I have a class which create a JFrame with an image but everytime I create the class and run the method to instantiate it, it doesn't appear. However, I have noticed that if I was to create the exact same class and run the same method in the main then the frame appears.
This is most of the code from the class with the JFrame that I am trying to create:
JFrame myFrame= new JFrame();
public void CreateFrame()
{
JLabel background=new JLabel(new ImageIcon("image.jpg"));
myFrame.add(background);
background.setLayout(new FlowLayout());
myFrame.setLayout(new GridLayout(1,1));
myFrame.setSize(360,250);
myFrame.setUndecorated(true);
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
myFrame.setLocation((dim.width/2-170), dim.height/2-125);
myFrame.pack();
myFrame.setVisible(true);
}
If I run the code
MyClass mc = new MyClass();
mc.CreateFrame();
in a method in another class it doesn't come up. However, if I run the exact same code in a main method, it works.
For example, this doesn't work:
Example 1
public class otherClass extends JFrame
{
public void MethodA()
{
MyClass mc = new MyClass();
mc.CreateFrame();
}
public static void main(String[] args)
{
otherClass oc = new otherClass();
oc.MethodA();
}
}
but this does work
Example 2
public class otherClass extends JFrame
{
public void MethodA()
{
//CODE
}
public static void main(String[] args)
{
otherClass oc = new otherClass();
oc.MethodA();
MyClass mc = new MyClass();
mc.CreateFrame();
}
}
Can anyone see where I'm going wrong? Sorry if a stupid mistake, I'm still getting to grips with Java.
Thanks
EDIT
import javax.swing.ImageIcon;
import javax.swing.JWindow;
import javax.swing.JLabel;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import javax.imageio.ImageIO;
import java.util.Timer;
import java.util.Date;
import javax.swing.JFrame;
public class MyClass
{
JFrame homeFrame = new JFrame();
public void createFrame()
{
JLabel background=new JLabel(new ImageIcon("images.jpg"));
myFrame.add(background);
background.setLayout(new FlowLayout());
myFrame.setLayout(new GridLayout(1,1));
myFrame.setSize(360,250);
myFrame.setUndecorated(true);
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
myFrame.setLocation((dim.width/2-170), dim.height/2-125);
myFrame.setAlwaysOnTop(true);
myFrame.pack();
myFrame.setVisible(true);
durationOfTime();
}
public void durationOfTime()
{
MainProgram mp = new MainProgram();
long startTime = System.currentTimeMillis();
long elapsedTime = 0L;
int count =0;
while (elapsedTime < 2*1000)
{
if(count==0)
{
mp.launchInitiation();
}
count+=1;
elapsedTime = (new Date()).getTime() - startTime;
}
myFrame.setVisible(false);
mp.homeFrame.setVisible(true);
}
public static void main(String[] args)
{
MyClass mc = new MyClass();
mc.createFrame();
}
}
Full code from class with JFrame trying to make. I am trying to use this JFrame as a splash screen but whatever class I call
MyClass mc = new MyClass();
mc.createFrame();
from, it just doesn't appear. Two seconds do pass by before my main GUI appears up but this method is supposed to be called in a login type frame. However, I have tested it with a blank JFrame / GUI to appear upon button click also and it still doesn't appear.
EDIT2
I also previously tried this SplashScreen example by # http://examples.oreilly.com/jswing2/code/ch08/SplashScreen.java but I couldn't get it to work (same problem, appears when called from main but not when called from action listener)
import java.awt.*;
import javax.swing.*;
public class SplashScreen extends JWindow {
private int duration;
public SplashScreen(int d) {
duration = d;
}
// A simple little method to show a title screen in the center
// of the screen for the amount of time given in the constructor
public void showSplash() {
JPanel content = (JPanel)getContentPane();
content.setBackground(Color.white);
// Set the window's bounds, centering the window
int width = 450;
int height =115;
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
int x = (screen.width-width)/2;
int y = (screen.height-height)/2;
setBounds(x,y,width,height);
// Build the splash screen
JLabel label = new JLabel(new ImageIcon("oreilly.gif"));
JLabel copyrt = new JLabel
("Copyright 2002, O'Reilly & Associates", JLabel.CENTER);
copyrt.setFont(new Font("Sans-Serif", Font.BOLD, 12));
content.add(label, BorderLayout.CENTER);
content.add(copyrt, BorderLayout.SOUTH);
Color oraRed = new Color(156, 20, 20, 255);
content.setBorder(BorderFactory.createLineBorder(oraRed, 10));
// Display it
setVisible(true);
// Wait a little while, maybe while loading resources
ClassToLoad ctl = new ClassToLoad();
try {
Thread.sleep(duration);
ctl.initiate();
} catch (Exception e) {}
setVisible(false);
}
public void showSplashAndExit() {
showSplash();
System.exit(0);
}
public static void main(String[] args) {
// Throw a nice little title page up on the screen first
SplashScreen splash = new SplashScreen(10000);
// Normally, we'd call splash.showSplash() and get on with the program.
