Question

Hi All I have followed the following example http://www.google.com/codesearch#search/&q=NumberFormattingTextWatcher&exact_package=android&type=cs

I have CurrencyTextWatcher as a seperate class. I need this as I will be applying to several pages.
I can’t figure out why, but if I use setContentView(text) it will work as only 1 big text box, then I can’t see the rest of my xml .
If I use setContentView(R.layout.main); my xml works properly except for the TextWatcher wont fire for my txta EditText box

Java

public class CalcTestActivity extends Activity {
    private EditText txta;
    private TextView txtb;
    private TextView txtc;
    private EditText text;

    private double a = 0;
    private double b = 0;
    private double c = 0;

    private Button buttonCalc;

    /** Called when the activity is first created. */
    @Override


public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);

            initControls();
            text = new EditText(this);
            text.addTextChangedListener(new CurrencyTextWatcher());
    //setContentView(text);
        }   

        private String FormatValue(double value)
        {
            NumberFormat nf = NumberFormat.getInstance();
            return "$ "+ nf.format(value);
        }

        private void initControls() {

            txta = (EditText)findViewById(R.id.txta);
            txtb = (TextView)findViewById(R.id.txtb);
            txtc = (TextView)findViewById(R.id.txtc);

            buttonCalc = (Button)findViewById(R.id.buttonCalc);
            buttonCalc.setOnClickListener(new Button.OnClickListener() {

            public void onClick(View v) {calculate(); }

            private void calculate() {

            a=Double.parseDouble(txta.getText().toString());

            b=Math.round(a*.88);                
            txtb.setText(FormatValue(b));

            c=Math.round((a*.87)-(b*.28));
            txtc.setText(FormatValue(c));
            }

        }); 
        }
    }

CurrencyTextWatcher Class

public class CurrencyTextWatcher implements TextWatcher {

boolean mEditing;

public CurrencyTextWatcher() {
    mEditing = false;
}

public void afterTextChanged(Editable s) {
    // TODO Auto-generated method stub
    if(!mEditing) {
        mEditing = true;

        String digits = s.toString().replaceAll("\\D", "");
        NumberFormat nf = NumberFormat.getCurrencyInstance();
        try{
            String formatted = nf.format(Double.parseDouble(digits)/100);
            s.replace(0, s.length(), formatted);
        } catch (NumberFormatException nfe) {
            s.clear();
        }

        mEditing = false;
    } 
}
public void beforeTextChanged(CharSequence s, int start, int count,
        int after) {
    // TODO Auto-generated method stub

}

public void onTextChanged(CharSequence s, int start, int before, int count) {
    // TODO Auto-generated method stub

}

}

XML

<TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Number1"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <EditText
        android:id="@+id/txta"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" android:numeric="integer"/>

   <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Number2"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/txtb"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Your Answer is"
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/txtc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" android:hint="0" />

    <Button
        android:id="@+id/buttonCalc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Calculate" />

</LinearLayout>

Answer 1

I took your code. I observed that the code you have shared here is getting all views from xml.
In this case you are calling

 text.addTextChangedListener(new CurrencyTextWatcher());

in your onCreate method, wherein text is done using java. You wont get a call back for your onTextChanged, beforeTextChanged or afterTextChanged because all your views are taken from xml. So please after your

initControls(); 

in onCreate() add below line

 txta.addTextChangedListener(new CurrencyTextWatcher());

and comment

text.addTextChangedListener(new CurrencyTextWatcher());

that line is not needed. I have verified its working fine.

if works vote and accept the answer