I want to create a simple Java Swing app with few buttons and text fields. However after I launch my program all I see is an empty window. All elements appear only when I manualy change the size of the window. How can I change that and make all elements appear immediately?
import java.awt.Dimension;
import java.awt.Toolkit;
import javax.swing.*;
class JavaLesson extends JFrame{
public static void main(String[] args){
new JavaLesson();
}
public JavaLesson(){
this.setSize(400,400);
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension dim = tk.getScreenSize();
int xPos = (dim.width / 2) - (this.getWidth() / 2);
int yPos = (dim.height / 2) - (this.getHeight() / 2);
this.setLocation(xPos,yPos);
this.setTitle("My app");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
JPanel panel = new JPanel();
JLabel label1 = new JLabel("This is label");
JButton button1 = new JButton("Send");
JTextField textField1 = new JTextField("Type here",7);
panel.add(label1);
panel.add(button1);
panel.add(textField1);
this.add(panel);
textField1.requestFocus();
}
}
you have to set your this.setVisible(true) on the line after you added your panel to your frame, doing so, it will display all the components you've added in the frame.
Try this and see if it works out.
public JavaLesson(){
this.setSize(400,400);
..
..
JPanel panel = new JPanel();
JLabel label1 = new JLabel("This is label");
JButton button1 = new JButton("Send");
JTextField textField1 = new JTextField("Type here",7);
panel.add(label1);
panel.add(button1);
panel.add(textField1);
this.add(panel);
this.setVisible(true);
}
Hope this helps.
Cheers :)
Related
I want to align Labels and a Panel (containing Buttons) to the left inside a vertical BoxLayout.
As long as I don't add the panel to the BoxLayout everything is aligned to the left perfectly, but adding it screws everything up.
import javax.swing.*;
import java.awt.*;
public class BoxLayoutDemo{
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel panel = new JPanel();
JPanel five = new JPanel();
JButton plus = new JButton("+");
JButton minus = new JButton("-");
panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
Font testFont = new Font("Arial", Font.BOLD, 20);
JLabel label1 = new JLabel("Label1");
label1.setFont(testFont);
JLabel label2 = new JLabel("Label2");
label2.setFont(testFont);
five.setLayout(new BoxLayout(five, BoxLayout.X_AXIS));
plus.setMinimumSize(new Dimension(30, 30));
plus.setMaximumSize(new Dimension(30, 30));
minus.setMinimumSize(new Dimension(30, 30));
minus.setMaximumSize(new Dimension(30, 30));
five.add(plus);
five.add(minus);
panel.add(label1);
panel.add(five);
panel.add(label2);
panel.setOpaque(true);
panel.setBackground(Color.red);
frame.setMinimumSize(new Dimension(200, 200));
frame.getContentPane().add(panel, BorderLayout.EAST);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
}
Your components need to have the same "x alignment":
label1.setAlignmentX(Component.LEFT_ALIGNMENT);
label2.setAlignmentX(Component.LEFT_ALIGNMENT);
five.setAlignmentX(Component.LEFT_ALIGNMENT);
Read the section from the Swing tutorial on Fixing Alignment Problems for more information.
You can use invisible components as fillers.
private static Box leftAlignedInHorizontalBox(Component component) {
Box box = Box.createHorizontalBox();
box.add(component);
box.add(Box.createHorizontalGlue());
return box;
}
and then:
panel.add(leftAlignedInHorizontalBox(label1));
I am attempting to make a PC Application using Java and JFrame. I'm trying to format 2 transparent buttons, each sized half of the full screen shown (vertically). The top half of the screen will hold to option to debate someone and the bottom half of the screen will hold the option to spectate a debate if clicked on. Here is what I have so far:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class BackgroundImageJFrame extends JFrame {
JButton b1;
JButton b2;
JPanel j1;
JPanel j2;
public BackgroundImageJFrame() {
setTitle("Background Color for JFrame");
setSize(340,563);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setVisible(true);
setLayout(null);
/*
One way
-----------------
setLayout(new BorderLayout());
JLabel background=new JLabel(new ImageIcon("C:\\Users\\Computer\\Downloads\\colorful design.png"));
add(background);
background.setLayout(new FlowLayout());
l1=new JLabel("Here is a button");
b1=new JButton("I am a button");
background.add(l1);
background.add(b1);
*/
// Another way
setLayout(new BorderLayout());
setContentPane(new JLabel(new ImageIcon("C:\\Users\\MLH-User\\Downloads\\Front.jpg")));
setLayout(new FlowLayout());
j1 = new JPanel();
j1.setLayout(null);
b1 = new JButton("Spectate");
//b1.setBounds(0,0,50,50);
b1.setOpaque(false);
b1.setContentAreaFilled(false);
b1.setBorderPainted(false);
j1.add(b1);
b2 = new JButton("Debate");
b2.setLocation(0,0);
b2.setOpaque(false);
b2.setContentAreaFilled(false);
b2.setBorderPainted(false);
j1.add(b2);
add(j1);
// Just for refresh :) Not optional!
