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Embedding two images (overlaid) in a JPanel [duplicate]

This question already has answers here:
How to draw an image over another image?
(2 answers)
Closed 5 years ago.
I Have used JPanel to embed two images. One is png image and another is jpeg. I have to overlay png image over jpeg. I have tried out. Please fix me if, I am wrong.
import java.awt.*;
import java.io.IOException;
import javax.swing.*;
public class Test extends JFrame
{
public Test()
{
super();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(1366,768);
onInit();
setVisible(true);
}
private void onInit()
{
JPanel panel=new JPanel();
panel.setLayout(null);
panel.setBounds(0,0,1366,768);
panel.setBackground(new Color(0,0,0,0));
JLayeredPane lp = getLayeredPane();
lp.setBounds(0,0,1366,768);
JLabel adLabel1=new JLabel();
adLabel1.setBounds(0,0,1366,768);
Image img1=new ImageIcon("F:\\wall papers\\Download-High-Res-Crazy-Concrete-Textures.jpg").getImage();
ImageIcon ad1=new ImageIcon(img1.getScaledInstance(1366,768,Image.SCALE_SMOOTH));
adLabel1.setIcon(ad1);
JLabel adLabel2 = new JLabel();
adLabel2.setBounds(0, 0, 1366, 768);
Image img2=new ImageIcon("<path>\\A100004.png").getImage();
ImageIcon ad2=new ImageIcon(img2.getScaledInstance(1366,768,Image.SCALE_SMOOTH));
adLabel2.setIcon(ad2);
adLabel2.setBackground(new Color(0,0,0,0));
adLabel2.revalidate();
lp.add(adLabel1,JLayeredPane.MODAL_LAYER);
lp.add(adLabel2,JLayeredPane.DRAG_LAYER);
panel.add(lp);
}
public static void main(String args[])
{
// Schedule a job for the event-dispatching thread:
// creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new Test();
}
});
}
}
If I do not use JPanel it is working, it shows only a blank panel. But I want it to be done in the JPanel.
Example:
and I tried with this png image:

You have a number of possible solutions, you could, for example try:
Using a GridBagLayout, although that would become insanely complex really quickly
Create you own LayoutManager, but that's probably overkill for the problem
Use a OverlayLayout manager, but since I don't have any experience with it, I can't say if it would solve your issue or not.
Or, you could...
Take control of the whole process and fallback to custom painting. This gives you the same level of flexibility as writing your own LayoutManager, but without the complexity and since you're only drawing images, makes a life a whole lot simpler.
If you need to display other components (like text or text fields) you could use a custom painting route to render the images as the background and one or layout mangers to deal with the other components.
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
try {
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (IOException ex) {
Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
}
public class TestPane extends JPanel {
private BufferedImage background;
private BufferedImage foreground;
public TestPane() throws IOException {
background = ImageIO.read(getClass().getResource("Background.png"));
foreground = ImageIO.read(getClass().getResource("Foreground.png"));
}
#Override
public Dimension getPreferredSize() {
return background == null ? new Dimension(200, 200) : new Dimension(background.getWidth(), background.getHeight());
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int x = 0;
int y = 0;
int width = getWidth();
if (background != null) {
x = (getWidth() - background.getWidth()) / 2;
y = (getHeight() - background.getHeight()) / 2;
width = background.getWidth();
g2d.drawImage(background, x, y, this);
}
if (foreground != null) {
x = x + width - foreground.getWidth();
g2d.drawImage(foreground, x, y, this);
}
g2d.dispose();
}
}
}

Animation sequence in JFrame

I wanted to create a JFrame and put a sequence of images for animation in there. But the images don't appear in the frame window. I just want basic troubleshooting tips to make it appear in the window. Just edit the code for an answer if you can.
My question:
Why isn't the window displaying any pictures? It shows a window with a background color of blue, but that's it. Please tell me an efficient way to store images in variables and display it in a loop.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import javax.swing.*;
import java.io.*;
public class Game extends JLabel implements ActionListener{
/**
*
*/
private static final long serialVersionUID = 1L;
public static Game blah;
BufferedImage nekopics[] = new BufferedImage[7];
BufferedImage currentimg;
public String nekosrcs[];
int xpos;
Timer timer;
public Game() throws IOException
{
JFrame jframe = new JFrame();
nekosrcs = new String[] { "walk1.png", "walk2.png",
"walk3.png", "walk4.png", "walk5.png",
"walk6.png"};
jframe.setTitle("Game");
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jframe.setLayout(new FlowLayout());
jframe.setSize(400, 400);
jframe.setResizable(false);
jframe.setVisible(true);
jframe.getContentPane().setBackground(Color.BLUE);
for (int i=0; i < nekopics.length; i++) {
nekopics[i] = ImageIO.read(new FileInputStream("D:/Programs
/pics"+nekosrcs[i]));
}
for (int i=0; i < nekopics.length; i++) {
timer = new Timer(1000, this);
timer.setInitialDelay(0);
timer.start();
currentimg = nekopics[i];
repaint();
}
}
public void paintComponent(Graphics g)
{
super.paint(g);
g.drawImage(currentimg,100,100,this);
}
public static void main(String[] args) throws IOException {
blah = new Game();
}
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}

