Disabling save button on AlertDialog unless input field is not blank

Question

We need this in order to prohibit the user from inputting null values as file names. The save button should be disabled unless userInput is not null.

Here is the current code:

public void openDialog() {
    @SuppressLint("InflateParams") View view = (LayoutInflater.from(AudioRecorder.this)).inflate(R.layout.audio_name_input, null);

    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(AudioRecorder.this);
    alertBuilder.setView(view);
    final EditText userInput = view.findViewById(R.id.userInput);

    alertBuilder.setCancelable(true);
    alertBuilder.setPositiveButton("Save", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            inputName = String.valueOf(userInput.getText());
            Toast.makeText(AudioRecorder.this, "Next audio clip will be named... " + inputName, Toast.LENGTH_SHORT).show();
            filePathMaking();
        }
    });
    alertBuilder.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialogInterface, int i) {
        }
    });

    Dialog dialog = alertBuilder.create();
    dialog.show();
}

Jithin P · Answer 1 · 2019-07-13T09:10:02.307

You need to add a listener to the input element edit text

   AlertDialog.Builder builder = new AlertDialog.Builder(AudioRecorder.this);
    builder.setIcon(android.R.drawable.ic_dialog_info);
    builder.setTitle("Record Sound");
    builder.setMessage("Enter Username");
    builder.setPositiveButton("PositiveButton",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface arg0, int arg1) {
                    // DO TASK
                }
            });
    builder.setNegativeButton("NegativeButton",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface arg0, int arg1) {
                    // DO TASK
                }
            });

    // Set `EditText` to `dialog`. You can add `EditText` from `xml` too.
    final EditText userInput = new EditText(AudioRecorder.this);

    LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.MATCH_PARENT,
            LinearLayout.LayoutParams.MATCH_PARENT
    );
    input.setLayoutParams(lp);


    builder.setView(input);

    final AlertDialog dialog = builder.create();
    dialog.show();

    // Initially disable the button
    ((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

    // OR you can use here setOnShowListener to disable button at first time.

    // Now set the textchange listener for edittext
    input.addTextChangedListener(new TextWatcher() {

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

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {

            // Check if edittext is empty
            if (TextUtils.isEmpty(s)) {
                // Disable ok button
                ((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(false);

            } else {
                // Something into edit text. Enable the button.
                ((AlertDialog) dialog).getButton(AlertDialog.BUTTON_POSITIVE).setEnabled(true);
            }

        }
    });

On the text changed method check if the length is greater than zero and assign the button property there

Tamir Abutbul · Accepted Answer · 2019-07-13T09:09:11.453

You can do something like this:

if(input != null){
    button.setEnabled(true); //you can  click your button now
}else{
    button.setEnabled(false); //you can not click your button
}

Edit according to your comment:

Here is an example for generic custom dialog:

This will be your dialog class (or something similar, it's only an example):

public class FullSizeImageDialog extends Dialog {
private ImageView imageView;
private ProgressBar fullImageProgreesBar;
private Context dialogContext;

public FullSizeImageDialog(@NonNull Context context) {
    super(context);
    setContentView(R.layout.full_size_image_dialog);
    dialogContext = context;
    imageView = findViewById(R.id.full_size_image);
    fullImageProgreesBar = findViewById(R.id.fullImageProgreesBar);
    }
}

And this is your layout for the dialog (R.id.full_size_image in my case):

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
   android:background="#66F9B639">


 <!--Place your views here-->


 </android.support.constraint.ConstraintLayout>

And when you want to show your dialog it's super easy:

FullSizeImageDialog dialog = new FullSizeImageDialog ();
dialog.show();

And now, you can put your logic inside of your custom dialog class.

How do you disable .setPositiveButton("Save")? it is not an ordinary button. — Greg, Jul 13 '19 at 09:05
I would make a custom dialog class for handling everything there, I will edit my answer — Tamir Abutbul, Jul 13 '19 at 09:05
I have edited my answer, notice that for this simple task you can use `TextChangedListener` like in the above answers but I wanted to show you a cleaner solution for more complicated tasks. — Tamir Abutbul, Jul 13 '19 at 09:10

score 1 · Answer 3 · answered Jul 13 '19 at 09:09

1

Add a TextChangedListener to the edit text. Make the button enabled or disabled by the user input.

You can access the positive button as dialog.getButton(AlertDialog.BUTTON1).setEnabled(false); and

answered Jul 13 '19 at 09:09

Bertram Gilfoyle

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Disabling save button on AlertDialog unless input field is not blank

3 Answers3

Edit according to your comment: