Question

How to make a Toast to pop up when the user tries to insert text longer than maximum limit?

<EditText
    android:maxLength="28"
    ...
 />

I tried to use TextWatcher but it doesn’t work properly:

public class MyActivity extends Activity implements TextWatcher
{

    // ...

    @Override
    public void afterTextChanged(Editable arg0){}

    @Override
    public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3){}

    @Override
    public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3)
    {
        if(etUsername.isFocused() && etUsername.getText().length() == 28)
            Toast.makeText(MyActivity.this, "The username must be at most 28 characters!" , Toast.LENGTH_SHORT).show();
        else if(etPassword.isFocused() && etPassword.getText().length() == 10)
            Toast.makeText(MyActivity.this, "The password must be at most 10 characters!" , Toast.LENGTH_SHORT).show();
    }
}

EDIT:

I also tried to put the code inside afterTextChanged and beforeTextChanged but it doesn’t solve the problem.

EDIT2:

What I want is that the Toast only can be popped up when there are 28 characters in the EditText and the user is trying to add a 29th character. The Toast in my code above will pop up only if there are 27 characters in the TextEdit and the user inserts a 28th character.

Answer 1

The only way to achieve desired functionality is to change android:maxLength to desiredMaxLength + 1 and to check for the length in afterTextChanged(). You will have to manually delete the last character when length == desiredMaxLength + 1 (i.e. manipulate the s parameter in afterTextChanged(Editable s)). Please be careful not to put yourself in infinite loop because after changing s afterTextChanged() will be called again.