I have a problem with java Xor method:
public class Okno extends JFrame {
public static void main(String[] args) {
Okno okno = new Okno();
}
Window()
{
this.setSize(300,300);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
JButton button= new JButton("Circle");
button.addActionListener(
new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Graphics2D g = (Graphics2D)Window.this.getGraphics();
g.setXORMode(Color.red);
g.setStroke(new BasicStroke(10));
g.drawOval(100, 100, 100, 100);
}
});
this.add("South",button);
this.setVisible(true);
}
It paints circle after second click on button. On Graphic from Image it works fine...
If the code works the second time, odds are good you are calling the code incorrectly. For example, you may be requesting a paint callback and then improperly invalidating the screen area, which means that while the view has changed, the is no event to start the repainting routines.
On the second button click, the paint will then detect the first button click's action, which was to change what is drawn.
Swing painting has changed slightly over the years. You might be stuck with an old tutorial or text. Take a look at the latest online offerings to get a good idea of how it should be done.
Related
After making an instance in a previous frame, I'm trying to the background image on the next frame but as a result, I just saw the debugged result and found out that the paint method was not called. From what I know, the paint method is inherited by the JFrame class and with this logic, I've made it overrided. As I guess, the reason happen the logical error is from what I used the event handler and made the instance in the EventHandlerClass.
if(e.getActionCommand().equals(ButtonTo))
if(idString.equals("USER"))
{
{
if("1234".equals(pwSt))
{
System.out.println("Wellcome");
if(gs==null)
{
gs=new GameStart();
}
}
else
{
System.out.println("Confirm your password");
}
}
}
This is a code that If an action is performed it will make an instance(gs). After doing this, I noticed that the instance has been used as to make a new console frame.
class GameStart extends JFrame {
private Image screenImage;
private Graphics screenGraphic;
private Image introBackgroundImage;
private ImageIcon img;
GameStart()
{
JFrame jf=new JFrame("Game Set");
jf.setBounds(300, 300, 400, 200);
jf.setLayout(new BorderLayout());
JButton bt1=new JButton("Start");
JButton bt2=new JButton("Exit");
JPanel panel1=new JPanel();
panel1.add(bt1);panel1.add(bt2);
setContentPane(panel1);
jf.add(panel1, BorderLayout.SOUTH);
bt1.addActionListener(new Choice());
bt2.addActionListener(new Choice());
jf.setVisible(true);
img=new ImageIcon("./Images/backGroundImage.jpg");
System.out.println("1");
}
public void paint(Graphics g) {
screenImage=createImage(200, 200);
screenGraphic=screenImage.getGraphics();
screenDraw(screenGraphic);
g.drawImage(screenImage, 0, 0, null);
System.out.println("2");
}
public void screenDraw(Graphics g)
{
this.repaint();
System.out.println("3");
}
Now, With making a frame and some buttons, I expect to show all the numbers(1, 2, 3) that indicate the result but Just did number 1.
There are some errors in your code that I can see at first glance:
You're extending JFrame, but you're not adding any extra functionality to it, see: Extends JFrame vs. creating it inside the program. Instead, build your GUI towards the use of JPanels and override their paintComponent(...) method and not the paint(...) one.
You're breaking the paint-chain: After doing the above point, in paintComponent(), call super.paintComponent(...)
Maybe there are others but I'm currently busy and can't test your code, but the ones above should help with your issue.
I have tried this code to draw a string on my frame using KeyListener interface such that whenever I hit a typeable key on keyboard, it should appear on frame but it doesn't work even though there are no errors.
Can someone tell what's the mistake?
