TextWatcher - cursor goes back to the start of EditText

Question

I've got the following TextWatcher definition:

   _textWatcher = new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {

        }

        @Override
        public void afterTextChanged(final Editable s) {
            if (!s.toString().equals(_prev)) {
                afterTextHandler.removeCallbacks(work);
                work = new Runnable() {
                    @Override
                    public void run() {                            
                        if (!s.toString().equals(_prevQuoteAmount)) {
                            _prev = s.toString();
                            doSomething();
                        }
                        _et.append("");                            
                    }
                };
                afterTextHandler.postDelayed(work, 1000);
            }
            _et.append("");                
        }
    };

Everything works as expected (sometimes doSomething() executes and sometimes not, so its execution isn't relevant to the question), but after the user types some text in the EditText component that has this watcher attached to it, the cursor of the text goes back to the beginning of the EditText.

I've got the following log that is shown after onTextChanged() execution (or its handler run() execution):

12-08 13:10:55.777 1855-1855/com.android.inputmethod.latin I/LatinIME: Starting input. Cursor position = 4,4

Why is the cursor of EditText placed in the beginning of the EditText right after onTextChanged() execution?

Edit 1: _et.append("") is a hack that should bring the cursor to the last place of the text. It doesn't work here (though it works on other occasions).

Edit 2: Requested knowledge about doSomething:

    if (isReady()) {
        Sender objSender = new Sender();
        objSender.setParam1(_tvParam1.getText().toString());
        objSender.setParam2(_tvParam2.getText().toString());
        objSender.setParam3(_et.getText().toString());
        Service.startActionSend(getActivity(), quote);
    }

isReady() - checks conditions (_tvParam1, _tvParam2, _et) before making a network request. Service.startActionSend() - making async network request (using IntentService).

Edit 3: The issue happens only when entering the handler's run() method.

score 3 · Accepted Answer · answered Sep 02 '20 at 17:21

you can use this function to get the cursor to be used in setSelection of the edit Text also

private fun getNewCursorPosition(digitCountToRightOfCursor : Int, numberString : String) : Int{
    var position = 0
    var c = digitCountToRightOfCursor
    for (i in numberString.reversed()) {
        if (c == 0)
            break

        if (i.isDigit())
            c --
        position ++


    }
    return numberString.length - position
}

for the whole sample use

editText.addTextChangedListener(object : TextWatcher {
        override fun afterTextChanged(p0: Editable?) {
        }

        override fun beforeTextChanged(p0: CharSequence?, start: Int, count: Int, after: Int) {
            beforeText = p0.toString()
        }

        override fun onTextChanged(p0: CharSequence?, start: Int, before: Int, count: Int) {
            
            if (p0 == null)
                return
            // 1. get cursor position : p0 = start + before
            val initialCursorPosition = start + before
            //2. get digit count after cursor position : c0
            val numOfDigitsToRightOfCursor = getNumberOfDigits(beforeText.substring(initialCursorPosition,
                    beforeText.length))
            val newAmount = formatAmount(p0.toString())
            editText.removeTextChangedListener(this)
            editText.setText(newAmount)
            //set new cursor position
            editText.setSelection(getNewCursorPosition(numOfDigitsToRightOfCursor, newAmount))
            editText.addTextChangedListener(this)



        }

    })

also you may need this function

 private fun getNumberOfDigits(@NonNull text : String) : Int{
    var count = 0
    for (i in text)
        if (i.isDigit())
            count++
    return count
}

Reference :FULL Code Description

score 2 · Answer 2 · answered Dec 08 '16 at 13:23

2

I am not sure what you are doing inside the doSomething(), but if that's somehow changing the position of the cursor, you can use the following (hack) to bring the cursor to the end to the input text.

mEdittext.setSelection(mEdittext.length());

answered Dec 08 '16 at 13:23

Swayam

16,294
14
64
102

I've edited some information about a hack that I'm already using in the question's code sample. I've tried yours too and it fails to work. Also, sometimes doSomething() is executed and sometimes not, which means it doesn't affect the outcome. – lionheart Dec 08 '16 at 13:29
Can I see your doSomething() function? I am curious what's going on inside. – Swayam Dec 08 '16 at 13:30
I've edited the question and put some more info about doSomething(). Thanks. – lionheart Dec 08 '16 at 13:48

score 0 · Answer 3 · answered Nov 12 '18 at 08:16

Try a Boolean variable to check the status

desc.addTextChangedListener(new TextWatcher() {
        boolean changed = false;
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void afterTextChanged(Editable editable) {
            if (desc.getText().toString().isEmpty()) {

                changed = false;
            } else {
                if(!changed) {
                    doSomething();
                }
                changed = true;
            }
        }
    });

score 0 · Answer 4 · answered Nov 06 '20 at 06:55

 <EditText
    android:id="@+id/user_input_first_name"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:maxLines="1"
    android:textAllCaps="true"
    android:textColor="@color/black"
    android:textSize="20sp"
    android:textStyle="bold" />

For me it resolved when I removed textAllCaps,focusable and focusableInTouchMode.

TextWatcher - cursor goes back to the start of EditText

4 Answers4