Cannot find symbol error on compile. - java

I am doing a project for class and was cleaning up my indentation etc and have done something to my code. I cannot see the forest for the trees and could use some help. I am getting a cannot find symbol error when I compile. Here is the code.
public class TrafficLights extends JFrame implements ItemListener
{
private JRadioButton jrbRed;
private JRadioButton jrbYellow;
private JRadioButton jrbGreen;
private ButtonGroup btg = new ButtonGroup();
private TrafficLights.Light light = new TrafficLights.Light();
// ^ error 1 is here ^ error 2 is here
public static void main(String[] args)
{
TrafficLights frame = new TrafficLights();
frame.setDefaultCloseOperation(3);
frame.setSize(200, 200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public TrafficLights()
{
setTitle("Traffic Light Signal");
JPanel p1 = new JPanel();
p1.setLayout(new FlowLayout(1));
p1.add(this.light);
JPanel p2 = new JPanel();
p2.setLayout(new FlowLayout());
p2.add(this.jrbRed = new JRadioButton("Red"));
p2.add(this.jrbYellow = new JRadioButton("Yellow"));
p2.add(this.jrbGreen = new JRadioButton("Green"));
this.jrbRed.setMnemonic('R');
this.jrbYellow.setMnemonic('Y');
this.jrbGreen.setMnemonic('G');
this.btg.add(this.jrbRed);
this.btg.add(this.jrbYellow);
this.btg.add(this.jrbGreen);
setLayout(new BorderLayout());
add(p1, "Center");
add(p2, "South");
this.jrbRed.addItemListener(this);
this.jrbYellow.addItemListener(this);
this.jrbGreen.addItemListener(this);
this.jrbGreen.setSelected(true);
this.light.turnOnGreen();
}
public void itemStateChanged(ItemEvent e)
{
if (this.jrbRed.isSelected())
{
this.light.turnOnRed();
}
if (this.jrbYellow.isSelected())
{
this.light.turnOnYellow();
}
if (this.jrbGreen.isSelected())
{
this.light.turnOnGreen();
}
class Light extends JPanel
{
private boolean red;
private boolean yellow;
private boolean green;
public Light()
{ }
public void turnOnRed()
{
this.red = true;
this.yellow = false;
this.green = false;
repaint();
}
public void turnOnYellow()
{
this.red = false;
this.yellow = true;
this.green = false;
repaint();
}
public void turnOnGreen()
{
this.red = false;
this.yellow = false;
this.green = true;
repaint();
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
if (this.red)
{
g.setColor(Color.red);
g.fillOval(10, 10, 20, 20);
g.setColor(Color.black);
g.drawOval(10, 35, 20, 20);
g.drawOval(10, 60, 20, 20);
g.drawRect(5, 5, 30, 80);
}
else if (this.yellow)
{
g.setColor(Color.yellow);
g.fillOval(10, 35, 20, 20);
g.setColor(Color.black);
g.drawRect(5, 5, 30, 80);
g.drawOval(10, 10, 20, 20);
g.drawOval(10, 60, 20, 20);
}
else if (this.green)
{
g.setColor(Color.green);
g.fillOval(10, 60, 20, 20);
g.setColor(Color.black);
g.drawRect(5, 5, 30, 80);
g.drawOval(10, 10, 20, 20);
g.drawOval(10, 35, 20, 20);
}
else
{
g.setColor(Color.black);
g.drawRect(5, 5, 30, 80);
g.drawOval(10, 10, 20, 20);
g.drawOval(10, 35, 20, 20);
g.drawOval(10, 60, 20, 20);
}
}
public Dimension getPreferredSize()
{
return new Dimension(100, 100);
}
}
}
}

This is the problem - I've indented the code to make it clearer...
public void itemStateChanged(ItemEvent e)
{
if (this.jrbRed.isSelected())
{
this.light.turnOnRed();
}
if (this.jrbYellow.isSelected())
{
this.light.turnOnYellow();
}
if (this.jrbGreen.isSelected())
{
this.light.turnOnGreen();
}
class Light extends JPanel
{
private boolean red;
private boolean yellow;
private boolean green;
...
You're currently declaring the Light class within the itemStateChanged method. I don't think you meant to do that.
