SE 450 Assignment #4: Animated Applet with Widgets

This animated applet "Catch a Falling Star" is the same as the applet for Assignment#3 except it now contains a GUI interface that allows the user to manipulate the objects in the applet. The widgets are derived from the java.awt. package.

As before, the frame rate of the applet is set with the fps a parameter tag in the HTML file.

The applet thread is controlled with the "Start" and "Stop" buttons. "Stop" brings all motion to a halt and "Start" allows the applet to continue.

The color of the star is controlled with the choice widget. Within this pulldown menu are a series of pre-definied color choices as well as a choice that allows a random color to be selected. All colors, including the one randomly selected remain until the user changes them.

Clicking the mouse pointer in the animation box will cause the top left corner of the 3D box to move to that location. It does not alter the path of the box in any other way.

The background color for the applet is controled by the check boxes labelled "Night" and "Day". Selecting "Night" sets the backgrond to black. Selecting "Day" sets the background to yellow. When the background color is changed, the FallingStarCanvas class also changes the outline color of the star.

Source code for Animated Applet with Widgets: and

Return: Home or to SE450 Main Page or to Assignment#3 Applet

From an implementation perspective, the applet is now somewhat different. The Border layout manager has been used to position the applet title, the canvas containing the animation, and the GUI widgits that control the applet's actions. The animation is now contained in an object that is an extension of the Canvas class. The implementation of the animation canvas is contained in the FallingStarCanvas class while the Layout and classes that implement the GUI widget function are in the FallingStar2 class.