override
public void importValue(String value) {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
}
}

Maybe use mousePressed(),when you move the card,you press it until the target.And in the process, you get the information about JButton.getLocation() by the event,and than you need to solve the collision problem between two cards.So it's good!Of course, this is my advice ,you should have better idea!

Java: Repaint in Swing Not Working

I am learning java swing and am having trouble with the following program. It creates a small frame with a quit button at top. The objective is to display coordinates wherever the mouse is clicked. When I click the mouse 2 unwanted things are happening:
the quit button is overridden by the mouse clicks and it no longer responds (instead of responding to event and quitting, it displays coordinates on top of the quit button).
when I click at a new location, the coordinates from the old location persist.
I used removeAll() and revalidate() before doing repaint() based on this discussion but that has not helped. This code is taken from here and the code to says to research online documentation for why this is happening.
Any pointers?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.BorderLayout;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JLabel;
public class QuitCoordinateTest {
public static void main(String[] args){
GUI gui = new GUI();
}
}
class MyFrame extends JFrame implements ActionListener{
int clickX;
int clickY;
public void paint(Graphics g){
g.drawString("" + clickX + ", " + clickY, clickX, clickY);
}
public void actionPerformed(ActionEvent e){
System.exit(0);
}
}
//=======================================================//
class GUI extends MyFrame {
JButton quitButton = new JButton("Quit");
public GUI(){
MyFrame displayWindow = new MyFrame();
displayWindow.setTitle("Title");
/*
JPanel buttonPanel = new JPanel();
buttonPanel.add(quitButton);
displayWindow.getContentPane().add(buttonPanel,BorderLayout.NORTH);
JPanel textPanel = new JPanel();
*/
displayWindow.getContentPane().add(quitButton,BorderLayout.NORTH);
quitButton.addActionListener(displayWindow);
displayWindow.setSize(201,201);
displayWindow.setVisible(true);
// displayWindow.pack();
displayWindow.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
displayWindow.addMouseListener(new MouseProc(displayWindow));
}//end constructor
}//end class GUI definition
//=======================================================//
//This listener class monitors for mouse presses and
// displays the coordinates of the mouse pointer when the
// mouse is pressed on the source object.
class MouseProc extends MouseAdapter{
MyFrame refToWin;
MouseProc(MyFrame inWin){
refToWin = inWin;
}
//Override the mousePressed method to determine and
// display the coordinates when the mouse is pressed.
public void mousePressed(MouseEvent e){
refToWin.removeAll();
refToWin.clickX = e.getX();
refToWin.clickY = e.getY();
//Force the JFrame object to be repainted in order to
// display the coordinate information.
refToWin.removeAll();
refToWin.validate();
refToWin.repaint();
}
}