Additionally, I would question whether you really need Light to be an inner or nested class itself. I would suggest making it a top-level class - at least to start with. It'll be easier to navigate that way, apart from anything else.
I'd also strongly suggest trying to keep on top of your indentation at all times. If the rest of your code is already nicely indented, it's easier to see when something goes wrong. IDEs such as Eclipse are able to indent all your code for you at the touch of a button - I would advise you to use that feature heavily.

Related

JButton query in Belisha Beacon Program

Basically my Belisha Beacon has to stay Orange when I click on the Steady button but in my Program when I click the Steady Button, the Beacon stays as Light Grey instead. Can someone please identify where I am going wrong please? Thank you much :). Here is my code:
package Homework;
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import javax.swing.Timer;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class BelishaBeacon {
private static Timer timer;
public class Drawing extends JPanel {
private int x = 125;
private int y = 80;
private boolean changeColors = false;
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
Rectangle box1 = new Rectangle(165, 180, 20, 45);
Rectangle box2 = new Rectangle(165, 225, 20, 45);
Rectangle box3 = new Rectangle(165, 270, 20, 45);
Rectangle box4 = new Rectangle(165, 315, 20, 45);
Rectangle box5 = new Rectangle(165, 360, 20, 45);
Rectangle box6 = new Rectangle(165, 405, 20, 45);
Ellipse2D.Double ball = new Ellipse2D.Double(x, y, 100, 100);
g2.draw(ball);
g2.draw(box1);
g2.draw(box2);
g2.draw(box3);
g2.draw(box4);
g2.draw(box5);
g2.draw(box6);
g2.setColor(Color.BLACK);
g2.fill(box1);
g2.fill(box3);
g2.fill(box5);
g2.setColor(Color.ORANGE);
g2.fill(ball);
changeColors = !changeColors;
if (changeColors) {
g2.setColor(Color.lightGray);
g2.fill(new Ellipse2D.Double(x, y, 100, 100));
}
}
public void changeColors() {
changeColors = true;
repaint();
}
}
public BelishaBeacon() {
JFrame frame = new JFrame();
frame.setSize(350, 570);
frame.setTitle("Belisha Beacon");
frame.setLayout(new BorderLayout(0, 0));
final Drawing shapes = new Drawing();
timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
shapes.repaint();
}
});
JButton jbtFlash = new JButton("Flash");
jbtFlash.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Flashing");
if (!timer.isRunning()) {
timer.start();
}
}
});
final JButton jbtSteady = new JButton("Steady");
jbtSteady.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
timer.stop();
}
});
JPanel controlPanel = new JPanel();
controlPanel.setLayout(new GridLayout(1, 2, 0, 0));
controlPanel.add(jbtFlash);
controlPanel.add(jbtSteady);
frame.add(controlPanel, BorderLayout.SOUTH);
frame.add(shapes);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) {
new BelishaBeacon();
timer.start();
}
}
Instead of trying to toggle the color in paintComponent(), give Drawing a Color and use it to render the ball:
private Color color = Color.lightGray;
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
…
g2.setColor(color);
g2.fill(ball);
…
}
Make changeColors() actually change colors:
public void changeColors() {
if (Color.orange.equals(color)) {
color = Color.lightGray;
} else {
color = Color.orange;
}
repaint();
}
And add a makeSteady() method:
public void makeSteady() {
color = Color.orange;
repaint();
}
Now, your timer's action can just do shapes.changeColors(), your Flash button handler can just do timer.restart() and your Steady button handler can just do this:
timer.stop();
shapes.makeSteady();
Also, don't forget to invokeLater().
