The application displays an artificial world of charged and electrically neutral particles that are governed by physical laws (i.e. electrical and gravitational forces as well Newton's law of motions). This world is referred in the rest of the documentation as the World of Particles or simply the WOP.
The motion for each particle in WOP is calculated in its own separate thread Particle.run() belonging to the instance of Particle class. The interacting forces between particles are calculated in WorldOfParticles.run() thread common for all particles belonging to the same WorldOfParticles. Instance of the WorldOfParticles is rendered (and animated) inside (as a part of) the JPWorld, which extends JComponent. Particles renders themselves with Particle.paint() in the JPWorld's graphical context.
Further, there are three separate classes T1, T2 and T3 that control creation of particles in the WOP (see T1.run, T2.run and T3.run) and as such they demonstrate a solution to IP1-1.1 Uppgift.
The jar file of the package can be found here.
Use RunAsApplet class to start application in applet mode.