Alright, there are a lot of problems in your code, let's step into each of them:
You have a lot of spaces between lines, that makes your code a lot larger and harder to read
You haven't indented your code correctly (see the last } on your code, it's at the same level than the others; your for loops, etc), it makes the code so much harder to read and understand as well
You're creating a JFrame but extending JLabel, I'm not sure why you're doing this, if you're doing it so you can use the paintComponent() method, it's not necessary, on my code you can see how you can do it w/o extending any Component
If you haven't read the Swing Timer docs you should click that link and read what the ActionListener parameter does. In this case, we're going to use this listener to call the repaint() method and update our currentImage (or nextImage in the code below) and change the image accordingly. You failed to do this.
You were creating more than 1 Timer too, you created 6 here! All of them new but they had no action to do when the time finished
for (int i=0; i < nekopics.length; i++) {
timer = new Timer(1000, this);
timer.setInitialDelay(0);
timer.start();
currentimg = nekopics[i];
repaint();
}
You're changing unnecessarily the visibility of the paintComponent() method to public from protected
However I want to congratulate you for not using a null layout and following the recommendations I made on the comments above.
And finally the code that changes one image for another inside a Timer is the following, you can copy-paste it and change the image's names so you can see how it works.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.FileInputStream;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class ImageSequence {
private JFrame frame;
private JPanel pane;
private Timer timer;
private int nextImage = 0;
private String[] images = {"tokyo", "tokyo2", "starwars"};
private Image img = null;
public static void main (String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new ImageSequence().createAndShowGui();
}
});
}
public void createAndShowGui() {
frame = new JFrame("Image Sequence");
timer = new Timer(1000, listener);
pane = new JPanel() {
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
try {
img = ImageIO.read(new FileInputStream("/home/jesus/Pictures/" + images[nextImage] + ".jpg"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
g.drawImage(img , 0, 0, 200, 200, this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
};
timer.start();
frame.getContentPane().add(pane);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
ActionListener listener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
System.out.println(nextImage);
nextImage = nextImage < images.length - 1 ? nextImage + 1 : 0;
System.out.println(nextImage);
pane.repaint();
}
};
}

Java JFrame - Key presses dont seem to be registering

I am using Java AWT Graphics and JFrame to make a gui application. I need to get key input, and the KeyListener implementation does not seem to be working, as my System.out.println("hello") Does not seem to be triggering. I cannot find an answer for this problem elsewhere on the internet so i have come here.
I am using eclipse and itdoes not seem to provide me with any insight, errors, warnings ect relating to the problem, I am also rather new to Java but i have experience with higher level languages including JavaScript.
Other than the forementioned problem, the application works as intended, moving the rectangle from the top left, to the top right of the screen and beyond.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Main extends JPanel implements ActionListener, KeyListener{
static int WIDTH;
static int HEIGHT;
int x = 0;
int y = 0;
int targetFPS = 60;
int currentFPS = targetFPS;
Timer timer = new Timer(1000/targetFPS, this);
public Main(){
timer.start();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.fillRect(x-25, y-25, 50, 50);
}
public static void main(String[] args){
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
WIDTH = (int) screenSize.getWidth();
HEIGHT = (int) screenSize.getHeight();
Main main = new Main();
JFrame frame = new JFrame();
frame.setTitle("Hello");
frame.setSize(WIDTH, HEIGHT);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(main);
}
#Override
public void actionPerformed(ActionEvent e) {
x++;
repaint();
}
#Override
public void keyPressed(KeyEvent e) {
int c = e.getKeyCode();
System.out.println("hello");
}
#Override
public void keyReleased(KeyEvent e) {
}
#Override
public void keyTyped(KeyEvent e) {
}
}

KeyListener suffers from focus related issues and in this respect, is unreliable, instead, you should be using the Key Bindings API which was designed to help solve this issue.
Take a look at How to Use Key Bindings for more details

Try:
public Main(){
timer.start();
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
==> requestFocus();
}

JPanel Animated Background

This is a really general question, but how should I add an animated background for a JPanel. I want the background to be behind all the panel's components and graphics. Right now, I have two separate classes (one for the main panel and the other for the background). The background class uses repaint() to animate a grid moving across the screen. I've tried to make the main panel background transparent, but that hasn't gotten me anywhere.
Even more info:
My main panel is part of a CardLayout and it has many different classes in it. So when I'm adding my main panel to my main frame, I'm doing frame.getContentPane().add(cards, BorderLayout.CENTER)
cards is a JPanel which acts as a container for the mainpanel and all the panels inside main panel.
Can anybody help me out in getting a panel animated background?