try this:
public class BelishaBeacon {
private static Timer timer;
public class Drawing extends JPanel {
private int x = 125;
private int y = 80;
private boolean changeColors = false;
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
Rectangle box1 = new Rectangle(165, 180, 20, 45);
Rectangle box2 = new Rectangle(165, 225, 20, 45);
Rectangle box3 = new Rectangle(165, 270, 20, 45);
Rectangle box4 = new Rectangle(165, 315, 20, 45);
Rectangle box5 = new Rectangle(165, 360, 20, 45);
Rectangle box6 = new Rectangle(165, 405, 20, 45);
Ellipse2D.Double ball = new Ellipse2D.Double(x, y, 100, 100);
g2.draw(ball);
g2.draw(box1);
g2.draw(box2);
g2.draw(box3);
g2.draw(box4);
g2.draw(box5);
g2.draw(box6);
g2.setColor(Color.BLACK);
g2.fill(box1);
g2.fill(box3);
g2.fill(box5);
g2.setColor(Color.ORANGE);
g2.fill(ball);
// changeColors = !changeColors;
if (changeColors) {
g2.setColor(Color.lightGray);
g2.fill(new Ellipse2D.Double(x, y, 100, 100));
}
}
public void changeColors() {
changeColors = !changeColors;
repaint();
}
public boolean getChangeColors() {
return changeColors;
}
}
public BelishaBeacon() {
JFrame frame = new JFrame();
frame.setSize(350, 570);
frame.setTitle("Belisha Beacon");
frame.setLayout(new BorderLayout(0, 0));
final Drawing shapes = new Drawing();
timer = new Timer(500, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
//shapes.repaint();
shapes.changeColors();
}
});
JButton jbtFlash = new JButton("Flash");
jbtFlash.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Flashing");
if (!timer.isRunning()) {
timer.start();
}
}
});
final JButton jbtSteady = new JButton("Steady");
jbtSteady.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
timer.stop();
if(shapes.getChangeColors()) {
shapes.changeColors();
}
}
});
JPanel controlPanel = new JPanel();
controlPanel.setLayout(new GridLayout(1, 2, 0, 0));
controlPanel.add(jbtFlash);
controlPanel.add(jbtSteady);
frame.add(controlPanel, BorderLayout.SOUTH);
frame.add(shapes);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static void main(String[] args) {
new BelishaBeacon();
timer.start();
}
}

Graphics2D on JPanel and adding JPanel to JFrame

I am trying to draw on a JPanel and add it to a JFrame in my createAndShowGui method. I have tried a few different things: creating the JPanel in the createAndShowGui method, adding the drawing to the JFrame, etc... The one thing that is common, I don't see any of my graphics!
Note: I am able to get the graphics to display in a JTabbedPane but not on a JPanel, which is what I actually want them to show up on to make the code more object oriented.
Edit:
Here is the working concept self contained example:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class DrawPanelMain extends JPanel {
/*
* Variables used to set the value of preferred height and width
*/
public static final double version = 0.0;
JPanel switchPanel = new JPanel();
JPanel testPanel = new JPanel();
JPanel btnPanel = new JPanel();
DrawEllipses drawEllipses = new DrawEllipses(POINT_LIST);
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
initializePointList();
createAndShowGui();
}
});
}
public static java.util.List<Point> POINT_LIST = new ArrayList<>();
/*
* This loop will initialize POINT_LIST with the set of points for drawing the ellipses.
* The for each loop initializes points for the top row and the second for loop draws the
* right triangle.
*/
public static void initializePointList() {
int ellipsePointsYCoordinate[] = {140, 200, 260, 320, 380, 440, 500, 560, 620};
int ellipsePointsXCoordinate[] = {140, 200, 260, 320, 380, 440, 500, 560, 620, 680};
int xx = 80;
for (int aXt : ellipsePointsXCoordinate) {
POINT_LIST.add(new Point(aXt, xx));
}
for (int i = 0; i < ellipsePointsYCoordinate.length; i++) {
for (int j = i; j < ellipsePointsYCoordinate.length; j++) {
