Java Swing | Popup and PopupFactory with examples

Popup and PopupFactory are a part of the Java Swing library. Popups are used when we want to display to the user a Component on the top of all the other Components in that particular containment hierarchy. PopupFactory is the class that is used to create popups. Popups have a very small life cycle, and generally are lightweight components having limited sub-components.

Constructor for the class are :

PopupFactory(): creates an object for popup factory

Commonly used methods:

method	explanation
getPopup(Component o, Component c, int x, int y)	Creates a Popup for the Component o containing the Component c at a location x, y on the owner component.
hide()	Hides and disposes of the Popup.
show()	Makes the Popup visible.

Below programs will illustrate the use of a popup:

Java Program to create a popup and display it on a parent frame: We create a popup p by creating a popup factory and using the function getpopup() which returns a popup. We add this popup to a frame f titled “pop” we will create a label and add t to a container panel p2 and set the background of panel p2 using setBackground() function. We will add the container panel p2 to the popup. We will also create a button b titled “click” added with an action listener and displays the popup when the button is pressed. The button b is added to a panel and the panel is added to the frame. Frame is set to the size 400,400 using setSize(400,400). Finally, the frame is displayed using show() function.

// Java Program to create a popup and display 
// it on a parent frame 
import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
class pop extends JFrame implements ActionListener { 
    // popup 
    Popup p; 
  
    // constructor 
    pop() 
    { 
        // create a frame 
        JFrame f = new JFrame("pop"); 
  
        // create a label 
        JLabel l = new JLabel("This is a popup"); 
  
        f.setSize(400, 400); 
  
        PopupFactory pf = new PopupFactory(); 
  
        // create a panel 
        JPanel p2 = new JPanel(); 
  
        // set Background of panel 
        p2.setBackground(Color.red); 
  
        p2.add(l); 
  
        // create a popup 
        p = pf.getPopup(f, p2, 180, 100); 
  
        // create a button 
        JButton b = new JButton("click"); 
  
        // add action listener 
        b.addActionListener(this); 
  
        // create a panel 
        JPanel p1 = new JPanel(); 
  
        p1.add(b); 
        f.add(p1); 
        f.show(); 
    } 
  
    // if the button is pressed 
    public void actionPerformed(ActionEvent e) 
    { 
        p.show(); 
    } 
    // main class 
    public static void main(String args[]) 
    { 
        pop p = new pop(); 
    } 
} 

Output:

Java Program to create a popup (add a panel) and display it on a parent frame and also add an action listener to the popup: We create a popup p by creating a popup factory and using the function getpopup() which returns a popup. We will set the look and feel to System look and feel. We add this popup to a frame f titled “pop”, we will create a label and a button b19 titled “OK”( we will set the font of the label to a specified font object) and add it to a container panel p2 and set the background of panel p2 using setBackground() function. We will add the container panel p2 to the popup. We will also create a button b titled “click” added with an action listener and displays the popup when the button is pressed. The button b is added to a panel and the panel is added to the frame. Frame is set to the size 400,400 using setSize(400,400). finally, the frame is displayed using show() function.

// Java Program to create a popup (add a panel) and 
// display it on a parent frame and also 
// add action listener to the popup 
import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
class pop1 extends JFrame implements ActionListener { 
    // popup 
    Popup po; 
  
    // frame 
    JFrame f; 
  
    // panel 
    JPanel p; 
  
    // popupfactory 
    PopupFactory pf; 
  
    // constructor 
    pop1() 
    { 
        // create a frame 
        f = new JFrame("pop"); 
  
        f.setSize(400, 400); 
  
        pf = new PopupFactory(); 
  
        // create a label 
        JLabel l = new JLabel("This  is a popup menu"); 
  
        // create a new button 
        JButton b19 = new JButton("OK"); 
  
        // add action listener 
        b19.addActionListener(this); 
  
        try { 
            // set windows look and feel 
            UIManager.setLookAndFeel(UIManager. 
                  getSystemLookAndFeelClassName()); 
        } 
        catch (Exception e) { 
        } 
  
        // create a panel 
        p = new JPanel(); 
  
        p.setBackground(Color.blue); 
  
        // create a font 
        Font fo = new Font("BOLD", 1, 14); 
  
        l.setFont(fo); 
  
        // add contents to panel 
        p.add(l); 
        p.add(b19); 
  
        p.setLayout(new GridLayout(2, 1)); 
  
        // create a popup 
        po = pf.getPopup(f, p, 180, 100); 
  
        // create a button 
        JButton b = new JButton("click"); 
  
        // add action listener 
        b.addActionListener(this); 
  
        // create a panel 
        JPanel p1 = new JPanel(); 
  
        p1.add(b); 
        f.add(p1); 
        f.show(); 
    } 
  
    // if the button is pressed 
    public void actionPerformed(ActionEvent e) 
    { 
        String d = e.getActionCommand(); 
        // if ok buton is pressed hide the popup 
        if (d.equals("OK")) { 
            po.hide(); 
  
            // create a popup 
            po = pf.getPopup(f, p, 180, 100); 
        } 
        else
            po.show(); 
    } 
    // main class 
    public static void main(String args[]) 
    { 
        pop1 p = new pop1(); 
    } 
}

Output:

Note: The above programs might not run in an online IDE please use an offline compiler.

Reference:

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