I am designing a program that contains two JPanels within a JFrame, one is for holding an image, the other for holding GUI components(Searchfields etc). I am wondering how do I draw the Image to the first JPanel within the JFrame?
Here is a sample code from my constructor :
public UITester() {
this.setTitle("Airplane");
Container container = getContentPane();
container.setLayout(new FlowLayout());
searchText = new JLabel("Enter Search Text Here");
container.add(searchText);
imagepanel = new JPanel(new FlowLayout());
imagepanel.paintComponents(null);
//other constructor code
}
public void paintComponent(Graphics g){
super.paintComponents(g);
g.drawImage(img[0], -50, 100, null);
}
I was trying to override the paintComponent method of JPanel to paint the image, but this causes a problem in my constructor when I try to write :
imagepanel.paintComponents(null);
As it will only allow me to pass the method null, and not Graphics g, anybody know of a fix to this method or another method i can use to draw the image in the JPanel? Help is appreciated! :)
All the best and thanks in advance!
Matt
I'd like to suggest a more simple way,
image = ImageIO.read(new File(path));
JLabel picLabel = new JLabel(new ImageIcon(image));
Yayy! Now your image is a swing component ! add it to a frame or panel or anything like you usually do! Probably need a repainting too , like
jpanel.add(picLabel);
jpanel.repaint();
You can use the JLabel.setIcon() to place an image on the JPanel as shown here.
On the other hand, if you want to have a panel with a background, you can take a look at this tutorial.
There is no need to manually invoke paintComponent() from a constructor. The problem is that you passing null for a Graphics object. Instead, override paintComponent() and you use the Graphics object passed in to the method you will be using for painting. Check this tutorial. Here is an example of JPanel with image:
class MyImagePanel extends JPanel{
BufferedImage image;
public void paintComponent(Graphics g){
super.paintComponent(g);
if(image != null){
g.drawImage(image, 0, 0, this);
}
}
}
Related
I'm making a game and I want to add a JTextField to a JPanel that has Paint Component. I repaint the JPanel every 16 milliseconds.
I add() the textfield to the panel but it show up only for a single frame when i click on it.
Then I tried to repaint() the textfield but now it is flashing.
public class Screen extends JPanel {
public Screen() {
JTextField txt = new JTextField();
txt.setBounds(10, 10, 300, 50);
this.add(txt);
}
#Override
public void paint(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
g2D.setColor(Color.BLACK);
g2D.fillRect(0, 0, this.getWidth(), this.getHeight());
g2D.setColor(Color.WHITE);
g2D.fillRect(0, 0, this.getWidth(), 20);
txt.repaint();
}
}
I want to show the textfield on the top of the panel
JTextField txt = new JTextField();
When you create a JTextField you should use code like:
JTextField txt = new JTextField(10);
Now the text field can calculate its own preferred size.
//txt.setBounds(10, 10, 300, 50);
Don't use setBounds() to give a component a size. Again each Swing component is responsible for determining its own preferred size. Then the layout manager will set the size/location of the component on the panel.
//public void paint(Graphics g) {
public void paintComponent(Graphics g)
{
super.paintComponent(g);
// add custom painting here
}
Don't override paint(). Custom painting is done by overriding the paintComponent() method. And the first statement in the method should be super.paintComopnent(g)
//g2D.setColor(Color.BLACK);
//g2D.fillRect(0, 0, this.getWidth(), this.getHeight());
Don't paint the background of the panel. That is the job of the panel and that is why you need to super.paintComponent(), to make sure the background is painted.
Then in the constructor of your JPanel class you simply use setBackground( Color.BLACK )
//txt.repaint();
Don't ever invoke repaint() on any component in a painting method.
Read the section from the Swing tutorial on Custom Painting for working examples to get you started. Use the demo code as the starting point for you program. Then you simply add a JTextField to the panel, so it will be a single line of code that is needed to display the text field.
It seems like you want to have a JTextField on a black panel. You don't need to set the colour of the panel every time in paint() method. Instead add this to the constructor:
public Screen() {
setOpaque(true);
setBackground(Color.BLACK);
//...
}
and remove paint() method.
Also, if you want to use absolute positioning with setBounds() method then you should set the layout to null setLayout(null) in constructor. If you use absolute positioning you will also need to specify the size of the panel explicitly. However, I would still suggest you use a layout manager that takes care of panel sizing as well.
See this post for more information about absolute positioning.