POINT_LIST.add(new Point(ellipsePointsXCoordinate[i], ellipsePointsYCoordinate[j]));
}
}
}
public DrawPanelMain() {
testPanel.setBackground(Color.RED);
switchPanel.add(drawEllipses);
setLayout(new BorderLayout());
add(switchPanel, BorderLayout.CENTER);
add(testPanel, BorderLayout.EAST);
add(btnPanel, BorderLayout.SOUTH);
getPreferredSize();
btnPanel.add(new JButton(new AddSwitchAction("Add Switch Panel")));
}
public static void createAndShowGui() {
JFrame frame = new JFrame("RF Connection Panel " + version);
frame.setLayout(new BorderLayout());
frame.add(new DrawPanelMain());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(false);
//frame.setLocationRelativeTo(null);
frame.pack();
frame.setVisible(true);
}
/*
* AddSwitchAction will add a new pane to the tabbedPane when the add switch button is clicked
*/
private class AddSwitchAction extends AbstractAction {
public AddSwitchAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
int index = 0;
DrawEllipses tabComponent = new DrawEllipses(POINT_LIST);
switchPanel.add(tabComponent, index++);
}
}
}
#SuppressWarnings("serial")
class DrawEllipses extends JPanel {
private final int PREF_W = 750; //Window width
private final int PREF_H = 750; //Window height
private static final int OVAL_WIDTH = 30;
private static final Color INACTIVE_COLOR = Color.RED;
private static final Color ACTIVE_COLOR = Color.green;
private java.util.List<Point> points;
private java.util.List<Ellipse2D> ellipses = new ArrayList<>();
private Map<Ellipse2D, Color> ellipseColorMap = new HashMap<>();
/*
* This method is used to populate "ellipses" with the initialized ellipse2D dimensions
*/
public DrawEllipses(java.util.List<Point> points) {
this.points = points;
for (Point p : points) {
int x = p.x - OVAL_WIDTH / 2;
int y = p.y - OVAL_WIDTH / 2;
int w = OVAL_WIDTH;
int h = OVAL_WIDTH;
Ellipse2D ellipse = new Ellipse2D.Double(x, y, w, h);
ellipses.add(ellipse);
ellipseColorMap.put(ellipse, INACTIVE_COLOR);
}
MyMouseAdapter mListener = new MyMouseAdapter();
addMouseListener(mListener);
addMouseMotionListener(mListener);
}
/*
* paintComponent is used to paint the ellipses
*/
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (Ellipse2D ellipse : ellipses) {
g2.setColor(ellipseColorMap.get(ellipse));
g2.fill(ellipse);
g2.setColor(Color.BLACK);
g2.setStroke(new BasicStroke(2));
g2.draw(ellipse);
}
/*
* Set the font characteristics, color, and draw the row labels.
*/
g.setFont(new Font("TimesRoman", Font.BOLD, 18));
g.setColor(Color.BLACK);
//Along the top row
g.drawString("External Port", 10, 50);
g.drawString("1", 135, 50);
g.drawString("2", 195, 50);
g.drawString("3", 255, 50);
g.drawString("4", 315, 50);
g.drawString("5", 375, 50);
g.drawString("6", 435, 50);
g.drawString("7", 495, 50);
g.drawString("8", 555, 50);
g.drawString("9", 615, 50);
g.drawString("10", 672, 50);
//Along the Y-axis
g.drawString("Radio 2", 40, 145);
g.drawString("3", 90, 205);
g.drawString("4", 90, 265);
g.drawString("5", 90, 325);
g.drawString("6", 90, 385);
g.drawString("7", 90, 445);
g.drawString("8", 90, 505);
g.drawString("9", 90, 565);
g.drawString("10", 90, 625);
//Along the X-Axis
g.drawString("1", 135, 670);
g.drawString("2", 195, 670);
g.drawString("3", 255, 670);
g.drawString("4", 315, 670);
g.drawString("5", 375, 670);
g.drawString("6", 435, 670);
g.drawString("7", 495, 670);
g.drawString("8", 555, 670);
g.drawString("9", 615, 670);
//Draws a 3DRect around the top row of ellipse2D objects
g2.setColor(Color.lightGray);
g2.draw3DRect(120, 60, 580, 40, true);
g2.draw3DRect(121, 61, 578, 38, true);
g2.draw3DRect(122, 62, 576, 36, true);
}
/*
* MouseAdapter is extended for mousePressed Event that detects if the x, y coordinates
* of a drawn ellipse are clicked. If the color is INACTIVE it is changed to ACTIVE and
* vice versa.
