How to use java classes within one activity?

Question

How can you use a java class within one activity, by that I mean is having different components of that activity spread out in a bunch of java classes. I\'m a little new to andr

Answer 1

I think that you should rearrange the code to have the onClickListener inside Something constructor:

Something.java

import android.view.View;
import android.widget.EditText;
import android.widget.Button;
import android.app.Activity;

public class Something {

    private Activity activity;
    private Button add, subtract, multiply, devide;
    private EditText editA, editB, editC;
    private double doubleA, doubleB, doubleC;

    public Something(Activity a) {

        activity = a;

        editA = (EditText) activity.findViewById(R.id.editText);
        editB = (EditText) activity.findViewById(R.id.editText2);
        editC = (EditText) activity.findViewById(R.id.editText3);

        add = (Button) activity.findViewById(R.id.add);
        subtract = (Button) activity.findViewById(R.id.subtract);
        multiply = (Button) activity.findViewById(R.id.multiply);
        devide = (Button) activity.findViewById(R.id.devide);

        add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                click(1);

            }
        });

        subtract.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                click(2);

            }
        });

        multiply.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                click(3);
            }
        });

        devide.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                click(4);
            }
        });
    }


    public void click(int calculate) {

        // assume number entered - no error
        doubleA = Double.parseDouble(editA.getText().toString());
        doubleB = Double.parseDouble(editB.getText().toString());

        switch (calculate) {

            case 1:
                doubleC = doubleA + doubleB;
                String s = "" + doubleC;
                editC.setText(s);
                break;

            case 2:
                doubleC = doubleA - doubleB;
                String s = "" + doubleC;
                editC.setText(s);
                break;

            case 3:
                doubleC = doubleA * doubleB;
                String s = "" + doubleC;
                editC.setText(s);
                break;

            case 4:
                doubleC = doubleA / doubleB;
                String s = "" + doubleC;
                editC.setText(s);
                break;

            default:
                break;

        }

    }

}

I think the problem was putting 'click()' method inside the main constructor runs through the code once only. I hope this helps!