I am new to making GUIs so I decided to try the the windows builder for eclipse, and while great I do have some doubts. I have been searching but I cannot seen to find a good way to add a background image to my "menu". For example I tried this:
public Menu() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(50, 50, 300, 250); //Dimensiones
contentPane = new JPanel() { //Imagen de Fondo
public void paintComponent(Graphics g) {
Image img = Toolkit.getDefaultToolkit().getImage(
Menu.class.getResource("/imgs/rotom.jpg"));
g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
}
};
And adding the following classes:
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
But to no avail the window remains with its dull grey color, so far my code is just the standard one WindowsBuilder cooks for you plus 4 buttons but I doubt they're of importance here. Shouldn't the code I added override the paintComponent() method of the jPanel and draw the image in it?
The class for the menu is in a package within my project and the image is within a imgs package is within the same project as well.
Thanks a lot in advance.
A simple method, if you're not interested in resizing the background image or applying any effects is to use a JLabel...
BufferedImage bg = ImageIO.read(Menu.class.getResource("/imgs/rotom.jpg"));
JLabel label = new JLabel(new ImageIcon(bg));
setContentPane(label);
setLayout(...);
There are limitations to this approach (beyond scaling), in that the preferred size of the label will always be that of the image and never take into account it's content. This is both good and bad.
The other approach, which you seem to be using, is to use a specialised component
public class BackgroundPane extends JPanel {
private BufferedImage img;
public BackgroundPane(BufferedImage img) {
this.img = img;
}
#Override
public Dimension getPreferredSize() {
return img == null ? super.getPreferredSize() : new Dimension(img.getWidth(), img.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, this);
}
}
You should avoid trying to perform any task in the paintComponent method which may take time to complete as paintComponent may be called often and usually in quick succession....
Getting the image to scale when the component is resized is an entire question into of it self, for some ideas, you could take a look at...
Java: maintaining aspect ratio of JPanel background image
Java: JPanel background not scaling
Quality of Image after resize very low -- Java
Reading/Loading images
Oh, and, you should avoid extending directly from top level containers, like JFrame, they reduce the reusability for your components and lock you into a single container
I am new to making GUIs so I decided to try the the windows builder for eclipse, and while great I do have some doubts. I have been searching but I cannot seen to find a good way to add a background image to my "menu". For example I tried this:
public Menu() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(50, 50, 300, 250); //Dimensiones
contentPane = new JPanel() { //Imagen de Fondo
public void paintComponent(Graphics g) {
Image img = Toolkit.getDefaultToolkit().getImage(
Menu.class.getResource("/imgs/rotom.jpg"));
g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
}
};
And adding the following classes:
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
But to no avail the window remains with its dull grey color, so far my code is just the standard one WindowsBuilder cooks for you plus 4 buttons but I doubt they're of importance here. Shouldn't the code I added override the paintComponent() method of the jPanel and draw the image in it?
The class for the menu is in a package within my project and the image is within a imgs package is within the same project as well.
Thanks a lot in advance.
A simple method, if you're not interested in resizing the background image or applying any effects is to use a JLabel...
BufferedImage bg = ImageIO.read(Menu.class.getResource("/imgs/rotom.jpg"));
JLabel label = new JLabel(new ImageIcon(bg));
setContentPane(label);
setLayout(...);
There are limitations to this approach (beyond scaling), in that the preferred size of the label will always be that of the image and never take into account it's content. This is both good and bad.
The other approach, which you seem to be using, is to use a specialised component
public class BackgroundPane extends JPanel {
private BufferedImage img;
public BackgroundPane(BufferedImage img) {
this.img = img;
}
#Override
public Dimension getPreferredSize() {
return img == null ? super.getPreferredSize() : new Dimension(img.getWidth(), img.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(img, 0, 0, this);
}
}
You should avoid trying to perform any task in the paintComponent method which may take time to complete as paintComponent may be called often and usually in quick succession....
Getting the image to scale when the component is resized is an entire question into of it self, for some ideas, you could take a look at...
