Android Java using a switch / case to calculate different percentages

Question

I'm having a bit of a conundrum..

I have a variable called "results" which is the result of a previously calculated variable and then appended either +10%, +20%, 0%(the same as it is..) -10% and so on depending on which radio button the user selects, trouble is the data is only calculated when the user clicks the button. So far my button works fine:

public void onClick(View v) {
        switch (v.getId()) {

        case R.id.btnCalcCalories:
            double weight = Integer.parseInt(etWeight.getText().toString());
            double bodyfat = Integer.parseInt(etBodyfat.getText().toString());
            ;
            lbm = weight * (100 - bodyfat) / 100;
            bmr = 370 + (21.6 * lbm);
            maintCals = bmr * actLevel;

            maintCalories.setText("Calories need to maintain current bodyweight: " + String.valueOf(maintCals));
            lbmResult.setText("Your Lean Body Mass is " + String.valueOf(lbm)
                    + "Kg");
            bmrResult.setText("Your Base Metabolic rate is "
                    + String.valueOf(bmr) + " calories");
            calorieResult.setText("Your Daily calorie goal is " + String.valueOf(calResult) + " calories");

Although I need to obtain wether the users wishes to lose/gain/maintain weight using a radiogroup like this:

public void onCheckedChanged(RadioGroup group, int checkedId) {
        switch (checkedId) {
        case R.id.radLW:
            setGPercentage = 10 * maintCals/100;
            calResult = maintCals - setGPercentage;
            break;
        case R.id.radLWF:
            setGPercentage = 20 * maintCals/100;
            calResult = maintCals - setGPercentage;
            break;
        case R.id.radM:
            setGPercentage = 0;
            break;
        case R.id.radGW:
            setGPercentage = 10 * maintCals/100;
            calResult = maintCals + setGPercentage;
            break;
        case R.id.radGWF:
            setGPercentage = 20 * maintCals/100;
            calResult = maintCals + setGPercentage;
            break;
        }

To clarify, I need 'calResult' to be calculated depending on what the user has selected, obviously this might be a problem if the variables are only calculated during the onClick method :/

Answer 1

final radiogroup:

public void onCheckedChanged(RadioGroup group, int checkedId) {
        switch (checkedId) {
        case R.id.radLW:
            setGPercentage = 10 * maintCals/100;
            finalGPercentage = maintCals - setGPercentage;
            break;
        case R.id.radLWF:
            setGPercentage = 20 * maintCals/100;
            finalGPercentage = maintCals - setGPercentage;
            break;
        case R.id.radM:
            setGPercentage = 0;
            break;
        case R.id.radGW:
            setGPercentage = 10 * maintCals/100;
            finalGPercentage = maintCals + setGPercentage;
            break;
        case R.id.radGWF:
            setGPercentage = 20 * maintCals/100;
            finalGPercentage = maintCals + setGPercentage;
            break;
        }

and onClick:

case R.id.btnCalcCalories:
            double weight = Integer.parseInt(etWeight.getText().toString());
            double bodyfat = Integer.parseInt(etBodyfat.getText().toString());
            ;
            lbm = weight * (100 - bodyfat) / 100;
            bmr = 370 + (21.6 * lbm);
            maintCals = bmr * actLevel;

            maintCalories.setText("Calories need to maintain current bodyweight: " + String.valueOf(maintCals));

            lbmResult.setText("Your Lean Body Mass is " + String.valueOf(lbm)
                    + "Kg");
            bmrResult.setText("Your Base Metabolic rate is "
                    + String.valueOf(bmr) + " calories");
            calorieResult.setText("Your Daily calorie goal is " + String.valueOf(finalGPercentage) + " calories");
            break;

I just needed another variable to hold the calculation :D

Answer 2

Your question is not entirely clear, but I think what you need to do is set up some kind of initialization for your activity, so your calResult has a calculated (default) value before the user makes a selection.

Have a look at the documentation for the Activity class to better understand the Activty lifecycle, and initialization-related methods such as onCreate.