class ExmPanel extends Panel
                     implements ActionListener,
                                AdjustmentListener {
    TScore     controller;
    TextField  exT_ex, exT_pc;
    Scrollbar  sB_ex,  sB_pc;
    Label      sumL;
    int        max = 100;
    int        block = 1;
    int        show_pc, exam_ex, epc_ex;
    float      s_ex, f_ex, s_pc, f_pc;
    float      c_factor;

    // exam_type  0  Final
    //            1, 2, 3, 4 
    ExmPanel(TScore u,int exam_type,int exam_x,int show_epc,int epc_x,
             float a,float b,float w,float m,float n,float ex_default) {
        GridBagConstraints   c = new GridBagConstraints();
        GridBagLayout        gridbag = new GridBagLayout();
        setLayout(gridbag);
        Label  tL;
        float  exam_ratio, epc_ratio;
        float  sum;
        int    tmp_i;

        controller = u; 
        c_factor   = w;
        show_pc = show_epc;
        exam_ex = exam_x;
        epc_ex  = epc_x;
        s_ex = a; f_ex = b; s_pc = m; f_pc = n;
        //Set up default layout constraints.
        c.fill = GridBagConstraints.NONE;

        //Add the label.  It displays this panel's title, centered.
        if(exam_type == 0 ) { // Final exam
           tL = new Label("Final", Label.LEFT);
        } else {
           tL = new Label("Exam " + exam_type, Label.LEFT);
        }
        c.anchor = GridBagConstraints.WEST;
        c.gridwidth = 1;
        c.gridx = 0;
        c.gridy = 0;
        gridbag.setConstraints(tL, c);
        add(tL);
        c.anchor = GridBagConstraints.CENTER;

        if( exam_x == 0 ) {
          // exam not extrapolated
          exam_ratio = (float)s_ex / (float)f_ex;
          tmp_i = (int) (10000 * exam_ratio );
          float percent = (float)tmp_i / (float)100.0;
          String cs =  " " + a + "/" + b + " = " + percent + " %";
          Label  cL = new Label(cs, Label.CENTER);
          c.gridwidth = 2;
          c.gridx = 1;
          c.gridy = 0;
          gridbag.setConstraints(cL, c);
          add(cL);
        } else {
          // extrapolate exam
          exam_ratio = ex_default;
          exT_ex = new TextField("0", 3);
          exT_ex.setName("EXAM");
          c.gridwidth = 1; //The default value.
          c.gridx = 2;
          c.gridy = 0;
          gridbag.setConstraints(exT_ex, c);
          add(exT_ex);
          exT_ex.addActionListener(this);

          sB_ex = new Scrollbar(Scrollbar.HORIZONTAL);
          sB_ex.setName("EXAMS");
          sB_ex.setMaximum(max + 10);
          sB_ex.setBlockIncrement(block);
          c.gridwidth = 2;
          c.gridx = 3;
          c.gridy = 0;
          gridbag.setConstraints(sB_ex, c);
          add(sB_ex);
          sB_ex.addAdjustmentListener(this);
        }
        epc_ratio = exam_ratio;
        if(show_pc == 1) {
          if(epc_x == 1) {
            epc_ratio = exam_ratio;
          } else {
            epc_ratio = (float)s_pc / (float)f_pc;
          }
          if( epc_ratio > exam_ratio ) {
            tmp_i= (int)(10000 * (exam_ratio + c_factor * (epc_ratio - exam_ratio)));
            sum  = (float)tmp_i / (float)100.0;
          } else {
            tmp_i= (int)(10000 * exam_ratio);
            sum  = (float)tmp_i / (float)100.0;
          }
        } else { 
          tmp_i= (int)(10000 * exam_ratio);
          sum  = (float)tmp_i / (float)100.0;
        }

        Label sL = new Label("subtotal=", Label.RIGHT);
        c.gridwidth = 1;
        c.gridx = 5;
        c.gridy = 0;
        gridbag.setConstraints(sL, c);
        add(sL);

        String  s = " " + sum + "%";
        sumL = new Label(s, Label.CENTER);
        c.anchor = GridBagConstraints.EAST; 
        c.gridwidth = GridBagConstraints.REMAINDER; //It ends a row.
        c.gridx = 6;
        c.gridy = 0;
        gridbag.setConstraints(sumL, c);
        add(sumL);
        c.anchor = GridBagConstraints.CENTER; 

