Numeric only editText

Based on what we have done yesterday (here ), it's very easy to limit our EditText to whatever we want !

And a common application would be to implement a numeric only editText :

Here's a first int version :

editEntryView.addTextChangedListener
(
new TextWatcher()
{
String CurrentWord;
private boolean IsValid( CharSequence s )
{
for ( int i = 0; i < s.length(); i ++ )
{
if ( !Character.isDigit( s.charAt(i)))
return false;
}
return true;
}
public void afterTextChanged(Editable s)
{
}
public void beforeTextChanged(CharSequence s, int start, int count, int after)
{
CurrentWord = s.toString();
}
public void onTextChanged(CharSequence s, int start, int before, int count)
{
if( !IsValid(s) )
{
editEntryView.setText(CurrentWord);
editEntryView.setSelection( start );
}
}
}
);

That simple !

And if you want any decimal numeric, just write another IsValid method :

private boolean IsValid( CharSequence s )
{
// special autorization for empty field
if (s.length() == 0)
return true;
// special autorization for '.', in order to enter .5
if (s.length() == 1 && s.charAt(0) == '.')
return true;
try
{
Double.parseDouble( s.toString() );
return true;
}
catch( Exception e)
{
return false;
}
}

We just have to be careful for special cases like the empty field, or just a dot ( this is the needed transition to enter something like .5 ).

And we must take into account those special cases when we will validate the entry.