I am working on an assignment (GASP) and having issues with my image displaying. I am not looking for someone to complete my assignment for me but I desperately need some help figuring out why my code is not working properly. I have reviewed my Java Programming book as well as searched for the answers online to no avail so if someone could lead me in the right direction I would greatly appreciate it!!
Here is my displayImage code:
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DisplayImage extends JFrame {
public void DislayImage(){
add (new ImagePanel());
}
public static void main(String[] args) {
JFrame frame = new DisplayImage ();
frame.setTitle("Go Bearcats!");
frame.setSize(300, 300);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
Assignment02 a = new Assignment02();
frame.add(a);
}
}
class ImagePanel extends JPanel {
public final static String LOC = "C:\\UCincinnatiLogo.jpg";
private ImageIcon imageIcon = new ImageIcon (LOC);
private Image image = imageIcon.getImage();
#Override /**Draw image on the panel*/
protected void paintComponent(Graphics g){
super.paintComponent(g);
if (image !=null)
g.drawImage(image, 200, 200, getWidth(), getHeight(), this);
}
}
You're adding a component right on top of your image panel. The JFrame uses borderLayout, so anything added to it as you're doing will cover anything added previously.
JFrame frame = new DisplayImage ();
frame.setTitle("Go Bearcats!");
frame.setSize(300, 300);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
Assignment02 a = new Assignment02();
frame.add(a); // here you add something on top of your imagePanel
Instead, make the ImagePanel the JFrame's contentPane via setContentPane(...), and then add things to the JFrame/contentPane, but be sure that they're not opaque.
public class DisplayImage extends JFrame {
public void DislayImage(){
setContentPane(new ImagePanel());
}
and then,
Assignment02 a = new Assignment02();
a.setOpaque(false);
frame.add(a);
Note, as an aside, I rarely create any classes that extend JFrame, and instead create my JFrame when needed. Instead I'd create my ImagePane and then add components directly to it before adding all to a JFrame.
Also you don't show us the Assignment02 class, but it had better have non-opaque JPanels and components.
Related
I have issue with drawing shapes inside of JPanel that I already added using Netbeans GUI. Now, I have no idea where to add code for drawing a circle inside of that JPanel and how to insert and call it in the JPanel that is sitting empty now, waiting for this shape to be drawn. I already set up destination JPanel to be Flow layout.
Netbeans Designer created a big class in which I have entire frame with this JPanel, and I want to keep it inside of it as I can't really add it any other way because Designer doesn't let me change main initComponents method in which all components are sitting now. I have been reading tutorials and previous posts but noone really encountered this using Netbeans Designer.
SO can someone just help me with adding proper method in this frame class and how to call it from JPanel I want to draw in. JPanel is 50x50 pixels.
So as per #Abra, I changed some code:
so I made a new Circle Class, adjusted it a bit as I don't want to create a new frame but put this in JPanel.
public class Circle extends JPanel {
Color color;
public void circle(Color color) {
this.color = color;
setPreferredSize(new Dimension (30,30));
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawOval(0, 0, r, r);
g.setColor(color);
}
private void showGUI() {
JPanel panel = new JPanel();
panel.add(this, FlowLayout.CENTER);
panel.setVisible(true);
}
}
Then I opened JPanel in Designer, and added code to run it, in initComponents method like this:
circlePanel.setPreferredSize(new java.awt.Dimension(40, 40));
new Circle().showGUI();
PanelDS.add(circlePanel);
circlePanel is destination for this drawing and is inside PanelDS itself. It doesn't work this way tho, but Netbeans shows no errors in code. Additionally, how can I forward color to circle class.
In order to draw on a JPanel you need to override the paintComponent() method of JPanel. In order to override the method, you need to create a class that extends JPanel. I don't think that there exists a GUI designer that can generate the required code for you. So you have to write the code of the class that extends JPanel.
Here is a minimal example. It displays a blue circle.
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.WindowConstants;
public class Drawing2 extends JPanel {
private JFrame frame;
public Drawing2() {
setPreferredSize(new Dimension(100, 100));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.BLUE);
g.fillOval(25, 25, 50, 50);
}
private void showGui() {
frame = new JFrame("Drawing");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.add(this, BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
new Drawing2().showGui();
}
}
Here's what you should see when you run the above code.