Below is my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class KeyevntFrame2 extends Frame {
Button b = new Button("ok");
Button b1 = new Button("hey");
char ch;
String s = "";
public KeyevntFrame2() {
setTitle("understand key events");
setSize(800, 600);
addKeyListener(new KeyHandler());
setFont(new Font("Arial", Font.PLAIN, 35));
setForeground(Color.BLACK);
add(b);
add(b1);
b.setBounds(200, 200, 100, 100);
b1.setBounds(200, 700, 100, 100);
setLayout(null);
b.addActionListener(new KeyHandler());
b1.addActionListener(new KeyHandler());
}
class KeyHandler implements KeyListener, ActionListener {
public void keyPressed(KeyEvent e) {
ch = e.getKeyChar();
s = s + ch;
repaint();
}
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
}
public void paint(Graphics g) {
g.drawString(s, 300, 200);
g.setFont(new Font("Arial", Font.PLAIN, 35));
}
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(b1, "thank you for using java");
}
}
public static void main(String a[]) {
KeyevntFrame2 f = new KeyevntFrame2();
f.setVisible(true);
}
}
Java GUIs have to work on different OS', screen size, screen resolution etc. using different PLAFs in different locales. As such, they are not conducive to pixel perfect layout. Instead use layout managers, or combinations of them along with layout padding and borders for white space. This advice is especially relevant to this GUI, given that the frame does not have enough height to display the second button.
Don't mix AWT (Frame) and Swing (JOptionPane) components in one GUI. Choose a GUI toolkit and stick with it.
Always use #Override notation when changing the behavior of existing methods or implementing the methods of an interface. Doing so would have warned you that neither the KeyListener nor ActionListener interfaces define a public void paint(Graphics) method!
Defining a combined KeyListener and ActionListener does not make much sense, and has confused you into thinking that calling Button.addActionListener(..) with the combined listener will also have the effect of adding it as a KeyListener. It won't.
new Font("Arial", Font.PLAIN, 35) for cross-platform robustness, that should be new Font(Font.SANS_SERIF, Font.PLAIN, 35) (e.g OS X will typically not have the Arial font installed, and users would prefer to see Helvetica in any case.)
It is not necessary to set the font of the frame, and also the font in the paint method. Just do it once in the frame.
Since the frame itself is not focusable, calling addKeyListener(..) will have no effect. Better to use Swing and implement key bindings in any case.
When custom painting, always call the super method first.
Swing and AWT GUIs should be started on the EDT.
"it doesn't work even though there are no errors." There are plenty of errors in the code seen above, it's just that they are neither compilation errors, nor run-time errors that throw exceptions. Plenty can still go wrong with code even if the compiler or virtual machine does not identify them. This is why 'cut & paste' coding sans understanding what the code does, never works. Hit the tutorials and read the Java docs.
im trying to insert a gif as a background for my app. I cut all frames and renamed them f1/f2/f3/f4/f5/f6/..... I would use a timer to change the frame so it looks like an animation.
There is a total of 42 frames, so f42.png is the last frame. The code seems to be fine, but there is no result. Any help?
Global variables:
private String backgroundFile;
public JPanel backgroundPanel, areaImage;
private BufferedImage background;
private javax.swing.Timer timerBackground;
Constructor where the Timer is initialized:
public Game()
{
entryWindow();
this.setLayout(null);
timerBackground = new javax.swing.Timer(100,this);
timerBackground.stop();
}
Animation method code:
private void backgroundAnimation()
{
backgroundFile = "f"+backgroundNum+".png";
try{
background=ImageIO.read(new File(backgroundFile));
}
catch(IOException e)
{
}
backgroundPanel = new JPanel()
{
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(background, 0, 0, 1100,800,null);
}
};
backgroundPanel.setBackground(Color.BLACK);
backgroundPanel.setBounds(0, 0, 1100, 800);
if (backgroundNum>42)backgroundNum++;
else backgroundNum=1;
add(backgroundPanel);
backgroundPanel.setVisible(true);
}
Action Listener for timer:
if (ae.getSource() == timerBackground)
{
backgroundAnimation();
}
In order to show JPanel, you need to add it to something like JFrame with an BorderLayout for instance, then you need to show the JFrame. JFrame is a application window, the JPanel can be only added and drawn on Window, it can't be viewed without something on which it can draw (like app Window). Beside that you don't need to create new JPanel each time the animation changes, just make a setter for the current image to show, and after assigning the image call repaint(), the ImagePanel could be like this:
public class ImagePanel extends JPanel {
private volatile BufferedImage image;
public void showImage(BufferedImage image) {
this.image=image;
repaint();
}
public void paintComponent(Graphics g) {
g.drawImage(image, 0,0,getWidth(),getHeight(),null);
}
}
add it to your JFrame at application start, also set the LayoutManager of JFrame to BorderLayout preferably, because without that your panel will have size(0,0) since you didn't set it, and it could be one of reasons why you don't see it (you can't see something which is 0 pixel in size, can you?).