*/
private class MyMouseAdapter extends MouseAdapter {
#Override
/*
* When mousePressed event occurs, the color is toggled between ACTIVE and INACTIVE
*/
public void mousePressed(MouseEvent e) {
Color c;
for (Ellipse2D ellipse : ellipses) {
if (ellipse.contains(e.getPoint())) {
c = (ellipseColorMap.get(ellipse) == INACTIVE_COLOR) ? ACTIVE_COLOR : INACTIVE_COLOR;
ellipseColorMap.put(ellipse, c);
}
}
repaint();
}
}
/*
* This method will set the dimensions of the JFrame equal to the preferred H x W
*/
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
}
switchPanel.add(title, tabComponent);
By default a JPanel uses a FlowLayout which respects the preferred size of the component. The preferred size of your component is (0, 0) so there is nothing to paint. Also, you are using the "title" string which is incorrect (and obsolete as has already been mentioned). That string represents a constraint for the layout manager. You can't just make up a String value. In any case FlowLayout does not accept any contraints so you should just be using:
switchPanel.add(tabComponent);
I am trying to draw on a JPanel
When doing custom painting you need to override the getPreferredSize() of the panel so the layout manager can use the information. If you don't override this method then the size is (0, 0) so there is nothing to paint.
Edit:
First some general comments:
Don't hardcode sizes of the panel. Your hardcoded size of (1200 x 750) is too large for my monitor. If you want full screen then use frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
Post code that you are actually testing. As has already been mentioned your posted code doesn't even add the "switchPanel" to the frame.
You haven't updated the code to show how you override the getPreferredSize() method.
Finally, I see in your code that you add the panel dynamically to the visible GUI. In this case the general code should be:
panel.add(....);
panel.revalidate(); // to invoke the layout manager otherwise size is still (0, 0)
panel.repaint();
You are adding DrawEllipses instances to switchPanel using an obsolete method add(String,Component); you should use something like add(component, index). Also, You don't add switchPanel to anything (commented out in DrawPanelMain ctor).

why when i add a for loop my jframe turns black?

I am trying to make a flashing light in my jframe by creating a list of the colors and then cycling through them with a for loop and then repainting. but when I add a for loop to my code the whole thing bugs out and I get a black screen and it frezzes. Why is this happening?
public class bb {
static Color colors[] = {Color.ORANGE, Color.GRAY};
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.setSize(400, 525);
JPanel panel = new JPanel() {
#Override
public void paintComponent(Graphics g) {
JButton smallerButton = new JButton("Flash");
JButton largerButton = new JButton("Steady");
JPanel southPanel = new JPanel();
southPanel.add(smallerButton);
southPanel.add(largerButton);
frame.add(southPanel, BorderLayout.SOUTH);
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(180, 110, 10, 30);
g.drawRect(180, 140, 9, 30);
g.fillRect(180, 170, 10, 30);
g.drawRect(180, 200, 9, 30);
g.fillRect(180, 230, 10, 30);
g.drawRect(180, 260, 9, 30);
g.fillRect(180, 290, 10, 30);
g.drawRect(180, 310, 9, 30);
g.fillRect(180, 340, 10, 30);
int i = 0;
g.setColor(colors[i]);
for(i=0; i <= colors.length; i++){
g.fillOval(160, 70, 50, 50);
if (i ==colors.length){
i=0;
}
frame.repaint();
}
smallerButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
String action = e.getActionCommand();
if (action.equals("Flash")){
}
}
});
}
};
frame.add(panel);
frame.validate();
}
}
This statement resets your loop index to 0 causing it to loop indefinitely blocking the EDT
if (i == colors.length) {
i = 0;
}
since you exceed the last array index in the for statement.
Take a look at using a Swing Timer to achieve this functionality.