// But, since this is only a test...
splash.showSplashAndExit();
}
}
I added the code in the lines with ClassToLoad and this SplashScreen is called on an action listener, what happens is the program waits the 2 seconds that I tell it to, no frame appears, and then the main class that I wanted to load while the splash screen is visible loads. I tried this method first but this didn't work which lead to me using the code listed above this edit
EDIT 3
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TestFrame extends JFrame implements ActionListener
{
JPanel thePanel = new JPanel(null); //layout
JButton button = new JButton();
public void startGUI()
{
this.setLayout(new GridLayout(1,1));
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
CREATEMYPANEL();
this.add(thePanel);
this.setTitle("NO_TITLE_SET");
this.setSize(400,400);
this.setVisible(true);
this.setResizable(true);
}
public void CREATEMYPANEL()
{
button.setLocation(242,151);
button.setSize(100,50);
button.addActionListener(this);
button.setText("button");
thePanel.add(button);
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==button)
{
System.out.println("button has been pressed ");
SplashScreen splash = new SplashScreen(1000);
splash.showSplash();
}
}
public static void main(String[] args )
{
TestFrame tf = new TestFrame();
tf.startGUI();
}
}
An example of where I call splash screen from. Still doesn't work. Also, just a note that the image I am loading is a local image
Apologies for bad question formatting
Your code works for me except for some details I noticed:
You're calling setSize(...) and then calling pack(). Probably your image isn't being loaded and thus your JFrame has a size of 0, 0. (And thus it looks like it never appears). .pack() and .setSize(...) are mutually exclusive.
You're setting the JLabel's layout manager to FlowLayout but never adding anything to it. (You can safely remove it)
I see you're importing java.util.Timer if you want to dispose the JFrame after 2 seconds, then you should be using a javax.swing.Timer instead. Otherwise you could get problems related to threading.
Also don't forget to place your program on the Event Dispatch Thread (EDT) as Swing is not thread safe
Following above recommendations you can have this code:
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class SplashscreenSample {
private JFrame myFrame;
private JLabel background;
private Timer timer;
public void createFrame() {
timer = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
myFrame.dispose();
#SuppressWarnings("serial")
JFrame frame = new JFrame(getClass().getSimpleName()) {
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
};
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
timer.stop();
}
});
myFrame = new JFrame(getClass().getSimpleName());
try {
background = new JLabel(new ImageIcon(new URL("http://cdn.bulbagarden.net/upload/thumb/6/6b/175Togepi.png/250px-175Togepi.png")));
} catch (MalformedURLException e) {
e.printStackTrace();
}
myFrame.add(background);
timer.setInitialDelay(2000);
timer.start();
myFrame.setLayout(new GridLayout(1, 1));
myFrame.setUndecorated(true);
myFrame.setAlwaysOnTop(true);
myFrame.pack();
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
myFrame.setLocation((dim.width/2-170), dim.height/2-125);
myFrame.setVisible(true);
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new SplashscreenSample().createFrame());
}
}
Or you can use the Splashscreen class...
For example:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Toolkit;
import java.net.MalformedURLException;
import java.net.URL;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JWindow;
public class SplashScreen extends JWindow {
private int duration;
public SplashScreen(int d) {
duration = d;
}
// A simple little method to show a title screen in the center
// of the screen for the amount of time given in the constructor
public void showSplash() {
ImageIcon icon = null;
try {
icon = new ImageIcon(new URL("http://www.cqsisu.com/data/wallpapers/5/718448.gif"));
} catch (MalformedURLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
JPanel content = (JPanel) getContentPane();
content.setBackground(Color.white);
// Set the window's bounds, centering the window
int width = icon.getIconWidth();
int height = icon.getIconHeight();
Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
int x = (screen.width - width) / 2;
int y = (screen.height - height) / 2;
setBounds(x, y, width, height);
// Build the splash screen
JLabel label = new JLabel(icon);
JLabel copyrt = new JLabel("Copyright 2002, O'Reilly & Associates", JLabel.CENTER);
copyrt.setFont(new Font("Sans-Serif", Font.BOLD, 12));
content.add(label, BorderLayout.CENTER);
content.add(copyrt, BorderLayout.SOUTH);
Color oraRed = new Color(156, 20, 20, 255);
content.setBorder(BorderFactory.createLineBorder(oraRed, 10));
// Display it
setVisible(true);
// Wait a little while, maybe while loading resources
loadResources();
setVisible(false);
}
public void loadResources() {
TestFrame tf = new TestFrame();
try {
Thread.sleep(duration);
tf.startGUI();
} catch (Exception e) {
}
}
public static void main(String[] args) {
SplashScreen splash = new SplashScreen(10000);
splash.showSplash();
}
}
Try creating and setting the frame visible in a constructor of the class.
