CUSTOMIZING FRAME WINDOWS

Chapter 11.2:

Frames Frame is a window that is not contained inside

another window.

Frame is the basis to contain other user interface components in Java GUI applications.

The Frame class can be used to create windows. The Frame class contains rudimentary functionalities to support features found in any frame window.

For Swing GUI programs, use JFrame class to create windows.

Two Ways to Create a Window Using JFrame First approach

Declare & Create object of type JFrame Use various methods to manipulate window

Second approach Create class containing application program by extending

definition of class JFrame Utilizes mechanism of inheritance

Creating Frames

1) First approach:

import javax.swing.*;public class MyFrame

{ public static void main(String[] args) { JFrame frame = new JFrame(“MyFrame"); frame.setSize(400, 300); frame.setVisible(true); frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE); }

}

Creating Framesimport javax.swing.*;public class MyFrame { public static void main(String[] args) { JFrame frame = new JFrame(“MyFrame"); frame.setSize(400, 300); frame.setVisible(true); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }

300

400setVisible() and setSize() – methods in Component class

setDefaultCloseOperation(EXIT_ON_CLOSE) - terminate when the frame isclosed

Creating Frames

2) Second approach:

import javax.swing.*;public class MyFrame extends JFrame{

public MyFrame() { setTitle(“MyFrame"); setSize(400, 300); setVisible(true); setDefaultCloseOperation(EXIT_ON_CLOSE); }

public static void main(String[] args) { MyFrame myFrame = new MyFrame(); }

}

The Content Pane of a Frame The content pane is where we put GUI objects such as

buttons, labels, scroll bars, and others. We access the content pane by calling the frame’s

getContentPane method.

This gray area is the content pane of this frame.

This gray area is the content pane of this frame.

Changing the Background Color

Here's how we can change the background color of a content pane to blue:

Container contentPane = getContentPane();

contentPane.setBackground(Color.BLUE);

Placing GUI Objects on a Frame

There are two ways to put GUI objects on the content pane of a frame:Use a layout manager

○ FlowLayout○ BorderLayout○ GridLayout○ others

Use absolute positioning○ null layout manager

Placing a Button A JButton object a GUI component that represents a

pushbutton. Here's an example of how we place a button with

FlowLayout.

contentPane.setLayout(

new FlowLayout());

JButton okButton

= new JButton("OK");

JButton cancelButton

= new JButton("CANCEL");

contentPane.add(okButton);

contentPane.add(cancelButton);