How to Calculate a sum with percentage in android studio-CodePudding

I have an app where I have to calculate 2 sums with a discounted rate. eg:200 50 - 10% the result should be shown automatically on the other textView without clicking any submit button I have done the addition part by textWatcher method. But I am not able to do the percentage part This is My code.

My Xml Code:

               <com.google.android.material.textfield.TextInputLayout
                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
                    android:layout_width="110dp"
                    android:layout_height="match_parent">

                    <com.google.android.material.textfield.TextInputEditText
                        android:id="@ id/productPriceEt"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:hint="Product Price"
                        android:inputType="number"/>

                </com.google.android.material.textfield.TextInputLayout>

                <com.google.android.material.textfield.TextInputLayout
                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
                    android:layout_width="110dp"
                    android:layout_height="match_parent"
                    android:layout_marginLeft="5dp">

                    <com.google.android.material.textfield.TextInputEditText
                        android:id="@ id/deliveryChargesEt"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:hint="Delivery Charges"
                        android:inputType="number"/>

                </com.google.android.material.textfield.TextInputLayout>

                <com.google.android.material.textfield.TextInputLayout
                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
                    android:layout_width="110dp"
                    android:layout_height="match_parent"
                    android:layout_marginLeft="5dp">

                    <com.google.android.material.textfield.TextInputEditText
                        android:id="@ id/discountEt"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:hint="Discount"
                        android:inputType="number"/>

                </com.google.android.material.textfield.TextInputLayout>

                <com.google.android.material.textview.MaterialTextView
                    android:id="@ id/prbtTv"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"
                    android:layout_marginLeft="5dp"
                    android:layout_marginTop="3dp"
                    android:background="@drawable/textview_border"
                    android:gravity="center_vertical"
                    android:padding="15dp"
                    android:text="Price Before Taxes"
                    android:textSize="16sp">
                </com.google.android.material.textview.MaterialTextView>

My Java Code :

     TextWatcher textWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            if (!productPriceEt.getText().toString().equals("") && 
                !deliveryChargeEt.getText().toString().equals("") && 
                !discountEt.getText().toString().equals("")){
                int temp1 = Integer.parseInt(productPriceEt.getText().toString());
                int temp2 = Integer.parseInt(deliveryChargeEt.getText().toString());
                int temp3 = Integer.parseInt(discountEt.getText().toString());
                prbTv.setText(String.valueOf(temp1   temp2 - temp3));
            }
        }

        @Override
        public void afterTextChanged(Editable editable) {

        }
    };
    productPriceEt.addTextChangedListener(textWatcher);
    deliveryChargeEt.addTextChangedListener(textWatcher);
    discountEt.addTextChangedListener(textWatcher);

CodePudding user response：

just save the result of the sum in a variable first like this:

private val sum = temp1   temp2

then calculate the off like this:

private val off = (temp3/100) * sum

and finally set text on text view like this:

prbTv.setText(String.valueOf(sum  - off ));

CodePudding user response：

Try this

Xml File

<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">


    <com.google.android.material.textfield.TextInputLayout
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@ id/productPriceEt"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Product Price"
            android:inputType="number" />

    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.textfield.TextInputLayout
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@ id/deliveryChargesEt"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Delivery Charges"
            android:inputType="number" />

    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.textfield.TextInputLayout
        style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp">

        <com.google.android.material.textfield.TextInputEditText
            android:id="@ id/discountEt"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Discount"
            android:inputType="number" />

    </com.google.android.material.textfield.TextInputLayout>

    <com.google.android.material.textview.MaterialTextView
        android:id="@ id/prbtTv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="5dp"
        android:layout_marginTop="3dp"
        android:gravity="center_vertical"
        android:padding="15dp"
        android:text="Price Before Taxes"
        android:textSize="16sp" />

</androidx.appcompat.widget.LinearLayoutCompat>

Code

public class MainActivity extends AppCompatActivity {
    TextInputEditText productPriceEt, deliveryChargesEt, discountEt;
    MaterialTextView prbtTv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        productPriceEt = findViewById(R.id.productPriceEt);
        deliveryChargesEt = findViewById(R.id.deliveryChargesEt);
        discountEt = findViewById(R.id.discountEt);
        prbtTv = findViewById(R.id.prbtTv);

        productPriceEt.addTextChangedListener(textWatcher);
        deliveryChargesEt.addTextChangedListener(textWatcher);
        discountEt.addTextChangedListener(textWatcher);


    }

    private final TextWatcher textWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

            if (!productPriceEt.getText().toString().equals("") &&
                    !deliveryChargesEt.getText().toString().equals("") &&
                    !discountEt.getText().toString().equals("")) {
                int amounts = Integer.parseInt(productPriceEt.getText().toString().trim())  
                        Integer.parseInt(deliveryChargesEt.getText().toString().trim());
                double amount = Double.parseDouble(String.valueOf(amounts));
                double res = (amount / 100.0f) * Double.parseDouble(discountEt.getText().toString());
                res = amount - res;
                prbtTv.setText("Price Before Taxes- "   amount   "\nPrice After Discount - "   res);

                Toast.makeText(getApplicationContext(), ""   res, Toast.LENGTH_SHORT).show();
            } else {
                prbtTv.setText("Price Before Taxes- "   0.00   "\nPrice After Discount - "   0.00);

            }
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    };


}