Could it be that while your program is counting
while (elapsedTime < 2*1000)
{
if(count==0)
{
mp.launchInitiation();
}
count+=1;
elapsedTime = (new Date()).getTime() - startTime;
}
it is blocking for said 2 seconds and waiting for this method to finish, return back to the create method and then just finish that one?
it seems this could be a better comment, but i need 50 rep for some reason to comment.
i wanted to make a java program for getting keystrokes without focusing and without keyevent class object for my project ..
is there any way to do so..??
i tried this but it is not fulfilling my requirements!!
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.text.Keymap;
public class key1 {
private static void showUI() {
JFrame jFrame = new JFrame("");
jFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container container = jFrame.getContentPane();
JTextField txt = new JTextField();
container.add(txt, BorderLayout.NORTH);
ActionListener actListener = new ActionListener() {
#Override
public void actionPerformed(ActionEvent event) {
System.out.println(event.getActionCommand() + " selected");
}
};
JPanel jPane = new JPanel();
JButton defaultButton = new JButton("Hit Enter");
defaultButton.addActionListener(actListener);
jPane.add(defaultButton);
JButton otherButton = new JButton("Onother Button");
otherButton.addActionListener(actListener);
jPane.add(otherButton);
container.add(jPane, BorderLayout.SOUTH);
Keymap map = txt.getKeymap();
KeyStroke stroke = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false);
map.removeKeyStrokeBinding(stroke);
jFrame.getRootPane().setDefaultButton(defaultButton);
jFrame.setSize(350, 250);
jFrame.setVisible(true);
}
public static void main(String args[]) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
showUI();
}
});
}
}
I don't believe this is possible at the Swing level..the entire KeyEvent API revolves around some Component having focus :(
In fact, I'm pretty sure the JVM only generates events based on what the OS gives to it..and you can only get those events if something is in focus.
However, I've found a library that might do what you want. I have never used it though..just looked up out of curiosity:
http://code.google.com/p/jnativehook/
I am writing a program designed to work on a two monitor system. I have to separate JFrame objects, and have it so be default, the first frame instance opens. The user then has to drag that frame over to a specific monitor, or leave it in place. When they click a button on that frame, I want the program to open up the second frame on the opposite monitor.
So, How would I figure out which monitor a frame object is on, and then tell another frame object to open on the opposite one?
Looking up GraphicsEnvironment, you can easily find out the bounds and location of each screen. After that, it is just a matter of playing with the location of the frames.
See small demo example code here:
import java.awt.Frame;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class TestMultipleScreens {
private int count = 1;
protected void initUI() {
Point p = null;
for (GraphicsDevice gd : GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices()) {
p = gd.getDefaultConfiguration().getBounds().getLocation();
break;
}
createFrameAtLocation(p);
}
private void createFrameAtLocation(Point p) {
final JFrame frame = new JFrame();
frame.setTitle("Frame-" + count++);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
final JButton button = new JButton("Click me to open new frame on another screen (if you have two screens!)");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
GraphicsDevice device = button.getGraphicsConfiguration().getDevice();
Point p = null;
for (GraphicsDevice gd : GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices()) {
if (!device.equals(gd)) {
p = gd.getDefaultConfiguration().getBounds().getLocation();
break;
}
}
createFrameAtLocation(p);
}
});
frame.add(button);
frame.setLocation(p);
frame.pack(); // Sets the size of the unmaximized window
frame.setExtendedState(Frame.MAXIMIZED_BOTH); // switch to maximized window
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TestMultipleScreens().initUI();
}
});
}
}
Yet, consider reading carefully The Use of Multiple JFrames, Good/Bad Practice? because they bring very interesting considerations.
