Develop Reference

How do I adjust the button sizes and move them to be in a different place?

I'm trying to get some of the buttons to be bigger and be able to move them around to get them more to what my professor wants them to be but I'm not sure how to do it.
I decided to use a GridBagLayout but my professor never talked about it so I'm not sure if I'm missing anything or how exactly it works.
The image is what he wants us to get it too. Exactly like this.
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class GUI {
public static JPanel buttonPanel;
private static JFrame frame;
public static void main(String[] args) {
frame = new JFrame("Layout Question");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500, 500);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
JPanel mainPanel = new JPanel();
mainPanel.setLayout(new GridBagLayout());
frame.add(mainPanel);
buttonPanel = new JPanel();
mainPanel.add(buttonPanel);
buttonPanel.add(new JButton("hi"));
buttonPanel.add(new JButton("long name"));
buttonPanel.add(new JButton("bye"));
buttonPanel.add(new JButton("1"));
buttonPanel.add(new JButton("2"));
buttonPanel.add(new JButton("3"));
buttonPanel.add(new JButton("4"));
buttonPanel.add(new JButton("5"));
buttonPanel.add(new JButton("6"));
buttonPanel.add(new JButton("7"));
buttonPanel.add(new JButton("Cancel"));
}
}

There are some improvements you can do to your code:
Don't use static variables, and place your program on the EDT, an easy way to do this is:
public static void main(String[] args) {
SwingUtilities.invokeLater(new LayoutManagersExample()::createAndShowGUI);
}
Don't call setSize(...) on your JFrame, it's going to make your window smaller than you think, it's taking the frame decorations into the calculation for the size, instead call frame.pack(), or override the getPreferredSize() of your JPanel, see Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing? for a more in-depth explanation.
Don't call frame.setVisible(true) before you've added all your components to your JFrame, otherwise you'll get strange bugs related to invisible components, that line should be the last one on your code.
Divide and conquer, you can use multiple JPanels with different Layout Managers, and you can combine them and join them together later on.
One possible approach (which isn't exactly as your teacher wants it to be but is close enough) is this one:
import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class LayoutManagersExample {
private JFrame frame;
private JPanel pane;
public static void main(String[] args) {
SwingUtilities.invokeLater(new LayoutManagersExample()::createAndShowGUI);
}
private void createAndShowGUI() {
frame = new JFrame("Layout Question");
pane = new JPanel();
JPanel topPanel = getTopPanel();
JPanel boxesPanel = getBoxesPanel();
JPanel buttonsPanel = getButtonsPanel();
pane.add(boxesPanel);
pane.add(buttonsPanel);
frame.add(pane);
frame.add(topPanel, BorderLayout.NORTH);
frame.add(new JButton("Cancel"), BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//frame.setSize(500, 500);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private JPanel getButtonsPanel() {
JPanel buttonsPanel = new JPanel();
buttonsPanel.setLayout(new GridLayout(2, 2));
buttonsPanel.add(new JButton("1"));
buttonsPanel.add(new JButton("2"));
buttonsPanel.add(getInnerButtonsPanel());
buttonsPanel.add(new JButton("7"));
return buttonsPanel;
}
private JPanel getInnerButtonsPanel() {
JPanel innerButtonsPanel = new JPanel();
innerButtonsPanel.setLayout(new GridLayout(2, 2));
innerButtonsPanel.add(new JButton("3"));
innerButtonsPanel.add(new JButton("4"));
innerButtonsPanel.add(new JButton("5"));
innerButtonsPanel.add(new JButton("6"));
return innerButtonsPanel;
}
private JPanel getBoxesPanel() {
JPanel boxesPanel = new JPanel();
boxesPanel.setLayout(new BoxLayout(boxesPanel, BoxLayout.PAGE_AXIS));
boxesPanel.add(new JCheckBox("Bold"));
boxesPanel.add(new JCheckBox("Italic"));
boxesPanel.add(new JCheckBox("Underline"));
boxesPanel.add(new JCheckBox("Strikeout"));
return boxesPanel;
}
private JPanel getTopPanel() {
JPanel topPanel = new JPanel();
JPanel topButtonsPanel = new JPanel();
topButtonsPanel.setLayout(new GridLayout());
topButtonsPanel.add(new JButton("hi"));
topButtonsPanel.add(new JButton("long name"));
topButtonsPanel.add(new JButton("bye"));
topPanel.add(new JLabel("Buttons: "));
topPanel.add(topButtonsPanel);
return topPanel;
}
}
Play around with the code, and try to find a different approach by combining the layouts, divide each piece of the window in your head and see how to apply a different layout manager to each of them, divide them in methods as I did to make things easier to follow.
Find a way to left align the elements in the JCheckBoxes for example, and other things