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
class game extends JFrame {
public game(){ //this is constructor
JFrame frame = new JFrame();
frame.setVisible(true);
frame.setSize(500,500);
frame.setTitle("Hello world");
}
public void paint(Graphics g){
Graphics2D g2 = (Graphics2D) g;
Line2D line = new Line2D.Double(60,90,150,100);
g2.draw(line);
}
public static void main(String args[]) {
game l = new game();
}
}
The above code is compiling in java but on running the code it only displays the frame and its title, but does not include any of the lines being drawn using the Graphics2D and Line2D, what is the mistake that is being made??? The frame being displayed does not show any content, why is that???
First, you are creating and displaying a JFrame which is not an instance of game, so there is no chance that it paints what you have in the paint method of game .
You usually don't want to create a subclass of JFrame for custom painting anyway, just create a subclass of JPanel, and set it as the content pane of the frame.
Also don't override paint, but paintComponent, which is the method responsible for painting the current component.
You should also call the parent method of paintComponent, to make sure that all the usual cleaning takes place correctly.
Also by convention, class names should start with an upper case letter.
One last thing, make the frame visible only once you have added all your components, or you may encounter visual glitches some day.
Putting it all together :
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Line2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
class Game extends JPanel {
#Override
public void paintComponent(final Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(Color.BLACK);
Line2D line = new Line2D.Double(60, 90, 150, 100);
g2.draw(line);
}
public static void main(final String args[]) {
Game l = new Game();
JFrame frame = new JFrame();
frame.setSize(500, 500);
frame.setTitle("Hello world");
frame.setContentPane(l);
frame.setVisible(true);
}
}
In your constructor call method of JFrame class using this keyword because you extends JFrame class in your class.
public game(){ //this is constructor
/*JFrame frame = new JFrame();
frame.setVisible(true);
frame.setSize(500,500);
frame.setTitle("Hello world");*/
this.setVisible(true);
this.setSize(500,500);
this.setTitle("Hello world");
}
This solve your problem.
you dont need to create instance of JFrame class ,
modified you constructor as shown below
public game(){ //this is constructor
setVisible(true);
setSize(500,500);
setTitle("Hello world");
}
This question already has an answer here:
Can't draw to JPanel with getGraphics
(1 answer)
Closed 4 years ago.
I'm having trouble getting the graphics of my JPanel to work. It refuses to draw anything, regardless of anything I've tried and anything I can find on the internet.
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.util.Timer;
import java.util.*;
import java.io.*;
public class Mandelbrot{
public static void main(String[] args){
JFrame win=new JFrame();
JPanel dis=new JPanel();
win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
win.setResizable(false);
win.setVisible(true);
win.add(dis);
dis.setPreferredSize(new Dimension(1000,500));
win.pack();
Graphics g=dis.getGraphics();
g.setColor(Color.red);
g.fillRect(0, 0, 100, 100);
}
}
Posting as an answer because I ran out of comment room:
Note:
If you need to be constantly changing things, then a JPanel is probably not your best option. I recommend you rethink what you are trying to do because you should probably use a Canvas or paint to a bunch of different labels/glass panes and overlay them however you want, this will allow you to have moving components/animations in a foreground item, and make different changes to the background item.
Alternatively, you can make the JPanel draw a buffered image, or you can store a list of items to paint, and you can paint them each time. For the buffered image method you can directly edit and draw to the buffered image every time you need to make a change.
Below is an example of how to use the buffered image method.
First create a custom JPanel in a new class:
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import javax.swing.JPanel;
public class DrawPanel extends JPanel{
public BufferedImage canvas = new BufferedImage(panelWidth, panelHeight, BufferedImage.TYPE_INT_ARGB);
#Override
public void paintComponent(Graphics g){
//Draw the canvas
g.drawImage(canvas, 0, 0, this);
}
}
Now in your main method you can replace JPanel dis=new JPanel() with this:
DrawPanel dis = new DrawPanel();
Graphics g=dis.canvas.getGraphics();
g.setColor(Color.red);
g.fillRect(0, 0, 100, 100);
Note how I use dis.canvas to get the graphics of the bufferedImage instead of the graphics of the JPanel.
It's as simple as that.
As per Andrews comment. You should consider extending a JLabel instead of a JPanel, it is much more lightweight, and easier to update using label.repaint();.
public static void main(String... args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
JPanel panel = new JPanel() {
#Override
public void paint(Graphics g) {
super.paint(g);
g.setColor(Color.red);
g.fillRect(0, 0, 100, 100);
}
};
panel.setPreferredSize(new Dimension(640, 480));
frame.add(panel);
frame.setVisible(true);
frame.pack();
}
Just an example - you should create a new Class subclassing JPanel, see Painting in AWT and Swing.
