RelativeLayout in CoordinatorLayout doesn't scroll

RelativeLayout in CoordinatorLayout doesn't scroll - android

I have a RelativeLayout within my CoordinatorLayout (as shown below). Also notice that within the RelativeLayout I have a RecyclerView.
However, when I scroll, I can only scroll on the RecyclerView and only the RecyclerView portion of the screen will actually scroll. If I try scrolling on the layout above the RecyclerView, it won't scroll the screen at all. Here's an illustration I made of what's going on:
So my question is, why can't I scroll on the inner RelativeLayout? Should I be organizing my layouts in a different way?
Here is my layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/drawer"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:openDrawer="start">
<android.support.design.widget.CoordinatorLayout
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/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<RelativeLayout
android:id="#+id/header"
android:layout_width="match_parent"
android:layout_height="250dp">
// some imageviews and textviews
</RelativeLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/header" />
</RelativeLayout>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin" />
</android.support.design.widget.CoordinatorLayout>
<android.support.design.widget.NavigationView
android:id="#+id/nav_view"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
app:headerLayout="#layout/nav_header_drawer"
app:menu="#menu/menu_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>
How can I fix this?

RelativeLayout is not scrollable if it's not within any Scrollable View. Try putting your RelativeLayout as a Header of your RecyclerView.
In this example you will be able to scroll its content
<ScrollView
...
...>
<!-- Scrollable Contents -->
</ScrollView>
In your case I think the best way is to let your RecyclerView take up the whole screen and then assign its header. Follow this link or this. There's many out there so just google it up

Alright, this can be done using single recyclerview and putting your header relativelayout as an item of recyclerview.
May you are familiar with getItemViewType method, that is used to decide item type of recyclerview item.
Add data to your dataset using which you'll be going to decide type of an item. Consider below example...
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private final int ITEM_ROW = 1;
private final int ITEM_HEADER = 2;
// Will be your dataset which will be containing first item as relativeLayout payload.
private ArrayList<Object> mData;
public MyRecyclerViewAdapter(ArrayList<Object> mData) {
this.mData = mData;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder vh = null;
if (viewType == ITEM_ROW) {
// Inflate your row item of recyclerview here...
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_checkout_review_cart_item, parent, false);
vh = new ItemHolder(view);
} else if (viewType == ITEM_HEADER) {
// Inflate your relativeLayout here...
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_order_detail_grand_total_item, parent, false);
vh = new RelativeLayoutHolder(view);
}
return vh;
}
#Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) {
if (holder instanceof ItemHolder) {
// Bind item of recyclerview here...
} else if (holder instanceof RelativeLayoutHolder) {
// Bind data of your relativeLayout
}
}
#Override
public int getItemCount() {
return mData.size();
}
#Override
public int getItemViewType(int position) {
// Decide type of an item using payload instances..
Object obj = mData.get(position);
if (obj instanceof ItemInfo) {
return ITEM_ROW;
} else if (obj instanceof RelativeLayoutInfo) {
return ITEM_HEADER;
} else {
return -1;
}
}
class ItemHolder extends RecyclerView.ViewHolder {
ItemHolder(View itemView) {
super(itemView);
}
}
class RelativeLayoutHolder extends RecyclerView.ViewHolder {
RelativeLayoutHolder(View itemView) {
super(itemView);
}
}
}
Your Payload of dataset will decide itemType. Two type of Pojo will going to be inserted into your dataset - RelativeLayoutInfo and ItemInfo. For an example
public class ItemInfo implements Serializable {
// Consider adding object and getter setter here
}
and
public class RelativeLayoutInfo implements Serializable {
// Consider adding object and getter setter here
}
There you go. your relativeLayout is added as an item of recyclerview.
Happy coding!!