Then in your timer just call the ImagePanel method public void showImage(BufferedImage image) with the image to show. If that's don't solve your problem, then post your entire code. As without that i'm just guessing, but those are common problems, so there's big chance you hit something from this.
I can see a few issues here
1. Assuming your Game class is extending JFrame, You need to add the JPanel to the ContentPane of the JFrame. Use one of the approaches setContentPane(backgroundPanel); or getContentPane().add(backgroundPanel)
You are not using a LayoutManager. So either use a LayoutManager or set the Size of the 'JFrame' and 'JPanel' explicitly using setBounds() method. I would recommend using a LayoutManager.
The JPanel or any Component for that matter does not automatically refresh itself. Once you change the image, you need to call repaint() on your JPanel.
You dont need to create a new JPanel every time you change the image. Just extend the JPanel and override the paintComponent()like you have done. Use the Timer to change the image of that single instance and call repaint() with every change.
The complete example, with hat output you are seeing will help understand the problem better and give you a solution. Please see How to create a Minimal, Complete, and Verifiable example
There are multiple problems here, but first let me answer your question:
You are creating a new JPanel and add it to the Game on every run through. That is wrong, since you add infinite panels to your Game
Also in your if/else you have a wrong condition. You increase the iterator when it is greater 42. You probably mean lesser than 42.
Here is how I would do it:
public class BackgroundPanel extends JPanel {
private int currImage = 0;
private BufferedImage[] backgroundImages;
public BackgroundPanel() {
int numberOfImages = 42;
backgroundImages = new BufferedImage[42];
for(int i = 1; i <= numberOfImages; i++) {
String backgroundFile = "f" + i + ".png";
backgroundImages[i] = ImageIO.read(new File(backgroundFile));
}
}
public void nextImage() {
/*if(currImage <= 42) currImage++;
else currImage = 1;*/
if(currImage++ > 42) currImage = 1;
repaint();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(backgroundImages[currImage], 0, 0, getWidth(), getHeight(), null);
}
}
You need to add this panel ONCE to your "Game":
//Somewhere in your Game
private BackgroundPanel backgroundPanel;
...
...
public Game() {
entryWindow();
this.setLayout(null);
backgroundPanel = new backgroundPanel();
backgroundPanel.setSize(getWidth(), getHeight());
add(backgroundPanel);
timerBackground = new javax.swing.Timer(100,this);
timerBackground.stop();
}
Your timer:
if (ae.getSource() == timerBackground) {
backgroundPanel.nextImage();
}
It's easier to put the background on JLabel. It requires only 3 lines of code and works fine! :) Hope it helps for anyone that will have the same problem :)
All you have to do is copy this code, change the name (i have all pictures in a folder called "Images") with any kind of Java supported picture/video/.... (just change the suffix .gif to your file format) and at last the size. Good luck! :)
public JLabel backgroundGIF;
backgroundGIF = new JLabel(new ImageIcon(getClass().getResource("Images/background.gif")));
backgroundGIF.setBounds(0,0,1100,800);
add(backgroundGIF);
When spending a few minutes tweaking my desktop clock, I discovered a problem that I seem unable to resolve without help... I read some posts with similar problem but solutions did not work for me.
The clock (in typical java form with an Action Listener and Calendar) works just fine. The intended tweak: To set the Frame, ContentPane and Label backgrounds to transparent so only the time/text shows.
What happens is this: When the label background is transparent (or until it's opaque enough by setting the Alpha when Opaque is true), the underlying previous display stay's and does not clear.
To help figure this out, I put together the following code - the time and date Calendar stuff/etc is excluded. This code is just one version of many I tried with/without opaque, placement of calls...etc.
What does make a difference is use of the Action Listener - if the Action Listener is commented/deleted, label's display fine. Un-comment the Action Listener and the problem occurs.
See the images… Any help appreciated… Thanks!
fyi - below: the code sans imports and comments...
