/**
* This method is called back when input is available. It implements the Template Method pattern
* to perform the sequence of steps associated with processing expression tree application
* commands.
*/
public void handleInput() throws Exception {
/** Call a hook method to obtain user input. */
promptUser();
/** Retrieves input from user. */
String input = retrieveInput();
if (input.equals("")) InputDispatcher.instance().endInputDispatching();
else {
/** Call a hook method to make a command based on the user input. */
UserCommand command = makeUserCommand(input);
/** Call a hook method to execute the command. */
executeCommand(command);
/** Saves last command to a variable. */
lastValidCommand = command;
/** Displays the menu associated the the command. */
command.printValidCommands(verboseField);
}
}
/** This hook method executes a command. */
void executeCommand(UserCommand command) throws Exception {
command.execute();
}