Related

AppBarLayout behavior when updating RecyclerView

An interesting situation arose. When updating the RecyclerView (moving animation), the app parameter is no longer taken into account: liftOnScroll = "true". That is, the shadow disappears until I start to scroll. Tried so appBarLayout.setLifted(true); - did not help.
include_toolbar
<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.appbar.AppBarLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
**app:liftOnScroll="true"**>
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_scrollFlags="scroll|enterAlways|snap"/>
</com.google.android.material.appbar.AppBarLayout>
Java
public class ListFragment extends Fragment {
...
private class Adapter extends RecyclerView.Adapter<ViewHolder> {
...
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
holder.elect.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
...
RuleDiffUtilCallback ruleDiffUtilCallback = new RuleDiffUtilCallback(rules, Labs.get(getActivity()).getRules());
DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(ruleDiffUtilCallback);
ruleAdapter.setRules(Labs.get(getActivity()).getRules());
diffResult.dispatchUpdatesTo(ruleAdapter);
}
});
...
}
...
}

smoothScrollToPosition does not work in nested RecyclerView

I have a recyclerView and each of it's item is a recyclerView. I want scroll to custom position of inner recyclerView at specific condition.
I used this code at innerRecyclerView but it didn't work:
innerRecyclerView.smoothScrollToPosition(position);
and this:
innerRecyclerView.scrollToPosition(position);
and this one:
layoutManager.scrollToPositionWithOffset(position, offset);
Now I have two question:
1) Is it possible scroll to custom position of inner recyclerView?
2) If that is possible, how?
Here is initialize main recyclerView:
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext(), RecyclerView.VERTICAL, false);
adapter = new FreightsListRVAdapter(new FreightListCallBack(), new FreightListVHFactory());
rvFreightsList.setLayoutManager(layoutManager);
rvFreightsList.setItemViewCacheSize(30);
rvFreightsList.setNestedScrollingEnabled(true);
rvFreightsList.setAdapter(adapter);
Here is initialize innerRecyclerview:
LinearLayoutManager layoutManager = new LinearLayoutManager(itemView.getContext(), RecyclerView.VERTICAL, false);
layoutManager.setItemPrefetchEnabled(true);
layoutManager.setInitialPrefetchItemCount(7);
rvFreights.setNestedScrollingEnabled(false);
rvFreights.setLayoutManager(layoutManager);
rvFreights.setItemViewCacheSize(20);
adapter = new FreightsRVAdapter(new FreightCallBack(), new FreightSingleVHFactory());
rvFreights.setAdapter(adapter);
Here is my main recyclerView adapter:
public class FreightsListRVAdapter extends ListAdapter<FreightListModel, FreightListVH> {
private final FreightListVHFactory mFactory;
private final PublishSubject<FreightListVHAction> mClickUserPS = PublishSubject.create();
#Inject
public FreightsListRVAdapter(#NonNull FreightListCallBack diffCallback, FreightListVHFactory factory) {
super(diffCallback);
mFactory = factory;
}
#NonNull
#Override
public FreightListVH onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return mFactory.create(parent);
}
#Override
public void onBindViewHolder(#NonNull FreightListVH holder, int position) {
holder.getVM().setObject(getItem(position));
holder.bind();
holder.itemOnClick(mClickUserPS);
}
public PublishSubject<FreightListVHAction> getmClickUserPS() {
return mClickUserPS;
}
}
Here is layout of each row of mainRecyclerView:
<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:descendantFocusability="blocksDescendants"
android:orientation="vertical">
<androidx.appcompat.widget.AppCompatTextView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/txtDescription"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="10dp"
android:paddingTop="5dp"
android:paddingRight="10dp"
android:textColor="#992C2C2C"
android:textSize="11sp"
app:fontFamily="#font/iransans"
tools:ignore="HardcodedText,SmallSp" />
<androidx.appcompat.widget.AppCompatTextView
android:id="#+id/txtDate"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:layout_marginLeft="15dp"
android:layout_marginRight="15dp"
android:layout_marginBottom="15dp"
android:gravity="right"
android:textColor="#2C2C2C"
android:textSize="20sp"
app:fontFamily="#font/iransans_medium"
tools:ignore="RtlHardcoded"/>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvFreights"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never"
android:scrollbars="none" />
</androidx.appcompat.widget.LinearLayoutCompat>

In Kotlin-androidX recyclerview solution
val parentViewHolder = parentRecyclerView?.findViewHolderForAdapterPosition(parentPosition) as? ParentViewHolder?
var childY = 0F
if (parentViewHolder != null)
childY = parentViewHolder.childRecyclerView?.getChildAt(lastPosition)?.y ?: 0F
parentRecyclerView.scrollBy(0, childY.toInt())
PrentViewHolder.kt
class PrentViewHolder(
view: InflateBinding
): RecyclerView.ViewHolder(view.root) {
var recyclerView: RecyclerView? = null
fun populateData(data: Data) {
viewDataBinding.recyclerview.adapter = adapter
recyclerView = viewDataBinding.recyclerview
}
}

Can you please try this:
float y = recyclerView.getY() + recyclerView.getChildAt(selectedPosition).getY();
mainRecyclerview.smoothScrollTo(0, (int) y);

How can I get access to outside views from an Adapter

I have a recyclerview in my app showing a list of content. If a user is subscribed, they can proceed to read the full content and if not the recyclerview is hidden and a subscribe layout is shown.
Layout file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/light_grey"
android:orientation="vertical"
android:weightSum="10"
tools:layout_editor_absoluteY="25dp">
<!--RECYCLER VIEW-->
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginEnd="10dp"
android:layout_marginStart="10dp"
android:layout_marginTop="5dp"
android:layout_weight="8.3"
android:padding="2dp"
android:visibility="gone" />
<!--SUBSCRIBE TO VIEW CONTENT LAYOUT-->
<RelativeLayout
android:id="#+id/rlSubscribeToView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:gravity="center"
android:visibility="gone"
android:layout_margin="10dp"
android:elevation="48dp"
android:layout_gravity="center"
android:layout_weight="8.3">
<TextView
android:id="#+id/tvSubscribe"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_centerInParent="true"
android:textColor="#color/maroon"
android:text="#string/subscribe_to_view"/>
<Button
android:id="#+id/btnSubscribe"
android:layout_width="match_parent"
android:layout_height="45dp"
android:layout_marginTop="15dp"
android:layout_marginStart="20dp"
android:layout_below="#id/tvSubscribe"
android:layout_marginEnd="20dp"
android:text="#string/subscribe"
android:textColor="#color/white" />
</RelativeLayout>
and the
RecyclerView Adapter
public void onBindViewHolder(#NonNull final ReadViewholder, final int position) {
holder.readMoreButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (userIsSubscribed) {
//Launch the next Activity
} else {
//Show the subscribe layout
holder.rlSubscribeToView .setVisibility(View.VISIBLE);
//Then hide the entire recyvlerView
}
}
});
}
class ReadViewholder extends RecyclerView.ViewHolder {
RelativeLayout rlSubscribeToView;
Button readMoreButton;
ReadViewholder(#NonNull View itemView) {
super(itemView);
//Not able to find (rlSubscribeToView ) since its not inside the recyclerview
rlSubscribeToView = itemView.findViewById(R.id.rlSubscribeToView);
readMoreButton= itemView.findViewById(R.id.readMoreButton);
}
}
How can I get access to the subscribe layout (rlSubscribeToView), which is on the same layout file as the recycler view and also hide the entire recycler view in the Adapter?

From a little bit of research, the are 2 callbacks that get can get you a reference to the actual RecyclerView, the onAttachedToRecyclerView and the onDetachedFromRecycler methods. My guess is that you are calling the Adapter constructor and passing in a context. If so use the below code, it will produce your desired result.
RelativeLayout rlSubscribeToView;
RecyclerView recyclerView;
public RecyclerAdapter(Context context) {
this.context = context;
this.videoItems = videoItems;
rlSubscribeToView = ((Activity) context).findViewById(R.id.rlSubscribeToView);
}
#Override
public void onAttachedToRecyclerView(#NonNull RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
this.recyclerView = recyclerView;
}
and in your onBindViewHolder you can now get access the subscribe layout
public void onBindViewHolder(#NonNull final ReadViewholder, final int position) {
...
rlSubscribeToView.setVisibility();
}

What you need is an interface passed in as a parameter when you create your Adapter.
Example:
class Adapter(private val actions: Actions) : RecyclerView.Adapter<ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
// Create ViewHolder
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
// Setup Binder
holder.readMoreButton.setOnClickListener(View.OnClickListener {
if (userIsSubscribed) {
actions.launchActivity() //Launch the next Activity
} else {
//Show the subscribe layout
holder.rlSubscribeToView.setVisibility(View.VISIBLE)
actions.hideRecylerView() //Then hide the entire recyclerView
}
})
}
}
internal interface Actions {
fun launchActivity()
fun hideRecylerView()
}

FAB Behavior when showing CardView (Up & Down)

