Android Multi-line EditText which prevents newline characters from being added

README.md

Using this code will allow you to set up a multi-line EditText where pressing the Return key on the virtual keyboard will remove focus from the EditText, thereby preventing the user from entering a newline character.

For mContent we set the raw input type as TYPE_CLASS_TEXT, IME Options as IME_ACTION_DONE to set up the Return key on the virtual keyboard as a DONE action. We also label the return key using setImeActionLabel.

The OnEditorActionListener lets us listen for actions on the keyboard. The giant nested if-statement is mostly empty because we only really need to check for a null event and IME_ACTION_DONE, since we set it earlier in the IME Options. I left the statements in to show you how it would look if you wanted to handle things differently.

NOTE: This has not been tested for hardware keyboards, but if you have tested it I would love to know if you found that it works.

Code.java

mContent = (EditText) v.findViewById(R.id.dialog_item_content_EditText);
mContent.setText(mContentInit);
mContent.setRawInputType(InputType.TYPE_CLASS_TEXT);
mContent.setImeActionLabel(getResources().getString(R.string.done), EditorInfo.IME_ACTION_DONE);
mContent.setImeOptions(EditorInfo.IME_ACTION_DONE);

mContent.setOnEditorActionListener(new TextView.OnEditorActionListener() {
    @Override
    public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
        if (event == null) {
            if (actionId == EditorInfo.IME_ACTION_DONE) {
                // Capture soft enters in a singleLine EditText that is the last EditText
                // This one is useful for the new list case, when there are no existing ListItems
                mContent.clearFocus();
                InputMethodManager inputMethodManager = (InputMethodManager) getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
                inputMethodManager.hideSoftInputFromWindow(v.getWindowToken(), InputMethodManager.RESULT_UNCHANGED_SHOWN);
            } else if (actionId == EditorInfo.IME_ACTION_NEXT) {
                // Capture soft enters in other singleLine EditTexts
            } else if (actionId == EditorInfo.IME_ACTION_GO) {
            } else {
                // Let the system handle all other null KeyEvents
                return false;
            }
        } else if (actionId == EditorInfo.IME_NULL) {
            // Capture most soft enters in multi-line EditTexts and all hard enters;
            // They supply a zero actionId and a valid keyEvent rather than
            // a non-zero actionId and a null event like the previous cases.
            if (event.getAction() == KeyEvent.ACTION_DOWN) {
                // We capture the event when the key is first pressed.
            } else {
                // We consume the event when the key is released.
                return true;
            }
        } else {
            // We let the system handle it when the listener is triggered by something that
            // wasn't an enter.
            return false;
        }
        return true;
    }
});

EditText.xml

<EditText
    android:id="@+id/dialog_item_content_EditText"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:maxLines="3"/>

Hey, Thank you very much for this. Its exactly what i needed and it solved my problem. 👍

Saved my day 👍 thanks

thank you!

The | in the textview is not changing position accordingly with your solution.

Thank you very much !