Textwacher loops after calling append

Question

I have a problem with TextWatcher. After i am done editing, i want to append " kg" string. But after i try to edit editView, it loops and my app crashes. Can somebody help me? Thanks

weight = findViewById(R.id.editText);
        weight.addTextChangedListener(new TextWatcher() {
            @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) {
                editable.append(" kg");
            }
        });

Look here: https://stackoverflow.com/a/14195571/9495357 – Oktawian Dec 18 '18 at 21:41 — Oktawian, Dec 18 '18 at 21:41

score 2 · Accepted Answer · answered Dec 18 '18 at 21:27

2

You can manage this with an if statement but I think that it can down in better way

    weight.addTextChangedListener(new TextWatcher() {

        @Override
        public void afterTextChanged(Editable editable) {

            if(!editable.getText().contains("kg"))
               editable.append(" kg");
        }
    });

answered Dec 18 '18 at 21:27

Mousa Jafari

677
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1

With few changes your idea works good. I couldnt use editable, because it doesnt have getText method. I just changed editable with weight and it works. thank you – Christián Szeman Dec 18 '18 at 21:53

Quinn · Answer 2 · 2018-12-18T21:30:32.477

0

Its looping because setting the text calls afterTextChanged. What you could do is remove the text watcher, change the text, then re-add the text watcher.

edited Dec 18 '18 at 21:30

answered Dec 18 '18 at 21:21

Quinn

7,072
7
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Tried your idea, it no longer loops but every time i press any key it adds " kg". – Christián Szeman Dec 18 '18 at 21:44
The messy solution i can think of is to set the editable to `editable.text.replaceFirst(" kg", "")` and then append " kg" to the end of that – Quinn Dec 18 '18 at 21:52

Oliver Metz · Answer 3 · 2018-12-18T21:46:28.070

0

Follow these steps:

Remove the TextWatcher temporarily
Do your changes to your content

Add the TextWatcher again

weight.addTextChangedListener(new TextWatcher() {
     @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 (editable.toString().contains("kg")) return
         weight.removeTextChangedListener(this);
         editable.append(" kg");
         weight.addTextChangedListener(this);
     }
 });

edited Dec 18 '18 at 21:46

answered Dec 18 '18 at 21:35

Oliver Metz

2,712
2
20
32

Tried this already. Every time i press a key ( letter, number, backspace or any other) it adds " kg". – Christián Szeman Dec 18 '18 at 21:43
this edit would likely cause it to add kg the first time you enter a character and then never add kg again – Quinn Dec 18 '18 at 21:47

Textwacher loops after calling append

3 Answers3