I want to show a CardView as prompt like in Material Guidelines Specs:
https://www.google.com/design/spec/growth-communications/onboarding.html#onboarding-quickstart
Here is the link to the image:
Image
I've changed the behavior of the FAB Button like this and set to the .xml file:
public class FABBehavior extends FloatingActionButton.Behavior {
public FABBehavior(Context context, AttributeSet attr) {
super();
}
#Override
public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
return dependency instanceof CardView;
}
#Override
public boolean onDependentViewChanged(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
float translationY = Math.min(0, dependency.getTranslationY() - dependency.getHeight());
child.setTranslationY(translationY);
return true;
}
}
My .xml file look like this:
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.nearme.client.activities.fragments.ScannerFragment">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
android:title="#string/title_scanner"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="#layout/fragment_scanner_content" />
<android.support.v7.widget.CardView
android:id="#+id/cvBluetooth"
android:layout_width="match_parent"
android:layout_height="150dp"
android:animateLayoutChanges="true"
android:layout_gravity="bottom" >
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Prueba" />
</android.support.v7.widget.CardView>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|bottom|end"
android:layout_margin="#dimen/fab_margin"
app:layout_behavior="com.nearme.client.utils.FABBehavior"
android:src="#android:drawable/ic_dialog_email" />
And the click listener of the FAB Button is this:
View.OnClickListener onClick = new View.OnClickListener() {
#Override
public void onClick(View v) {
if (v == fab) {
if (cardBluetooth.isShown()) {
cardBluetooth.setVisibility(View.GONE);
} else
cardBluetooth.setVisibility(View.VISIBLE);
}
}
};
The problem is when the CardView's visibility goes GONE the FAB button remain up in its position.
How can I update the position of the FAB when the CardView is GONE?
Even if I set the CardView in the CoordinatorLayout dinamically and remove it doesnt work.

Well, the problem was that onDependentViewChangedfrom FloatingActionButton.Behavior only get called when the dependent view have changed its position. But I only was changing its visibility so it didnt get called.
Now in the onClick I add to the view and remove it:
View.OnClickListener onClick = new View.OnClickListener() {
#Override
public void onClick(View v) {
if (v == fab) {
if (cardBluetooth.isShown()) {
coordinatorLayout.removeView(cardBluetooth);
} else
coordinatorLayout.addView(cardBluetooth);
}
}
};
And in FloatingActionButton.Behavior I added:
#Override
public void onDependentViewRemoved(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
child.animate().translationY(0);
child.setTranslationY(0);
}
And this is the result:
GIF of result

Change the method layoutDependsOn method according to this:
#Override
public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton child, View dependency) {
return dependency instanceof CardView && onDependentViewChanged(parent, child, dependency);
}
Otherwise, the fab button is going to move up only the first time it gets clicked.

Toolbar in AppBarLayout is scrollable although RecyclerView has not enough content to scroll

Is it really intended that the Toolbar in a AppBarLayout is scrollable although the main container with the "appbar_scrolling_view_behavior" has not enough content to really scroll?
What I have tested so far:
When I use a NestedScrollView (with "wrap_content" attribute) as main container and a TextView as child, the AppBarLayout works properly and does not scroll.
However, when I use a RecyclerView with only a few entries and the "wrap_content" attribute (so that there is no need to scroll), the Toolbar in the AppBarLayout is scrollable even though the RecyclerView never receives a scroll event (tested with a OnScrollChangeListener).
Here's my layout code:
<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/coordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:theme="#style/ToolbarStyle" />
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>
With the following effect that the toolbar is scrollable although it's not necessary:
I've also found a way to deal with this by checking if all RecyclerView items are visible and using the setNestedScrollingEnabled() method of the RecyclerView.
Nevertheless, it does seem more like a bug as intended to me. Any opinions? :D
EDIT #1:
For people who are might be interested in my current solution, I had to put the setNestedScrollingEnabled() logic in the postDelayed() method of a Handler with 5 ms delay due to the LayoutManager which always returned -1 when calling the methods to find out whether the first and the last item is visible.
I use this code in the onStart() method (after my RecyclerView has been initialized) and every time after a content change of the RecyclerView occurs.
final LinearLayoutManager layoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
//no items in the RecyclerView
if (mRecyclerView.getAdapter().getItemCount() == 0)
mRecyclerView.setNestedScrollingEnabled(false);
//if the first and the last item is visible
else if (layoutManager.findFirstCompletelyVisibleItemPosition() == 0
&& layoutManager.findLastCompletelyVisibleItemPosition() == mRecyclerView.getAdapter().getItemCount() - 1)
mRecyclerView.setNestedScrollingEnabled(false);
else
mRecyclerView.setNestedScrollingEnabled(true);
}
}, 5);
EDIT #2:
I just played around with a new app and it seems that this (unintended) behavior has been fixed in support library version 23.3.0 (or even earlier). Thus, there is no need for workarounds anymore!

