How to add components to the frame? - java

I am new to Swing programming. And I m trying to develop a desktop application.
First all I need to create a login window, which should not be draggable and its position must be in center of the screen.
So by learning , I have created a window by the following code:
import com.sun.awt.AWTUtilities;
import java.awt.Dimension;
import java.awt.Toolkit;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Newframe {
private JLabel label;
JFrame frame;
JButton btn;
Newframe(){
prepareGUI();
}
public static void main(String arg[]) {
Newframe n=new Newframe();
}
public void prepareGUI(){
frame=new JFrame();
frame.setUndecorated(true);
frame.setSize(300, 300);
frame.setVisible(true);
Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
frame.setLocation(dim.width/2-frame.getSize().width/2, dim.height/2-frame.getSize().height/2);
}
}
Now, I want to add components (e.g textfields, labels, buttons, etc...) to this created frame.
I m trying to add the components to the frame by initialize the components and add them to the frame ( by this frame.add(jbutton)) , but components are not going to add to the created frame...
Can any one help me for this?

frame.getContentPane().add(component)
Note this may vary depending on the layout you use.
Also, it'd be better to put the UI in the Event Dispatch Thread, with this:
public static void main(String arg[]) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Newframe n=new Newframe();
} catch (IOException e) {
e.printStackTrace();
}
}
});
}

You can use below code to add component to the frame and to center the frame you can use frame.setLocationRelativeTo(null);.
public class Newframe {
private JLabel label;
private JTextField txt;
JFrame frame;
JButton btn;
Newframe() {
prepareGUI();
}
public static void main(String arg[]) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
Newframe n = new Newframe();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public void prepareGUI() {
frame = new JFrame();
frame.setLayout(null);
frame.setSize(300, 300);
frame.setUndecorated(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
// Dimension dim = Toolkit.getDefaultToolkit().getScreenSize();
// frame.setLocation(dim.width/2-frame.getSize().width/2, dim.height/2-frame.getSize().height/2);
label = new JLabel("Name");
label.setBounds(10, 10, 100, 20);
frame.add(label);
txt = new JTextField();
txt.setBounds(50, 10, 100, 20);
frame.add(txt);
btn = new JButton("OK");
btn.setBounds(40, 40, 80, 20);
frame.add(btn);
}
}

Related

Why i can't change variable in JLabel?

i just wanna count in jlabel. i think, I have tried all the solutions posted in the site but i couldn't find out any solution. I am a beginner, have one month to learn Java. I am sorry if my question is too stupid.
package asdf;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.JLabel;
public class asd extends JFrame implements ActionListener {
int a=0; // variable
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
asd window = new asd();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public asd() {
super();
Timer time=new Timer(1000, this);
time.start();
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JPanel panel = new JPanel();
panel.setBounds(20, 11, 137, 111);
frame.getContentPane().add(panel);
panel.setLayout(null);
***JLabel Jtable = new JLabel();
Jtable.setBounds(0, 25, 127, 58);
Jtable.setText("" + a);
panel.add(Jtable);***
System.out.println(a); //it is counting on console but in Jlabel variable is not.
}
#Override
public void actionPerformed(ActionEvent arg0) {
a++;
initialize();
}
}
i just wanna count in jlabel. i think, I have tried all the solutions posted in the site but i couldn't find out any solution. I am a beginner, have one month to learn Java. I am sorry if my question is too stupid.
You shouldn't be initializing a new frame and all the components on every action performed, you should only be updating the text of the label. You can do this via JLabel.setText https://docs.oracle.com/javase/7/docs/api/javax/swing/JLabel.html#setText(java.lang.String)
int a = 0; // variable
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
asd window = new asd();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public asd() {
super();
Timer time=new Timer(1000, this);
time.start();
initialize();
}
/**
* Initialize the contents of the frame.
*/
private JLabel label;
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JPanel panel = new JPanel();
panel.setBounds(20, 11, 137, 111);
frame.getContentPane().add(panel);
panel.setLayout(null);
label = new JLabel();
label.setBounds(0, 25, 127, 58);
label.setText("" + a);
panel.add(label);
System.out.println(a); //it is counting on console but in Jlabel variable is not.
}
#Override
public void actionPerformed(ActionEvent arg0) {
a++;
label.setText("" + a);
}

