I am currently working on a simple pong-like game, but I got stucked with positioning the rectangle.
I want to change it's Y position to be at the half of the actual panel's height.
package com.game;
import javax.swing.*;
import java.awt.*;
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame("gEngine");
Player playerOne = new Player(frame);
Player playerTwo = new Player(frame);
}
}
package com.game;
import javax.swing.*;
import java.awt.*;
public class Player {
public Player(JFrame frame) {
MyPanel panel = new MyPanel();
frame.add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBackground(Color.BLACK);
frame.setSize(1280, 720);
frame.setVisible(true);
}
}
class MyPanel extends JPanel {
public void paintComponent(Graphics g) {
g.setColor(Color.WHITE);
g.fillRect(50, 60, 20, 120);
}
}
Your code has a lot of "problems". I suggest you to find some kind of tutorials or something. You frame.setVisible(true) and stuff inside Player's class constructor. Do you realize that every time you create a Player object, all these things will be applied to the JFrame? Is this necessary? Maybe you should do them only once. Also in order to paint the compnent according to its position according size, you can do g.fillRect(50, getHeight() / 2, 20, 120);
public class Test {
public static void main(String[] args) {
JFrame frame = new JFrame("gEngine");
Player playerOne = new Player();
Player playerTwo = new Player();
// Set the proper layout manager
frame.setLayout(new GridLayout());
frame.add(playerOne.getMyPanel());
frame.add(playerTwo.getMyPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBackground(Color.BLACK);
frame.setSize(1280, 720);
frame.setVisible(true);
}
public static class Player {
private JPanel myPanel;
public Player() {
this.myPanel = new MyPanel();
}
public JPanel getMyPanel() {
return myPanel;
}
}
static class MyPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
// let the component be painted "natural"
super.paintComponent(g);
// Do custom painting
g.setColor(Color.WHITE);
g.fillRect(50, getHeight() / 2, 20, 120);
}
}
}
Edit (based on comment):
The background is the default one because GridLayout splits the screen into 2 panels (in the middle of the frame). Even the frame has BLACK background, these 2 panels cover it. So the background you see is from the panels, and not from the frame. In order to change it you will have to change the background of the panels (and make them non-transparent):
static class MyPanel extends JPanel {
public MyPanel() {
super();
setOpaque(true);
setBackground(Color.BLACK);
}
#Override
public void paintComponent(Graphics g) {
// let the component be painted "natural"
super.paintComponent(g);
// Do custom painting
g.setColor(Color.WHITE);
g.fillRect(50, getHeight() / 2, 20, 120);
}
}
Related
I am creating a Video Player using VLCJ.
The player uses a Canvas as it's video surface.
videoPlayer.newVideoSurface(canvas);
So I am bounded to use Canvas.
I want to show message over the Canvas like, "Player Started". I tried using a JLayeredPane and a JLabel to accomplish this.
A short-demo code:
package canvasexample;
import java.awt.*;
import javax.swing.*;
import javax.swing.border.LineBorder;
public class CanvasExample extends JFrame
{
public JLabel label = new JLabel("Message");
public Canvas canvas = new MyCanvas();
public CanvasExample()
{
setSize(500, 500);
setLocationRelativeTo(null);
createWindow();
setVisible(true);
}
public void createWindow()
{
JLayeredPane pane = new JLayeredPane();
JPanel panel1 = new JPanel(new BorderLayout());
JPanel panel2 = new JPanel(new BorderLayout());
panel1.setSize(500, 500);
panel2.setSize(500, 500);
label.setBorder(new LineBorder(Color.BLUE));
panel1.add(canvas);
panel2.add(label, BorderLayout.NORTH);
pane.add(panel1, 1, 0);
pane.add(panel2, 2, 0);
add(pane);
}
private class MyCanvas extends Canvas
{
public MyCanvas() {
setBackground (Color.GRAY);
setSize(500, 500);
}
public void paint(Graphics g)
{
g.setColor(Color.red);
g.fillOval(75, 75, 150, 75);
}
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable(){
#Override
public void run(){
new CanvasExample();
}
});
}
}
But soon I found out that you can't mix heavyweight AWT component and lightweight Swing components.
So, can anyone tell me how can I display a message over a Canvas?
