What does setPreferredSize do in Java?

What does setPreferredSize do in Java?

Generally, setPreferredSize() will lay out the components as expected if a layout manager is present; most layout managers work by getting the preferred (as well as minimum and maximum) sizes of their components, then using setSize() and setLocation() to position those components according to the layout’s rules.

How do you create a JComponent?

Java JComponent Example

1. import java.awt.Color;
2. import java.awt.Graphics;
3. import javax.swing.JComponent;
4. import javax.swing.JFrame;
5. class MyJComponent extends JComponent {
6. public void paint(Graphics g) {
7. g.setColor(Color.green);
8. g.fillRect(30, 30, 100, 100);

What is a JPanel in Java?

JPanel, a part of the Java Swing package, is a container that can store a group of components. The main task of JPanel is to organize components, various layouts can be set in JPanel which provide better organization of components, however, it does not have a title bar.

What are the parameters of the JFrame’s setSize method?

More JFrame size information

• setSize – Resizes this component so that it has width w and height h.
• setMinimumSize – Sets the minimum size of this window to a constant value.
• setPreferredSize – Sets the preferred size of this component to a constant value.

What is paintComponent method in Java?

By now you know that the paintComponent method is where all of your painting code should be placed. It is true that this method will be invoked when it is time to paint, but painting actually begins higher up the class hierarchy, with the paint method (defined by java. awt.

How do you use JComponent?

To use JComponent, the procedure is usually as follows:

1. create a subclass of JComponent;
2. override the paintComponent() method to draw whatever graphics are required;
3. override getPreferredSize(), getMinimumSize() and getMaximumSize() to make your new component “behave” properly.

How do I create a JPanel?

Java JPanel Example

1. import java.awt.*;
2. import javax.swing.*;
3. public class PanelExample {
4. PanelExample()
5. {
6. JFrame f= new JFrame(“Panel Example”);
7. JPanel panel=new JPanel();
8. panel.setBounds(40,80,200,200);

Can we add JFrame to JPanel?

You could call getContentPane() on the JFrame to extract its main contents as a JPanel (usually) and without the menu bar and decorations, and display that as a JPanel though best would probably be to update the original program so that it produces a JPanel and not a JFrame.

What happens if setSize is not called on JFrame?

What happens if setSize is not called on a window? 1) The window is displayed at its preferred size. 2) It is a syntax error.

How do I code a JFrame in Netbeans?

In the Projects window, right-click the ContactEditor node and choose New > JFrame Form. Alternatively, you can find a JFrame form by choosing New > Other > Swing GUI Forms > JFrame Form….Creating a JFrame Container

1. Enter ContactEditorUI as the Class Name.
2. Enter my. contacteditor as the package.
3. Click Finish.

How do I call a paintComponent method?

Never call paintComponent() method directly. Change instance variables. The listener code should set instance variables that paintComponent() uses in drawing the panel. After changing the values, the next time paintComponent() is called, these new values will be used.