Detecting backspace on an empty EditText

I'm trying to detect a soft keyboard backspace in an empty EditText view. I've searched Stack Overflow and also Google and ~20 similar questions, but
none have a solution for detecting a backspace in an empty EditText.

EditText

EditText

All of the answers evolve around this blog article https://code.i-harness.com/en/q/4a914a
which specifically notes in the end that this does not detect backspace on an empty EditText view.

EditText

Help is much appreciated.

3 Answers
3

Most reliable solution to detect any event or text change of an EditText is using TextWatcher but if EditText is already empty, you can not detect backspace/delete key event on all devices.

Please keep it in mind that it is not possible and hopefully you or any other will not waste your time.

You can detect if edittext is empty or not with this code:

EditText usernameEditText = (EditText) findViewById(R.id.editUsername);
sUsername = usernameEditText.getText().toString();
if (sUsername.matches(""))
Toast.makeText(this, "You did not enter a username", Toast.LENGTH_SHORT).show();
return;


EditText

There are a couple ways you could detect a backspace click on an EditText.

EditText

This way doesn't work on all devices, but from this post you can do the following, which sets an OnKeyListener for the EditText:

OnKeyListener

EditText

editText.setOnKeyListener(new OnKeyListener()
@Override
public boolean onKey(View v, int keyCode, KeyEvent event)
// You can identify which key was pressed by checking the keyCode value with KeyEvent.KEYCODE_
if (keyCode == KeyEvent.KEYCODE_DEL)
// Do something here

return false;

);


Or you can try the following method, which detects if a backspace has been clicked:

@Override
public boolean onKeyUp(int keyCode, KeyEvent event)
switch (keyCode)
case KeyEvent.KEYCODE_DEL:
// Do something here
return true;
default:
return super.onKeyUp(keyCode, event);




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