How to stop repaint() flickering

I am trying to make a program to java and i have the common problem with flickering. I have try many things to eliminate but all the same. while the oval that i paint is moving the japplet is flickering. i need your help to solve this problem. here is my code:
import java.awt.Color;
public class all extends JApplet implements Runnable {
double x=0;
double y=0;
int m=0;
int n=0;
int f=30;
int μ=0;
Thread kinisi;
JPanel panel;
JFrame frame;
private boolean running = false;
private JTextField textField1;
private JTextField textField2;
Image backGround;
JPanel panel_3;
Image bf = createImage(m, n);
private Graphics doubleg;
private Image i;
public void init() {
this.setSize(800, 700);
}
public all() {
getContentPane().setLayout(null);
JButton btnNewButton = new JButton("Start");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
String b=textField2.getText();
String z =textField1.getText();
if (textField1.getText().equals("") ||
textField2.getText().equals("")){
JOptionPane.showMessageDialog(
new JFrame(),
"Δωστε τιμή για το φ και το μ!",
"ERROR",JOptionPane.ERROR_MESSAGE);
} else{
f = Integer.parseInt(b);
μ = Integer.parseInt(z);
Start(); }
}
});
btnNewButton.setBounds(469, 168, 89, 23);
getContentPane().add(btnNewButton);
JButton btnStop = new JButton("Pause");
btnStop.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
pause();
}
});
btnStop.setBounds(588, 168, 89, 23);
getContentPane().add(btnStop);
JButton btnReset = new JButton("Reset");
btnReset.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Reset();
}
});
btnReset.setBounds(701, 168, 89, 23);
getContentPane().add(btnReset);
JLabel label = new JLabel("\u03BC");
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setBounds(549, 63, 46, 14);
getContentPane().add(label);
textField1 = new JTextField();
textField1.setBounds(529, 101, 86, 20);
getContentPane().add(textField1);
textField1.setColumns(10);
JLabel label_1 = new JLabel("\u03C6");
label_1.setHorizontalAlignment(SwingConstants.CENTER);
label_1.setBounds(681, 63, 46, 14);
getContentPane().add(label_1);
textField2 = new JTextField();
textField2.setBounds(667, 101, 86, 20);
getContentPane().add(textField2);
textField2.setColumns(10);
JButton btnNewButton_1 = new JButton("");
btnNewButton_1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
JOptionPane.showMessageDialog(
new JFrame(),
"Οδηγίες προγράμματος","Οδηγίες",
JOptionPane.INFORMATION_MESSAGE);
}
});
btnNewButton_1.setIcon(
new ImageIcon(all.class.getResource("/Images/info.png")));
btnNewButton_1.setBounds(732, 5, 39, 35);
getContentPane().add(btnNewButton_1);
JLabel label_2 = new JLabel("");
label_2.setIcon(
new ImageIcon(all.class.getResource("/Images/earth.jpg")));
label_2.setBounds(-20, 0, 820, 361);
getContentPane().add(label_2);
JPanel panel_1 = new JPanel();
panel_1.setBorder(
new BevelBorder(BevelBorder.LOWERED, null, null, null, null));
panel_1.setBounds(10, 372, 369, 290);
getContentPane().add(panel_1);
JPanel panel_2 = new JPanel();
panel_2.setBorder(
new BevelBorder(BevelBorder.LOWERED, null, null, null, null));
panel_2.setBounds(408, 372, 369, 290);
getContentPane().add(panel_2);
}
public void paint(Graphics g){
super.paint(g);
g.drawLine(0,f,350,200);
g.drawLine(0,200,350,200);
g.drawOval(m,n,40,40);
Color brown=new Color(137,66,0);
g.setColor(brown);
g.fillOval(m, n, 40, 40);
//Graphics2D g2d = (Graphics2D) g;
g.drawLine(460,400,460,650);
g.drawLine(20, 620, 350, 620);
g.drawLine(50,400,50,650);
g.drawLine(430, 620, 760, 620);
}
public void Start() {
kinisi = new Thread(this);
kinisi.start();
running = true;
}
public void run() {
while (running) {
if (x < 340){
double l = 200-f;
double k = l/350;
double y=k*x+f-30;
x= x+1;
m = (int) x;
n = (int) y;
repaint();
try {
Thread.sleep(μ);
} catch (InterruptedException ie) {}
}
}
}
public void update(Graphics g) {
if(i==null){
i=createImage(800,700);
doubleg = i.getGraphics();
}
doubleg.setColor(getBackground());
doubleg.fillRect(0,0,800,700);
doubleg.setColor(getForeground());
paint(doubleg);
g.drawImage(i,0,0,this);
}
public void paint1(Graphics g){
g.drawLine(0, f ,350, 200);
g.drawOval(m, n, 40, 40);
Color brown=new Color(137,66,0);
g.setColor(brown);
g.fillOval(m, n, 40, 40);
}
public void pause() {
if (kinisi != null) {
running = false;
}
}
public boolean Reset() {
if (kinisi != null) {
running = false;
kinisi.interrupt();
kinisi = null;
x=0;
y=0;
f=30;
m=0;
n=0;
repaint();
textField1.setText("");
textField2.setText("");
}
Graphics g = getGraphics();
g.drawOval(m,n,40,40);
Color brown=new Color(137,66,0);
g.setColor(brown);
g.fillOval(m, n, 40, 40);
return false;
}
public static void main(String[] args) {
JFrame frame = new JFrame("FISIKI");
frame.getContentPane().add(new all());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(800, 700);
frame.setVisible(true);
frame.setResizable(false);
}
}
Thank you very much and sorry for my english are not very good!
