basic calculator

basiccalculator.java

package com.example.deniz.calculator04;

import android.annotation.SuppressLint;
import android.media.Image;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private Button one, two, three, four, five, six, seven, eight, nine, zero, equal, mult, div, sub, sum, delete;
    private ImageButton back;
    private TextView result,data;
    private EditText input;
    float choosen1=0,choosen2=0;
    String choosenone="",choosentwo="";
    int check=1;
    int multcheck=0;
    String sign = null;
    int b=1,pass=1,finish=0,zerochoosed=1,equalcounter=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        one = (Button) findViewById(R.id.one);
        two = (Button) findViewById(R.id.two);
        three = (Button) findViewById(R.id.three);
        four = (Button) findViewById(R.id.four);
        five = (Button) findViewById(R.id.five);
        six = (Button) findViewById(R.id.six);
        seven = (Button) findViewById(R.id.seven);
        eight = (Button) findViewById(R.id.eight);
        nine = (Button) findViewById(R.id.nine);
        zero = (Button) findViewById(R.id.zero);
        equal = (Button) findViewById(R.id.equal);
        mult = (Button) findViewById(R.id.mult);
        div = (Button) findViewById(R.id.div);
        sub = (Button) findViewById(R.id.sub);
        sum = (Button) findViewById(R.id.sum);
        delete = (Button) findViewById(R.id.delete);
        back = (ImageButton) findViewById(R.id.back);
        result = (TextView) findViewById(R.id.result);
        input = (EditText) findViewById(R.id.input);
        data = (TextView) findViewById(R.id.data);

    }
    public void onClick(View v){
        if (check==1){
            if(equalcounter==1){
             equalcounter=0;
                if (v.getId() == R.id.sum || v.getId() == R.id.sub || v.getId() == R.id.mult || v.getId() == R.id.div) {

                    result.setText(Float.toString(choosen1));
                    check = 0;
                    sign = setsign(v, sign, choosen1);
                    input.setText(Float.toString(choosen1) + ((Button) v).getText());


                } else if (v.getId() == R.id.delete) {
                    input.setText("");
                    data.setText("");
                    result.setText("RESULT:");
                    choosenone = "";
                    sign = null;
                    choosen1 = 0;
                    check = 1;

                }


                else if (v.getId() == R.id.equal) {
                    input.setText(Float.toString(choosen1));

                }

            }
            else {
                choosenone = setnum(v, choosenone);
                result.setText(choosenone);
                choosen1 = Float.parseFloat(choosenone);
                input.setText(choosenone);


                if (v.getId() == R.id.sum || v.getId() == R.id.sub || v.getId() == R.id.mult || v.getId() == R.id.div) {

                    result.setText(Float.toString(choosen1));
                    check = 0;
                    sign = setsign(v, sign, choosen1);
                    input.setText(Float.toString(choosen1) + ((Button) v).getText());


                } else if (v.getId() == R.id.delete) {
                    input.setText("");
                    data.setText("");
                    result.setText("RESULT:");
                    choosenone = "";
                    sign = null;
                    choosen1 = 0;
                    check = 1;

                }

                else if (v.getId() == R.id.equal) {
                    input.setText(Float.toString(choosen1));

                }

            }
        }

        else if(check==0) {


            choosentwo=setnum(v,choosentwo);

                choosen2 = Float.parseFloat(choosentwo);
                calculation(sign, choosen1, choosen2, zerochoosed);


            if(choosen2==0){
               zerochoosed=0;
            }

            input.setText(input.getText().toString() + ((Button) v).getText());

            if(v.getId()==R.id.sum||v.getId() == R.id.sub||v.getId()==R.id.mult||v.getId()==R.id.div)
        {
            choosen1=calculation(sign, choosen1, choosen2, zerochoosed);
            result.setText(Float.toString(choosen1));
            choosen2=0;
            choosentwo="";
            sign=setsign(v,sign,choosen1);
        }
        else if(v.getId() == R.id.delete){
                input.setText("");
                data.setText("");
                result.setText("RESULT:");
                choosenone="";
                sign= null;
                choosen1=0;
                check=1;

            }

            else if(v.getId() == R.id.equal){
                choosen1=calculation(sign, choosen1, choosen2, zerochoosed);
                choosen2=0;
                choosentwo="";
                input.setText(Float.toString(choosen1));
                result.setText(Float.toString(choosen1));
                data.setText(Float.toString(choosen1)+sign+Float.toString(choosen2));
                check=1;
                equalcounter=1;


            }

        }


    }

    public float calculation(String a,float choosen1,float choosen2,int zerochoosed){
        switch(a){
            case "+":
                choosen1+=choosen2;
                result.setText(Float.toString(choosen1));
                data.setText(Float.toString(choosen1)+sign+Float.toString(choosen2));
                return choosen1;

            case "-":
                choosen1-=choosen2;
                result.setText(Float.toString(choosen1));
                return choosen1;
            case "*":
                if(choosen2==0  && zerochoosed==1){
                    choosen2=1;
                }
                choosen1*=choosen2;
                result.setText(Float.toString(choosen1));
                return choosen1;
            case "/":
                if(choosen2==0  && zerochoosed==1){
                    choosen2=1;
                }
                choosen1/=choosen2;
                result.setText(Float.toString(choosen1));
                return choosen1;

        }
        return choosen1;
    }

    public String setnum(View v,String choosens){

        switch (v.getId()) {
            case R.id.one:
                return choosens += "1";
            case R.id.two:
                return choosens += "2";
            case R.id.three:
                return choosens += "3";
            case R.id.four:
                return choosens += "4";
            case R.id.five:
                return choosens += "5";
            case R.id.six:
                return choosens += "6";
            case R.id.seven:
                return choosens += "7";
            case R.id.eight:
                return choosens += "8";
            case R.id.nine:
                return choosens += "9";
            case R.id.zero:
                return choosens += "0";

        }
        return choosens;
    }
    public String setsign(View v,String sign,float choosen1){
        switch(v.getId()){


            case R.id.sum:
                return sign="+";

            case R.id.sub:
                return sign="-";

            case R.id.mult:
                return sign="*";

            case R.id.div:
                return sign="/";

        }
        return sign;
    }

}