A gif that I tried to put into a JPanel isn't showing up after clicking the button that triggers it until I resize the window. When it does show up, it does not fit the JPanel and is not animated. I looked at several posts that dealt with this but I don't understand how to use them in my case.
/*
* Author: Raymo111
* Date: 13/04/2018
* Description: Wishes happy birthday to a special someone
*/
//Imports java GUI classes
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
// Main class with JFrame and ActionListener enabled
public class Happy_Birthday_GUI extends JFrame implements ActionListener {
// Class variables
private static JButton startButton = new JButton("CLICK TO START");
private static JPanel startPanel = new JPanel(), gifPanel = new JPanel();
private static Color blue = new Color(126, 192, 238), pink = new Color(255, 192, 203);
private static GridLayout grid1 = new GridLayout(1, 1);
// Constructor
public Happy_Birthday_GUI() {
// Initial screen
startButton.addActionListener(this);
startButton.setFont(new Font("Comic Sans MS", Font.PLAIN, 50));
startPanel.setLayout(grid1);
startPanel.add(startButton);
startPanel.setBorder(BorderFactory.createLineBorder(blue, 100));
startButton.setBackground(pink);
getContentPane().add(startPanel);
// Sets title, size, layout (grid 1x1), and location of GUI window (center)
setTitle("Happy Birthday from Dolphin");
setSize(840, 840);
setLayout(grid1);
setLocationRelativeTo(null);
setVisible(true);
}
// Main method
public static void main(String[] args) {
new Happy_Birthday_GUI();
}
// Action Performed method
public void actionPerformed(ActionEvent event) {
// Proceed to gif and song
if (startButton == event.getSource()) {
getContentPane().removeAll();
BufferedImage dolphin;
gifPanel.setLayout(grid1);
gifPanel.setBorder(BorderFactory.createLineBorder(pink, 100));
try {
dolphin = ImageIO.read(new File("C:\\Users\\raymo\\Pictures\\dolphin.gif"));
JLabel gifLabel = new JLabel(new ImageIcon(dolphin));
gifPanel.add(gifLabel);
} catch (IOException e) {
e.printStackTrace();
}
getContentPane().add(gifPanel);
}
}
}
Here is dolphin.gif. It's cute.
How do I get it to show up immediately after clicking the start button as an animated gif that fits the JPanel? Thanks in advance.
BufferedImage doesn't support painting animated Gifs, instead, you'll need to make use of Image (or preferably, ImageIcon).
This could then be applied directly to a JLabel, which will perform the animation operation itself.
animated gif that fits he JPanel?
Okay, that's a much more complex problem. One approach would be to convert the Gif to the required size, but needless to say, that's very, very complex.
A simpler solution might be to use a AffineTransform and scale the image to meet the requirements of the component itself. This would require a custom component, capable of calculating the scale and painting each frame of the image.
Luckily for you, JPanel is an ImageObserver, this means it's capable of painting the gif animation
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import javax.swing.ImageIcon;
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();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private ImageIcon image;
public TestPane() {
image = new ImageIcon("/Users/swhitehead/Downloads/NbENe.gif");
}
#Override
public Dimension getPreferredSize() {
return new Dimension(600, 600);
}
#Override
protected void paintComponent(Graphics g) {
int imageWidth = image.getIconWidth();
int imageHeight = image.getIconHeight();
if (imageWidth == 0 || imageHeight == 0) {
return;
}
double widthScale = (double)getWidth() / (double)imageWidth;
double heightScale = (double)getHeight() / (double)imageHeight;
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(image.getImage(), AffineTransform.getScaleInstance(widthScale, heightScale), this);
g2d.dispose();
}
}
}
I tried to put into a JPanel isn't showing up after clicking the button
When you add (or remove) components from a visible GUI the basic code is:
panel.add(...);
panel.revalidate();
panel.repaint();
The revalidate() is need to invoke the layout manager so the component is given a size.
is not animated.
Use a JLabel with an ImageIcon to display images. A JLabel will animated the gif.
When it does show up, it does not fit the JPanel and
You can try the Stretch Icon which is designed to fill the space available to the label.
I ended up doing:
gifPanel.add(new TestPane());
getContentPane().add(gifPanel);
revalidate();
repaint();
using camickr's revalidate and repaint, and MadProgrammer's TestPane class,
which worked very well to get the gif to animate, resize correctly and display immediately.