Changing Jpanel location from Jframe to JDialog

Let's say that I have 1 frame, 1 JDialog and 1 panel. The panel is on the frame. What I want to do is if a button is clicked i wanna switch the location of the panel to JDialog. I need two windows so i use Jdialog for that. Maybe there is a better way of creating that window rather then using JDialog.
Part of my code:
public class Bestellterminal {
private static JPanel panel;
public static void addComponentsToPane(final Container pane) {}
public static void addComponentsToPane1(final Container pane) {}
public static void addComponentsToPane2(final Container pane) {
final JPanel kpanel1 = new JPanel();
kpanel1.setBounds(0 + insets.left, 0 + insets.top, size.width + 900,
size.height + 700);
kpanel1.setVisible(true);
final JDialog meinJDialog = new JDialog();
meinJDialog.setTitle("Küchenterminal");
meinJDialog.setSize(1200,900);
meinJDialog.setVisible(true);
meinJDialog.setLayout(null);
meinJDialog.add(kpanel1);
Classic.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (brclassic == 1) {
if (kunde == 1)
{Bestellpanel.add(buttonx);buttonx.setVisible(true);brclassic++;
kpanel1.add(Bestellpanel);
}
}
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
addComponentsToPane(frame.getContentPane());
addComponentsToPane1(frame.getContentPane());
addComponentsToPane2(frame.getContentPane());
Insets insets = frame.getInsets();
frame.setSize(1200 + insets.left + insets.right,
900 + insets.top + insets.bottom);
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
I made a simple example using two JFrames, it could be done with any type of container/layout really.
package helloworld;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import java.awt.BorderLayout;
/**
* Created on 4/30/17.
*/
public class SwapPanel {
public static void main(String[] args){
JPanel panel = new JPanel();
panel.add(new JLabel("mover"));
JFrame a = new JFrame("frame a");
JButton aButton = new JButton("swap");
JFrame b = new JFrame("frame b");
JButton bButton = new JButton("swap");
bButton.setEnabled(false);
a.getContentPane().add(aButton, BorderLayout.SOUTH);
a.getContentPane().add(panel, BorderLayout.CENTER);
b.getContentPane().add(bButton, BorderLayout.SOUTH);
aButton.addActionListener(evt->{
if(aButton.isEnabled()){
aButton.setEnabled(false);
a.getContentPane().remove(panel);
b.getContentPane().add(panel, BorderLayout.CENTER);
bButton.setEnabled(true);
a.pack();
b.pack();
a.repaint();
b.repaint();
}
});
bButton.addActionListener(evt->{
if(bButton.isEnabled()){
bButton.setEnabled(false);
b.getContentPane().remove(panel);
a.getContentPane().add(panel, BorderLayout.CENTER);
aButton.setEnabled(true);
a.pack();
b.pack();
a.repaint();
b.repaint();
}
});
a.pack();
a.setVisible(true);
b.pack();
b.setVisible(true);
a.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
The main thing that needs to be done, first remove the panel from one layout/container, then add the component panel to another container, and finally validate/repaint.

