EditText OnClick Exception

Question

So I am making an app for an assignment.

Basically convert Miles to KM or KM to Miles.

I've now got the radio buttons working but when I add the onclick event, upon clicking the edittext fields I get an exception. :

java.lang.IllegalArgumentException: 
          Expected receiver of type a00891437.set3s.comp3975.convertunits.MainActivity, 
          but got android.support.v7.internal.widget.TintContextWrapper  

Here is the code

    package a00891437.set3s.comp3975.convertunits;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;



public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }


    public void onRadioButtonClicked(final View view) {
        View mText = findViewById(R.id.MilesText);
        View kmText = findViewById(R.id.KilometersText);

        if (view.getId() == R.id.KmToMButton) {
            mText.setEnabled(false);
            kmText.setEnabled(true);

        }
        if (view.getId() == R.id.MToKmButton) {
            kmText.setEnabled(false);
            mText.setEnabled(true);
        }
    }

    public void onClickedText(final View view) {
        Log.d("MainActivity", "Clicked");
    }

}

The layout

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"
    android:id="@+id/screen">

    TextView android:text="@string/hello_world" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="110dp" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/KilometersText"
        android:layout_above="@+id/button"
        android:layout_marginBottom="134dp"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:enabled="false"
        android:onClick="onClickedText"
       />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        android:ems="10"
        android:id="@+id/MilesText"
        android:layout_centerVertical="true"
        android:layout_alignLeft="@+id/KilometersText"
        android:layout_alignStart="@+id/KilometersText"
        android:enabled="false"
        android:onClick="onClickedText"
        />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="Km"
        android:id="@+id/Kilometers"
        android:layout_alignTop="@+id/KilometersText"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginLeft="43dp"
        android:layout_marginStart="43dp"
        />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="M"
        android:id="@+id/Miles"
        android:layout_alignTop="@+id/MilesText"
        android:layout_alignRight="@+id/Kilometers"
        android:layout_alignEnd="@+id/Kilometers" />

    <RadioGroup
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Kilometers to Miles"
            android:id="@+id/KmToMButton"
            android:layout_alignParentTop="true"
            android:layout_alignLeft="@+id/MToKmButton"
            android:layout_alignStart="@+id/MToKmButton"
            android:checked="false"
            android:onClick="onRadioButtonClicked"/>/>

        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Miles to Kilometers"
            android:id="@+id/MToKmButton"
            android:layout_below="@+id/KmToMButton"
            android:layout_alignLeft="@+id/Kilometers"
            android:layout_alignStart="@+id/Kilometers"
            android:checked="false"
            android:onClick="onRadioButtonClicked"/>/>
    </RadioGroup>

    <ProgressBar
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/progressBar"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginLeft="59dp"
        android:layout_marginStart="59dp" />

</RelativeLayout>

Answer 1

You are specifying the onClick event method through XML, and it looks like this does not work with support library AppCompatActivity.

You should just get the reference to the EditText and call setOnClickListener().

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    EditText kilometers = (EditText) findViewById(R.id.KilometersText);
    kilometers.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            onClickedText(v);
        }
    });

    // repeat this for the miles EditText

    // you'll need to add an id for the radio group for this to work:

    RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radio_group);
    radioGroup.setOnCheckedChangedListener(new RadioGroup.OnCheckedChangedListener() {

        // I leave the code inside here for you to do as an exercise
    });
}