Universidad Carlos III de Madrid

AWT is structural part of Java and was designed to create user interfaces. Although Swing provides and improves AWT components (like Button, Label, ComboBox...), AWT handles heavy containers where Swing components are placed, such as layouts (FlowLayout, GridLayout... in java.awt package), besides of acting as an interface between Swing (Java) and the Operative System's Windows Manager.

The MVC pattern distinguishes between data (model), graphical interface (view) and control logic (controller) of an application, so it is easier to make changes on the GUI or business layer without other application components be affected. The model represents the data involved in the application. The view shows how to access the model. The controller enables model and view's state changes. So, if you modify a graphical interface component, its actions, or you change changing certain application data, that will lead to specific and delimited changes.

In the case of Swing, the data model is previous and independent. You have spent time to the design and implementation of this model, and you are going to show part of this model in the GUI using Swing. As view, you use classes that derive from the Component class in Swing. The controller is made up from existing Action classes which are related to events caused by the various Swing components.

This layout places components from left to right by rows (using the getPreferredSize() method) while there is space available. Therefore, if the resolution changes or there are component size modifications, final composition could change substantially.

This layout places components from left to right and from top to bottom in the different cells that this structure displays. The components inside have the same size and they are distributed uniformly occupying all available space in the cell. So, if not used carefully, some components may be larger than expected.

All of them inherit from the javax.swing.AbstractButton abstract class. Get an idea of the importance of inheritance and check which is the similar behavior from all them.

That button is called focus and it's set using the setDefaultButton() method from class JRootPane.

It is enough to carry out the change procedure invoking the UIManager.setLookAndFeel() method and then updating the view with SwingUtilities.updateComponentTreeUI() method.

	  					
UIManager.setLookAndFeel(
	"javax.swing.plaf.metal.MetalLookAndFeel");
SwingUtilities.updateComponentTreeUI (frame);
					

There are listeners to detect any changes in the status of a component (ChangeListener) or when user uses the mouse over a component (MouseListener). The procedure you have to take is similar; implement the corresponding interface, associate it with the desired component and acknowledge the reason for the event occurrence.

A Swing component is not considered for graphical purposes while is not activated. The activation is carried out using setVisible(), show() or pack() methods on the top-level containers, such as JFrame or JDialog. If we are talking about components like Label, Button etc., we have to add them to an activated top-level container.

frame.setBounds(0,0,300,150);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel label = new JLabel("Welcome our application.");
frame.getContentPane().add(label);
frame.setVisible(true);
					

The BorderFactory class included in javax.swing package provides a set of methods which, due to their static condition, don't require to keep back memory to initialize instances of Border type. Besides the fact that its interface is quite simple, you just have to import that class to work with borders, instead of importing every border class you need.

myComponent.setBorder(
	BorderFactory.createLineBorder(Color.red, 1));

myComponent.setBorder(
	new LineBorder(Color.red, 4, true)));