Masked EditText with comma as decimal separator

Question

I'm trying to display an EditText with decimal values, however I'm having trouble with phones set to English language. I need this EditText to use comma as the decimal separator, but Android keyboard does not have a feature to localize the decimal separator. So I'm using the following code and it is not working.

import java.text.DecimalFormat;
import java.text.ParseException;

import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;

public class NumberTextWatcher implements TextWatcher {

    private DecimalFormat df;
    private DecimalFormat dfnd;
    private boolean hasFractionalPart;

    private EditText et;

    public NumberTextWatcher(EditText et)
    {
    Locale locale  = new Locale("pt", "BR");
    df = (DecimalFormat) NumberFormat.getNumberInstance(locale);
    DecimalFormatSymbols.getInstance().setDecimalSeparator(',');
    DecimalFormatSymbols.getInstance().setGroupingSeparator('.');

    // THE ERROR HAPPENS IN THE NEXT LINE
    df.applyPattern("#.###,##");

    df.setDecimalSeparatorAlwaysShown(true);
    dfnd = (DecimalFormat) NumberFormat.getNumberInstance(locale);
    dfnd.applyPattern("#.###");
    this.et = et;
    hasFractionalPart = false;
    }

    @SuppressWarnings("unused")
    private static final String TAG = "NumberTextWatcher";

    @Override
    public void afterTextChanged(Editable s)
    {
    et.removeTextChangedListener(this);

    try {
        int inilen, endlen;
        inilen = et.getText().length();

        String v = s.toString().replace(String.valueOf(df.getDecimalFormatSymbols().getGroupingSeparator()), "");
        Number n = df.parse(v);
        int cp = et.getSelectionStart();
        if (hasFractionalPart) {
        et.setText(df.format(n));
        } else {
        et.setText(dfnd.format(n));
        }
        endlen = et.getText().length();
        int sel = (cp + (endlen - inilen));
        if (sel > 0 && sel <= et.getText().length()) {
        et.setSelection(sel);
        } else {
        // place cursor at the end?
        et.setSelection(et.getText().length() - 1);
        }
    } catch (NumberFormatException nfe) {
        // do nothing?
    } catch (ParseException e) {
        // do nothing?
    }

    et.addTextChangedListener(this);
    }

    @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 (s.toString().contains(String.valueOf(df.getDecimalFormatSymbols().getDecimalSeparator())))
        {
        hasFractionalPart = true;
        } else {
        hasFractionalPart = false;
    }
    }

}

Here is the exception:

10-26 16:59:23.100  16231-16231/com.br.myapp.debug E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.br.myapp.debug, PID: 16231
    java.lang.IllegalArgumentException: syntax error: DecimalFormat::applyPattern failed: U_UNEXPECTED_TOKEN: #.###,##
            at libcore.icu.NativeDecimalFormat.applyPattern(NativeDecimalFormat.java:490)
            at libcore.icu.NativeDecimalFormat.applyPattern(NativeDecimalFormat.java:278)
            at java.text.DecimalFormat.applyPattern(DecimalFormat.java:589)
            at com.br.myapp.util.NumberTextWatcher.(NumberTextWatcher.java:27)
            at com.br.myapp.fragments.PriceDialogFragment.onCreateDialog(PriceDialogFragment.java:73)
            at android.support.v4.app.DialogFragment.getLayoutInflater(DialogFragment.java:307)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:942)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1121)
            at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
            at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1484)
            at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:450)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:146)
            at android.app.ActivityThread.main(ActivityThread.java:5679)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
            at dalvik.system.NativeStart.main(Native Method)

Answer 1

Problem solved using the code below. It's not a generic code, but may help other people.

import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;


public class NumberTextWatcher implements TextWatcher {

    private EditText mEditText;

    public NumberTextWatcher(EditText editText) {
        mEditText = editText;
    }

    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {

    }

    @Override
    public void afterTextChanged(Editable editable) {
        mEditText.removeTextChangedListener(this);

        try {
            int inilen, endlen;
            inilen = mEditText.getText().length();

            String v = editable.toString().replace(".", ",");

            // Se começar com vírgula, acrescento o zero automaticamente
            if (inilen == 1 && v.equals(",")) {
                v = "0,";
            }

            // Se já tiver vírgula, não deixo inserir novamente
            if (v.indexOf(",") != v.lastIndexOf(",")) {
                if (v.lastIndexOf(",") == v.length() - 1) {
                    v = v.substring(0, v.length() - 1);
                }
            }

            // Se já tiver vírgula, não deixo ficar com 3 dígitos na parte decimal
            int separatorPosition = v.indexOf(",");
            String decimalPart = v.substring(separatorPosition + 1);
            if (decimalPart.length() > 2) {
                v = v.substring(0, v.length() - 1);
            }

            int cp = mEditText.getSelectionStart();
            mEditText.setText(v);
            endlen = mEditText.getText().length();

            int sel = (cp + (endlen - inilen));
            if (sel > 0 && sel <= mEditText.getText().length()) {
                mEditText.setSelection(sel);
            } else {
                if (mEditText.getText().length() > 0) {
                    // place cursor at the end?
                    mEditText.setSelection(mEditText.getText().length() - 1);
                }
            }
        } catch (NumberFormatException nfe) {
            // do nothing?
        }

        mEditText.addTextChangedListener(this);
    }
}