If you are trying to overlay static text on an vlcj embedded canvas you need to use Marquess
Or use the marque options directly in the mediaplayer here
For overlays besides text you can have a look AbstractJWindowOverlayComponent
or I haven't tried this approach u can create an JLayeredPane where you have your canvas at layer 1 and can have your JComponent which will draw your overlays at layer 0 with transparent background you can override it's paintComponent() method and draw whatever you need
I am making kind of my paint that creates shapes, it worked fine until I added layers(panel and frame), now the shapes aren't visible on button press I assume it is under the layers?i tried using paintComponent and revalidate etc and still couldn't get it to appear
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Main2 extends JPanel implements ActionListener {
private static Square mySquare;
private static Circle myCircle;
private static Color myColor;
public boolean SquareCheck;
public boolean CircleCheck;
JButton buttonSquare;
JButton buttonCircle;
JFrame frame;
JPanel panel;
public void paint(Graphics g) {
if (SquareCheck) {
g.setColor(myColor);
g.fillRect(mySquare.x, mySquare.y, mySquare.width, mySquare.length);
} else if (CircleCheck) {
g.setColor(myColor);
g.fillOval(myCircle.x, myCircle.y, myCircle.width, myCircle.length);
}
}
public void start() {
frame = new JFrame();
panel = new JPanel();
//setLayout(new BorderLayout());
buttonSquare = new JButton("■");
buttonCircle = new JButton("●");
buttonSquare.setPreferredSize(new Dimension(200, 20));
buttonCircle.setPreferredSize(new Dimension(200, 20));
buttonCircle.addActionListener(this);
buttonSquare.addActionListener(this);
//add(buttonCircle, BorderLayout.NORTH);
//add(buttonSquare, BorderLayout.SOUTH);
JToggleButton red = new JToggleButton();
panel.add(buttonCircle);
panel.add(buttonSquare);
frame.add(panel);
frame.setSize(500, 500);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == buttonSquare) {
SquareCheck = true;
} else if (e.getSource() == buttonCircle) {
CircleCheck = true;
}
repaint();
}
public static void main(String[] args) {
mySquare = new Square(30, 50, 50, 50);
myCircle = new Circle(60, 100, 50, 50);
myColor = Color.red;
Main2 x = new Main2();
x.start();
}
}
Basiclly the buttons changes the boolean then the repaint is called and based on the boolean it draws either a cirlce or a square,the code worked before adding frame and panel
Your paint method is a method of the Main2 class, but you never add a Main2 instance to the JFrame or to any component that goes into the JFrame, and so the Main2 instance will never be displayed, and the Swing painting manager will never call its paint method.
For starters, get rid of this variable, panel = new JPanel(); and every place you use panel, substitute this. This way you'll be working with a correct Main2 instance and adding it to the GUI.
Other issues:
You need to call the super's equivalent painting method in your override on its first line
Override paintComponent, not paint, and yes call super.paintComponenet(g); in this override
You will want to learn and use Java naming conventions. Variable names should all begin with a lower letter while class names with an upper case letter. Learning this and following this will allow us to better understand your code, and would allow you to better understand the code of others.
For safety's sake, add the #Override annotation above any method that you think may be overriding a parent method (such as paint), to make sure that you are doing it correctly.
For example:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
#SuppressWarnings("serial")
public class Main2 extends JPanel implements ActionListener {
private static Square mySquare;
private static Circle myCircle;
private static Color myColor;
private JToggleButton buttonSquare;
private JToggleButton buttonCircle;
JFrame frame;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (buttonSquare.isSelected()) {
g.setColor(myColor);
g.fillRect(mySquare.x, mySquare.y, mySquare.width, mySquare.length);
}
if (buttonCircle.isSelected()) {
g.setColor(myColor);
g.fillOval(myCircle.x, myCircle.y, myCircle.width, myCircle.length);
}
}
public Main2() {
frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
buttonSquare = new JToggleButton("■");
buttonCircle = new JToggleButton("●");
buttonCircle.addActionListener(this);
buttonSquare.addActionListener(this);
this.add(buttonCircle);
this.add(buttonSquare);
frame.add(this);
frame.setSize(500, 500);
frame.setVisible(true);
}
public void actionPerformed(ActionEvent e) {
repaint();
}
public static void main(String[] args) {
mySquare = new Square(30, 50, 50, 50);
myCircle = new Circle(60, 100, 50, 50);
myColor = Color.red;
new Main2();
}
}
class MyShape {
public int x, y, width, length;
public MyShape(int x, int y, int width, int length) {
this.x = x;
this.y = y;
this.width = width;
this.length = length;
}
}
I'm trying to draw a basic object to a JPanel
although it doesn't seem to be working.