JPanel doesn't add button and text field

I don't understand why the panel.add(txtnum1) and panel.add(button2) doesn't show up when I compile the program. The panel.add(button) works just fine, my compiler doesn't throw any warning or errors, did I miss something?
package gui;
import javax.swing.*;
import java.awt.*;
public class GUI {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setVisible(true);
frame.setSize(new Dimension(300, 500));
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.setBackground(Color.GRAY);
frame.getContentPane().add(panel);
JButton button = new JButton("Submit");
panel.add(button);
JTextField txtnum1 = new JTextField();
txtnum1.setPreferredSize(new Dimension(30, 50));
panel.add(txtnum1);
JButton button2 = new JButton("Clear");
panel.add(button2);
}
}

When implementing GUI applications with Swing, I like to have this approach in the code that builds the JFrame (we assume a simple GUI that does not have JPanel containers inside JPanel containers and stuff like that):
Create JFrame and initialize it
Create JPanel
Create GUI components for that panel and add them
Add panel to the JFrame (repeat from 2) for every JPanel inside the JFrame)
Make the JFrame visible on the screen
So, your code would look something like this:
package gui;
import javax.swing.*;
import java.awt.*;
public class GUI {
public static void main(String[] args) {
/* step 1 */
JFrame frame = new JFrame();
frame.setSize(new Dimension(300, 500));
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
/* step 2 */
JPanel panel = new JPanel();
panel.setBackground(Color.GRAY);
/* step 3 */
JButton button = new JButton("Submit");
panel.add(button);
JTextField txtnum1 = new JTextField();
txtnum1.setPreferredSize(new Dimension(30, 50));
panel.add(txtnum1);
JButton button2 = new JButton("Clear");
panel.add(button2);
/* step 4 */
frame.getContentPane().add(panel);
/* step 5 */
frame.setVisible(true);
}
}
Tested and it works in Eclipse.

You should call setVisible(true) at the end, after all components have been added.
Put frame.setVisible(true); at the end and it will work as expected.

Dynamically add fixed-height panels to a JScrollPane

JPanel panel = new JPanel(new GridLayout(0,1));
JScrollPane contentpane = new JScrollPane(panel);
JButton add = new JButton("ADD");
add.actionListener(new ActionListener() {
public void actionPerformed(){
MyPanel newpanel = new MyPanel("title","Button"); //MyPanel is a class which extends JPanel and contains constructor MyPanel(String TitleToSet ,String ButtonTitleTOAdd)
panel.add(newpanel);
panel.repaint();
}) ;
I have used this code thinking that it will add the MyPanel to the grid layout dynamically and "panel" would be scrollable if more "MyPanel"s are added. However, this was not the case, 1st "MyPanel" filled whole "panel" and on adding second "MyPanel" (by clicking button "Add"), the 1st "MyPanel" was shrinked to make space for second one to be added.. and on adding more, all the "MyPanel"s were fit in the viewport instead of making the "panel" scrollable.. How to add those "MyPanel"s dynamically and making the "panel" scrollable on adding more of those?? Any help would be appreciated.

http://docs.oracle.com/javase/7/docs/api/javax/swing/JScrollPane.html :
By default JScrollPane uses ScrollPaneLayout to handle the layout of
its child Components. ScrollPaneLayout determines the size to make the
viewport view in one of two ways:
[...]
getPreferredSize is used.
You should add the line
panel.setPreferredSize(new Dimension(0, panel.getComponents().size() * SUB_PANEL_HEIGHT));
to your ActionListener.
Full example:
package main;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.Timer;
class Test {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setPreferredSize(new Dimension(400, 400));
frame.setSize(400, 400);
JPanel panel = new JPanel(new GridLayout(0, 1));
panel.add(new JLabel("BOO"));
panel.add(new JButton("BBBB"));
JScrollPane contentpane = new JScrollPane(panel);
frame.add(contentpane);
new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
JPanel newpanel = new JPanel();
newpanel.add(new JLabel("LOL"));
panel.add(newpanel);
System.out.println(100 * panel.getComponents().length);
panel.setPreferredSize(new Dimension(0, 100 * panel.getComponents().length));
contentpane.validate();
}
}).start();
frame.setVisible(true);
}
}