Edit 2:
Turns out the only way to ensure Toolbar is not scrollable when RecyclerView is not scrollable is to set setScrollFlags programmatically which requires to check if RecyclerView's is scrollable. This check has to be done every time adapter is modified.
Interface to communicate with the Activity:
public interface LayoutController {
void enableScroll();
void disableScroll();
}
MainActivity:
public class MainActivity extends AppCompatActivity implements
LayoutController {
private CollapsingToolbarLayout collapsingToolbarLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
collapsingToolbarLayout =
(CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar);
final FragmentManager manager = getSupportFragmentManager();
final Fragment fragment = new CheeseListFragment();
manager.beginTransaction()
.replace(R.id.root_content, fragment)
.commit();
}
#Override
public void enableScroll() {
final AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams)
collapsingToolbarLayout.getLayoutParams();
params.setScrollFlags(
AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL
| AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS
);
collapsingToolbarLayout.setLayoutParams(params);
}
#Override
public void disableScroll() {
final AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams)
collapsingToolbarLayout.getLayoutParams();
params.setScrollFlags(0);
collapsingToolbarLayout.setLayoutParams(params);
}
}
activity_main.xml:
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawer_layout"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:fitsSystemWindows="true">
<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.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary">
<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"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:id="#+id/root_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="fill_vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
</android.support.v4.widget.DrawerLayout>
Test Fragment:
public class CheeseListFragment extends Fragment {
private static final int DOWN = 1;
private static final int UP = 0;
private LayoutController controller;
private RecyclerView rv;
#Override
public void onAttach(Context context) {
super.onAttach(context);
try {
controller = (MainActivity) getActivity();
} catch (ClassCastException e) {
throw new RuntimeException(getActivity().getLocalClassName()
+ "must implement controller.", e);
}
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rv = (RecyclerView) inflater.inflate(
R.layout.fragment_cheese_list, container, false);
setupRecyclerView(rv);
// Find out if RecyclerView are scrollable, delay required
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
if (rv.canScrollVertically(DOWN) || rv.canScrollVertically(UP)) {
controller.enableScroll();
} else {
controller.disableScroll();
}
}
}, 100);
return rv;
}
private void setupRecyclerView(RecyclerView recyclerView) {
final LinearLayoutManager layoutManager = new LinearLayoutManager(recyclerView.getContext());
recyclerView.setLayoutManager(layoutManager);
final SimpleStringRecyclerViewAdapter adapter =
new SimpleStringRecyclerViewAdapter(
getActivity(),
// Test ToolBar scroll
getRandomList(/* with enough items to scroll */)
// Test ToolBar pin
getRandomList(/* with only 3 items*/)
);
recyclerView.setAdapter(adapter);
}
}
Sources:
Change scroll flags programmatically
Original code by Chris Banes
Need a postDelayed to ensure RecyclerView children are ready for calculations
Edit:
You should CollapsingToolbarLayout to control the behaviour.
Adding a Toolbar directly to an AppBarLayout gives you access to the enterAlwaysCollapsed and exitUntilCollapsed scroll flags, but not the detailed control on how different elements react to collapsing.
[...] setup uses CollapsingToolbarLayout’s app:layout_collapseMode="pin" to ensure that the Toolbar itself remains pinned to the top of the screen while the view collapses.http://android-developers.blogspot.com.tr/2015/05/android-design-support-library.html
<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<android.support.v7.widget.Toolbar
android:id="#+id/drawer_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"/>
</android.support.design.widget.CollapsingToolbarLayout>
Add
app:layout_collapseMode="pin"
to your Toolbar in xml.
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:layout_collapseMode="pin"
app:theme="#style/ToolbarStyle" />