I'm certain I am doing something wrong with where the paint method
is being called
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
public class testGui {
static colors gc_colors;
static gui gc_gui;
public static void main(String[] args) {
gc_colors = new colors();
gc_gui = new gui();
gc_gui.cv_frame.setVisible(true);
}
public static class colors {
Color cv_ltGrey;
Color cv_mdGrey;
Color cv_dkGrey;
public colors() {
cv_ltGrey = Color.decode("#DDDDDD");
cv_mdGrey = Color.decode("#CCCCCC");
cv_dkGrey = Color.decode("#111111");
}
}
public static class gui {
JFrame cv_frame;
JPanel cv_panel;
JPanel cv_content;
public gui() {
cv_frame = new JFrame();
cv_frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
cv_frame.setTitle("Test GUI");
cv_frame.setSize(600, 400);
cv_frame.setLayout(new FlowLayout());
cv_panel = new JPanel();
cv_panel.setBackground(gc_colors.cv_ltGrey);
cv_panel.setPreferredSize(new Dimension(500, 300));
cv_frame.add(cv_panel);
cv_content = new content();
cv_panel.add(cv_content);
}
}
public static class content extends JPanel {
public void paint(Graphics graphic) {
super.paint(graphic);
draw(graphic);
}
public void update() {
repaint();
}
public void draw(Graphics graphic) {
Graphics2D graphic2D = (Graphics2D) graphic;
graphic2D.setPaint(gc_colors.cv_ltGrey);
graphic2D.fillRect(10, 10, 100, 100);
}
}
}
I have a class for my gui which I am adding a JPanel to (a light grey one).
Which I am then trying to add my drawing to using a JPanel extended class
called content.
When I run it though it seems to create the grey JPanel which I want but
the drawing is just a tiny white square and I'm not sure why.
So, you content panel has a default preferred size of 0x0, FlowLayout honours the preferredSize of its components (with a little margin), hence the reason why you have a nice little small white rectangle.
What you need to do is override the getPreferredSize method of the content panel and return a suitable size, for example
public static class content extends JPanel {
#Override
public Dimension getPreferredSize() {
return new Dimension(120, 120);
}
public void paint(Graphics graphic) {
super.paint(graphic);
draw(graphic);
}
public void update() {
repaint();
}
public void draw(Graphics graphic) {
Graphics2D graphic2D = (Graphics2D) graphic;
graphic2D.setPaint(gc_colors.cv_ltGrey);
graphic2D.fillRect(10, 10, 100, 100);
}
}
I've decided to just leave out the second JPanel altogether.
It was too much of a hassle to put the JPanel inside of another JPanel
so instead I am only going to use a single JPanel
public static class gui {
JFrame cv_frame;
JPanel cv_panel;
JPanel cv_content;
public gui() {
cv_frame = new JFrame();
cv_frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
cv_frame.setTitle("Test GUI");
cv_frame.setSize(600, 400);
cv_frame.setLayout(new FlowLayout());
cv_content = new content();
cv_content.setBackground(gc_colors.cv_ltGrey);
cv_content.setPreferredSize(new Dimension(500, 300));
cv_frame.add(cv_content);
}
}
This what I am doing but is nothing is getting displayed on Jframe window. I have not extended class JFrame to do my, is it necessary to do so for displaying objects on window.