There are a number of things that jump out at me.
You're extending from JApplet, but are adding it to a JFrame
You're mixing components with you custom painting
Not using layout managers.
Using getGraphics.
Firstly...
You should never override paint of a top level container (like JApplet). There are many reasons and you've found one. Top level containers are not double buffered. Instead, you should be creating a custom component (by extending something like JPanel) and overriding it's paintComponent method...
Secondly
Decided how you application is going to be. Is it an applet or application? If you follow the first point, then it really doesn't matter, as you only simply need to add the panel to the top level container.
Thirdly
I would create a panel that did the custom painting. Then I would create separate containers for all the fields and other parts of the application. This will allow you to separate the areas of responsibility. It would also allow you to use layout managers ;)
Fourthly
Use layout managers. The layout manager API has being designed to solve one of this most annoying aspects of GUI design, you're asking for a lot of trouble and work you decided to discard it - IMHO.
Fifthly
getGraphics should never be used. Apart from the fact that it can return null, it is only a snap shot of what is currently on the screen. As soon as the RepaintManager decides to perform a repaint, anything rendered to it will be lost. You should use paintComponent to update the state of your custom pane.

How to make Timer countdown along with progress bar?

How can I make it so that the progress bar slowly goes down with the time limit?
class GamePanel extends JPanel implements MouseListener, ActionListener
{
private JButton quit;
private JButton q;
private Font loadFont;
public GamePanel()
{
setBackground(Color.blue); // sets background color
this.setLayout(null);
quit = new JButton("Quit");
quit.addActionListener(this);
quit.setBounds(550, 700, 100, 30);
this.add(quit);
q = new JButton("Questions");
q.addActionListener(this);
q.setBounds(100, 100, 120, 30);
this.add(q);
loadFont = new Font("Serif", Font.PLAIN, 30);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(Color.black);
g.fillRect(80, 100, 610, 560);
g.setColor(Color.white);
g.fillRect(90, 110, 110, 100);// 1st column
g.fillRect(90, 220, 110, 100);//
g.fillRect(90, 330, 110, 100);//
g.fillRect(90, 440, 110, 100);//
g.fillRect(90, 550, 110, 100);//
g.fillRect(210, 110, 110, 100);// 2nd column
g.fillRect(210, 220, 110, 100);//
g.fillRect(210, 330, 110, 100);//
g.fillRect(210, 440, 110, 100);//
g.fillRect(210, 550, 110, 100);//
g.fillRect(330, 110, 110, 100);// 3rd column
g.fillRect(330, 220, 110, 100);//
g.fillRect(330, 330, 110, 100);//
g.fillRect(330, 440, 110, 100);//
g.fillRect(330, 550, 110, 100);//
g.fillRect(450, 110, 110, 100);// 4th column
g.fillRect(450, 220, 110, 100);//
g.fillRect(450, 330, 110, 100);//
g.fillRect(450, 440, 110, 100);//
g.fillRect(450, 550, 110, 100);//
g.fillRect(570, 110, 110, 100);// 5th column
g.fillRect(570, 220, 110, 100);//
g.fillRect(570, 330, 110, 100);//
g.fillRect(570, 440, 110, 100);//
g.fillRect(570, 550, 110, 100);//
g.setColor(Color.green);
g.setFont(loadFont);
g.drawString(input + ":", 100, 710);
}
public void actionPerformed(ActionEvent e)
{
String order = e.getActionCommand();
if(order.equals("Quit"))
cards.show(c, "Introduction");
if(order.equals("Questions"))
cards.show(c, "Questions");
}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseClicked(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
}
class QuestionPanel extends JPanel implements ActionListener
{
private long startTime, elapsedTime;
private Timer timer;
private int countdown;
private Font loadFont;
public QuestionPanel()
{
setBackground(Color.pink); // sets background color
this.setLayout(null); // moved into constructor from ActionPerformed: only change layout in constructor
startTime = 0;
elapsedTime = 0;
countdown = 590;
loadFont = new Font("Segoe Script", Font.BOLD, 20);
if(timer == null)
{// use the biggest value possible that provides your desired time keeping precision (usually no less than 15 on Windows)
timer = new Timer(100, this);
