Command

The Command class is used to implement various commands, for example drawing a line. The Command class is part of the Controller architecture. It evolved to replace the original mode variable in Controller. The Command class is used to mage mouse clicks, i.e. first, click, subsequent click, etc. It coordinates the applications efforts to create graphics primitives by creating Temp object, updating it as the mouse moves, then ultimately destroying the temp object and creating a permanent record of the primitive in the Model.

MVC