/*
 *Java script: prog6_calc.java
 *Author:  Ashwin Prakash
 *Bioinformatics Lab, Department of Medicine
 *HSC, University of Toledo, Toledo, Ohio, USA
 *written January, 2011
 *Contact ashwin.prakash@rockets.utoledo.edu
 *
 *LICENSE:  GPL version 3 or later
*/

/*
 * The program provides a web based GUI for a simple implementation of a calculator applet
 * The user can enter numerical values within the text area in the applet and execute mathematical
 * operators to obtain results of these calculations within the above mentioned text area.
 * The calculator also provides certain scientific functions such as log, ln, etc.
 * The applet also houses a random number generator which can be executed using the "rand" button
 * The applet also includes a Memory function which can be used to store one number, which can be
 * retreived later and used for further calculations.
 */


import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.lang.*;





public class prog6_calc extends JApplet implements ActionListener{
	Container c;
	TextField ta1;
	//JLabel L1;
	JButton beq, bcs, bcl, b1, b2, b3, b4, b5, b6, b7, b8, b9, b0, bdot;
	JButton bM, badd, bmul, bdiv, bsub;
	JButton blog, bln, bsqrt, bcbrt, binv;
	JButton bround, bexp, bsqr, bcub, brand; 
	String num;
	String operate="";
	String mem = "";
	//String useFloat="NO";

	public void init(){
		c=getContentPane();
		c.setLayout(null);
	
		ta1 = new TextField();
		ta1.setLocation(10,40);
		ta1.setSize(435, 50);
		
		beq = new JButton("=");
		beq.setLocation(452, 40);
		beq.setSize(50,50);		
		beq.addActionListener(this);				
		
		bcl = new JButton("Bk");
		bcl.setLocation(510, 40);
		bcl.setSize(60,50);		
		bcl.addActionListener(this);

//-------------------------------------------------------------------------------------
		b1 = new JButton("1");
		b1.setLocation(10, 100);
		b1.setSize(75,75);		
		b1.addActionListener(this);

		b2 = new JButton("2");
		b2.setLocation(100, 100);
		b2.setSize(75,75);		
		b2.addActionListener(this);
	
		b3 = new JButton("3");
		b3.setLocation(190, 100);
		b3.setSize(75,75);		
		b3.addActionListener(this);

		b4 = new JButton("4");
		b4.setLocation(10, 180);
		b4.setSize(75,75);		
		b4.addActionListener(this);

		b5 = new JButton("5");
		b5.setLocation(100, 180);
		b5.setSize(75,75);		
		b5.addActionListener(this);

		b6 = new JButton("6");
		b6.setLocation(190, 180);
		b6.setSize(75,75);		
		b6.addActionListener(this);

		b7 = new JButton("7");
		b7.setLocation(10, 260);
		b7.setSize(75,75);		
		b7.addActionListener(this);

		b8 = new JButton("8");
		b8.setLocation(100, 260);
		b8.setSize(75,75);		
		b8.addActionListener(this);

		b9 = new JButton("9");
		b9.setLocation(190, 260);
		b9.setSize(75,75);		
		b9.addActionListener(this);
		
		bM = new JButton("M");
		bM.setLocation(10, 340);
		bM.setSize(75,75);		
		bM.addActionListener(this);		

		b0 = new JButton("0");
		b0.setLocation(100, 340);
		b0.setSize(75,75);		
		b0.addActionListener(this);

		bdot = new JButton(".");
		bdot.setLocation(190, 340);
		bdot.setSize(75,75);		
		bdot.addActionListener(this);

//-------------------------------------------------------------------------------------
		
		badd = new JButton("+");
		badd.setLocation(280, 100);
		badd.setSize(90,55);		
		badd.addActionListener(this);
		
		bsub = new JButton("-");
		bsub.setLocation(280, 160);
		bsub.setSize(90,55);		
		bsub.addActionListener(this);

		bmul = new JButton("x");
		bmul.setLocation(280, 220);
		bmul.setSize(90,55);		
		bmul.addActionListener(this);

		bdiv = new JButton("/");
		bdiv.setLocation(280, 280);
		bdiv.setSize(90,55);		
		bdiv.addActionListener(this);

		brand = new JButton("rand");
		brand.setLocation(280, 340);
		brand.setSize(90,75);		
		brand.addActionListener(this);

