Develop Reference

Custom Behaviour with Coordinator Layout

I am trying to hide and show a view when my recyclerview scrolls with the help of coordinator layout.
My view is a linearlayout with button and it is not a fab, toolbar or tablayout as I already know how to hide them on scroll.
Please note this is not a duplicate as all answers show how to fab toolbar or tablayout
This is xml i am using
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/prodMain"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/transparent"
android:orientation="vertical"
xmlns:app="http://schemas.android.com/apk/res-auto">
<RelativeLayout
android:id="#+id/LinearLayout01"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/gray_light"
android:orientation="vertical"
android:paddingLeft="10dp"
android:paddingRight="10dp">
<LinearLayout
android:id="#+id/linearFilterLayout"
android:layout_width="match_parent"
app:layout_behavior="fc.admin.fcexpressadmin.itemdecorators.FABFloatOnScroll"
android:layout_height="wrap_content"
android:layout_marginTop="#dimen/margin10dp"
android:background="#color/white"
android:orientation="horizontal"
android:padding="#dimen/margin10dp"
android:visibility="visible"
android:weightSum="3">
</LinearLayout>
<ViewFlipper
android:id="#+id/ViewFlipper01"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/linearFilterLayout"
android:layout_marginBottom="#dimen/margin10dp"
android:layout_marginTop="#dimen/margin6dp"
android:background="#color/gray_light"
android:visibility="visible">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<Button
android:id="#+id/btnFooterRefresh"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="5dp"
android:text="Refresh"
android:visibility="visible"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/gridview"
android:layout_width="match_parent"
android:clipToPadding="false"
android:layout_height="match_parent"
android:layout_above="#+id/btnFooterRefresh"
android:cacheColorHint="#android:color/transparent"
android:listSelector="#android:color/transparent"
android:scrollbars="vertical"
android:scrollingCache="false"
android:visibility="visible"/>
</RelativeLayout>
</ViewFlipper>
</RelativeLayout>
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>
and this is code of my custom behaviour:
public class FABFloatOnScroll extends CoordinatorLayout.Behavior {
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private int mDySinceDirectionChange=0;
public FABFloatOnScroll() {
super();
}
public FABFloatOnScroll(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean layoutDependsOn(CoordinatorLayout parent, View child, View dependency) {
Log.e("scroll", "dependent on views");
return dependency instanceof LinearLayout;
}
#Override
public boolean onDependentViewChanged(CoordinatorLayout parent, View child, View dependency) {
// Adjust the child View accordingly
Log.e("scroll","dependent");
return true;
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
Log.e("scroll","called");
//child -> Floating Action Button
if (dyConsumed > 0) {
CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
int fab_bottomMargin = layoutParams.bottomMargin;
child.animate().translationY(child.getHeight() + fab_bottomMargin).setInterpolator(new LinearInterpolator()).start();
} else if (dyConsumed < 0) {
child.animate().translationY(0).setInterpolator(new LinearInterpolator()).start();
}
}
#Override
public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy, int[] consumed) {
if (dy > 0 && mDySinceDirectionChange < 0
|| dy < 0 && mDySinceDirectionChange > 0) {
mDySinceDirectionChange = 0;
}
mDySinceDirectionChange += dy;
if (mDySinceDirectionChange > child.getHeight()
&& child.getVisibility() == View.VISIBLE) {
hide(child);
} else if (mDySinceDirectionChange < 0
&& child.getVisibility() == View.GONE) {
show(child);
}
}
#Override
public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild, View target, int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL;
}
private void hide(final View view) {
view.animate()
.translationY(view.getHeight())
.setInterpolator(INTERPOLATOR)
.setDuration(200)
.setListener(new Animator.AnimatorListener() {
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationEnd(Animator animator) {
// Prevent drawing the View after it is gone
view.setVisibility(View.GONE);
}
#Override
public void onAnimationCancel(Animator animator) {
// Canceling a hide should show the view
show(view);
}
#Override
public void onAnimationRepeat(Animator animator) {
}
})
.start();
}
private void show(final View view) {
view.animate()
.translationY(0)
.setInterpolator(INTERPOLATOR)
.setDuration(200)
.setListener(new Animator.AnimatorListener() {
#Override
public void onAnimationStart(Animator animator) {
}
#Override
public void onAnimationEnd(Animator animator) {
// Prevent drawing the View after it is gone
view.setVisibility(View.VISIBLE);
}
#Override
public void onAnimationCancel(Animator animator) {
// Canceling a hide should show the view
hide(view);
}
#Override
public void onAnimationRepeat(Animator animator) {
}
})
.start();
}
}
But the problem is the custom behaviour class is not calling no logs are printed whatsoever

A Behavior can be effective only when associated to a direct child of a CoordinatorLayout.

How to hide FloatingActionMenu inside CoordinatorLayout on Scroll?