JButton Wont Display JPanel

I want to call My JPanel with button. My Jpanel is actually a sub JPanel from main Panel with card layout.
to do that, i am using card layout api method HERE to show the JPanel after a button was clicked.
JButton btnCallPanel1 = new JButton("Call PanelOne");
btnCallPanel1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
CardLayout card = (CardLayout)mainPanel.getLayout();
card.show(mainPanel, "PanelOne"); //call Panel One
}
output :
nothing appear, panel not called and no error pop out.
My Code is HERE
package wan.dev.sample.cardlayout;
import java.awt.CardLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JLabel;
public class HowToUseCardLayout {
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
HowToUseCardLayout window = new HowToUseCardLayout();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public HowToUseCardLayout() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 688, 358);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JPanel mainPanel = new JPanel();
mainPanel.setBounds(0, 0, 672, 260);
frame.getContentPane().add(mainPanel);
mainPanel.setLayout(new CardLayout(0, 0));
JPanel PrePanel = new JPanel();
mainPanel.add(PrePanel, "name_246268073832057");
PrePanel.setLayout(null);
JLabel lblPanel_1 = new JLabel("Pre Panel");
lblPanel_1.setBounds(280, 115, 57, 20);
PrePanel.add(lblPanel_1);
JPanel panelOne = new JPanel();
mainPanel.add(panelOne, "name_246268067657434");
panelOne.setLayout(null);
JLabel lblPanel = new JLabel("panel 1");
lblPanel.setBounds(279, 118, 46, 14);
panelOne.add(lblPanel);
JButton btnPan1 = new JButton("Call PanelOne");
btnPan1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
CardLayout card = (CardLayout) mainPanel.getLayout();
card.show(mainPanel, "PanelOne");
}
});
btnPan1.setBounds(262, 286, 144, 23);
frame.getContentPane().add(btnPan1);
}
}
ANSWER
The reason i cant call my panel because i did not call it by using identifier.
i have to give identifier name to my desire jpanel and use the identifier on my cardLayout.show(..)
Public Static final String PANEL_ONE = "panel one"; //Name of JPanel Identifier
//add panel to main panel and declare panelOne identifier
mainPanel.add(panelOne, PANEL_ONE); //PANEL_ONE function like
//an identifier
JButton btnCallPanel1 = new JButton("Call PanelOne");
btnCallPanel1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
CardLayout card =
(CardLayout)mainPanel.getLayout();
card.show(mainPanel, PANEL_ONE); //call panelOne using PANEL_ONE
//instead of JPanel name
}
As I suspected — You're calling the CardLayout.show(...) method with the String parameter "PanelOne", but yet you've not added any component to the CardLayout-using container using this same String, so it makes sense that it won't work. Solution: don't do this. Use the Same String that you add the component to the CardLayout using container as the one that you use to display it.
i.e., If you want to display container foo and use the String "bar" to add it to the CardLayout-using container, then you must pass "bar" into the CardLayout's show(...) method. Again, use String constants for this so that you reduce the chances of messing up.
Other issues: You're using null layout and setBounds — Don't. Doing this makes for very inflexible GUI's that while they might look good on one platform look terrible on most other platforms or screen resolutions and that are very difficult to update and maintain.
e.g.,
import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class CardLayoutFoo extends JPanel {
public static final String BAR = "bar";
public static final String BUTTON_PANEL = "button panel";
private CardLayout cardlayout = new CardLayout();
public CardLayoutFoo() {
setLayout(cardlayout);
JLabel fooLabel = new JLabel("Foo", SwingConstants.CENTER);
add(fooLabel, BAR); // added using String constant, BAR
JButton showFooBtn = new JButton(new AbstractAction("Show Foo") {
#Override
public void actionPerformed(ActionEvent evt) {
// use same String, BAR, to get the fooLabl shown
cardlayout.show(CardLayoutFoo.this, BAR);
}
});
JPanel btnPanel = new JPanel();
btnPanel.add(showFooBtn);
add(btnPanel, BUTTON_PANEL);
cardlayout.show(this, BUTTON_PANEL);
}
private static void createAndShowGui() {
CardLayoutFoo mainPanel = new CardLayoutFoo();
JFrame frame = new JFrame("CardLayoutFoo");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

How to add scrollbar in JFrame with null layout?

I want to add a vertical scroll-bar on my JFrame with null layout.
Is it possible or not? please help!
Just set the JScrollPane as ContentPane for JFrame as it is described here:
public class TabbedPaneTest {
public static void main(String [] a) {
final JFrame frame = new JFrame();
frame.setSize(500, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JScrollPane pane = new JScrollPane(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
frame.setContentPane(pane);
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
frame.setVisible(true);
}
});
}
}
In eclipse IDE you can use following code
import java.awt.Dimension;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JLabel;
public class Test {
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Test window = new Test();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public Test() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel container = new JPanel();
JScrollPane jsp = new JScrollPane(container);
container.setPreferredSize(new Dimension(500, 250));
container.setLayout(null);
JLabel lblHelloWorld = new JLabel("Hello World");
lblHelloWorld.setBounds(10, 11, 101, 14);
container.add(lblHelloWorld);
frame.getContentPane().add(jsp);
}
}

