To overlap only, use this approach:
PopupMenu popupMenu = new PopupMenu(getContext(), this, Gravity.NO_GRAVITY, R.attr.actionOverflowMenuStyle, 0);
To get a PopupMenu with a bright background and a detailed control over the offsets use this approach:
styles.xml
<style name="PopupMenuOverlapAnchor" parent="@style/Theme.AppCompat.Light">
<item name="android:overlapAnchor">true</item>
<item name="android:dropDownVerticalOffset">0dp</item>
<item name="android:dropDownHorizontalOffset">0dp</item>
</style>
Code:
ContextThemeWrapper contextThemeWrapper = new ContextThemeWrapper(getContext(), R.style.PopupMenuOverlapAnchor);
PopupMenu popupMenu = new PopupMenu(contextThemeWrapper, this);