Im using this great library to create a FloatingActionMenu. I use it inside a coordinator layout:
<android.support.design.widget.CoordinatorLayout
android:id="#+id/evaluations_list_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#+id/evaluations_list_textview_time"
android:layout_below="#+id/evaluations_list_textview_name"
android:importantForAccessibility="no">
<android.support.v4.widget.SwipeRefreshLayout
android:id="#+id/evaluations_list_swipe_refresh_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:importantForAccessibility="no">
<android.support.v7.widget.RecyclerView
android:id="#+id/evaluations_list_row_parent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:importantForAccessibility="no"
android:padding="10dp"
android:textColor="#color/textcolorprimary" />
</android.support.v4.widget.SwipeRefreshLayout>
<com.github.clans.fab.FloatingActionMenu
android:id="#+id/evaluations_list_floating_action_menu"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:layout_marginEnd="16dp"
android:clickable="true"
android:scaleType="fitXY"
android:src="#drawable/vector_drawable_ic_add_white"
app:layout_anchor="#id/evaluations_list_row_parent"
app:layout_anchorGravity="bottom|right|end"
app:layout_behavior="my.project.views.buttons.ScrollFAMBehaviour"
app:menu_animationDelayPerItem="50"
app:menu_colorNormal="#color/primaryColorDark"
app:menu_colorPressed="#color/accentColor"
app:menu_fab_size="normal"
app:menu_openDirection="up">
<com.github.clans.fab.FloatingActionButton
android:id="#+id/evaluations_list_floating_action_button_filter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="true"
android:scaleType="fitXY"
android:src="#drawable/vector_drawable_ic_check_white"
app:fab_colorNormal="#color/primaryColorDark"
app:fab_colorPressed="#color/accentColor"
app:fab_label="#string/fab_filter"
app:fab_size="mini" />
<com.github.clans.fab.FloatingActionButton
android:id="#+id/evaluations_list_floating_action_button_search"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="true"
android:scaleType="fitXY"
android:src="#drawable/vector_drawable_ic_search_white"
app:fab_colorNormal="#color/primaryColorDark"
app:fab_colorPressed="#color/accentColor"
app:fab_label="#string/fab_search"
app:fab_size="mini" />
</com.github.clans.fab.FloatingActionMenu>
</android.support.design.widget.CoordinatorLayout>
Now i want to create a CoordinatorLayout.Behavior to hide the complete menu when the user is scrolling down and i want it to show up again when the user is scrolling up.
Bevor i used the FloatingActionMenu i used the classic FloatingActionButton. For that it was easily possible to achieve what i want using the following code:
public class ScrollFABBehaviour extends FloatingActionButton.Behavior {
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private boolean isAnimatingOut = false;
public ScrollFABBehaviour(Context context, AttributeSet attrs) {
super();
}
#Override
public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && !this.isAnimatingOut && child.getVisibility() == View.VISIBLE) {
this.animateOut(child);
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
this.animateIn(child);
}
}
private void animateOut(final FloatingActionButton button) {
ViewCompat.animate(button).scaleX(0.0F).scaleY(0.0F).alpha(0.0F).setInterpolator(INTERPOLATOR).withLayer().setListener(new ViewPropertyAnimatorListener() {
public void onAnimationStart(View view) {
ScrollFABBehaviour.this.isAnimatingOut = true;
}
public void onAnimationCancel(View view) {
ScrollFABBehaviour.this.isAnimatingOut = false;
}
public void onAnimationEnd(View view) {
ScrollFABBehaviour.this.isAnimatingOut = false;
view.setVisibility(View.GONE);
}
}).start();
}
private void animateIn(FloatingActionButton button) {
button.setVisibility(View.VISIBLE);
ViewCompat.animate(button).scaleX(1.0F).scaleY(1.0F).alpha(1.0F).setInterpolator(INTERPOLATOR).withLayer().setListener(null).start();
}
}
Unfortunately i cant use this code on the FloatingActionMenu because it is not a FloatingActionButton and also does not inherit it. It is a custom ViewGroup.
How could i create such a behavior for the FloatingActionMenu?

This behavior is really obtained by creating a CoordinatorLayout.Behavior<View>. So instead of extending from FloatingActionButton.Behavior extend from CoordinatorLayout.Behavior<FloatingActionMenu> directly.
Here is the equivalent code that will work with the FloatingActionMenu.
public class ScrollFAMBehaviour extends CoordinatorLayout.Behavior<FloatingActionMenu>{
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private boolean isAnimatingOut = false;
public ScrollFAMBehaviour(Context context, AttributeSet attrs) {
super();
}
#Override
public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionMenu child, View directTargetChild, View target, int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionMenu child, View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && !this.isAnimatingOut && child.getVisibility() == View.VISIBLE) {
this.animateOut(child);
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
this.animateIn(child);
}
}
private void animateOut(final FloatingActionMenu menu) {
ViewCompat.animate(menu).scaleX(0.0F).scaleY(0.0F).alpha(0.0F).setInterpolator(INTERPOLATOR).withLayer().setListener(new ViewPropertyAnimatorListener() {
public void onAnimationStart(View view) {
ScrollFAMBehaviour.this.isAnimatingOut = true;
}
public void onAnimationCancel(View view) {
ScrollFAMBehaviour.this.isAnimatingOut = false;
}
public void onAnimationEnd(View view) {
ScrollFAMBehaviour.this.isAnimatingOut = false;
view.setVisibility(View.GONE);
}
}).start();
}
private void animateIn(FloatingActionMenu menu) {
menu.setVisibility(View.VISIBLE);
ViewCompat.animate(menu).scaleX(1.0F).scaleY(1.0F).alpha(1.0F).setInterpolator(INTERPOLATOR).withLayer().setListener(null).start();
}
}

How to animate both top and bottom Toolbars(or any other view) enter/exit screen on scroll in CoordinatorLayout?