You can use Toolkit.getImage() to load animated image and then draw the image in container's paintComponent. Make sure the ImageObserver is set (not null) in order to update animation frames properly. For details how image is loaded, observed and updated see How Images are Loaded appendix in Java AWT Reference.
Here is a simple example:
import java.awt.*;
import javax.swing.*;
import java.net.URL;
class AnimatedPanelDemo {
static class ImagePanel extends JPanel {
private Image image;
ImagePanel(Image image) {
this.image = image;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image,0,0,getWidth(),getHeight(),this);
}
}
private static void createAndShowUI() {
try {
JFrame frame = new JFrame("Image");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
Image image = Toolkit.getDefaultToolkit().getImage(new URL(
"http://duke.kenai.com/iconSized/duke.running.gif"));
ImagePanel imagePanel = new ImagePanel(image);
imagePanel.add(new JLabel("Some label"));
frame.add(imagePanel);
frame.setSize(100, 100);
frame.setVisible(true);
}
catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}

Well, this is my first answer on stackoverflow.
Will try to help with my learning curve with this complex AWT and Swift API.
Below there's the contructor that extends JFrame
package xpto;
import java.awt.Dimension;
import java.awt.GraphicsConfiguration;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.awt.event.WindowStateListener;
import java.awt.image.ImageObserver;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import sun.java2d.SunGraphicsEnvironment;
import java.awt.Graphics;
import java.awt.Graphics2D;
public class FrameLuckyRaffle extends JFrame {
/**
*
*/
private JLabel backgroundLabel;
private ImageIcon imageIcon;
private Image bgImage;
/**
* Constructor of this frame.
*/
public FrameLuckyRaffle(String background, final String dbname) {
try {
setTitle("Lucky Raffle of "+ dbname);
GraphicsConfiguration config = this.getGraphicsConfiguration();
Rectangle usableBounds = SunGraphicsEnvironment.
getUsableBounds(config.getDevice());
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
setBounds(100, 100, (int)(usableBounds.getWidth()*0.8),
(int)(usableBounds.getHeight()*0.8));
setMinimumSize(new Dimension(1024, 700));
setResizable(true);
setDefaultLookAndFeelDecorated(true);
backgroundLabel = new JLabel() {
public void paintComponent(Graphics g) {
// alternative --> g.drawImage(bgImage, 0, 0, null);
// I prefer to control the new ImageObserver parameter as bellow
g.drawImage(bgImage, 0, 0, new ImageObserver() {
#Override
public boolean imageUpdate(Image img, int infoflags,
int x, int y, int width, int height) {
img.getScaledInstance(getWidth(),getHeight(),
Image.SCALE_FAST);
return true;
}
});
// this is used to have easier control on
// image manipulation on my application
Graphics2D g2d = (Graphics2D)g;
super.paintComponent(g2d);
revalidate();
repaint();
}
};
backgroundLabel.setBounds(0, 0, 0, 0);
// this is necessary if you want more child
// components to be visible on the JFrame afterwards
backgroundLabel.setOpaque(false);
setContentPane(backgroundLabel);
addWindowListener(new WindowListener() {
#Override
public void windowOpened(WindowEvent e) {
// Set Frame Background
imageIcon = new ImageIcon(Toolkit.getDefaultToolkit().
createImage(FrameBusinessPure.class.getResource(background)));
bgImage = imageIcon.getImage().
getScaledInstance(getWidth(),getHeight(), Image.SCALE_FAST);
}
// Even after closing the window, JVM didn't Garbage Collected the instanced
// objects, for some reason. Forcing the objects to null helped on that.
#Override
public void windowClosed(WindowEvent e) {
backgroundLabel = null;
imageIcon = null;
bgImage = null;
System.gc();
}
});
addWindowStateListener(new WindowStateListener() {
#Override
public void windowStateChanged(WindowEvent e) {
// if you flush the object on runtime you will surpass the
// memory leak on using GIFs and most complex graphics
bgImage.flush();
bgImage = imageIcon.getImage().
getScaledInstance(getWidth(),getHeight(), Image.SCALE_FAST);
}
});
addMouseMotionListener(new MouseMotionListener() {
#Override
public void mouseDragged(MouseEvent e) {
// if you flush the object on runtime you will surpass the
// memory leak on using GIFs and most complex graphics
bgImage.flush();
bgImage = imageIcon.getImage().
getScaledInstance(getWidth(),getHeight(), Image.SCALE_FAST);
});
}catch (Exception e) {
e.printStackTrace();
}
}
}
Feel free to learn more on below link
https://www.oracle.com/java/technologies/painting.html

