Untitled

package com.example.calculator;

import android.content.Context;
import android.os.Bundle;
import android.text.Html;
import android.text.Spanned;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.util.Stack;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {

    public TextView input, output;
    Button btnAC, btnDel, btnPersent, btnDivision,btn7, btn8,btn9,btn5,btn6,btn4,btn3,btn2,btn1,btn0,btnPoint,multiply, subtract, add, equal;
    Button btnx2, btnDeg, btnSin, btnCos, btnTan, btnpow, btnlg, btnLn, btnMoNgoac, btnDongNgoac, btnSqrt, btnGiaiThua, btn1ChiaX, btnPi, btnRand,btnE;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        input = findViewById(R.id.input);
        output = findViewById(R.id.output);

        // initializing all our variables.
        btnAC = findViewById(R.id.btnAC);
        btnDel = findViewById(R.id.btnDel);
        btnMoNgoac = findViewById(R.id.btnMoNgoac);
        btnDongNgoac = findViewById(R.id.btnDongNgoac);
//        btnSin = findViewById(R.id.btnSin);
//        btnCos = findViewById(R.id.btnCos);
//        btnTan = findViewById(R.id.btnTan);
//        btnlg = findViewById(R.id.btnlg);
//        btnLn = findViewById(R.id.btnLn);
//        btnGiaiThua = findViewById(R.id.btnGiaiThua);
//        btnx2 = findViewById(R.id.btnx2);
//        btnSqrt = findViewById(R.id.btnSqrt);
//        btn1ChiaX = findViewById(R.id.btn1ChiaX);
        btn0 = findViewById(R.id.btn0);
        btn9 = findViewById(R.id.btn9);
        btn8 = findViewById(R.id.btn8);
        btn7 = findViewById(R.id.btn7);
        btn6 = findViewById(R.id.btn6);
        btn5 = findViewById(R.id.btn5);
        btn4 = findViewById(R.id.btn4);
        btn3 = findViewById(R.id.btn3);
        btn2 = findViewById(R.id.btn2);
        btn1 = findViewById(R.id.btn1);
        btnPi = findViewById(R.id.btnPi);
        multiply = findViewById(R.id.multiply);
        subtract = findViewById(R.id.subtract);
        add = findViewById(R.id.add);
        equal = findViewById(R.id.equal);
        btnPoint = findViewById(R.id.btnPoint);
        btnDivision = findViewById(R.id.btnDivision);
// adding on click listener to our all buttons.
        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "1");
            }
        });
        btn2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "2");
            }
        });
        btn3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "3");
            }
        });
        btn4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "4");
            }
        });
        btn5.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "5");
            }
        });
        btn6.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "6");
            }
        });
        btn7.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "7");
            }
        });
        btn8.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "8");
            }
        });
        btn9.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "9");
            }
        });
        btn0.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "0");
            }
        });
        add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "+");
            }
        });
        btnDivision.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "/");
            }
        });
        btnMoNgoac.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + "(");
            }
        });
        btnDongNgoac.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + ")");
            }
        });
        btnPoint.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                input.setText(input.getText().toString() + ".");
            }
        });
//        btnPi.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                input.setText(input.getText().toString() + Math.PI);
//                output.setText(btnPi.getText().toString());
//            }
//        });
//        btnSin.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                input.setText(input.getText().toString() + "sin");
//            }
//        });
//        btnCos.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                input.setText(input.getText().toString() + "cos");
//            }
//        });
//        btnTan.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                input.setText(input.getText().toString() + "tan");
//            }
//        });
//        btn1ChiaX.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                input.setText(input.getText().toString() + "^" + "(-1)");
//            }
//        });
//        btnLn.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                input.setText(input.getText().toString() + "ln");
//            }
//        });
        subtract.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String str = input.getText().toString();
                if (str.charAt(str.length() - 1) != '-') {
                    input.setText(input.getText().toString() + "-");
                }
            }
        });
        multiply.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String str = input.getText().toString();
                if (str.charAt(str.length() - 1) != '*') {
                    input.setText(input.getText().toString() + "*");
                }
            }
        });
//        btnSqrt.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                if (input.getText().toString().isEmpty()) {
//                    Toast.makeText(getApplicationContext(),
//                            "Please enter a valid number..", Toast.LENGTH_SHORT).show();
//                } else {
//                    String str = input.getText().toString();
//
//                    double r = Math.sqrt(Double.parseDouble(str));
//                    input.setText(String.valueOf(r));
//                }
//            }
//        });
        equal.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String curdata = input.getText().toString();
                String res = String.valueOf(Calculator.evaluateExpression(curdata));

                if(curdata.length()>80) output.setTextSize(28);
                else {
                    if(curdata.length()>25) output.setTextSize(42);
                    else output.setTextSize(55);}
//                Integer checkD = checkDau(curdata);
//                for(Integer i=1;i<=checkD;i++) curdata = curdata + ")";
//                input.setText(curdata);
                if(res.endsWith(".0")) res = res.replace(".0","");
                res = "="+res;
                output.setText(res);
            }
        });
        btnAC.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                output.setTextSize(60);
                input.setTextSize(40);
                input.setText("");
                output.setText("");
            }
        });
        btnDel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String curdata = input.getText().toString();
                if(!curdata.equals("0")) curdata=curdata.substring(0,curdata.length()-1);
                input.setText(curdata);
                output.setText("");
            }
        });
//        btnx2.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                if (input.getText().toString().isEmpty()) {
//                    Toast.makeText(getApplicationContext(),
//                            "Please enter a valid number..", Toast.LENGTH_SHORT).show();
//                } else {
//                    Double d = Double.parseDouble(input.getText().toString());
//                    Double square = d * d;
//                    input.setText(square.toString());
//                    output.setText("$d²");
//                }
//            }
//        });
//        btnGiaiThua.setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View view) {
//                if (input.getText().toString().isEmpty()) {
//                    // if the entered number is empty we are displaying an error message.
//                    Toast.makeText(getApplicationContext(),
//                            "Please enter a valid number..", Toast.LENGTH_SHORT).show();
//                } else {
//                    int value= Integer.parseInt(input.getText().toString());
//                    int  fact = factorial(value);
//                    output.setText(String.valueOf(fact));
//                    input.setText(value+"!");
//                }
//            }
//        });
    }
    int factorial(int n){
        return  (n == 1 || n == 0) ? 1 : n * factorial(n - 1);
    }

    // Check dấu đóng mo ngoặc
    Integer checkDau(String data)
    {
        Integer checkp=0;
        for(Integer i=0;i<= data.length()-1;i++)
        {
            if(data.charAt(i)=='(') checkp++;
            if(data.charAt(i)==')') checkp--;
        }
        return checkp;
    }
}