My activity contains 2 AppBarLayouts in a CoordinatorLayout, one on the top of screen, and the other bottom. I want to make both of the 2 AppBarLayouts hide on scroll of a RecyclerView.
When there is only the top one, it's easy to make it hide on scroll by adding app:layout_scrollFlags="scroll|enterAlways" to the Toolbar, and app:layout_behavior="#string/appbar_scrolling_view_behavior" to the container of RecyclerView.
When there is only the bottom AppBarLayout which hide on scroll, it was realized by making a custom behavior BottomAppBarLayoutBehavior extends AppBarLayout.Behavior.
However, when both of them are made hide on scroll, they succeed to hide but the RecyclerView shakes on scroll. And the area of top Toolbar leaves empty white space after hiding.
Below is the xml:
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/topToolbar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways" />
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:layout_width="fill_parent"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:id="#+id/RecyclerViewContainer"
android:layout_height="fill_parent"/>
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_gravity="bottom"
app:layout_behavior="myPackage.BottomAppBarLayoutBehavior">
<LinearLayout
android:layout_width="match_parent"
android:orientation="horizontal"
android:layout_height="match_parent">
<!-- some Views -->
</LinearLayout>
</android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>
Below is the code of BottomAppBarLayoutBehavior:
public class BottomAppBarLayoutBehavior extends AppBarLayout.Behavior {
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private boolean mIsAnimatingOut = false;
public BottomAppBarLayoutBehavior(Context context, AttributeSet attrs) {
super();
}
#Override
public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final AppBarLayout child,
final View directTargetChild, final View target, final int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
|| super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
}
#Override
public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final AppBarLayout child,
final View target, final int dxConsumed, final int dyConsumed,
final int dxUnconsumed, final int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && !this.mIsAnimatingOut && child.getVisibility() == View.VISIBLE) {
animateOut(child);
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
animateIn(child);
}
}
private void animateOut(final AppBarLayout appBarLayout) {
if (Build.VERSION.SDK_INT >= 14) {
ViewCompat.animate(appBarLayout).translationY(168F).alpha(0.0F).setInterpolator(INTERPOLATOR).withLayer()
.setListener(new ViewPropertyAnimatorListener() {
public void onAnimationStart(View view) {
BottomAppBarLayoutBehavior.this.mIsAnimatingOut = true;
}
public void onAnimationCancel(View view) {
BottomAppBarLayoutBehavior.this.mIsAnimatingOut = false;
}
public void onAnimationEnd(View view) {
BottomAppBarLayoutBehavior.this.mIsAnimatingOut = false;
view.setVisibility(View.GONE);
}
}).start();
} else {
Animation anim = AnimationUtils.loadAnimation(appBarLayout.getContext(), R.anim.fab_out);
anim.setInterpolator(INTERPOLATOR);
anim.setDuration(200L);
anim.setAnimationListener(new Animation.AnimationListener() {
public void onAnimationStart(Animation animation) {
BottomAppBarLayoutBehavior.this.mIsAnimatingOut = true;
}
public void onAnimationEnd(Animation animation) {
BottomAppBarLayoutBehavior.this.mIsAnimatingOut = false;
appBarLayout.setVisibility(View.GONE);
}
#Override
public void onAnimationRepeat(final Animation animation) {
}
});
appBarLayout.startAnimation(anim);
}
}
private void animateIn(AppBarLayout appBarLayout) {
appBarLayout.setVisibility(View.VISIBLE);
if (Build.VERSION.SDK_INT >= 14) {
ViewCompat.animate(appBarLayout).scaleX(1.0F).scaleY(1.0F).alpha(1.0F)
.setInterpolator(INTERPOLATOR).withLayer().setListener(null)
.start();
} else {
Animation anim = AnimationUtils.loadAnimation(appBarLayout.getContext(), R.anim.fab_in);
anim.setDuration(200L);
anim.setInterpolator(INTERPOLATOR);
appBarLayout.startAnimation(anim);
}
}
}