So, proper credit, this answer almost solved it for me https://stackoverflow.com/a/32923226/5050087. But since it was not showing the toolbar when you actually had an scrollable recyclerview and its last item was visible (it would not show the toolbar on the first scroll up), I decided to modify it and adapt it for an easier implementation and for dynamic adapters.
First, you must create a custom layout behavior for you appbar:
public class ToolbarBehavior extends AppBarLayout.Behavior{
private boolean scrollableRecyclerView = false;
private int count;
public ToolbarBehavior() {
}
public ToolbarBehavior(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public boolean onInterceptTouchEvent(CoordinatorLayout parent, AppBarLayout child, MotionEvent ev) {
return scrollableRecyclerView && super.onInterceptTouchEvent(parent, child, ev);
}
#Override
public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes, int type) {
updatedScrollable(directTargetChild);
return scrollableRecyclerView && super.onStartNestedScroll(parent, child, directTargetChild, target, nestedScrollAxes, type);
}
#Override
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, AppBarLayout child, View target, float velocityX, float velocityY, boolean consumed) {
return scrollableRecyclerView && super.onNestedFling(coordinatorLayout, child, target, velocityX, velocityY, consumed);
}
private void updatedScrollable(View directTargetChild) {
if (directTargetChild instanceof RecyclerView) {
RecyclerView recyclerView = (RecyclerView) directTargetChild;
RecyclerView.Adapter adapter = recyclerView.getAdapter();
if (adapter != null) {
if (adapter.getItemCount()!= count) {
scrollableRecyclerView = false;
count = adapter.getItemCount();
RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
if (layoutManager != null) {
int lastVisibleItem = 0;
if (layoutManager instanceof LinearLayoutManager) {
LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
lastVisibleItem = Math.abs(linearLayoutManager.findLastCompletelyVisibleItemPosition());
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager staggeredGridLayoutManager = (StaggeredGridLayoutManager) layoutManager;
int[] lastItems = staggeredGridLayoutManager.findLastCompletelyVisibleItemPositions(new int[staggeredGridLayoutManager.getSpanCount()]);
lastVisibleItem = Math.abs(lastItems[lastItems.length - 1]);
}
scrollableRecyclerView = lastVisibleItem < count - 1;
}
}
}
} else scrollableRecyclerView = true;
}
}
Then, you only need to define this behavior for you appbar in your layout file:
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
app:layout_behavior="com.yourappname.whateverdir.ToolbarBehavior"
>
I haven't tested it for screen rotation so let me know if it works like this. I guess it should work as I don't think the count variable is saved when the rotation happens, but let me know if it doesn't.
This was the easiest and cleanest implementation for me, enjoy it.

It is not a bug, all the events in a viewGroup are handled this way. Because your recyclerview is a child of coordinatorLayout so whenever the event is generated, it is first checked for parent and if parent is not interested only then it is passed down to child.
See google documentation

Something like this in a LayoutManager subclass seems to result in the desired behavior:
#Override
public boolean canScrollVertically() {
int firstCompletelyVisibleItemPosition = findFirstCompletelyVisibleItemPosition();
if (firstCompletelyVisibleItemPosition == RecyclerView.NO_POSITION) return false;
int lastCompletelyVisibleItemPosition = findLastCompletelyVisibleItemPosition();
if (lastCompletelyVisibleItemPosition == RecyclerView.NO_POSITION) return false;
if (firstCompletelyVisibleItemPosition == 0 &&
lastCompletelyVisibleItemPosition == getItemCount() - 1)
return false;
return super.canScrollVertically();
}
The documentation for canScrollVertically() says:
/**
* Query if vertical scrolling is currently supported. The default implementation
* returns false.
*
* #return True if this LayoutManager can scroll the current contents vertically
*/
Notice the wording of "can scroll the current contents vertically", which I believe implies that the current state should be reflected by the return value.
However, that is not done by any of the LayoutManager subclasses provided through the v7 recyclerview library (23.1.1), which makes me somewhat hesitant whether it is a correct solution; it might cause undesired effects in other situations than the one discussed in this question.