Screenshot of clock with black bg
Screenshot of the problem:
public class Clear extends JFrame {
private JPanel contentPane;
Color ppColor = new Color(255, 255, 0, 0); // r,g,b,a
Color lblColor = new Color(225, 200, 200, 0);
Color lbl2Color = new Color(225, 200, 200, 254);
int delay = 1000;
JLabel lblTime = new JLabel("TESTING");
JLabel lblTime2 = new JLabel("XXXXXX");
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
final Clear frame = new Clear();
frame.setVisible(true);
}
catch (Exception e) {
e.printStackTrace();
}
}
});
}
public Clear() {
setUndecorated(true);
setBackground(ppColor);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(1680, 975, 128, 74);
contentPane = new JPanel();
contentPane.setBackground(ppColor);
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
lblTime.setOpaque(true);
lblTime.setBackground(lblColor);
lblTime.setBounds(0, 0, 125, 30);
contentPane.add(lblTime);
lblTime2.setOpaque(true);
lblTime2.setBackground(lbl2Color);
lblTime2.setBounds(0, 33, 125, 16);
contentPane.add(lblTime2);
ActionListener myTaskPerformer = new ActionListener() {
#Override
public void actionPerformed(ActionEvent evt) {
lblTime.setText("Does it");
lblTime2.setText("work? ");
}
};
new Timer(delay, myTaskPerformer).start();
}
}
Swing components do not work well with alpha based colors. They are either completely transparent or completely opaque.
If you specifiy that a component is isOpaque, but fill it using a translucent (alpha) color, the repaint manager won't update the area behind the component and the Graphics context will not be cleared properly. Remember, the Graphics context is shared resource, so everything that was painted before your component will still be painted
You can take a look at Java Swing Graphical Glitches Dealing with Transparency and Images for more details.
However. The simplest solution would be to create a TranslucentPane, the extends from something like JPanel, make it transparent (not opaque), override it's paintComponent method and paint the translucent (alpha) color from within it. Then add your label onto this.
Check out Performing Custom Painting and Painting in AWT and Swing for more details
I wan't to make my main JFrame become darken when the focus is on another window.
This is an example from the game Football Manager 2012. First the main window is selected and it looks like it should, then when it is loading, it turns darker and unselectable. I wan't to have this effects on my own application, but im not really sure how, not even sure what to google?
Im guessing its a JWindow that appears and the JFram becomes unselectable in the background. I'm planing to use it on a help-window in my application, that is a JWindow right now.
Andrew Thompson has the right idea, only it's easier to use the glass pane feature of your frame's JRootPane. Here's some working code: In your frame class, invoke
getRootPane().setGlassPane(new JComponent() {
public void paintComponent(Graphics g) {
g.setColor(new Color(0, 0, 0, 100));
g.fillRect(0, 0, getWidth(), getHeight());
super.paintComponent(g);
}
});
Then, to show the "curtain", invoke
getRootPane().getGlassPane().setVisible(true);
In the code above, change the alpha transparency value of 100 in order to find the suitable darkness.
..wan't the JFrame to go back to normal after the new window is closed. I tried setVisible(false) but it didn't work.
It works in this example.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class ShadowedFrame extends JFrame {
ShadowedFrame() {
super("Shadowed Frame");
getRootPane().setGlassPane(new JComponent() {
public void paintComponent(Graphics g) {
g.setColor(new Color(0, 0, 0, 100));
g.fillRect(0, 0, getWidth(), getHeight());
super.paintComponent(g);
}
});
JButton popDialog = new JButton("Block Frame");
popDialog.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
getRootPane().getGlassPane().setVisible(true);
JOptionPane.showMessageDialog(ShadowedFrame.this, "Shady!");
getRootPane().getGlassPane().setVisible(false);
}
});
setContentPane(popDialog);
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationByPlatform(true);
setSize(350,180);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ShadowedFrame().setVisible(true);
}
});
}
}
(Untested, but..) Seems like a good task for a JLayeredPane. Create a JComponent that is set transparent and add that to the top level of the layered pane. In the paintComponent(Graphics) method of the component, set a semi-transparent color and fill the full area with it. In normal use (non-dimmed), call customComponent.setVisible(false).
Update
Or, as Ingo pointed out, use the glass pane.
I'm guessing its a JWindow that appears and the JFrame becomes unselectable in the background
It is more likely a modal JDialog. When a modal dialog is visible, the frame/window that is the owner becomes inaccessible (cannot be clicked on).