Problema com o source

public void UITexto()
    {

		//DoubleDiferenteZero = NumberFormat.getNumberInstance();
		//DoubleDiferenteZero.setMinimumFractionDigits(1);

		//Criando Labels com as Mensagens a serem exibidas
		LabelA = new JLabel(MsgA);
		LabelB = new JLabel(MsgB);
		LabelC = new JLabel(MsgC);
		LabelPrecisao = new JLabel(MsgPrecisao);
		LabelEscala = new JLabel(MsgEscala);

		//Crianto os FormattedTextField e setando-os
		FTFA = new JFormattedTextField(NumberFormat.getNumberInstance());
		FTFA.setValue(a);
		FTFA.setColumns(5);
		FTFA.addPropertyChangeListener("value", this);

		FTFB = new JFormattedTextField(NumberFormat.getNumberInstance());
		FTFB.setValue(b);
		FTFB.setColumns(5);
		FTFB.addPropertyChangeListener("value", this);

		FTFC = new JFormattedTextField(NumberFormat.getNumberInstance());
		FTFC.setValue(c);
		FTFC.setColumns(5);
		FTFC.addPropertyChangeListener("value", this);

		FTFPrecisao = new JFormattedTextField(NumberFormat.getNumberInstance());
		FTFPrecisao.setValue(precisao);
		FTFPrecisao.setColumns(4);
		FTFPrecisao.addPropertyChangeListener("value", this);

		FTFEscala = new JFormattedTextField(NumberFormat.getNumberInstance());
		FTFEscala.setValue(escala);
		FTFEscala.setColumns(4);
		FTFEscala.addPropertyChangeListener("value", this);

		//Unindo os labels aos FTF
		LabelA.setLabelFor(FTFA);
		LabelB.setLabelFor(FTFB);
		LabelC.setLabelFor(FTFC);
		LabelPrecisao.setLabelFor(FTFPrecisao);
		LabelEscala.setLabelFor(FTFEscala);

        //Juntando os Labels criados em um único painel
        JPanel PainelABC = new JPanel();
        PainelABC.add(LabelA);
        PainelABC.add(FTFA);
        PainelABC.add(LabelB);
        PainelABC.add(FTFB);
		PainelABC.add(LabelC);
		PainelABC.add(FTFC);

		JPanel PainelPE = new JPanel(new GridLayout(2,2));
        PainelPE.add(LabelPrecisao);
        PainelPE.add(FTFPrecisao);
        PainelPE.add(LabelEscala);
        PainelPE.add(FTFEscala);

        PainelABC.setBackground(Color.white);
        PainelPE.setBackground(Color.white);

		this.setLayout(null);

		//Adicionando os painéis
		setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
		this.add(PainelABC);
		Dimension Dim = PainelABC.getPreferredSize();
		PainelABC.setBounds(220,334, Dim.width, Dim.height);
		this.add(PainelPE);
		Dim = PainelPE.getPreferredSize();
		PainelPE.setBounds(5,30, Dim.width, Dim.height);

		//Criando e adicionando os botões

		JButton BPlotarGrafico = new JButton("Plotar Gráfico");
		//JButton BPrecisao = new JButton("Alterar Precisão");
		//JButton BEscala = new JButton(" Alterar Escala ");

		this.add(BPlotarGrafico);
		//this.add(BPrecisao);
		//this.add(BEscala);

		Dim = BPlotarGrafico.getPreferredSize();
        BPlotarGrafico.setBounds(45,336,Dim.width,Dim.height);
		//Dim = BPrecisao.getPreferredSize();
		//BPrecisao.setBounds(5,75,Dim.width,Dim.height);
		//BEscala.setBounds(5,105,Dim.width,Dim.height);

		BPlotarGrafico.setActionCommand("Plotar");
        BPlotarGrafico.addActionListener(this);
	}


    public void propertyChange(PropertyChangeEvent e)
    {
	    Object source = e.getSource();
	    if (source == FTFA) {
	        a = ((Number)FTFA.getValue()).doubleValue();
        }
	    else if (source == FTFB) {
			b = ((Number)FTFB.getValue()).doubleValue();
        }
        else if (source == FTFC) {
	        c = ((Number)FTFC.getValue()).doubleValue();
        }
        else if (source == FTFPrecisao) {
			precisao = ((Number)FTFPrecisao.getValue()).doubleValue();
        }
        else if (source == FTFEscala) {
			escala = ((Number)FTFEscala.getValue()).intValue();
        }
	}