I've implemented it using my own Behavior class which might be attached to AppBarLayout:
public class CustomAppBarLayoutBehavior extends AppBarLayout.Behavior {
private RecyclerView recyclerView;
private int additionalHeight;
public CustomAppBarLayoutBehavior(RecyclerView recyclerView, int additionalHeight) {
this.recyclerView = recyclerView;
this.additionalHeight = additionalHeight;
}
public boolean isRecyclerViewScrollable(RecyclerView recyclerView) {
return recyclerView.computeHorizontalScrollRange() > recyclerView.getWidth() || recyclerView.computeVerticalScrollRange() > (recyclerView.getHeight() - additionalHeight);
}
#Override
public boolean onStartNestedScroll(CoordinatorLayout parent, AppBarLayout child, View directTargetChild, View target, int nestedScrollAxes) {
if (isRecyclerViewScrollable(mRecyclerView)) {
return super.onStartNestedScroll(parent, child, directTargetChild, target, nestedScrollAxes);
}
return false;
}
}
And below is the code how to set this behavior:
final View appBarLayout = ((DrawerActivity) getActivity()).getAppBarLayoutView();
CoordinatorLayout.LayoutParams layoutParams = (CoordinatorLayout.LayoutParams) appBarLayout.getLayoutParams();
layoutParams.setBehavior(new AppBarLayoutNoEmptyScrollBehavior(recyclerView, getResources().getDimensionPixelSize(R.dimen.control_bar_height)));

I suggested you try this sample that for support desing library elements.
this a layout like your layout in the sample.
<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.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>

Thanks, I created a custom class of RecyclerView but the key is still using setNestedScrollingEnabled(). It worked fine on my side.
public class RecyclerViewCustom extends RecyclerView implements ViewTreeObserver.OnGlobalLayoutListener
{
public RecyclerViewCustom(Context context)
{
super(context);
}
public RecyclerViewCustom(Context context, #Nullable AttributeSet attrs)
{
super(context, attrs);
}
public RecyclerViewCustom(Context context, #Nullable AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
}
/**
* This supports scrolling when using RecyclerView with AppbarLayout
* Basically RecyclerView should not be scrollable when there's no data or the last item is visible
*
* Call this method after Adapter#updateData() get called
*/
public void addOnGlobalLayoutListener()
{
this.getViewTreeObserver().addOnGlobalLayoutListener(this);
}
#Override
public void onGlobalLayout()
{
// If the last item is visible or there's no data, the RecyclerView should not be scrollable
RecyclerView.LayoutManager layoutManager = getLayoutManager();
final RecyclerView.Adapter adapter = getAdapter();
if (adapter == null || adapter.getItemCount() <= 0 || layoutManager == null)
{
setNestedScrollingEnabled(false);
}
else
{
int lastVisibleItemPosition = ((LinearLayoutManager) layoutManager).findLastCompletelyVisibleItemPosition();
boolean isLastItemVisible = lastVisibleItemPosition == adapter.getItemCount() - 1;
setNestedScrollingEnabled(!isLastItemVisible);
}
unregisterGlobalLayoutListener();
}
private void unregisterGlobalLayoutListener()
{
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
{
getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
else
{
getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
}
}

I would like to add a little to user3623735's answer. The following code is absolutely incorrect.
// Find out if RecyclerView are scrollable, delay required
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
if (rv.canScrollVertically(DOWN) || rv.canScrollVertically(UP)) {
controller.enableScroll();
} else {
controller.disableScroll();
}
}
}, 100);
And even when it works - it doesn't cover all cases. There is absolutely no guarantee that a data will be displayed in 100 ms, and the data can stretch the height of the view in the process of working with it, not only in the onCreateView method. That's why you should use next code and track changes in view height:
view.addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
#Override
public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom) {
if(bottom != oldBottom)
{
mActivity.setScrollEnabled(view.canScrollVertically(0) || view.canScrollVertically(1));
}
}
});
Moreover no need to create two separated method to control scrolling status, you should use one setScrollEnabled method:
public void setScrollEnabled(boolean enabled) {
final AppBarLayout.LayoutParams params = (AppBarLayout.LayoutParams)
mToolbar.getLayoutParams();
params.setScrollFlags(enabled ?
AppBarLayout.LayoutParams.SCROLL_FLAG_SCROLL | AppBarLayout.LayoutParams.SCROLL_FLAG_ENTER_ALWAYS : 0);
mToolbar.setLayoutParams(params);
}

In your Toolbar remove the scroll flag, leaving only the enterAlways flag and you should get the effect you intended. For completeness, your layout should look 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/coordinatorLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="enterAlways"
app:theme="#style/ToolbarStyle" />
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>

Develop Reference

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