Removing JPanel from a JFrame

I am trying to remove a JPanel not hide it but i can't find anything that works.
This is the code in the panel that needs to remove itself when a button is pressed:
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Frame frame = new Frame(); //referencing to my JFrame class (this class is a JPanel)
//need to remove this panel on this line
frame.ThreeD(); // adds a new panel
}
});
UPDATED
This is the full code:
package ThreeD;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.UIManager;
import Run.Frame;
public class Launcher extends JPanel{
private JButton play, options, help, mainMenu;
private Rectangle rplay, roptions, rhelp, rmainMenu;
private int buttonWidthLocation, buttonWidth, buttonHeight;
private int width = 1280;
public Launcher() {
this.setLayout(null);
drawButtons();
}
private void drawButtons() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch(Exception e) {
e.printStackTrace();
}
play = new JButton("Play");
options = new JButton("Options");
help = new JButton("Help");
mainMenu = new JButton("Main Menu");
buttonWidthLocation = (width / 2) - (buttonWidth / 2);
buttonWidth = 80;
buttonHeight = 40;
rplay = new Rectangle(buttonWidthLocation, 150, buttonWidth, buttonHeight);
roptions = new Rectangle(buttonWidthLocation, 300, buttonWidth, buttonHeight);
rhelp = new Rectangle(buttonWidthLocation, 450, buttonWidth, buttonHeight);
rmainMenu = new Rectangle(buttonWidthLocation, 600, buttonWidth, buttonHeight);
play.setBounds(rplay);
options.setBounds(roptions);
help.setBounds(rhelp);
mainMenu.setBounds(rmainMenu);
add(play);
add(options);
add(help);
add(mainMenu);
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
Frame frame = new Frame();
//need to remove this panel here
frame.ThreeD();
}
});
options.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("options");
}
});
help.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("help");
}
});
mainMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("mainMenu");
}
});
}
}
And this is my Frame class:
package Run;
import javax.swing.*;
import ThreeD.Display;
import ThreeD.Launcher;
import TowerDefence.Window;
import java.awt.*;
import java.awt.image.BufferedImage;
public class Frame extends JFrame{
public static String title = "Game";
/*public static int GetScreenWorkingWidth() {
return java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().width;
}*/
/*public static int GetScreenWorkingHeight() {
return java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds().height;
}*/
//public static Dimension size = new Dimension(GetScreenWorkingWidth(), GetScreenWorkingHeight());
public static Dimension size = new Dimension(1280, 774);
public static void main(String args[]) {
Frame frame = new Frame();
System.out.println("Width of the Frame Size is "+size.width+" pixels");
System.out.println("Height of the Frame Size is "+size.height+" pixels");
}
public Frame() {
setTitle(title);
setSize(size);
setResizable(false);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ThreeDLauncher();
}
public void ThreeDLauncher() {
Launcher launcher = new Launcher();
add(launcher);
setVisible(true);
}
public void TowerDefence() {
setLayout(new GridLayout(1, 1, 0, 0));
Window window = new Window(this);
add(window);
setVisible(true);
}
public void ThreeD() {
BufferedImage cursor = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
Cursor blank = Toolkit.getDefaultToolkit().createCustomCursor(cursor, new Point(0, 0), "blank");
getContentPane().setCursor(blank);
Display display = new Display();
add(display);
setVisible(true);
display.start();
}
}
Basically - you are creating new instance of Frame in line:
Frame frame = new Frame(); //referencing to my JFrame class (this class is a JPanel)
New instance of Frame is not visible, and you're try to remove your Launcher from not visible new Frame. But this is wrong - you should remove Launcher from Frame that you created previously in main function (that is: parent of Launcher component).
Here goes an example:
public class TestFrame extends JFrame {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
TestFrame frame = new TestFrame();
frame.getContentPane().add(new MyPanel(frame));
frame.setSize(200, 200);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
And MyPanel class:
public class MyPanel extends JPanel {
public MyPanel(final TestFrame frame) {
JButton b = new JButton("Play");
add(b);
b.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Container pane = frame.getContentPane();
pane.remove(MyPanel.this);
JPanel otherPanel = new JPanel();
otherPanel.add(new JLabel("OtherPanel"));
pane.add(otherPanel);
pane.revalidate();
}
});
}
}
In your example you should add a reference to Frame in your Launcher constructor:
public Launcher(Frame frame) {
this.frame = frame;
...
Init Launcher:
public void ThreeDLauncher() {
Launcher launcher = new Launcher(this);
and use:
play.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//need to remove this panel here
frame.getContentPane().remove(Launcher.this);
frame.ThreeD();
}
});
Say your panel is myPanel you can remove it from the main frame by:
frame.getContentPane().remove(myPanel);

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