im new in android and i created a simple calculator. Now i want it to show me history of operations in textView. I dont know how to do that, can someone help me with it? I know it's very simple programing but i just started lerning java and im working in android studio. Thanks. Edit: i found 1 error so i edited main and im adding layout code.
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.GridLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MainActivity extends AppCompatActivity {
Button b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, bplus, bminus, bmulti, bdiv, beq, bc;
EditText edit1;
TextView hist;
int nr1, nr2;
boolean plus, minus, multi, div;
//List<String> history= new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b0 = (Button) findViewById(R.id.b0);
b1 = (Button) findViewById(R.id.b1);
b2 = (Button) findViewById(R.id.b2);
b3 = (Button) findViewById(R.id.b3);
b4 = (Button) findViewById(R.id.b4);
b5 = (Button) findViewById(R.id.b5);
b6 = (Button) findViewById(R.id.b6);
b7 = (Button) findViewById(R.id.b7);
b8 = (Button) findViewById(R.id.b8);
b9 = (Button) findViewById(R.id.b9);
bplus = (Button) findViewById(R.id.bplus);
bminus = (Button) findViewById(R.id.bminus);
bmulti = (Button) findViewById(R.id.bmulti);
bdiv = (Button) findViewById(R.id.bdiv);
bc = (Button) findViewById(R.id.bc);
beq = (Button) findViewById(R.id.beq);
edit1 = (EditText) findViewById(R.id.edit1);
hist = (TextView) findViewById(R.id.hist);
//history.get(index);
b0.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "0");
}
});
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "1");
}
});
b2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "2");
}
});
b3.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "3");
}
});
b4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "4");
}
});
b4.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "4");
}
});
b5.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "5");
}
});
b6.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "6");
}
});
b7.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "7");
}
});
b8.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "8");
}
});
b9.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText(edit1.getText() + "9");
}
});
bplus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (edit1 == null){
edit1.setText("");
}else {
nr1 = Integer.parseInt(edit1.getText() + "");
plus= true;
edit1.setText(null);
}
}
});
bminus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
nr1 = Integer.parseInt(edit1.getText() + "");
minus = true ;
edit1.setText(null);
}
});
bmulti.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
nr1 = Integer.parseInt(edit1.getText() + "");
multi = true ;
edit1.setText(null);
}
});
bdiv.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
nr1 = Integer.parseInt(edit1.getText()+"");
div = true ;
edit1.setText(null);
}
});
bc.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
edit1.setText("");
}
});
beq.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
nr2 = Integer.parseInt(edit1.getText() + "");
double res = '0';
if (plus == true){
edit1.setText(nr1 + nr2+"");
plus=false;
}
if (minus == true){
edit1.setText(nr1 - nr2+"");
minus=false;
}
if (multi == true){
edit1.setText(nr1 * nr2+"");
multi=false;
}
if (div == true){
edit1.setText(nr1 / nr2+"");
div=false;
}
}
});
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="1">
<TextView
android:layout_width="match_parent"
android:id="@+id/hist"
android:layout_height="100dp" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/edit1" />
<GridLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1.10"
android:id="@+id/GridLayout">
<Button
android:text="5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b5"
android:layout_row="1"
android:layout_column="1"/>
<Button
android:text="6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b6"
android:layout_row="1"
android:layout_column="2"/>
<Button
android:text="-"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bminus" />
<Button
android:text="7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b7"
android:layout_row="2"
android:layout_column="0"/>
<Button
android:text="8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b8"
android:layout_row="2"
android:layout_column="1" />
<Button
android:text="9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b9"
android:layout_row="2"
android:layout_column="2" />
<Button
android:text="*"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bmulti"
android:layout_row="2"
android:layout_column="3" />
<Button
android:text="+"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bplus"
android:layout_row="0"
android:layout_column="3" />
<Button
android:text="3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b3"
android:layout_row="0"
android:layout_column="2" />
<Button
android:text="4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b4"
android:layout_row="1"
android:layout_column="0" />
<Button
android:text="0"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b0"
android:layout_row="3"
android:layout_column="1" />
<Button
android:text="2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b2"
android:layout_row="0"
android:layout_column="1" />
<Button
android:text="1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/b1"
android:layout_row="0"
android:layout_column="0" />
<Button
android:text="/"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bdiv"
android:layout_row="3"
android:layout_column="3" />
<Button
android:text="="
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/beq"
android:layout_row="3"
android:layout_column="2" />
<Button
android:text="C"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/bc"
android:layout_row="3"
android:layout_column="0" />
</GridLayout>
</LinearLayout>
