android viewmodel with/without baseObservable

Question

I was trying to view-model in android, so for MainViewModel.java I wrote this :

public class MainViewModel extends ViewModel {

    private String textView;
    private String editText;

    //@Bindable
    public String getTextView(){
        return textView;
    }

    private void setTextView(String value){
        textView=value;
    }

    //@Bindable
    public TextWatcher getEditTextWatcher() {
        return new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                setTextView(s.toString());
            }
            ...
        };
    }

}

And in the ActivityMain.xml I wrote this :

        <TextView
            android:text="View-Model / Data-Binding"
            android:layout_width="match_parent"
            android:layout_height="40dp"/>

        <TextView
            android:id="@+id/main_text_view"
            android:text="@{mainvm.textView}"
            android:layout_width="match_parent"
            android:layout_height="40dp"/>

        <EditText
            android:id="@+id/main_edit_text"
            app:textChangeListener="@{mainvm.editTextWatcher}"
            android:layout_width="match_parent"
            android:layout_height="40dp"/>

I'm getting 2 errors:

Cannot find a setter for <android.widget.EditText app:textChangeListener> that accepts parameter type 'android.text.TextWatcher'

If a binding adapter provides the setter, check that the adapter is annotated correctly and that the parameter type matches.

And,

error: cannot find symbol class ActivityMainBindingImpl

Some article uses @Binable annotation extending BaseObservable, which is not a ViewModel thing.

So my question how can I solve this ?

Answer 1

I was making thing complicated for no reason. Here is my code :

public class MyViewModel extends ViewModel{
     private Observable<String> data=new Observable<>("");//initializing with empty string, so that it doesn't crash
     
     public String getData(){
         return data.get();//if I return the observable itself that will become mutable, outside the class right
     }
     public void setData(String data){
          data.setValue(data);//if I accept Observable as parameter that will change reference of data, that's why passing string
     }
}

In xml:

        <TextView
            android:id="@+id/main_text_view"
            android:text="@{myvm.data}"
            ...
        />

        <EditText
            android:id="@+id/main_edit_text"
            android:text=@{myvm.data}
            ....
        />

And bind this to Activity or Fragment as usual.