AutoCompleteTextView CoordinatorLayout.Behavior that is aware of Snackbar and changes autocompletes popup when Snackbar is shown.

AutoCompleteTextViewBehaviour.java

package com.example.rzagorski.coordinatorawareautocompletetextviewapp;

import android.content.Context;
import android.support.annotation.Nullable;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.Snackbar;
import android.support.v7.widget.AppCompatAutoCompleteTextView;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AutoCompleteTextView;
import android.widget.ListPopupWindow;

import java.lang.reflect.Field;

/**
 * Created by Robert Z on 05.06.2017.
 */

public class AutoCompleteTextViewBehaviour extends CoordinatorLayout.Behavior<AutoCompleteTextView> {

    View popupList;

    public AutoCompleteTextViewBehaviour(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, AutoCompleteTextView child, View dependency) {
        return dependency instanceof Snackbar.SnackbarLayout;
    }

        @Override
        public boolean onDependentViewChanged(CoordinatorLayout parent, final AutoCompleteTextView child, View dependency) {
            if (popupList == null) {
                popupList = getPopupList(child);
                if (popupList == null) {
                    return super.onDependentViewChanged(parent, child, dependency);
                }
            }
            int dropdownBottom = child.getBottom() + child.getDropDownVerticalOffset() + popupList.getHeight();
            int snackBarTop = dependency.getTop();
            int difference = dropdownBottom - snackBarTop;
            if (difference > 0) {
                child.setDropDownHeight(popupList.getHeight() - difference);
                return true;
            } else {
                child.setDropDownHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
            }
            return super.onDependentViewChanged(parent, child, dependency);
        }

        @Nullable
        private View getPopupList(AutoCompleteTextView child) {
            try {
                Field popupField;
                Class clazz;
                if (child instanceof AppCompatAutoCompleteTextView) {
                    clazz = child.getClass().getSuperclass();
                } else {
                    clazz = child.getClass();
                }
                popupField = clazz.getDeclaredField("mPopup");
                popupField.setAccessible(true);
                ListPopupWindow popup = (ListPopupWindow) popupField.get(child);
                Field popupListViewField = popup.getClass().getDeclaredField("mDropDownList");
                popupListViewField.setAccessible(true);
                return (View) popupListViewField.get(popup);
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
            return null;
        }

}

view.xml

<AutoCompleteTextView
    android:id="@+id/actv"
    android:layout_marginTop="56dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="de"
    app:layout_behavior="com.example.rzagorski.coordinatorawareautocompletetextviewapp.AutoCompleteTextViewBehaviour"/>