setSize(339,562);
setSize(340,563);
}
public static void main(String args[]) {
new BackgroundImageJFrame();
}
}
This is some stuff I experimented with so far, can anyone help me out about where I went wrong?
You should use a layout manager. Here is an example with GridLayout:
public class Example extends JFrame {
private static final int SIZE = 300;
public Example() {
setLayout(new GridLayout(2, 1, 0, 5));
getContentPane().setBackground(Color.WHITE);
JButton debate = new JButton("DEBATE") {
public Dimension getPreferredSize() {
return new Dimension(SIZE, SIZE);
}
};
Font font = debate.getFont().deriveFont(30f);
debate.setFont(font);
// debate.setBorderPainted(false);
debate.setBackground(Color.BLUE.brighter());
debate.setForeground(Color.WHITE);
JButton spectate = new JButton("SPECTATE") {
public Dimension getPreferredSize() {
return new Dimension(SIZE, SIZE);
}
};
spectate.setFont(font);
// spectate.setBorderPainted(false);
spectate.setBackground(Color.RED.brighter());
spectate.setForeground(Color.WHITE);
add(debate);
add(spectate);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setVisible(true);
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(() -> new Example());
}
}
Notes:
You have to realize that screen sizes vary. Setting SIZE to 300 was an arbitrary choice for presentation, screens might not have the required size. You can also set the insets or an empty border instead of specifying the size of the component directly.
You can consider creating a class for these buttons if you have more of them.
This is an example of setting the sizes. I don't know about the location part though.
JFrame frame = new JFrame("test");
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new GridLayout(4,4,4,4));
for(int i=0 ; i<16 ; i++){
JButton btn = new JButton(String.valueOf(i));
btn.setPreferredSize(new Dimension(40, 40));
panel.add(btn);
}
frame.setContentPane(panel);
frame.pack();
frame.setVisible(true);
I am trying to set the width of the JTextField but non of the methods to change it's size are working I have tried to change the amount of columns to change the width of the JTextField but it's not working?
What is causing this?
And how will I be able to change the width?
import javax.swing.*;
import java.awt.*;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
public class main {
public static void main(String[] args) {
//Create and set up the window.
final JFrame frame = new JFrame("Layout 1");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(0, 0, 1500, 1000);
frame.setBackground(new Color(255,255,255));
frame.setLayout(null);
Container pane = frame.getContentPane();
pane.setLayout(null);
JLayeredPane jlp = new JLayeredPane();
frame.setContentPane(jlp);
JPanel container = new JPanel();
//container.setBackground(new Color(241,241,241));
container.setBackground(Color.RED);
container.setBounds(0,0,frame.getWidth(), 75);
container.setLayout(null);
JPanel containerA = new JPanel();
containerA.setBackground(Color.blue);
containerA.setBounds(90 ,10,50,50);
JPanel containerB = new JPanel();
containerB.setBackground(Color.RED);
containerB.setBounds(95 ,20,50,50);
//This is the top textfield
JTextField textField = new JTextField(1000);
textField.setLayout(null);
textField.setPreferredSize(new Dimension(1000,1000));
textField.setBounds(0,0,2300,50);
textField.setColumns(1000);
textField.setSize(1000,10);
textField.invalidate();
textField.setMinimumSize(new Dimension(1000,100));
container.add(textField);
jlp.add(container, Integer.valueOf(2));
jlp.add(containerA, Integer.valueOf(1));
jlp.add(containerB, Integer.valueOf(3));
container.setVisible(true);
frame.invalidate();
frame.setVisible(true);
}
}
You need to change just this line, and will get width of text field,
textField.setSize(1000,25);
I need to make a scrolling background for this platformer. It needs to scroll a 2400x500 image while the frame size is about 1440x900. If it could just gradually change over time that would be great. This is my code:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.*;
import javax.swing.*;
public class Main extends JFrame {
public Main() {
//Creates Title Image
JLabel title = new JLabel(" ");
ImageIcon tl = new ImageIcon("title.gif");
title.setIcon(tl);
//Creates Start Image