Java: maintaining aspect ratio of JPanel background image
Java: JPanel background not scaling
Quality of Image after resize very low -- Java
Reading/Loading images
Oh, and, you should avoid extending directly from top level containers, like JFrame, they reduce the reusability for your components and lock you into a single container
I want add JScrolpane to JPanel, but that not appears. In JLabel works fine and its very easy. I am using JPanel beacuse I'll add some image proccessing stuff to my program. There is my code:
public void draw(){
panel=new JPanel(){
protected void paintComponent(Graphics g){
Graphics g2 = g.create();
g2.drawImage(image, 0, 0, this);
g2.dispose();
}
};
panel.setBorder(BorderFactory.createEtchedBorder());
panel.setPreferredSize(new Dimension(400, 330));
s=new JScrollPane(panel);
s.setPreferredSize(new Dimension(400,285));
this.getContentPane().add(s,BorderLayout.CENTER);
add(panel);
revalidate();
repaint();
}
s=new JScrollPane(panel);
s.setPreferredSize(new Dimension(400,285));
this.getContentPane().add(s,BorderLayout.CENTER);
add(panel); // ****** ????????????
revalidate();
repaint();
}
You're adding the JPanel to the GUI not the JScrollPane, so you really shouldn't expect to see any scrollpanes if they've not been added anywhere.
Solution: Add your JScrollPane, s, that holds the JPanel to the GUI, not JPanel itself.
You dont honor the paint chain, call super.paintComponent(g) as first call in overridden paintComponent method. i.e
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
//draw here
}
or visual artifacts may occur.
Also note the #Override annotation which should be used with overridden methods in order to gain the advantage of compiler checking that we overrode the method correctly.
There is no need for getContentPane().add(..) simply call add on JFrame instance as add(..) along with remove(..) and setLayout(..) have been forward to the JFrames contentPane
Also not a good idea to go extending JFrame for nor reason, simply create an instance and use that i.e:
JFrame frame=new JFrame("Title here");
...
frame.add(..);
...
frame.pack();
frame.visible(true);
Also draw onto the Graphics object passed into paintComponent g dont go creating your own in paintComponent. Unless of course you're doing if for the reason #HFOE mentioned in below comment :).
No need for this parameter in drawImage(..) unless your JPanel implements on ImageObserver or the image may not be fully loaded when painting occurs. Simply use null.
And just for the cherry on top use some Graphics2D and RenderHints as seen here. This will allow for a better quality image to be drawn and text.
I got it! The main reason for me was no-layout manager and no-declarated size of this. There is my code:
public void draw(){
panel=new JPanel(new BorderLayout()){
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(img, 0, 0, null);
}
};
panel.setBounds(0, 0, img.getWidth(), img.getHeight());
panel.setPreferredSize(new Dimension(img.getWidth(),obraz.getHeight()));
JScrollPane scrolls=new JScrollPane(panel,ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
add(scrolls);
validate();
repaint();
}
But if someone will want copy this code in the future, there is one thing to be known- a size of Jpanel isn't refreshing (it's always one size of first opened image), but I have scrolsl and I am satisfied for now ;). Thanks a lot for everyone.
I'm having a problem adding a JPanel on top of an Image. This is what I'm trying to do:
Image bgImage = loadImage(filename);
JPanel jp = new JPanel();
jp.setBounds(100,100,100,100);
jp.setOpaque(true);
jp.setBackgroudColor(Color.red);
bgImage.add(jp);
After doing this, I only see the bgImage. I tried everything but I still can't show the panel. Can somebody help me?
You cannot place a component inside an Image. What you want to do is paint the Image onto the background of a swing component (like JPanel). All swing components have a paint() method that calls these three methods (perhaps not quite this order): paintComponent(), paintChildren(), paintBorder(). So, you want to override the paintComponent() method to paint your background image over the panel. When this runs, your custom method will be called, and then the paintChildren() method will be called, which will paint all "child" components over the top of your background image:
class BackgroundImagePanel extends JPanel {
public void setBackgroundImage(Image backgroundImage) {
this.backgroundImage = backgroundImage;
}
#Override
protected void paintComponent(Graphics graphics) {
super.paintComponent(graphics);
graphics.drawImage(backgroundImage, 0, 0, this);
}
private Image backgroundImage;
}
BackgroundImagePanel panel = new BackgroundImagePanel();
panel.setBackgroundImage(image);
panel.add(new JTextField("Enter text here..."));
panel.add(new JButton("Press Me"));
The "BackgroundImagePanel" solution paints the image at its actual size. If this is a requirement, then you can just use a JLabel instead of creating a custom component.
The BackgroundPanel entry shows how you can do this. It also provides a background panel with more custom image painting solutions, that will allow you to scale and tile the image, if this is part of your requirement.