repaint() is working fine.
Avoid drawing directly on the JFrame.
Instead draw in the protected void paintComponent(Graphics g) method override of a JPanel that is then displayed in your JFrame.
Be sure to call the super's paintComponent(g) method inside of your paintComponent override -- this will erase the old images and is the reason for one of your problems.
Use reasonable comments in your code. Too many comments and too much text distracts and makes understanding your code harder, not easier.
Calling removeAll() on your JFrame will do just that -- remove all components including your button. Why are you calling this? Are you sure that you want to call this method?
A minor nitpick -- you'll want to avoid directly setting the fields of another class, such as your clickX and clickY fields. Instead, make them private, and only allow outside classes to modify them through public methods. While it may not matter much for this small program, it will matter greatly when you start scaling up your programming and create large programs with complex interactions. The key to success here will be to limit and control all communication between classes to avoid hard to detect side effects.
For example, something like...
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
String str = String.format("[%d, %d]", clickX, clickY);
g.drawString(str, clickX, clickY);
}
public int getClickX() {
return clickX;
}
public void setClickX(int clickX) {
this.clickX = clickX;
}
public int getClickY() {
return clickY;
}
public void setClickY(int clickY) {
this.clickY = clickY;
}
For example
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class DetectClicks extends JPanel {
private static final int PREF_W = 800;
private static final int PREF_H = 650;
private int clickX;
private int clickY;
public DetectClicks() {
MyMouseListener mouseAdapter = new MyMouseListener(this);
addMouseListener(mouseAdapter);
addMouseMotionListener(mouseAdapter); // to allow dragging!
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
String str = String.format("[%d, %d]", clickX, clickY);
g.drawString(str, clickX, clickY);
}
public int getClickX() {
return clickX;
}
public void setClickX(int clickX) {
this.clickX = clickX;
}
public int getClickY() {
return clickY;
}
public void setClickY(int clickY) {
this.clickY = clickY;
}
private static void createAndShowGui() {
DetectClicks mainPanel = new DetectClicks();
JFrame frame = new JFrame("DetectClicks");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
class MyMouseListener extends MouseAdapter {
private DetectClicks detectClicks;
public MyMouseListener(DetectClicks detectClicks) {
this.detectClicks = detectClicks;
}
#Override
public void mousePressed(MouseEvent evt) {
showPoint(evt);
}
#Override
public void mouseDragged(MouseEvent evt) {
showPoint(evt);
}
private void showPoint(MouseEvent evt) {
detectClicks.setClickX(evt.getX());
detectClicks.setClickY(evt.getY());
detectClicks.repaint();
}
}

Your event is getting consumed by the handler that prints the coordinates, you need to redispatch the event so that the button can see it. You can do it like this, inside the coordinate display event handler:
Component c = e.getComponent();
c.getParent().dispatchEvent( e );
Also, I'd be tempted to use the glass pane of the frame, and put a JLabel on it with the co-ordinates rather than messing with the paint method.

you don't have to use any of repaint(),invalidate() etc.
i highly recommend to use
SwingUtilities.invokeLater(new Runnable() {
public void run() {
//TODO udpdate UI compontents, layouts etc.
}
});
this guarantees that UI components update on real time. Because we don't know when the system update UI hierarchy so we can't force it. This allow system to determine by it's self.

Trouble using mouse to click on JComponent

Hey Everyone I am trying to create a somewhat dynamic program in which you can add shapes or images to a JPanel and then select and move the shapes after you have added them. The problem is that when I click on the specific JComponent nothing happens. In fact clicking on any of the components I have created to test the project returns false for all JComponents. However it seems that if I click inside the bounds of my JComponent in the top left corner I will get returned true for all JComponents, ie click in the area bounded by (0,0,50,68).
The idea is that if I click one of the JComponents it will set that specific JComponent to be movable however I cannot get past the part of actually selecting a specific JComponent.
Here is a basic SSCE that I built to recreate the problem:
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class SSCE1 extends JPanel {
private ArrayList<Shape> shapeList = new ArrayList<Shape>();
SSCE1() {
setLayout(null);
/* Debug Stuff */
System.out.println("Debug:");
/* Add The First Shape To The List */
shapeList.add(0, new Shape(100, 100));
add(shapeList.get(0));
shapeList.add(1, new Shape(610, 0));
add(shapeList.get(1));
shapeList.add(2, new Shape(500, 900));
add(shapeList.get(2));
addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
for (Shape shape : shapeList) {
if (shape.contains(e.getPoint())) {
System.out.println("Hello");
} else {
System.out.println("Goodbye");
}
}
}
});
}
}
class Shape extends JComponent {
int xLocation, yLocation, xBounds1, yBounds1;
Shape(int xLocation, int yLocation) {
this.xLocation = xLocation;
this.yLocation = yLocation;
this.xBounds1 = 50;
this.yBounds1 = 68;
setBounds(xLocation, yLocation, xBounds1, yBounds1);
setLocation(xLocation, yLocation);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.blue);
g.fillRect(0, 0, 100, 100);
}
}
class Run {
public static void main(String[] args) {
JFrame main = new JFrame();
SSCE1 p1 = new SSCE1();
main.setSize(new Dimension(1000, 1000));
main.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
main.setLocation(new Point(0, 0));
main.setVisible(true);
main.add(p1);
}
}