I have found the solution by myself. The AppBarLayout wrapper for the bottom LinearLayout is redundant. Remove the AppBarLayout wrapper and make the Behavior class extends CoordinatorLayout.Behavior<LinearLayout>. Finally add the behavior to LinearLayout, then the top Toolbar and bottom LinearLayout enter and exit screen on scroll correctly.
The correct activity xml:
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/top_toolbar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways" />
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:layout_width="fill_parent"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:id="#+id/recycler_view_container"
android:layout_height="fill_parent"/>
<LinearLayout
android:id="#+id/bottom_bar"
android:layout_width="match_parent"
android:orientation="horizontal"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:layout_behavior="*THE_FULL_PACKAGE_NAME*.LinearLayoutBehavior ">
<!-- child views -->
</LinearLayout>
</android.support.design.widget.CoordinatorLayout>
The correct Behavior class:
public class LinearLayoutBehavior extends CoordinatorLayout.Behavior<LinearLayout> {
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private boolean mIsAnimatingOut = false;
public LinearLayoutBehavior(Context context, AttributeSet attrs) {
super();
}
#Override
public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final LinearLayout child,
final View directTargetChild, final View target, final int nestedScrollAxes) {
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
|| super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
}
#Override
public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final LinearLayout child,
final View target, final int dxConsumed, final int dyConsumed,
final int dxUnconsumed, final int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && !this.mIsAnimatingOut && child.getVisibility() == View.VISIBLE) {
// User scrolled down and the FAB is currently visible -> hide the FAB
animateOut(child);
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
// User scrolled up and the FAB is currently not visible -> show the FAB
animateIn(child);
}
}
private void animateOut(final LinearLayout linearLayout) {
if (Build.VERSION.SDK_INT >= 14) {
ViewCompat.animate(linearLayout).translationY(168F).alpha(0.0F).setInterpolator(INTERPOLATOR).withLayer()
.setListener(new ViewPropertyAnimatorListener() {
public void onAnimationStart(View view) {
LinearLayoutBehavior.this.mIsAnimatingOut = true;
}
public void onAnimationCancel(View view) {
LinearLayoutBehavior.this.mIsAnimatingOut = false;
}
public void onAnimationEnd(View view) {
LinearLayoutBehavior.this.mIsAnimatingOut = false;
view.setVisibility(View.GONE);
}
}).start();
} else {
Animation anim = AnimationUtils.loadAnimation(linearLayout.getContext(), R.anim.fab_out);
anim.setInterpolator(INTERPOLATOR);
anim.setDuration(200L);
anim.setAnimationListener(new Animation.AnimationListener() {
public void onAnimationStart(Animation animation) {
LinearLayoutBehavior.this.mIsAnimatingOut = true;
}
public void onAnimationEnd(Animation animation) {
LinearLayoutBehavior.this.mIsAnimatingOut = false;
linearLayout.setVisibility(View.GONE);
}
#Override
public void onAnimationRepeat(final Animation animation) {
}
});
linearLayout.startAnimation(anim);
}
}
private void animateIn(LinearLayout linearLayout) {
linearLayout.setVisibility(View.VISIBLE);
if (Build.VERSION.SDK_INT >= 14) {
ViewCompat.animate(linearLayout).translationY(0).scaleX(1.0F).scaleY(1.0F).alpha(1.0F)
.setInterpolator(INTERPOLATOR).withLayer().setListener(null)
.start();
} else {
Animation anim = AnimationUtils.loadAnimation(linearLayout.getContext(), R.anim.fab_in);
anim.setDuration(200L);
anim.setInterpolator(INTERPOLATOR);
linearLayout.startAnimation(anim);
}
}
}

FloatingActionButton hide on list scroll

Im using the FloatingActionButton from the android.support.design.widget package:
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
android:layout_marginBottom="20dp"
android:layout_marginEnd="16dp"
android:clickable="true"
android:backgroundTint="#color/primaryColor"
android:src="#drawable/ic_search_white_24dp"
app:borderWidth="0dp"
app:elevation="6dp"
app:backgroundTint="#color/primaryColorDark"
app:rippleColor="#color/accentColor" />
Is it possible to configure that button to hide with an animation when the listview is scrolling down and to show it again when listview is scrolling up to the top?

Those who are looking to make it with recyclerview can do this:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
if (dy > 0 || dy < 0 && fab.isShown())
fab.hide();
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (newState == RecyclerView.SCROLL_STATE_IDLE)
fab.show();
super.onScrollStateChanged(recyclerView, newState);
}
});

Sorry! I am late by years to answer this. I hope this still helps someone. This is also my first answer.
Mates! No need to implement scroll listeners.
Add the following to the floating action button xml:
app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
giving:
<com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
android:id="#+id/fabAddOItransferIn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
android:text="#string/btn_text_transfer_in"
app:icon="#android:drawable/ic_input_add"
app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent" />
In response to the following comment of mine,
"Sorry! I just noticed this has a weird side effect. Any snackbars will overlap this floating action button if app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior is added. ☹️ Taking this line off will prevent the overlap and the floating action button will behave as it is intended to inside the coordinator layout. "
To counter this, do use the following:
Snackbar.make(floating_action_button, "Some snackbar text!", BaseTransientBottomBar.LENGTH_SHORT).setAnchorView(floating_action_button).show();

A small improvement to the code from Irfan Raza:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener(){
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy){
if (dy<0 && !fab.isShown())
fab.show();
else if(dy>0 && fab.isShown())
fab.hide();
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
});
The Floating Action Button hides when scrolling down and shows when scrolling up.

