BottomSheetDialog background blinking

Question

BottomSheetDialog\'s background is blinking when switching between apps. What am I doing wrong ?

MainActivity.java

public class MainActi         


        

Answer 1

According to documentation the setPeekHeight method is responsible for the pop up behavior. Using the

bottomSheet.setState(STATE_HIDDEN) should do the trick.

Answer 2

Use Coordinate layout instead of constraint layout, and define bottomsheet layout in xml like below

    <android.support.design.widget.CoordinatorLayout 
        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">

         <Button
            android:id="@+id/btn1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Hello World!"
            android:layout_gravity="center" />

         <android.support.v4.widget.NestedScrollView 
            xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:app="http://schemas.android.com/apk/res-auto"
            android:id="@+id/bottom_sheet_map"
            android:layout_width="match_parent"
            android:layout_height="150dp"
            app:layout_behavior="android.support.design.widget.BottomSheetBehavior">

               <include layout="@layout/layout_bottom_sheet" />
        </android.support.v4.widget.NestedScrollView>
    </android.support.design.widget.CoordinatorLayout>

In Java Class Use like this.

    private BottomSheetBehavior mBottomSheetBehavior;
    private View bottomSheet;
    private isBottomSheetExpand = false;
    ...
    btn1.setOnClickListner(new View.OncliView.OnClickListener(){
    @Override
        public void onClick(View v) {
            if(isBottomSheetExpand){
                openBottomSheet();
            }else{
                closeBottomSheet();
            }
        }
    });
    ...
    public void closeBottomSheet() {
       if (mBottomSheetBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED) {
            mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
            isBottomSheetExpand = false;
        }
    }

    public void openBottomSheet() {
        if (mBottomSheetBehavior.getState() != BottomSheetBehavior.STATE_EXPANDED) {
            mBottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
            isBottomSheetExpand = true;
        }
    }

Answer 3

The main reason for the flickering is due to the default styling of the BottomSheetDialog which defines a default animation and the dim behavior.

We can resolve the above issue by defining a custom theme using bottomSheetDialogTheme which in turn:

1. Disables the default window animation for the BottomSheet by setting windowAnimationStyle to @null.
2. Sets the backgroundDimEnabled attribute to false.

Example:

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>

    <item name="bottomSheetDialogTheme">@style/AppTheme.BottomSheetDialog</item>
</style>

<style name="AppTheme.BottomSheetDialog" parent="Theme.Design.BottomSheetDialog">
    <item name="android:windowAnimationStyle">@null</item>
    <item name="android:backgroundDimEnabled">false</item>

    <!-- optional -->
    <item name="android:windowBackground">#99323232</item> 
</style>