Ever wanted to use an image as a background of your JList component? Unfortunately the Swing library does not provide a simple method to set a image as a background. In order to do so, you are force to do some custom painting inside the paintComponent method. In the case of a JList, our custom painting has to be performed inside a custom implementation of a ListCellRenderer. Check out the video below to see it in action.
Tag Archives: Java
JTable Mastery: convertColumnIndexToModel
Posted by Jim
on May 25, 2010
1 comment
Study the code below. There is something wrong with it! Can you guess what it is?
public class JTableViewToModelColumn {
public static void main(String[] args) {
JFrame f = new JFrame("View To Model Column Example");
final DefaultTableModel model = new DefaultTableModel();
model.setColumnIdentifiers(new String[]{"Col A", "Col B", "Col C"} );
model.setRowCount(10);
final JTable table = new JTable(model);
table.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent e) {
int col = table.columnAtPoint(e.getPoint());
System.out.println("You click on column " + model.getColumnName(col));
}
});
f.add(new JScrollPane(table), BorderLayout.CENTER);
f.pack();
f.setVisible(true);
}
}
How to add a Gradient Background to any JComponent
Posted by Jim
on April 27, 2010
4 comments
Almost every “web 2.0″ application have a cool linear gradient background instead of the plain old boring single color solid background. Adding a gradient background to your application is very simple with only a few lines of additional code. In the example program, I am using Java2D and the GradientPaint class to draw the linear gradient background.
Below is the program that I used to create the image above. We override the paintComponent of the JPanel (or any JComponent) and fill the background with a gradient paint. The begin and end colors for the gradient paint are derived from the component’s background color using the brighter and darker variations.
How to create a Callout Border
Posted by Jim
on April 9, 2010
No comments
Using the power of Java2D, I was able to create more advance and stylish borders. Using a combination of a round rectangle and a triangle shape, I created the callout border shown on the left. This is also very similar to the balloon tips on the Windows OS. Decorate a JLabel with a callout border and you got an awesome tooltip replacement.
4 Ways to Capture a Screenshot
Posted by Jim
on March 30, 2010
No comments
How to format numbers in a JTable with a NumberCellRenderer
Posted by Jim
on March 25, 2010
5 comments
By default, the JTable show the cell values as regular text using a JLabel. To display numbers properly, you are force to pre-format the number as string values before setting them in the table model. There is a better way, by using your own implementation of TableCellRenderer. This will allow you to store the values in their intrinsic form inside the table model.
Why adopt a Rich Client Platform (RCP)?
Posted by Jim
on March 24, 2010
No comments
Ten years ago, I became a founding member of a company on a quest to build a tool for Fixed Income Analysis. Our goal was to build our own rich client desktop application for performing analysis in a niche market. If we had to do it again today, I would highly recommend NetBeans RCP and save ourselves much of the pain of rolling your own desktop platform. Leveraging NetBeans RCP would have allowed us to focus on delivering more of our core values.
How to create a custom Swing Border
Posted by Jim
on January 13, 2010
No comments
A dash border in Java Swing
Eventually every Swing developer comes to a point where the borders packaged with Java Swing is considered too plain. Either you will be googling for your next border or you become adventurous and create your own border. This tutorial is for the adventurous. I will teach you how to create your own dashing border. Anyone who done web development is already familiar with the border styled with alternating lines and spaces.
Easy animated transitions in Java Swing with TimingFrameworks
Posted by Jim
on January 8, 2010
5 comments
Creating animated transitions use to be a tedious task in Java Swing… until TimingFrameworks came along. TimingFrameworks (https://timingframework.dev.java.net/), written by Chet Haase, is a library for making Java animation and timing-based control easier. There are two good introductory articles on their website worth reading.
Crash course in animation
Below is the code to move a JFrame 100 pixels from left to right in 1 second.