See this. Here it tells how to do what you are trying to achieve. You have to use it like this in a CoordinatorLayout and ListView :
<android.support.design.widget.CoordinatorLayout
android:id="#+id/main_content"
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">
<ListView
android:id="#+id/lvToDoList"
android:layout_width="match_parent"
android:layout_height="match_parent"></ListView>
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|right"
android:layout_margin="16dp"
android:src="#drawable/ic_done"
app:layout_anchor="#id/lvToDoList"
app:layout_anchorGravity="bottom|right|end" />
</android.support.design.widget.CoordinatorLayout>

using this class you can easily animate you FAB, here I have implemented onStopNestedScroll() method to show your Fab whenever scroll stop.
I set 1000 miliSeconds as delay using Handler();
public class FabBehaviour extends CoordinatorLayout.Behavior<FloatingActionButton> {
private static final String TAG = "ScrollingFABBehavior";
Handler mHandler;
public FabBehaviour(Context context, AttributeSet attrs) {
super();
}
public FabBehaviour() {
super();
}
#Override
public void onStopNestedScroll(#NonNull CoordinatorLayout coordinatorLayout, #NonNull final FloatingActionButton child, #NonNull View target, int type) {
super.onStopNestedScroll(coordinatorLayout, child, target, type);
if (mHandler == null)
mHandler = new Handler();
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
child.animate().translationY(0).setInterpolator(new LinearInterpolator()).start();
Log.d("FabAnim", "startHandler()");
}
}, 1000);
}
#Override
public void onNestedScroll(#NonNull CoordinatorLayout coordinatorLayout, #NonNull FloatingActionButton child, #NonNull View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int type) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, type);
if (dyConsumed > 0) {
Log.d("Scrolling", "Up");
CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
int fab_bottomMargin = layoutParams.bottomMargin;
child.animate().translationY(child.getHeight() + fab_bottomMargin).setInterpolator(new LinearInterpolator()).start();
} else if (dyConsumed < 0) {
Log.d("Scrolling", "down");
child.animate().translationY(0).setInterpolator(new LinearInterpolator()).start();
}
}
#Override
public boolean onStartNestedScroll(#NonNull CoordinatorLayout coordinatorLayout, #NonNull FloatingActionButton child, #NonNull View directTargetChild, #NonNull View target, int axes, int type) {
if (mHandler != null) {
mHandler.removeMessages(0);
Log.d("Scrolling", "stopHandler()");
}
return axes == ViewCompat.SCROLL_AXIS_VERTICAL;
}
}
your_layout.xml
<android.support.design.widget.FloatingActionButton
android:id="#+id/imageViewYes"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end|right"
android:layout_margin="#dimen/fab_margin"
android:src="#drawable/ic_yes"
app:backgroundTint="#color/white"
android:scaleType="center"
app:elevation="6dp"
app:fabSize="normal"
app:layout_behavior="com.your.package.FabBehaviour"
app:pressedTranslationZ="12dp"
app:rippleColor="#color/gray" />

hey there is o require to take the recyclerview for auto hiding the floating action button on scrolling down for this purpose we can use default listview with floating action button in normal way only make modifications on listview.onscroll listener then we can get feel like recycle
listview.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
int lastItem = firstVisibleItem + visibleItemCount;
if (lastItem == totalItemCount) {
fab.setVisibility(View.INVISIBLE);
}else {
fab.setVisibility(View.VISIBLE);
}
}
});

There is my code in kotlin.
class ScrollAwareFABBehavior (val recyclerView: RecyclerView, val floatingActionButton: FloatingActionButton) {
fun start() {
recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
if (dy > 0) {
if (floatingActionButton!!.isShown) {
floatingActionButton?.hide()
}
} else if (dy < 0) {
if (!floatingActionButton!!.isShown) {
floatingActionButton?.show()
}
}
}
})
}
}
Now, you just need to call the ScrollAwareFABBehavior with the recyclerView and the fab on constructor, then call method start().
ScrollAwareFABBehavior(recyclerView = recyclerViewPlaceFormContainer, floatingActionButton = floatingActionButton).start()

Another method for recycleView using kotlin extensions.
fun RecyclerView.attachFab(fab : FloatingActionButton) {
this.addOnScrollListener(object : RecyclerView.OnScrollListener(){
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
if (dy > 0)
fab.hide()
else if (dy < 0)
fab.show()
}
})
}
Now you can attach fab to any recycleView with:
rv.attachFab(requireActivity().fab)
// in my case i made fab public on activity

Here I am adding extra padding for last view item to avoid overlapping list item with floating action button
I used this in a RecyclerView.Adapter's onBindViewHolder method to set the bottom margin of the last item in the list to 72dp so that it will scroll up above the floating action button.
This does not require a dummy entry in the list.
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// other binding code goes here.
if (position + 1 == getItemCount()) {
// set bottom margin to 72dp.
setBottomMargin(holder.itemView, (int) (72 * Resources.getSystem().getDisplayMetrics().density));
} else {
// reset bottom margin back to zero. (your value may be different)
setBottomMargin(holder.itemView, 0);
}
}
public static void setBottomMargin(View view, int bottomMargin) {
if (view.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
ViewGroup.MarginLayoutParams params = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
params.setMargins(params.leftMargin, params.topMargin, params.rightMargin, bottomMargin);
view.requestLayout();
}
}

