When the soft keyboard appears, it makes my EditText field lose focus

You need to change in your AndroidManifest.xml

Add android:windowSoftInputMode=”adjustPan” in the activity holding the listview.
This will solve your problem.

    <activity android:name=".MyEditTextInListView"
              android:label="@string/app_name"
              android:windowSoftInputMode="adjustPan">

Regards