final JButton start = new JButton("");
ImageIcon st = new ImageIcon("start.gif");
start.setIcon(st);
//Creates Options Image
JButton options = new JButton("");
ImageIcon opt = new ImageIcon("options.gif");
options.setIcon(opt);
options.setBackground(Color.BLACK);
//Creates label for level 0 background image
JLabel background = new JLabel(" ");
ImageIcon back = new ImageIcon("level0.gif");
background.setIcon(back);
//Creates a panel for level 0
final JPanel p5 = new JPanel();
p5.setLayout (new BorderLayout(1, 1));
p5.add(background);
//Create first frame for "Start" button
final JPanel p1 = new JPanel();
p1.setLayout(new GridLayout(1, 1));
p1.add(start, BorderLayout.CENTER);
//Create second panel for title label
final JPanel p2 = new JPanel(new BorderLayout());
p2.setLayout(new GridLayout(1, 3));
p2.add(title, BorderLayout.WEST);
//Create third panel for "Options" button
final JPanel p3 = new JPanel(new BorderLayout());
p3.setLayout(new GridLayout(1, 1));
p3.add(options, BorderLayout.SOUTH);
//Creates fourth panel to organize all other primary
final JPanel p4 = new JPanel(new BorderLayout());
p4.setLayout(new GridLayout(1, 3));
p4.add(p1, BorderLayout.WEST);
p4.add(p2, BorderLayout.CENTER);
p4.add(p3, BorderLayout.EAST);
//When button is clicked, it changes the level
start.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if(start.isEnabled()) {
remove(p4);
add(p5, BorderLayout.CENTER);
invalidate();
validate();
}
else {
return;
}
}
});
//Adds fourth panel to frame
add(p4, BorderLayout.CENTER);
}
public static void main(String args[]) {
Main frame = new Main();
//Finds screen size of monitor
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
//Creates the frame
frame.setTitle("Cockadoodle Duty: Awakening");
frame.setSize(screenSize);
frame.setLocale(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
String background = "#000000";
frame.setBackground(Color.decode(background));
}
}
Add the label containing the icon to a scroll panel
Use a Swing Timer to schedule the scrolling
When the Timer fires you can scroll background.
The scrolling code might be something like:
JViewport viewport = scrollPane.getViewport();
Point position = viewport.getViewPosition();
position.x += 2;
viewport.setViiewPosition( position );
the code is used to create an application which shows picture and if your anwser is correct your supposed to see the next picture but the pictureCount does not go up. all of the variables ar declared after the main class and i created an Actionlistener to check if the awnser is correct.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class Main {
public static void main(String[] args) {new Main().test();}
public int pictureCount = 1;
JFrame frame = new JFrame();
JButton button1 = new JButton("Submit");
JTextField text = new JTextField();
JPanel panel1 = new JPanel();
JPanel panel2 = new JPanel();
JPanel panel3 = new JPanel();
JLabel label = new JLabel(new ImageIcon("C:\\Users\\Admin\\Desktop\\practicum 3\\" + pictureCount + ".jpg"));
void test(){
button1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e)
{
if(text.getText().equals("5")){
pictureCount++;
new Main().test();
}
}
});
panel1.add(button1);
panel2.add(text);
panel3.add(label);
text.setPreferredSize(new Dimension(100,50));
panel1.setPreferredSize(new Dimension(1000, 200));
panel2.setPreferredSize(new Dimension(1000, 100));
panel3.setPreferredSize(new Dimension(1000, 450));
frame.getContentPane().add(BorderLayout.SOUTH, panel1);
frame.getContentPane().add(BorderLayout.CENTER, panel2);
frame.getContentPane().add(BorderLayout.NORTH, panel3);
frame.setSize(1000,750);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Operation Screen");
frame.setLocationRelativeTo(null);
}
}
You need to read in all the pictures as ImageIcons into an array or ArrayList, say called imageIconArray and then display imageIconArray[0] in your JLabel when you start.
When the button is pressed, increment pictureCount, and then reset the JLabel's icon via its setIcon(...) method:
// in the ActionListener code:
pictureCount++;
label.setIcon(imageIconArray[pictureCount];
Whatever you do, don't create a new Main object, despite what others might say. Why create a new GUI when all you need to do is swap displayed images?