Kotlin + DataBinding Adapter
#BindingAdapter("bindAdapter:attachFloatingButton")
fun bindRecyclerViewWithFB(recyclerView: RecyclerView, fb: FloatingActionButton) {
recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
if (dy > 0 && fb.isShown) {
fb.hide()
} else if (dy < 0 && !fb.isShown) {
fb.show()
}
}
})
}
and the xml
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/main_recyclerview"
android:layout_width="match_parent"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
android:layout_height="wrap_content"
android:clipToPadding="false"
android:paddingBottom="8dp" app:layout_constraintEnd_toEndOf="parent" android:layout_marginEnd="8dp"
app:layout_constraintStart_toStartOf="parent" android:layout_marginStart="8dp"
android:layout_marginTop="8dp" app:layout_constraintTop_toBottomOf="#+id/main_chips"
android:layout_marginBottom="8dp"
**bindAdapter:attachFloatingButton="#{mainFb}"**
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintVertical_bias="0.0"/>
<com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
android:id="#+id/main_fb"
android:layout_width="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
style="#style/Widget.Design.FloatingActionButton"
app:layout_constraintEnd_toEndOf="parent"
android:layout_height="wrap_content"
android:layout_margin="18dp"
android:background="#color/colorPrimaryDark"
app:icon="#drawable/ic_add_black_24dp"/>

According to me the best way to implement this would be as below.
public class ScrollingFABBehavior extends FloatingActionButton.Behavior {
private static final String TAG = "ScrollingFABBehavior";
public ScrollingFABBehavior(Context context, AttributeSet attrs) {
super();
// Log.e(TAG, "ScrollAwareFABBehavior");
}
public boolean onStartNestedScroll(CoordinatorLayout parent, FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
return true;
}
#Override
public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
if (dependency instanceof RecyclerView)
return true;
return false;
}
#Override
public void onNestedScroll(CoordinatorLayout coordinatorLayout,
FloatingActionButton child, View target, int dxConsumed,
int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
// TODO Auto-generated method stub
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed);
//Log.e(TAG, "onNestedScroll called");
if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
// Log.e(TAG, "child.hide()");
child.hide();
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
// Log.e(TAG, "child.show()");
child.show();
}
}}
For detailed answer check this out. Hide FloatingActionButton on scroll of RecyclerView

for Kotlin it is very simple (API 23+)
myRecyclerView.setOnScrollChangeListener { _, _, _, _, oldScrollY ->
if (oldScrollY < 0) myFAB.hide() else myFAB.show()
}

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (dy > 0 && mFloatingActionButton.getVisibility() == View.VISIBLE) {
mFloatingActionButton.hide();
} else if (dy < 0 && mFloatingActionButton.getVisibility() != View.VISIBLE) {
mFloatingActionButton.show();
}
}});

Just to add, for NestedScrollView the approach will be something like the following:
// register the extended floating action Button
final ExtendedFloatingActionButton extendedFloatingActionButton = findViewById(R.id.extFloatingActionButton);
// register the nestedScrollView from the main layout
NestedScrollView nestedScrollView = findViewById(R.id.nestedScrollView);
// handle the nestedScrollView behaviour with OnScrollChangeListener
// to extend or shrink the Extended Floating Action Button
nestedScrollView.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {
#Override
public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
// the delay of the extension of the FAB is set for 12 items
if (scrollY > oldScrollY + 12 && extendedFloatingActionButton.isExtended()) {
extendedFloatingActionButton.shrink();
}
// the delay of the extension of the FAB is set for 12 items
if (scrollY < oldScrollY - 12 && !extendedFloatingActionButton.isExtended()) {
extendedFloatingActionButton.extend();
}
// if the nestedScrollView is at the first item of the list then the
// extended floating action should be in extended state
if (scrollY == 0) {
extendedFloatingActionButton.extend();
}
}
});
I've taken this code from GeeksForGeeks

How to animate FloatingActionButton like in Google+ app for Android?

I set FloatingActionButton to bottom of screen and I want to animate the button.
Hidden when scrolling down
Shown when scrolling up
Like google implemented it in their Google+ app.
I think CoordinatorLayout and AppBarLayout is needed but how to implement it to use it with the FloatingActionButton?