//-------------------------------------------------------------------------------------
		
		blog = new JButton("log");
		blog.setLocation(380, 100);
		blog.setSize(90,55);		
		blog.addActionListener(this);
		
		bln = new JButton("ln");
		bln.setLocation(380, 160);
		bln.setSize(90,55);		
		bln.addActionListener(this);

		bsqrt = new JButton("sqrt");
		bsqrt.setLocation(380, 220);
		bsqrt.setSize(90,55);		
		bsqrt.addActionListener(this);

		bcbrt = new JButton("cbrt");
		bcbrt.setLocation(380, 280);
		bcbrt.setSize(90,55);		
		bcbrt.addActionListener(this);
	
		binv = new JButton("1/x");
		binv.setLocation(380, 340);
		binv.setSize(90,75);		
		binv.addActionListener(this);

//-------------------------------------------------------------------------------------

		bround = new JButton("round");
		bround.setLocation(480, 100);
		bround.setSize(90,55);		
		bround.addActionListener(this);
		
		bexp = new JButton("exp");
		bexp.setLocation(480, 160);
		bexp.setSize(90,55);		
		bexp.addActionListener(this);

		bsqr = new JButton("x^2");
		bsqr.setLocation(480, 220);
		bsqr.setSize(90,55);		
		bsqr.addActionListener(this);

		bcub = new JButton("x^3");
		bcub.setLocation(480, 280);
		bcub.setSize(90,55);		
		bcub.addActionListener(this);
	
		bcs = new JButton("CE");
		bcs.setLocation(480, 340);
		bcs.setSize(90,75);		
		bcs.addActionListener(this);

//-------------------------------------------------------------------------------------

