How can I get object from recyclerview when it leaves screen while scrolling? For example I have note with id 11 how can I get this note id whenever it leaves screen?
One way you could do it:
Boolean upScrolling;
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
LinearLayoutManager mgr = (LinearLayoutManager) recyclerView.getLayoutManager();
int topPosition = mgr.findFirstVisibleItemPosition();
/// your code
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (dy < 0) {
upScrolling = true;
} else if (dy > 0) {
upScrolling = false;
}
}
});
After scrolling up, in the listener you get the 1st visible item. At the position your code you write the code to check if the 1st visible item is the one below the item you want. If this is the case then you get the time it went off the screen.
Edited to check if it scrolls up or down.
Related
I have a RecyclerView with Horizontal LinearLayoutManager.
I would like to check ScrollListener.
My goal is to check these steps:
Check when RecyclerView start scroll
Check when RecyclerView end scroll
Check when RecyclerView's scroll is in center position
Here is a my RecyclerView code with LinearLayoutManager.
LinearLayoutManager horizontalManager = new LinearLayoutManager(context);
horizontalManager.setOrientation(LinearLayoutManager.HORIZONTAL);
viewHolderStory.recyclerView.setLayoutManager(horizontalManager);
viewHolderStory.recyclerView.addItemDecoration(new PaddingItemDecoration((Activity) context));
viewHolderStory.recyclerView.setHasFixedSize(true);
viewHolderStory.recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
});
viewHolderStory.recyclerView.setNestedScrollingEnabled(false);
Is any way to add validation on my addOnScrollListener method?
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if(newState==RecyclerView.SCROLL_STATE_IDLE){
/// User Stops Scroll
}
if(newState==RecyclerView.SCROLL_STATE_DRAGGING){
/// User Starts Scroll
}
}
You can find more from this.
You can compute this with computeVerticalScrollExtent() , computeVerticalScrollOffset() and computeVerticalScrollRange()
if your recyler view is horizontal, these functions have a horizontal counterpart
full code :
viewHolderStory.recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener()
{
#Override
public void onScrolled(#NonNull RecyclerView recyclerView, int dx, int dy) {
int extent = recyclerView.computeVerticalScrollExtent();
int offset = recyclerView.computeVerticalScrollOffset();
int range = recyclerView.computeVerticalScrollRange();
if(offset == 0){
//fire when recycler view hit top
Log.i("myTag", "onScrolled: top");
}
else if(offset + extent == range){
//fire when recycler view hit bottom
Log.i("myTag", "onScrolled: bottom");
}
else {
//fire the rest of the time
Log.i("myTag", "onScrolled: middle");
}
}
});
I am using RecyclerView with CarouselLayoutManager library and i want to detect the most elevated item.
I have the method below to know if the user scrolled the recyclerview and change the current most elevated recyclerview item.
recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
int overallXScroll = 0;
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
overallXScroll = overallXScroll + dx;
//if the scroll amount will change the recyclerView item order :
if(overallXScroll > 100){
Toast.makeText(MainActivity.this, "123", Toast.LENGTH_SHORT).show();
overallXScroll = 0;
}
Log.i("check","overallXScroll->" + overallXScroll);
}
});
This method works very slow and with a delay , what can i do ?
I have implemented addonscrollListener for my recyclerview since I want to
hide my FAB when recyclerview is scrolled as follows :
mRvNearby.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
Log.e("DY",""+dy);
if(dy<0){
mFloatingActionMenu.hideMenuButton(true);
}else{
mFloatingActionMenu.showMenuButton(true);
}
}
});
But unfortunately, when I use this listener, the "dy" only changes once, and when I scrolled continuously, the value
hasn't changed.
I was expecting that when scrolled down, The value will be less than 0.
and when scrolled up, the value is greater than 0.
Use greater than sign instead of less than. When you scroll down the value is greater than 0. So your code will be :
mRvNearby.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
Log.e("DY",""+dy);
if(dy>0){
mFloatingActionMenu.hideMenuButton(true);
}else{
mFloatingActionMenu.showMenuButton(true);
}
}
});
You can use FloatingActionButton.Behavior for showing/hiding FAB while Recyclerview scrolls.
Check out this Tutorial
I need to implement a simple chat client on Android and in this application there is a stackFromEnd in my RecyclerView which I need to populate its data from database (or my server). So I added OnScrollListener to my list as below.
messageList.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
if (messageLoading == false && layoutManager.findFirstCompletelyVisibleItemPosition() == 0) {
messageLoading = true;
ActionManager.getInstance().getChatAction().getThreadMessages(thread);
}
super.onScrolled(recyclerView, dx, dy);
}
});
The problem is when its called, the RecyclerView jumps to the first item of the list.
P.S:
ActionManager.getInstance().getChatAction().getThreadMessages(thread)
Just adds new items to adapter and calls notifyDataSetChanged
P.S.S:
Is there any library for message list (e.g. whatsapp, messenger etc.?!)
I am developing an App for Android TV via Nexus Player. In my App, I use the VerticalGridFragment to show TV shows. For shows' number is 2000+, I want to use page loading when the VerticalGridView scrolls to its bottom.
However, I get stuck on how to judge the VerticalGridView has scrolled to bottom.
I use reflect to get the VerticalGridView,and addScrollListener() to it.Here the codes:
private void addGridScrollListener() {
try {
Class<VerticalGridFragment> VerticalGridFragmentClass = VerticalGridFragment.class;
Field verticalGridViewHolder = VerticalGridFragmentClass.getDeclaredField("mGridViewHolder");
verticalGridViewHolder.setAccessible(true);
VerticalGridPresenter.ViewHolder viewHolder = (VerticalGridPresenter.ViewHolder) verticalGridViewHolder.get(this);
VerticalGridView gridView = viewHolder.getGridView();
gridView.addOnScrollListener(scrollListener);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (NoSuchFieldException e) {
e.printStackTrace();
}
}
private RecyclerView.OnScrollListener scrollListener = new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
};
RecyclerView doesn't has the function such as getLastVisiableItemPosition, so I can't know if the VerticalGridView has scrolled to bottom or not.
What should I do in the scrollListener ? Or is there any other solutions?
Thanks!
I found the solution:
private RecyclerView.OnScrollListener scrollListener = new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if (newState != RecyclerView.SCROLL_STATE_IDLE) {
return;
}
//get current last child View
View lastChildView = recyclerView.getLayoutManager().getChildAt(recyclerView.getLayoutManager().getChildCount() - 1);
//get the bottom
int lastChildBottom = lastChildView.getBottom();
// get recyclerView's bottom
int recyclerBottom = recyclerView.getBottom() - recyclerView.getPaddingBottom();
//get last childview's position
int lastPosition = recyclerView.getLayoutManager().getPosition(lastChildView);
if (lastChildBottom == recyclerBottom && lastPosition == recyclerView.getLayoutManager().getItemCount() - 1) {
// yes to bottom.
}
}
};