You can achieve it using the default FloatingActionButton changing its
default Behavior using the app:layout_behavior attribute:
You can use a layout like:
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:layout_scrollFlags="scroll|enterAlways" />
</android.support.design.widget.AppBarLayout>
// Your layout, for example a RecyclerView
<RecyclerView
.....
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:layout_margin="#dimen/fab_margin"
android:src="#drawable/ic_done"
app:layout_behavior="com.support.android.designlibdemo.ScrollAwareFABBehavior" />
</android.support.design.widget.CoordinatorLayout>
With the app:layout_behavior you can define your own Behavior. With the onStartNestedScroll() and onNestedScroll() methods you can interact with scroll events.
You can use a Behavior like this.
You can find the original code here:
public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
private boolean mIsAnimatingOut = false;
public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
super();
}
#Override
public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
final View directTargetChild, final View target, final int nestedScrollAxes) {
// Ensure we react to vertical scrolling
return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
|| super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
}
#Override
public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
final View target, final int dxConsumed, final int dyConsumed,
final int dxUnconsumed, final int dyUnconsumed) {
super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
if (dyConsumed > 0 && !this.mIsAnimatingOut && child.getVisibility() == View.VISIBLE) {
// User scrolled down and the FAB is currently visible -> hide the FAB
animateOut(child);
} else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
// User scrolled up and the FAB is currently not visible -> show the FAB
animateIn(child);
}
}
// Same animation that FloatingActionButton.Behavior uses to hide the FAB when the AppBarLayout exits
private void animateOut(final FloatingActionButton button) {
if (Build.VERSION.SDK_INT >= 14) {
ViewCompat.animate(button).scaleX(0.0F).scaleY(0.0F).alpha(0.0F).setInterpolator(INTERPOLATOR).withLayer()
.setListener(new ViewPropertyAnimatorListener() {
public void onAnimationStart(View view) {
ScrollAwareFABBehavior.this.mIsAnimatingOut = true;
}
public void onAnimationCancel(View view) {
ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
}
public void onAnimationEnd(View view) {
ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
view.setVisibility(View.GONE);
}
}).start();
} else {
Animation anim = AnimationUtils.loadAnimation(button.getContext(), R.anim.fab_out);
anim.setInterpolator(INTERPOLATOR);
anim.setDuration(200L);
anim.setAnimationListener(new Animation.AnimationListener() {
public void onAnimationStart(Animation animation) {
ScrollAwareFABBehavior.this.mIsAnimatingOut = true;
}
public void onAnimationEnd(Animation animation) {
ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
button.setVisibility(View.GONE);
}
#Override
public void onAnimationRepeat(final Animation animation) {
}
});
button.startAnimation(anim);
}
}
// Same animation that FloatingActionButton.Behavior uses to show the FAB when the AppBarLayout enters
private void animateIn(FloatingActionButton button) {
button.setVisibility(View.VISIBLE);
if (Build.VERSION.SDK_INT >= 14) {
ViewCompat.animate(button).scaleX(1.0F).scaleY(1.0F).alpha(1.0F)
.setInterpolator(INTERPOLATOR).withLayer().setListener(null)
.start();
} else {
Animation anim = AnimationUtils.loadAnimation(button.getContext(), R.anim.fab_in);
anim.setDuration(200L);
anim.setInterpolator(INTERPOLATOR);
button.startAnimation(anim);
}
}
}

