Here is a method from a class called CommandProcessor: public void processCommand(String command, String parameter1, String parameter2) {
if ("addThoughtBubble".equals(command)) {
myLayers.add(new ThoughtBubble(parameter1));
myLayers.add(new Text(parameter2));
} else if ("addSpeechBubble".equals(command)) {
myLayers.add(new SpeechBubble(parameter1));
myLayers.add(new Text(parameter2));
} else if ("prepareNewImage".equals(command)) {
myLayers.prepareNewImage(parameter1, parameter2);
}
} You need to change this code to support 2 new command types and also need to add the ability to roll back commands.
if ("addThoughtBubble".equals(command)) {
myLayers.add(new ThoughtBubble(parameter1));
myLayers.add(new Text(parameter2));
} else if ("addSpeechBubble".equals(command)) {
myLayers.add(new SpeechBubble(parameter1));
myLayers.add(new Text(parameter2));
} else if ("prepareNewImage".equals(command)) {
myLayers.prepareNewImage(parameter1, parameter2);
}
} You need to change this code to support 2 new command types and also need to add the ability to roll back commands.
myLayers.add(new ThoughtBubble(parameter1));
myLayers.add(new Text(parameter2));
} else if ("addSpeechBubble".equals(command)) {
myLayers.add(new SpeechBubble(parameter1));
myLayers.add(new Text(parameter2));
} else if ("prepareNewImage".equals(command)) {
myLayers.prepareNewImage(parameter1, parameter2);
}
//以下是让你做的
else if (("newCommand1".equals(command)){
......
} else if(("newCommand2".equals(command)){
......
} else if(("rollbackCommand".equals(command)){
......
}