Learning Java

I am sometimes down on the Java documentation, but in the sand plains of lugubrious and often confusing material there is the occasional gem. One example is a lesson from The Java Tutorial entitled Performing Custom Painting . I was directed to it by a reply to this thread in the Oracle Java Desktop forum . When I first began my efforts to create a rainbow colored Gaussian distribution curve I began with one of the Tutorial lessons on colors. I have unfortunately lost the URL for the lesson but the code began something like this: import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class Colors extends JPanel { public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D) g; g2d.setColor(new Color(255, 0, 0));//vivid red g2d.fillRect(10, 15, 90, 60); ... } public static void main(String[] args) { JFrame frame = new JFrame("Colors"); frame.s...

I always return to my blog when I'm stuck, and I'm stuck right now. I want to create a custom Swing component. Specifically, I want something like a JProgressBar , with the following changes: In place of a flat Foreground color, I want a rainbow spectrum, showing only the red range for low Values, and the whole spectrum for values close to the Maximum value; Instead of a rectangular box, I want the progress "bar" to take the shape of a normal, or Gaussian, distribution curve; I want progress to be displayed by the area under the curve, rather than by a simple linear scale along the x axis. It's not that there isn't stuff out there. I have five tabs open in my browser, specifically addressing the creation of custom components in Swing, as well as the source code for the JProgressBar . It is that, like everything to do with Java, it is bloody difficult to read. I shall begin from the horse's mouth as it were, with an article on the Java...

My unfamiliarity with PHP and JavaScript is illustrated by the fact that it has only just occurred to me that I don't have to choose between one or the other, but can in fact enjoy both. So for example, bringing my Add User screen into the PHP fold was simply a matter of changing the file extension and adding: session_start(); at the top of the file. Everything else remained the same. All the JavaScript remained untouched, all the business rules remained the same, and if the business rules were satisfied, the same PHP file was called to run the data transaction. For display purposes the username was called, and usertype was called to ensure only administrators added to the database. I had also been scratching my head about passing PHP variables back to the Applet to enrich the data stored in my database, but then it finally sunk into my head that they didn't need to be passed backwards and forwards. Variables (such as username, and IP) gathered by PHP, could ...