public CustomTextArea(MainWindow main) {
		super.setText(">");
		commandsHistory=new ArrayList<>(50);	//ɱ50¼
		commandIndex=1;							//
		this.mainWindow=main;
		mDocument=this.getStyledDocument();
		mHighlighter=new FunctionHighlighter(mDocument);
		mUnableEditLength=mDocument.getLength();
		this.setCaretPosition(mDocument.getLength());
		this.addKeyListener(this);
		//߾,
		this.setMargin(new Insets(0, 40, 0, 0));
	}