Advanced GUI

As you can see from the GUI section, GUI in Java can offer a lot of benefits. Using more advanced GUI concepts you can do things like add menus, change button layout and change color of content.

Swing Components

In Java when you use GUI elements you are using what is called the Swing component. This is why when you use GUI in a class you must import the javax.swing.* class. Swing components are usually put into a container. A container is a component that holds other components. A container is often in the form of a window that you can resize, and move. There is also a thing called a frame. A frame is a window that has a title bar and border. A frame is also the most common component you will use.

Using JFrame

A JFrame is how most components in Java are displayed. The JFrame class has four constructors that you can set when creating the JFrame.

Constructor	Use
JFrame()	constructs a new frame
JFrame(String title)	creates new frame with specified title
JFrame(GraphicsConfiguration gc	creates JFrame in the specified configuration
JFrame(String title, GraphicsConfiguration gc	creates JFrame in the specified configuration and title

You can create JFrame just like you do other objects in Java.

JFrame newFrame = new JFrame("This is a title");

Now that you have the JFrame object you can use different methods to set the title of the frame, the size of the frame and many more attributes.

JFrame newFrame = new JFrame("This is a title");
newFrame.setSize(200 , 100); //sets he size of the frame to 200 pixels x 100 pixels
newFrame.setVisible(true); //sets the frame to be visible 

Output

Put screenshot here

Using JLabel

A JLabel is an uneditable component that is used to provide information to the user. Just like with the JFrame the JLabel component has a lot of constructors available.

Constructor	Use
JLabel()	creates label with no image and empty string for title
JLabel(Icon Image)	create label with image
JLabel(Icon Image, int horizontalAlignment)	creates label with image and specified horizontal alignment
JLabel(String text)	create label with specified text
JLabel(String text, Icon Image, int horizontalAlignment)	creates label with text and alignment and image
JLabel(String text, int horizontalAlignment	creates label with text and alignment

You can create a label to display text and then combine it with the JFrame to display the label.

JLabel greeting = new JLabel("Hello there");

JFrame newFram = new JFrame("Test Frame");
newFrame.setSize(200 , 100); //sets he size of the frame to 200 pixels x 100 pixels
newFrame.setVisible(true); //sets the frame to be visible 
newFrame.add(greeting);

Output

add screenshot here

With JLabel you can also change the font with the setFont() method.

Font newFont  = new Font("Arial", Font.BOLD, 36);
JLabel greeting = new JLabel("Hello there");

greeting.setFont(newFont);

Output

Add screenshot here

Layout Manager

The layout manager manager in Java is an object that controls where the components are positioned. By default, the border layout manager is used which may result in multiple components to obscure each other. A better layout to use is the flow layout manager which places the components in rows instead. The layout can be set in three different positions which are LEFT, CENTER, and RIGHT. If you do not specify the layout then by default it is centered.

FlowLayout flow = new FlowLayout(FlowLayout.RIGHT);

JLabel greeting = new JLabel("Hello there");
Jlabel nextGreeting - new JLabel("Bubba");

JFrame newFram = new JFrame("Test Frame");
newFrame.setSize(200 , 100); //sets he size of the frame to 200 pixels x 100 pixels
newFrame.setVisible(true); //sets the frame to be visible 
newFrame.setLayout(flow);
newFrame.add(greeting);
newFrame.add(nextGreeting);

Output

insert screenshot here

Adding components to the JFrame

In Java, you can also add components to the JFrame to en

Adding TextFields

In a JFrame, it may be necessary to accept userInput. To do this you will need to add a text field to the JFrame to accept this input. Let's say you wanted to set a field with a length that was long enough for the user to enter 12 characters.

FlowLayout flow = new FlowLayout();

JLabel greeting = new JLabel("Hello there");
JLabel nextGreeting = new JLabel("Bubba");
//creates the text field of size 12
JTextField userResponse = new JTextField(12);

JFrame newFrame = new JFrame("Test Frame");
newFrame.setSize(255 , 100); //sets he size of the frame to 200 pixels x 100 pixels
newFrame.setVisible(true); //sets the frame to be visible 
newFrame.setLayout(flow);
newFrame.add(greeting);
newFrame.add(nextGreeting);
//adds the text field to the frame
newFrame.add(userResponse);

Output

Place screen shot here

With the JTextField you can also use it to get what the user entered using the getTesxtMethod.

String userInput = userResponse.getText();

Adding Buttons

Now that you have text fields you will also need a button in order to confirm the input. To do this you would use the JButtons component. JButtons have a total of five constructors.

Constructor	Use
JButton()	creates a button with no text
JButton(Icon icon)	creates button with an Icon
JBUtton(String text)	creates button with specified test
JButton(String text, Icon icon)	creates button with text and icon
JButton(Action a)	creates a button whose action is supplied from action class