		//c.add(L1);
		c.add(ta1);
		c.add(beq);
		c.add(bcl);
		c.add(b1);
		c.add(b2);
		c.add(b3);
		c.add(b4);
		c.add(b5);
		c.add(b6);
		c.add(b7);
		c.add(b8);
		c.add(b9);
		c.add(bM);
		c.add(b0);
		c.add(bdot);
		c.add(badd);
		c.add(bsub);
		c.add(bmul);
		c.add(bdiv);
		c.add(bcs);
		c.add(blog);
		c.add(bln);
		c.add(bsqrt);
		c.add(bcbrt);
		c.add(binv);
		c.add(bround);
		c.add(bexp);
		c.add(bsqr);
		c.add(bcub);
		c.add(brand);
	}
//-------------------------------------------------------------------------------------
	public void actionPerformed(ActionEvent e){
		if(e.getSource()==beq){	
			String x = ta1.getText();
			if(x==""){
				ta1.setText(""+num);
			}
			//if(useFloat=="YA"){
				double num2 = Double.parseDouble(x);
				double num1 = Double.parseDouble(num);
				double ans;
				if(operate=="+"){
					ans = num1 + num2;
					ta1.setText(""+ans);
				}
				if(operate == "-"){
					ans = num1-num2;
					ta1.setText(""+ans);
				}
				if(operate == "x"){
					ans = num1*num2;
					ta1.setText(""+ans);
				}
				if(operate == "/"){
					ans = num1/num2;
					ta1.setText(""+ans);
				}
			/*}else if(useFloat=="NO"){
				int num2 = Integer.parseInt(x);
				int num1 = Integer.parseInt(num);
				int ans;
				if(operate=="+"){
					ans = num1 + num2;
					ta1.setText(""+ans);
				}
				if(operate == "-"){
					ans = num1-num2;
					ta1.setText(""+ans);
				}
				if(operate == "x"){
					ans = num1*num2;
					ta1.setText(""+ans);
				}
				if(operate == "/"){
					ans = num1/num2;
					ta1.setText(""+ans);
				}
			}*/
		}
		if(e.getSource()==bcl){
			String x = ta1.getText();
			int len = x.length();
			if(len>0){x = x.substring(0, len-1);}
			else{};
			ta1.setText(x);
		}
		if(e.getSource()==bdot){
			String x = ta1.getText();
			if(x.contains(".")==false){
				//useFloat="YA";
				ta1.setText(x+".");
			}else{
				ta1.setText(x);
			}
		}
		if(e.getSource()==bcs){
			ta1.setText("");
		}
		if(e.getSource()==b1){
			String x = ta1.getText();
			ta1.setText(x+"1");
		}
		if(e.getSource()==b2){
			String x = ta1.getText();
			ta1.setText(x+"2");
		}
		if(e.getSource()==b3){
			String x = ta1.getText();
			ta1.setText(x+"3");
		}
		if(e.getSource()==b4){
			String x = ta1.getText();
			ta1.setText(x+"4");
		}
		if(e.getSource()==b5){
			String x = ta1.getText();
			ta1.setText(x+"5");
		}
		if(e.getSource()==b6){
			String x = ta1.getText();
			ta1.setText(x+"6");
		}
		if(e.getSource()==b0){
			String x = ta1.getText();
			ta1.setText(x+"0");
		}
		if(e.getSource()==b7){
			String x = ta1.getText();
			ta1.setText(x+"7");
		}
		if(e.getSource()==b8){
			String x = ta1.getText();
			ta1.setText(x+"8");
		}
		if(e.getSource()==b9){
			String x = ta1.getText();
			ta1.setText(x+"9");
		}
		if(e.getSource()==bM){
			String x = ta1.getText();
			if(x.length()>0){
				mem = x;
			}else{
				ta1.setText(x+mem);
			}
		}
		if(e.getSource()==badd){
			String x = ta1.getText();
			num = x;
			operate = "+";
			ta1.setText("");
		}
		if(e.getSource()==bsub){
			String x = ta1.getText();
			if(x.length()>0){
				num = x;
				operate = "-";
				ta1.setText("");
			}else{ta1.setText(x+"-");}
		}
		if(e.getSource()==bmul){
			String x = ta1.getText();
			num = x;
			operate = "x";
			ta1.setText("");
		}
		if(e.getSource()==bdiv){
			String x = ta1.getText();
			num = x;
			operate = "/";
			ta1.setText("");	
		}
		if(e.getSource()==bln){
			String x = ta1.getText();
			double num = Double.parseDouble(x);
			double ans = Math.log(num);
			ta1.setText(""+ans);	
		}
		if(e.getSource()==blog){
			String x = ta1.getText();
			double num = Double.parseDouble(x);
			double ans = Math.log10(num);
			ta1.setText(""+ans);	
		}
		if(e.getSource()==bsqrt){
			String x = ta1.getText();
			double num = Double.parseDouble(x);
			double ans = Math.sqrt(num);
			ta1.setText(""+ans);	
		}
		if(e.getSource()==bcbrt){
			String x = ta1.getText();
			double num = Double.parseDouble(x);
			double ans = Math.cbrt(num);
			ta1.setText(""+ans);	
		}
		if(e.getSource()==binv){
			String x = ta1.getText();
			double num = Double.parseDouble(x);
			double ans = 1/num;
			ta1.setText(""+ans);	
		}
		if(e.getSource()==bround){
			String x = ta1.getText();
			float num = Float.parseFloat(x);
			float ans = Math.round(num);
			ta1.setText(""+ans);	
		}
		if(e.getSource()==bexp){
			String x = ta1.getText();
			double num = Double.parseDouble(x);
			double ans = Math.exp(num);
			ta1.setText(""+ans);	
		}
		if(e.getSource()==bsqr){
			String x = ta1.getText();
			float num = Float.parseFloat(x);
			float ans = num*num;
			ta1.setText(""+ans);	
		}
		if(e.getSource()==bcub){
			String x = ta1.getText();
			float num = Float.parseFloat(x);
			float ans = num*num*num;
			ta1.setText(""+ans);	
		}
		if(e.getSource()==brand){
			double ans = Math.random();
			ta1.setText(""+ans);	
		}
	}	
}