public class testGraphics {
static JFrame workingFrame = null;
public static void main(String args[])
{
JFrame workingManager = new JFrame("Hello");
workingManager.setSize(500, 500);
workingManager.setVisible(true);
Graphics g = workingManager.getGraphics();
JPanel jp = (JPanel) workingManager.getContentPane();
workingManager.paintComponents(g);
g.fillOval(0, 0, 30, 30);
g.drawOval(0, 50, 30, 30);
g.setColor(Color.CYAN);
}
}
Do not ever call getGraphics() or explicitly call paintXxx() to do custom painting. The correct way to do custom painting is to override the paintComponent method of the panel to paint on. The overriden method will be implicitly called for you. Then add that panel to the frame. Also you should override the getPreferredSize() of the panel, so it has a preferred size, so you can just pack the frame
class PaintPanel extends JPanel {
#Override
protected paintComponent(Grapchics g) {
super.paintComponent(g);
g.drawString(....);
}
#Override
public Dimension getPreferredSize() {'
return new Dimension(300, 300);
}
}
Then add it to the frame (or if you want to set it as the content pane of the frame, do that instead)
PaintPanel panel = new PaintPaint();
frame.add(panel);
...
frame.pack();
See more at Performing Custom Painting
I made several changes to your code to get it to work properly.
I changed your main method to call the SwingUtilities invokeLater method to make sure that the Swing components were defined and used on the Event Dispatch thread.
I created a drawing JPanel. I set the color first, then drew the ovals.
I added a JFrame default close operation. You must specify a default close operation, or else your Java application will continue running after you close the JFrame.
I moved the size to the drawing panel. The frame size will be calculated when you call the JFrame pack method.
And here's the modified code:
package com.ggl.testing;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TestGraphics implements Runnable{
private JFrame workingManager;
private JPanel drawingPanel;
#Override
public void run() {
workingManager = new JFrame("Hello");
workingManager.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
drawingPanel = new DrawingPanel();
workingManager.add(drawingPanel, BorderLayout.CENTER);
workingManager.pack();
workingManager.setLocationByPlatform(true);
workingManager.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new TestGraphics());
}
public class DrawingPanel extends JPanel {
private static final long serialVersionUID =
-3701718376300985046L;
public DrawingPanel() {
this.setPreferredSize(new Dimension(500, 500));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.CYAN);
g.fillOval(0, 0, 30, 30);
g.drawOval(0, 50, 30, 30);
}
}
}
The setSize() and setVisible() must be at the bottom of the method:
JFrame workingManager = new JFrame("Hello");
Graphics g = workingManager.getGraphics();
JPanel jp = (JPanel) workingManager.getContentPane();
workingManager.paintComponents(g);
g.fillOval(0, 0, 30, 30);
g.drawOval(0, 50, 30, 30);
g.setColor(Color.CYAN);
workingManager.setSize(500, 500);
workingManager.setVisible(true);
I'm trying to draw a image onto a JPanel by overriding the paintComponent method. However, I'm having no luck with it at all and I don't know why.
Here's the code I've got at the moment:
DrawPanel
public class DrawPanel extends JPanel{
private Image backgroundImg;
public DrawPanel()
{
backgroundImg = Toolkit.getDefaultToolkit().createImage("C:\\Users\\Administrator\\workspace\\Scrub\\src\\loginBackground.png");
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.drawImage(backgroundImg, 0, 0, null);
}
}
LoginWindow Class
import java.awt.*;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class LoginWindow extends Window{
private DrawPanel panel;
public LoginWindow(int width, int height)
{
super("", width, height);
panel = new DrawPanel();
this.add(panel);
panel.setVisible(true);
}
}
Main
public class Main
{
public static void main(String[] args)
{
LoginWindow loginWindow = new LoginWindow(500, 300);
}
}
There are lots of reasons this might not work
The image might not be getting loaded. You should use ImageIO.read instead, as it will throw an IOException if something goes wrong
The layout manager is using the preferred size of your panel, which is defaulted to 0x0, making the component effectively invisible
You're not setting the window to be visible...
For example
public class DrawPanel extends JPanel{
//...
public Dimension getPreferredSize() {
return backgroundImg == null ? new Dimesion(100, 100) : new Dimension(backgroundImg.getWidth(this), backgroundImg.gtHeight(this));
}
And then in your Window class...
public LoginWindow(int width, int height)
{
super("", width, height);
panel = new DrawPanel();
this.add(panel);
// Swing components are visible by default
//panel.setVisible(true);
// windows aren't
setVisible(true);
}
A simpler soliton would be to use a JLabel...
setLayout(new BorderLayout());
BufferedImage img = ImageIO.read(new File(...));
JLabel label = new JLabel(new ImageIcon(img));
add(label);
setVisible(true);
Take a look at How to use Labels and Reading/Loading an Image for more details