Java buttons not showing up on JFrame

I am fairly new to java, and I am starting a sort of glossary program.
At the start, I am trying to use a JFrame with buttons on.
But only 1 button shows up when I run it.
Also, I don't think I am positioning the buttons right.
package glossary;
import java.awt.BorderLayout;
import javax.swing.JFrame;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class Glossary {
public static void main(String[] args) {
JFrame frame = new JFrame("Glossary");
frame.setVisible(true);
frame.setSize(400,200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel1 = new JPanel();
frame.add(panel1);
JButton LookUpWord = new JButton("Look up word");
panel1.add(LookUpWord, BorderLayout.NORTH);
JPanel panel2 = new JPanel();
frame.add(panel2);
JButton SubmitNewWord = new JButton("Submit word");
panel2.add(SubmitNewWord, BorderLayout.SOUTH);
}
}
Please tell me what I am doing horribly wrong!

I think you are just getting mixed up about where to add your components. You probably aren't intending to add the buttons to NORTH and SOUTH, but rather adding the panels to the frame at NORTH and SOUTH. Also, wait until you've added all your components before calling frame.setVisible(true).
Try this:
public static void main(String[] args) {
JFrame frame = new JFrame("Glossary");
frame.setSize(400, 200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton LookUpWord = new JButton("Look up word"); // create the button
JPanel panel1 = new JPanel(); // create the panel
panel1.add(LookUpWord); // add the button to the panel
frame.add(panel1, BorderLayout.NORTH); // add the panel to the frame
JButton SubmitNewWord = new JButton("Submit word");
JPanel panel2 = new JPanel();
panel2.add(SubmitNewWord);
frame.add(panel2, BorderLayout.SOUTH);
frame.setVisible(true);
}

Add frame.setVisible(true);
Hoping this tutorial help you
How to Make Frames

Java: Objects in JFrame are messed up

I'm creating a simple Java JFrame in Eclipse with a label, 2 radio buttons with 2 textfields, and a JButton. When i run the program, the objects inside it are messed up, the buttons and textfields don't show up and sometimes a textfield takes the entire size of the frame. However, when I minimize/maximize the frame and then restore it, they work normally. Here's the code:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JTextField;
public class myframe {
public static void main(String s[]) {
JFrame frame = new JFrame("Title");
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
// This is an empty content area in the frame
JLabel jlbempty = new JLabel("");
jlbempty.setPreferredSize(new Dimension(500, 400));
frame.getContentPane().add(jlbempty, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
frame.setBounds(0, 0, 500, 400);
JPanel panel = new JPanel();
frame.getContentPane().add(panel, BorderLayout.NORTH);
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
panel.add(Box.createRigidArea(new Dimension(0,5)));
panel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
JLabel label = new JLabel("My label");
panel.add(label);
JPanel buttonPane = new JPanel();
frame.add(buttonPane);
buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.LINE_AXIS));
buttonPane.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
JRadioButton cb = new JRadioButton("1");
buttonPane.add(cb);
JTextField tf = new JTextField(0);
tf.setText("");
buttonPane.add(tf);
JPanel panel3 = new JPanel();
frame.add(panel3);
panel3.setLayout(new BoxLayout(panel3, BoxLayout.LINE_AXIS));
panel3.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
JRadioButton cb2 = new JRadioButton("2");
panel3.add(cb2);
JTextField tf2 = new JTextField(0);
tf.setText("");
panel3.add(tf2);
JPanel panel2 = new JPanel();
JButton button = new JButton("click me");
frame.add(panel2);
panel2.add(button);
button.addActionListener(new Action());
panel.add(buttonPane);
panel.add(panel3);
panel.add(panel2);
}
static class Action implements ActionListener{
public void actionPerformed(ActionEvent arg0) {
JFrame frame2 = new JFrame("Clicked");
frame2.setVisible(true);
frame2.setSize(100, 200);
JLabel label2 = new JLabel("You clicked me");
JPanel panel2 = new JPanel();
frame2.add(panel2);
frame2.add(label2);
}
}
}

In your main method you need to do this at the very end:
frame.pack();
frame.setVisible(true);

You should call frame.pack(); again after adding all the components, so that all the container elements can resize to fit their components best.
http://docs.oracle.com/javase/7/docs/api/java/awt/Window.html#pack()
You should also call frame.SetVisible(true); at the very end, so the form is only displayed ones all components are loaded (otherwise you can see a black box while it loads).