MouseWheel Flicker, More about the why

A few days ago I posted a question about a program that caused text on screen to change color when the mousewheel was scrolled. It was unfortunately a badly put together question with too much code posted to be particularly useful.
I had several responses, one of which was from the user trashdog who posted something that fixed the problem (which can be found at the bottom of this page here: Window going blank during MouseWheelMotion event) , however having read the class descriptions of all the things I didn't know about in the program he posted and gone through its execution I don't understand why his achieves a different effect from mine.
His seems to log every mouse wheel movement where as mine only does the initial movement. Also several people commented that they couldn't replicate the effect of my program probably because it was so big.
Below is an extremely simplified version which still elicits the same effect (I hope).
Question: What is the fundamental difference between the two programs that fixes the screen going blank when the mouse wheel events are being processed?
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.util.LinkedList;
import javax.swing.JFrame;
public class WheelPrinter implements MouseWheelListener, Runnable {
JFrame frame;
LinkedList colorList;
int colorCount;
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
WheelPrinter w = new WheelPrinter();
w.run();
}
public WheelPrinter() {
frame = new JFrame();
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.addMouseWheelListener(this);
frame.setVisible(true);
frame.setBackground(Color.WHITE);
colorList = new LinkedList();
colorList.add(Color.BLACK);
colorList.add(Color.BLUE);
colorList.add(Color.YELLOW);
colorList.add(Color.GREEN);
colorList.add(Color.PINK);
}
#Override
public void mouseWheelMoved(MouseWheelEvent e) {
colorChange();
}
#Override
public void run() {
while(true) {
draw(frame.getGraphics());
try {
Thread.sleep(20);
} catch (Exception ex) {
}
}
}
public void draw(Graphics g) {
g.setColor(frame.getBackground());
g.fillRect(0,0,frame.getWidth(),frame.getHeight());
g.setFont(new Font("sansserif", Font.BOLD, 32));
g.setColor(frame.getForeground());
g.drawString("yes", 50, 50);
}
public void colorChange() {
colorCount++;
if (colorCount > 4) {
colorCount = 0;
}
frame.setForeground((Color) colorList.get(colorCount));
}
}
(Try spinning your mouse wheel really hard if you try running my code and it will become even more obvious)

while(true) { is endless loop, without break; f.e.
use Swing Timer instead of Runnable#Thread delayed by Thread.Sleep()
paint to the JPanel or JComponent, not directly to the JFrame
all painting to the Swing JComponent should be done in paintComponent()
more in the 2D Graphics tutorial
edit
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseWheelEvent;
import java.util.LinkedList;
import java.util.Queue;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
/**
* based on example by #trashgod
*
* #see http://stackoverflow.com/a/10970892/230513
*/
public class ColorWheel extends JPanel {
private static final int N = 32;
private static final long serialVersionUID = 1L;
private final Queue<Color> clut = new LinkedList<Color>();
private final JLabel label = new JLabel();
public ColorWheel() {
for (int i = 0; i < N; i++) {
clut.add(Color.getHSBColor((float) i / N, 1, 1));
}
//clut.add(Color.BLACK);
//clut.add(Color.BLUE);
//clut.add(Color.YELLOW);
//clut.add(Color.GREEN);
//clut.add(Color.PINK);
label.setFont(label.getFont().deriveFont(36f));
label.setForeground(clut.peek());
label.setText("#see http://stackoverflow.com/a/10970892/230513");
setBackground(Color.white);
add(label);
label.addMouseWheelListener(new MouseAdapter() {
#Override
public void mouseWheelMoved(MouseWheelEvent e) {
label.setForeground(clut.peek());
clut.add(clut.remove());
}
});
}
#Override
public Dimension getPreferredSize() {
int w = SwingUtilities.computeStringWidth(label.getFontMetrics(
label.getFont()), label.getText());
return new Dimension(w + 20, 80);
}
private void display() {
JFrame f = new JFrame("ColorWheel");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new ColorWheel().display();
}
});
}
}

The fundamental difference is that you are trying to interact with the Graphics object from the wrong thread and without knowing anything about the state the Graphics object is in at the time.
The generally correct way to interact with a Graphics object in Swing is by making a custom component which overrides the paintComponent(Graphics) method. You do your drawing while inside that method.
Your colorChange() method can tell your component to re-draw itself by calling repaint(), which will eventually lead to a call to paintComponent(Graphics) on the correct thread at the correct time.
See tutorial here