As of this post, there are no methods that will automatically handle hiding and showing the FloatingActionButton in the Design Support Libraries. I know this because this was my first assignment at work.
The methods you are thinking of are used to animate the FloatingActionButton up and down when a Snackbar is created, and yes, that will work if you are using a CoordinatorLayout.
Here's my code. It's based off of this repo. It has listeners for RecyclerView and AbsListView that handle animating the button automatically. You can either do
button.show();
or
button.hide();
to hide the button manually, or you can call:
button.attachToListView(listView);
and
button.attachToRecyclerView(recyclerView);
and it will hide on scroll down and show on scroll up with no further code.
Hope this helps!
AnimatedFloatingActionButton:
public class AnimatedFloatingActionButton extends FloatingActionButton
{
private static final int TRANSLATE_DURATION_MILLIS = 200;
private final Interpolator mInterpolator = new AccelerateDecelerateInterpolator();
private boolean mVisible;
public AnimatedFloatingActionButton(Context context, AttributeSet attrs)
{
super(context, attrs);
Log.i("Abscroll", "mVisible" + mVisible);
}
public void show() {
show(true);
}
public void hide() {
hide(true);
}
public void show(boolean animate) {
toggle(true, animate, false);
}
public void hide(boolean animate) {
toggle(false, animate, false);
}
private void toggle(final boolean visible, final boolean animate, boolean force) {
if (mVisible != visible || force) {
mVisible = visible;
int height = getHeight();
if (height == 0 && !force) {
ViewTreeObserver vto = getViewTreeObserver();
if (vto.isAlive()) {
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
ViewTreeObserver currentVto = getViewTreeObserver();
if (currentVto.isAlive()) {
currentVto.removeOnPreDrawListener(this);
}
toggle(visible, animate, true);
return true;
}
});
return;
}
}
int translationY = visible ? 0 : height + getMarginBottom();
Log.i("Abscroll", "transY" + translationY);
if (animate) {
this.animate().setInterpolator(mInterpolator)
.setDuration(TRANSLATE_DURATION_MILLIS)
.translationY(translationY);
} else {
setTranslationY(translationY);
}
}
}
private int getMarginBottom() {
int marginBottom = 0;
final ViewGroup.LayoutParams layoutParams = getLayoutParams();
if (layoutParams instanceof ViewGroup.MarginLayoutParams) {
marginBottom = ((ViewGroup.MarginLayoutParams) layoutParams).bottomMargin;
}
return marginBottom;
}
public void attachToListView(#NonNull AbsListView listView)
{
listView.setOnScrollListener(new AbsListViewScrollDetector() {
#Override
void onScrollUp() {
hide();
}
#Override
void onScrollDown() {
show();
}
#Override
void setScrollThreshold() {
setScrollThreshold(getResources().getDimensionPixelOffset(R.dimen.fab_scroll_threshold));
}
});
}
public void attachToRecyclerView(#NonNull RecyclerView recyclerView) {
recyclerView.addOnScrollListener(new RecyclerViewScrollDetector() {
#Override
void onScrollUp() {
hide();
}
#Override
void onScrollDown() {
show();
}
#Override
void setScrollThreshold() {
setScrollThreshold(getResources().getDimensionPixelOffset(R.dimen.fab_scroll_threshold));
}
});
}
}
AbsListViewScrollDetector:
abstract class AbsListViewScrollDetector implements AbsListView.OnScrollListener {
private int mLastScrollY;
private int mPreviousFirstVisibleItem;
private AbsListView mListView;
private int mScrollThreshold;
abstract void onScrollUp();
abstract void onScrollDown();
abstract void setScrollThreshold();
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if(totalItemCount == 0) return;
if (isSameRow(firstVisibleItem)) {
int newScrollY = getTopItemScrollY();
boolean isSignificantDelta = Math.abs(mLastScrollY - newScrollY) > mScrollThreshold;
Log.i("Abscroll", "mLastScrollY " + mLastScrollY);
Log.i("Abscroll", "newScrollY " + newScrollY);
if (isSignificantDelta) {
Log.i("Abscroll", "sig delta");
if (mLastScrollY > newScrollY) {
onScrollUp();
Log.i("Abscroll", "sig delta up");
} else {
onScrollDown();
Log.i("Abscroll", "sig delta down");
}
}
mLastScrollY = newScrollY;
} else {
if (firstVisibleItem > mPreviousFirstVisibleItem) {
onScrollUp();
Log.i("Abscroll", "prev up");
} else {
onScrollDown();
Log.i("Abscroll", "prev down");
}
mLastScrollY = getTopItemScrollY();
mPreviousFirstVisibleItem = firstVisibleItem;
}
}
public void setScrollThreshold(int scrollThreshold) {
mScrollThreshold = scrollThreshold;
Log.i("Abscroll", "LView thresh " + scrollThreshold);
}
public void setListView(#NonNull AbsListView listView) {
mListView = listView;
}
private boolean isSameRow(int firstVisibleItem) {
return firstVisibleItem == mPreviousFirstVisibleItem;
}
private int getTopItemScrollY() {
if (mListView == null || mListView.getChildAt(0) == null) return 0;
View topChild = mListView.getChildAt(0);
return topChild.getTop();
}
}
RecyclerViewScrollDetector:
abstract class RecyclerViewScrollDetector extends RecyclerView.OnScrollListener {
private int mScrollThreshold;
abstract void onScrollUp();
abstract void onScrollDown();
abstract void setScrollThreshold();
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
boolean isSignificantDelta = Math.abs(dy) > mScrollThreshold;
if (isSignificantDelta) {
if (dy > 0) {
onScrollUp();
Log.i("Abscroll", "Rview up");
} else {
onScrollDown();
Log.i("Abscroll", "RView down");
}
}
}
public void setScrollThreshold(int scrollThreshold) {
mScrollThreshold = scrollThreshold;
Log.i("Abscroll", "RView thresh " + scrollThreshold);
}
}

Googles Design Support Library will do that.
Try to implement this code to your layout file:
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/ic_add_black"
android:layout_gravity="bottom|end"
app:elevation="6dp"
app:pressedTranslationZ="12dp"/>
It's important that you add compile 'com.android.support:design:22.2.0' to your build.gradle. If you're using eclipse there is another way to add this library to your project.
Important resources:
Design Support Library (II): Floating Action Button
Android Design Support Library
Google Releasing A FABulous New Design Support Library [Updated]

ExtendedFloatingActionButton enough to achieve your goal, no need to handle any logic code, just extend() and shrink() on scrolling
Full example:
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="0dp"
android:layout_height="0dp"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
<com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
android:id="#+id/extendedFloatingButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="end|bottom"
android:text="Reorder List"
android:layout_margin="12dp"
app:icon="#drawable/ic_reorder" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
And in your code:
recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrollStateChanged(recyclerView: RecyclerView, newState:
Int) {
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
extendedFloatingButton.extend()
}
super.onScrollStateChanged(recyclerView, newState)
}
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
if (dy > 0 || dy < 0 && extendedFloatingButton.isExtended) {
extendedFloatingButton.shrink()
}
}
})