        if( show_epc == 1 ) {
           Label eL = new Label("Correction " + exam_type, Label.LEFT);
           c.gridwidth = 1;
           c.gridx = 0;
           c.gridy = 1;
           gridbag.setConstraints(eL, c);
           add(eL);
           if( epc_x == 0 ) {
             float ratio = (float) ( s_pc / f_pc);
             tmp_i = (int) (10000 * ratio );
             float percent = (float)tmp_i / (float)100.0;
             String cs =  " " + s_pc + "/" + f_pc + " = " + percent + " %";
             Label  cL = new Label(cs, Label.CENTER);
             c.gridwidth = 2;
             c.gridx = 1;
             c.gridy = 1;
             gridbag.setConstraints(cL, c);
             add(cL);
           } else {
             exT_pc = new TextField("0", 3);
             exT_pc.setName("PC");
             c.anchor = GridBagConstraints.EAST;
             c.gridwidth = 1; //The default value.
             c.gridx = 2;
             c.gridy = 1;
             gridbag.setConstraints(exT_pc, c);
             add(exT_pc);
             exT_pc.addActionListener(this);

             sB_pc = new Scrollbar(Scrollbar.HORIZONTAL);
             sB_pc.setName("PCS");
             sB_pc.setMaximum(max + 10);
             sB_pc.setBlockIncrement(block);
             c.gridwidth = GridBagConstraints.REMAINDER;
             c.anchor = GridBagConstraints.CENTER;
             c.fill = GridBagConstraints.HORIZONTAL;
             // c.gridwidth = 2;
             c.gridx = 3;
             c.gridy = 1;
             gridbag.setConstraints(sB_pc, c);
             add(sB_pc);
             sB_pc.addAdjustmentListener(this);
           }
        }
        setExValue(exam_ratio,epc_ratio);
    }
    // Draws a box around this panel. 
    public void paint(Graphics g) {
        Dimension d = getSize();
        g.drawRect(0,0, d.width - 1, d.height - 1);
    }
    public Insets getInsets() {
        return new Insets(5,5,5,8);
    }
    float  getSubTotal() {
        String s_str = sumL.getText().replace('%','\0').trim();
        float  s_real = Float.valueOf(s_str).floatValue();
        return (s_real);
    }
    // entered into exT
    public void actionPerformed(ActionEvent e) {
        TextField source = (TextField)e.getSource();
        String name = source.getName();
        int tf = (int)Integer.valueOf(source.getText()).intValue();
        if (tf > max)
            tf = max;
        if (tf < 0)
            tf = 0;
        if( name.equals(String.valueOf("EXAM")) ) {
          sB_ex.setValue(tf);
          exT_ex.setText(String.valueOf((int)tf));
        } else {
          sB_pc.setValue(tf);
          exT_pc.setText(String.valueOf((int)tf));
        }
        recalcSumm();
    }    
    //  slider sB changed
    public void adjustmentValueChanged(AdjustmentEvent e) {
        Scrollbar source = (Scrollbar)e.getSource();
        String    name = source.getName();
           int    my_i =  (int)source.getValue();
        
        if( name.equals(String.valueOf("EXAMS")) ) {
          sB_ex.setValue(my_i);
          exT_ex.setText(String.valueOf((int)my_i));
        } else {
          sB_pc.setValue(my_i);
          exT_pc.setText(String.valueOf((int)my_i));
        }
        recalcSumm();
    }
    void  recalcSumm() {
        int   tmp_i;
        float exam , epc, sum;
        
        if( exam_ex == 1 ) {
           tmp_i = (int)Integer.valueOf(exT_ex.getText()).intValue();
           exam = (float) tmp_i / (float)100.0;
        } else {
           exam = (float)s_ex / (float)f_ex;
        }
        if( show_pc == 1 ) {
          if(epc_ex == 1) {
            tmp_i = (int)Integer.valueOf(exT_pc.getText()).intValue();
            epc = (float) tmp_i / (float)100.0;
          } else {
            epc = (float)s_pc / (float)f_pc;
          }
          if( epc > exam ) {
            tmp_i= (int)(10000 * (exam + c_factor * (epc - exam)));
            sum  = (float)tmp_i / (float)100.0;
          } else {
            tmp_i= (int)(10000 * exam);
            sum  = (float)tmp_i / (float)100.0;
          }
        } else {
          tmp_i= (int)(10000 * exam);
          sum  = (float)tmp_i / (float)100.0;
        }
        sumL.setText(sum + "%");
        controller.recalcTermScore();
    }
    void setExValue (float a, float b) {
        int  exm, epc;
        exm = (int) (a*100.0); 
        epc = (int) (b*100.0); 
        if (exm > max)
            exm = max;
        if (exm < 0)
            exm = 0;
        if (epc > max)
            epc = max;
        if (epc < 0)
            epc = 0;
        if( exam_ex ==1 ) {
          sB_ex.setValue(exm);
          exT_ex.setText(String.valueOf(exm));
        }
        if( (show_pc == 1) && (epc_ex==1) ) {
          sB_pc.setValue(epc);
          exT_pc.setText(String.valueOf(epc));
        }
     }
}