Basically, the problem is, Shape is expecting any mouse coordinates you pass it to be defined within the context of the Shape. That is, the top, left corner of Shape is always 0x0
The mouse point you are processing is within the context of the parent container, therefore, unless Shape is positioned at 0x0 within the parent container, Shape will never contain the mouse point.
You need to translate the mouse point to the context of the Shape before checking it
For example...
addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
for (Shape shape : shapeList) {
Point shapePoint = SwingUtilities.convertPoint(e.getComponent(), e.getPoint(), shape);
if (shape.contains(shapePoint) {
System.out.println("Hello");
} else {
System.out.println("Goodbye");
}
}
}
});

Use next mouseListener it works:
addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
for (Shape shape : shapeList) {
Point convertPoint = SwingUtilities.convertPoint(SSCE1.this, e.getPoint(), shape);
if (shape.contains(convertPoint)) {
System.out.println("Hello");
} else {
System.out.println("Goodbye");
}
}
}
});
The reason is next according docs in contains method the point's x and y coordinates are defined to be relative to the coordinate system of this component. because of that works for (0,0,50,68). All what you need convert point from JPanel to Shape with help of SwingUtilities.convertPoint(...)

Where can I put mouse event handling code so that it is out of the way but can still manipulate objects?

I'm learning Java here and trying to get to grips with classes and how best to catch mouse events etc. for my little game, so please be patient and give my some hints.
The main class of my project extends JFrame and upon construction adds to itself an object of a class which extends JPanel. This JPanel covers the whole window and it is this I am using to paint stuff to the screen. Then I have a class called Scene which extends nothing but which stores all the references to the current objects on the screen and is responsible for compiling them all and passing them back to the JPanel. I didn't want to put the full mouse event code in the JPanel because it would be so messy so I though I'd create another class for that called MEs and let each scene have one. My thinking was, this way each mes object can access the objects in each scene easily. So my code is looking like this:
class DPanel extends JPanel {
Scene scCurrent;
public DPanel() {
scCurrent = new Scene();
addMouseMotionListener(new MouseAdapter() {
public void mouseMoved(MouseEvent me) { scCurrent.mes.moved(me); }
});
...
}
...
but of course, inside scCurrent.mes.moved() I don't even know how to change the cursor. It doesn't recognise setCursor() in there. How can I change the cursor and access objects that are higher up the tree like I'd need to to switch scene? Or is there some other place I can tuck my mouse event handling code that will not bumph-out out my JPanel?

You are trying to separate out the control code from the view (GUI) code, and this is a good thing. A solution is to give the view code public methods that allow outside code to change its state, and give the control classes a reference to the view so that the controls (i.e., MouseListeners, MouseMotionListeners, ActionListeneres) can call these methods on a proper reference and change the view's states.
Edit 1
It may be easier just to show you an example:
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
public class ViewControl {
private static void createAndShowGui() {
View view = new View();
Control control = new Control(view);
view.addMouseAdapter(control);
JFrame frame = new JFrame("ViewControl");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(view);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
#SuppressWarnings("serial")
class View extends JPanel {
private static final int PREF_W = 400;
private static final int PREF_H = PREF_W;
private List<Point> points = new ArrayList<Point>();
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (points.size() > 1) {
for (int i = 0; i < points.size() - 1; i++) {
int x1 = points.get(i).x;
int y1 = points.get(i).y;
int x2 = points.get(i + 1).x;
int y2 = points.get(i + 1).y;
g.drawLine(x1, y1, x2, y2);
}
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(PREF_W, PREF_H);
}
public void addMouseAdapter(MouseAdapter adapter) {
// addMouseListener(adapter);
addMouseMotionListener(adapter);
}
public void addPoint(Point p) {
points.add(p);
repaint();
}
}
class Control extends MouseAdapter {
private View view;
public Control(View view) {
this.view = view;
}
#Override
public void mouseDragged(MouseEvent e) {
view.addPoint(e.getPoint());
}
}