I hope I'm not posting a duplicate question, but I wasn't able to find a question like this so maybe I'm safe? Anyway...
For the applications that I'm making, I'm going to have two applications (two separate processes and windows) open at the same time. The computer on which these applications will be running on will have multiple monitors. I want the first application/ window to fullscreen and occupy one of my monitors (easy part), and the other one to be fullscreen on the second monitor. If possible, I would like for them to initialize this way.
At the moment, I am making my windows fullscreen by using this code:
this.setVisible(false);
this.setUndecorated(true);
this.setResizable(false);
myDevice = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice();
myDevice.setFullScreenWindow(this);
The class that this is in is an extension of the JFrame class and myDevice is of the type "GraphicsDevice". It's certainly possible that there's a better way to make my window fullscreen so that I can have two different applications fullscreen over two different monitors.
If I was unclear in any way, please say and I'll try to edit in clarifications!
First, you need to position your frames on each screen devices.
frame1.setLocation(pointOnFirstScreen);
frame2.setLocation(pointOnSecondScreen);
Then to maximize a frame, simply call this on your JFrame:
frame.setExtendedState(Frame.MAXIMIZED_BOTH);
Here is a working example illustrating that:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Frame;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Point;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class Test {
protected void initUI() {
Point p1 = null;
Point p2 = null;
for (GraphicsDevice gd : GraphicsEnvironment.getLocalGraphicsEnvironment().getScreenDevices()) {
if (p1 == null) {
p1 = gd.getDefaultConfiguration().getBounds().getLocation();
} else if (p2 == null) {
p2 = gd.getDefaultConfiguration().getBounds().getLocation();
}
}
if (p2 == null) {
p2 = p1;
}
createFrameAtLocation(p1);
createFrameAtLocation(p2);
}
private void createFrameAtLocation(Point p) {
final JFrame frame = new JFrame();
frame.setTitle("Test frame on two screens");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new BorderLayout());
final JTextArea textareaA = new JTextArea(24, 80);
textareaA.setBorder(BorderFactory.createLineBorder(Color.DARK_GRAY, 1));
panel.add(textareaA, BorderLayout.CENTER);
frame.setLocation(p);
frame.add(panel);
frame.pack();
frame.setExtendedState(Frame.MAXIMIZED_BOTH);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test().initUI();
}
});
}
}
I have a JProgressBar displaying a BoundedRangeModel which is extremely fine grained and I was concerned that updating it too often would slow down my computer. So I wrote a quick test program (see below) which has a 10Hz timer but each timer tick makes 10,000 calls to microtick() which in turn increments the BoundedRangeModel. Yet it seems to play nicely with a JProgressBar; my CPU is not working hard to run the program.
How does JProgressBar or DefaultBoundedRangeModel do this? They seem to be smart about how much work it does to update the JProgressBar, so that as a user I don't have to worry about updating the BoundedRangeModel's value.
package com.example.test.gui;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoundedRangeModel;
import javax.swing.DefaultBoundedRangeModel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.Timer;
public class BoundedRangeModelTest1 extends JFrame {
final private BoundedRangeModel brm = new DefaultBoundedRangeModel();
final private Timer timer = new Timer(100, new ActionListener()
{
#Override public void actionPerformed(ActionEvent arg0) { tick(); }
});
public BoundedRangeModelTest1(String title) {
super(title);
JPanel p = new JPanel();
p.add(new JProgressBar(this.brm));
getContentPane().add(p);
this.brm.setMaximum(1000000);
this.brm.setMinimum(0);
this.brm.setValue(0);
}
protected void tick() {
for (int i = 0; i < 10000; ++i)
{
microtick();
}
}
private void microtick() {
this.brm.setValue(this.brm.getValue()+1);
}
public void start()
{
this.timer.start();
}
static public void main(String[] args)
{
BoundedRangeModelTest1 f =
new BoundedRangeModelTest1("BoundedRangeModelTest1");
f.pack();
f.setVisible(true);
f.setDefaultCloseOperation(EXIT_ON_CLOSE);
f.start();
}
}
See the nested class DoPostEvent in the class javax.swing.Timer and the comments on the field notify.
Addendum: Events from the DefaultBoundedRangeModel are forwarded to the UI delegate by the fireStateChanged() method of JProgressBar. The events are coalesced in the EventQueue when postEvent() is invoked by repaint().
One way to follow the trail is to set a breakpoint in the UI delegate's paint() method and examine the call stack.
JProgressBar jpb = new JProgressBar(brm);
jpb.setUI(new BasicProgressBarUI());