Alternative for TextWatcher (Dynamic change text)

Question

I have to implement textedit where last three chars are bold. I have 3 specific situactions:

1. when user scan barcode
2. when user insert value with keyboard
3. when device insert value from db

so I implement it with html that I put into textedit, to implement this 3 situations I using function doOnTextChanged, but the device is specific scanner and when I use any method from TextWatcher the one important functionality from scanner device stop working.

The functionality is after scan barcode system android return Keycode_ENTER (onKeyListener).

I need to find something like TextWatcher to get dynamically what user types in textedit.

I tried: 1)Don't setText from WatchText object. 2)WatchText update livedata variable and execute settext in observer 3) I cant manually execute keycode_Enter! I have to know if value is scanned

Answer 1

You could be to use the addTextChangedListener method instead of the TextWatcher interface to listen for changes in the text editor.

Here's an example code snippet to get you started:

import android.text.Editable;
import android.text.Html;
import android.text.TextWatcher;
import android.view.KeyEvent;
import android.widget.EditText;
import androidx.core.text.HtmlCompat;
import androidx.core.widget.TextViewCompat;
import org.jetbrains.annotations.NotNull;

public class CustomTextWatcher extends SimpleTextWatcher {
    private EditText editText;
    private String lastThreeChars = "";

    public CustomTextWatcher(EditText editText) {
        this.editText = editText;
    }

    @Override
    public void afterTextChanged(Editable s) {
        // get the current text entered by the user
        String text = s.toString();

        // check if the text is scanned or entered manually
        boolean isScanned = /* your logic to detect if the value is scanned */

        // update the last three characters with bold formatting
        if (text.length() >= 3) {
            lastThreeChars = text.substring(text.length() - 3);
            String formattedText = text.substring(0, text.length() - 3) +
                    "<b>" + lastThreeChars + "</b>";
            editText.setText(Html.fromHtml(formattedText));
        }

        // if the value is scanned, manually execute the ENTER key event
        if (isScanned) {
            KeyEvent event = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_ENTER);
            editText.onKeyDown(KeyEvent.KEYCODE_ENTER, event);
        }
    }
}

Then, to use this custom TextWatcher class in your text editor, you can register it with the addTextChangedListener method like this:

EditText editText = findViewById(R.id.editText);
CustomTextWatcher customTextWatcher = new CustomTextWatcher(editText);
editText.addTextChangedListener(customTextWatcher);