This program allows you to create different shapes supported by the canvas and move them around, etc. It has several modes:

The creation mode works like this:
Click on Create; then click on a shape type to create. After doing that, drag on the green drawing pane to specify the location and size of the shape. You will see the shape as you drag. If you want to change the color, click on Choose Color. For some shapes (specifically, Rectangles, Arcs and Ellipses) it is possible to make them filled solid with their color. To switch from borderline to filled and back to borderline, click Toggle Filled. The most recently created shape is selected.

The selection mode works like this:
The most recently created shape is selected by default. Once you enter Selection mode, you can click on any shape to select it. The buttons are pretty self-explanatory; Printing from an applet has no effect -- you must be able to see the text output of the program for that to do something. Keep in mind that each shape has a bounding rectangle that listens for the selection click. If you want to select a shape that is under another one, select the one that is on top, move it to the back, and click on the shape you want.

The transformation mode works like this:
This mode has several submodes. To Move the currently selected shape, simly select Move and click or drag anywhere on the canvas; the upper-left corner of the shape will snap to the mouse location. To Resize the currently selected shape, select Resize and click or drag anywhere on the canvas. The selected shape's upper-left corner will be unchanged, but the lower-right corner will snap to the mouse location and the shape will properly adjust its size.
There are two types of rotation; rotation about a point and rotation about the center. To rotate the currently selected shape about an arbitrary point, select that mode, click (be careful not to move the mouse while you are clicking) the point you want to rotate about on the green pane, and then drag the selected shape around it. To rotate about the center, select that mode and simply drag on the green drawing pane; the shape will follow your lead.