I am trying to display a large image inside a JFrame's contentpane. I would like to make the image or contentpane scrollable as the image is large. I tried to do it using Jscrollpane and add it into the contentpane but it didn't work. Did some searching for solution but end up failed to find one. Can someone guide me? My code are below
FinalEnvironment.java
package environment;
import java.awt.*;
import java.net.URL;
import javax.swing.*;
public class FinalEnvironment{
public FinalEnvironment(){
Image Eastlake;
URL EastlakeURL = null;
EastlakeURL = FinalEnvironment.class.getResource("/image1/eastlake_night.png");
Eastlake = Toolkit.getDefaultToolkit().getImage(EastlakeURL);
JFrame frame = new JFrame("UniCat World");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(800, 600);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
JMenuBar yellowMenuBar = new JMenuBar();
Map map = new Map(800, 550, Eastlake);
yellowMenuBar.setOpaque(true);
yellowMenuBar.setBackground(Color.YELLOW);
yellowMenuBar.setPreferredSize(new Dimension(800, 50));
frame.setJMenuBar(yellowMenuBar);
JScrollPane scroller = new JScrollPane(map);
scroller.setAutoscrolls(true);
scroller.setPreferredSize(new Dimension(800, 550));
frame.getContentPane().add(scroller, BorderLayout.CENTER);
frame.setSize(800, 600);
frame.setVisible(true);
}
public static void main(String[] args){
FinalEnvironment fe = new FinalEnvironment();
}
}
Here is my map.java
package environment;
import java.awt.*;
import javax.swing.*;
public class Map extends JPanel{
private int width;
private int height;
private Image img;
public Map(int width, int height, Image img){
this.width = width;
this.height = height;
this.img = img;
}
protected void paintComponent(Graphics g)
{
super.paintComponents(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(img,0,0,2624,1696,null);
}
}
Lastly, I would like to place Jbuttons on top of this image. Should I call a Rectangle and place it on top the image in the contentpane which then I use Point to position my buttons or should I straight away use the image or the component itself to do it? I need the button to be able to synchronize with the image when it is scrolled instead of static in the contentpane.
Thanks
What I would do here:
1.Have a panel (canvas) which only responsibility is to paint a given image independent of the real image size in overridden method paintComponent()
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
2.Make sure the canvas preferred size equals to image real size.
3.Have a second panel which will serve as content pane of a frame.
4.In it you will set a JScrollPane as its centre.
5.In the scroll pane viewport will be the component from step 1.
6.Add your button to canvas panel from step 1. It will be scrolled together with the image.
7.Add the content pane, the panel from step 3, to a frame, and run the application.
EDIT:
Code sample with button added to canvas, which stays always in its place, independent of scroll position or frame size.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
public class ScrollImageTest extends JPanel {
private static final long serialVersionUID = 1L;
private BufferedImage image;
private JPanel canvas;
public ScrollImageTest() {
try {
this.image = ImageIO.read(new URL("http://interviewpenguin.com/wp-content/uploads/2011/06/java-programmers-brain.jpg"));
}catch(IOException ex) {
Logger.getLogger(ScrollImageTest.class.getName()).log(Level.SEVERE, null, ex);
}
this.canvas = new JPanel() {
private static final long serialVersionUID = 1L;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}
};
canvas.add(new JButton("Currently I do nothing"));
canvas.setPreferredSize(new Dimension(image.getWidth(), image.getHeight()));
JScrollPane sp = new JScrollPane(canvas);
setLayout(new BorderLayout());
add(sp, BorderLayout.CENTER);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JPanel p = new ScrollImageTest();
JFrame f = new JFrame();
f.setContentPane(p);
f.setSize(400, 300);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
});
}
}
What if you use your dimensions to set the Map's preferred size. For instance, give Map this method:
// method in the Map class
#Override
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
This way the Map JPanel will take up the necessary room to show the entire image. Also, why does your drawImage method in the paintComponent method have the large magic numbers? Why not use the width and height there as well? Edit 1: or don't even specify the image size as Boro suggests in his answer (1+ to him).
Why is everybody reinventing the wheel??? There is no need for a custom panel to paint the image!!!
All you need to do is create a JLabel and add an ImageIcon to the label and you won't have a problem. The label will:
paint the image at (0, 0) at its original size (which is exactly what the custom code is doing).
determine the preferred size of the image based on the image size. Now scrolling will happen automatically.
Also there is rarely any reason to use the setPreferredSize() method since all components have a default preferred size. So you should not set the default size of the menu bar. The only time I set a preferred size would be on the JScrollPane. This will allow the frame to be packed at a reasonable size and then scrollbars will appear automatically based on the size of the image in the label.
In addition to other helpful answers, you might like studying this example that uses mouse gestures to scroll arbitrary content.