startTime = System.currentTimeMillis(); // gets start time in milliseconds
timer.start();
}
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.fillRect(100, 100, 600, 25);
g.setColor(Color.green);
g.fillRect(105, 105, countdown, 15);
g.setColor(Color.black);
g.setFont(loadFont);
g.drawString("" + ((System.currentTimeMillis() - startTime) / 1000.0), 100, 80); // display remaining time
}
public void actionPerformed(ActionEvent e)
{
String command = e.getActionCommand();
elapsedTime = System.currentTimeMillis() - startTime;
if(elapsedTime < (5000))
{
countdown--;
repaint();
}
else
{
timer.stop();
if(timer == null)
{
timer = new Timer(500, this);
timer.start();
}
}
if(elapsedTime >= (5000)) // can't use == here because of limited precision of system clock
cards.show(c, "Correct!");
}
}
class AnswerPanel extends JPanel implements ActionListener
{
private JButton revert;
public AnswerPanel()
{
setBackground(Color.yellow); // sets background color
this.setLayout(null);
revert = new JButton("Back");
revert.addActionListener(this);
revert.setBounds(340, 700, 100, 30);
this.add(revert);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
}
public void actionPerformed(ActionEvent e)
{
String directive = e.getActionCommand();
if(directive.equals("Back"))
cards.show(c, "Start");
}
}
class FailPanel extends JPanel implements ActionListener
{
private JButton turnaround;
public FailPanel()
{
setBackground(Color.green); // sets background color
this.setLayout(null);
turnaround = new JButton("Back");
turnaround.addActionListener(this);
turnaround.setBounds(340, 700, 100, 30);
this.add(turnaround);
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
}
public void actionPerformed(ActionEvent e)
{
String bidding = e.getActionCommand();
if(bidding.equals("Back"))
cards.show(c, "Start");
}
}
}// end of the entire program
Sorry, I still could not find the motivation to actually read your code, but just threw together this example based on the question. See if it gives you some ideas.
Note that it is an SSCCE and uses just 40 lines of code in all.
import java.awt.event.*;
import javax.swing.*;
class CountDownProgressBar {
Timer timer;
JProgressBar progressBar;
CountDownProgressBar() {
progressBar = new JProgressBar(JProgressBar.VERTICAL, 0, 10);
progressBar.setValue(10);
ActionListener listener = new ActionListener() {
int counter = 10;
public void actionPerformed(ActionEvent ae) {
counter--;
progressBar.setValue(counter);
if (counter<1) {
JOptionPane.showMessageDialog(null, "Kaboom!");
timer.stop();
}
}
};
timer = new Timer(1000, listener);
timer.start();
JOptionPane.showMessageDialog(null, progressBar);
}
public static void main(String[] args) {
SwingUtilities.invokeLater( new Runnable() {
public void run() {
CountDownProgressBar cdpb = new CountDownProgressBar();
}
});
}
}
From the looks of it, all of this code is within a big Java file? That is a bad idea.
You should have a good reason to define a class as an inner class, and from the looks of it, you do not have one for QuestionPanel and others.
As for the problem, your paintComponent method is called every time your counter is updated, which is right now roughly once every 0.1 seconds, yet you only tick by 1 pixel on each update, so by the end of 5 seconds, you've cut off 10*5 pixels (50). What you should do is update the progress bar by a different mechanism, such as a calculating the current time processed:
long processed = System.currentTimeMillis() - startTime;
double percent = Math.max(0, 1 - processed / 5000.0);
int width = (int)(590 * percent);
That is definitely too much information, and a very broad question. I'd say at most you only need to include the code for the class where the timer is, and the class where the progress bar gets drawn.
From skimming the code, I'm guessing you're using a rectangle to draw the progress bar. Based on that, one way you could go about it would be using a variable to store the width of the bar, and every time the timer ticks, decrease the width of the bar by a set amount. Then just set the width of the rectangle drawn to the value stored in the variable.

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