I want to achieve the scrolling technique used in Google Play Store app. The app portrays tabs below action bar. Once the content is scrolled up, it pushes the action bar up and finally hides it. At that point the tabs remain sticky at the top.
I tried the following code, but the flickering is there -
mRecyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
private static final int SCROLL_DIRECTION_UP = 1;
private static final int SCROLL_DIRECTION_DOWN = 2;
private int verticalDirection;
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if(newState == RecyclerView.SCROLL_STATE_SETTLING) {
if (verticalDirection == SCROLL_DIRECTION_UP && getActivity().getActionBar().isShowing()) {
getActivity().getActionBar().hide();
} else if (newState == SCROLL_DIRECTION_DOWN && !getActivity().getActionBar().isShowing()) {
getActivity().getActionBar().show();
}
}
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (dy > 0) {
verticalDirection = SCROLL_DIRECTION_UP;
} else {
verticalDirection = SCROLL_DIRECTION_DOWN;
}
}
});
Also, I'm not using ACTION_BAR_OVERLAY as I didn't find any justification to use it in my use case.
Can anyone point me to any resource regarding this?
Now you can easily achieve this using the official Android Design library.
Check this example:
https://github.com/chrisbanes/cheesesquare
Related
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.
my app has 3 fragments that are being inflated from mainActivity with BottomNavigationView. One of the fragments uses RecyclerView and is scrollable, with BottomNavigationView the last item in recyclerView is being covered up. According to Google's guidelines bottomNavigationView should hide on scroll down and show on scroll up. It's easy enough to make it hide from the mainAcitivity but it doesn't work when Im trying to hide it from the other fragment. How do I do this properly?
This code from recyclerView checks for the scroll state:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
if (dy > 0) {
//mainActivity.setNavigationVisibility(false);
} else if (dy < 0 ) {
//mainActivity.setNavigationVisibility(true);
}
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
});
And should call this method in the mainActivity that hides the bottomNavigationView:
public void setNavigationVisibility(boolean visible) {
if (navigation.isShown() && !visible) {
navigation.setVisibility(View.GONE);
}
else if (!navigation.isShown() && visible){
navigation.setVisibility(View.VISIBLE);
}
}
try this
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
if (dy > 0) {
((MainActivity)getActivity()).setNavigationVisibility(false);
} else if (dy < 0 ) {
((MainActivity)getActivity()).setNavigationVisibility(true);
}
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
});
When you use activity method from fragment then you have to create your method public and you can access that method by typecasting.
Basically I want my recyclerview to automatically scroll to a position where the item is not half shown. Like the one in googleplay.
I have written a code
public void scrollToVisible(){
int firstVisibleItemPosition = ((LinearLayoutManager) recyclerView.getLayoutManager()).findFirstVisibleItemPosition();
View view = recyclerView.getLayoutManager().getChildAt(0);
if (firstVisibleItemPosition > 0 && view != null) {
int offsetTop = view.getTop();
if (firstVisibleItemPosition - 1 >= 0 && adapter.getItemCount() > 0) {
((LinearLayoutManager) recyclerView.getLayoutManager()).scrollToPositionWithOffset(firstVisibleItemPosition - 1, offsetTop);
}
}
}
The problem comes next. I dont know where to put this code. I have a vague idea to put it when the recyclerview stops on scrolling but I've been searching for quite some time now and i cant find such a method. when i put it on the onScroll some unexpected behavior comes out
You may create a CustomRecyclerView extending RecyclerView
public class CustomRecyclerView extends RecyclerView {
#Override
public void onScrollStateChanged(int state) {
super.onScrollStateChanged(state);
// check if scrolling has stopped
if (state == SCROLL_STATE_IDLE) {
LinearLayoutManager linearLayoutManager = (LinearLayoutManager) getLayoutManager();
// use code here
}
}
If it maybe of any help to someone:
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
Log.d("y value",String.valueOf(dy));
if (dy > 0) {
//scrolling up
} else {
// Scrolling down
}
}
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if (newState == AbsListView.OnScrollListener.SCROLL_STATE_FLING) {
// Do something
Log.e("SCROLL_STATE_FLING","SCROLL_STATE_FLING");
} else if (newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL) {
Log.e("SCROLLTOUCH_SCROLL","SCROLL_STATE_TOUCH_SCROLL");
//slideUp(party_view);
// Do something
} else if (newState==AbsListView.OnScrollListener.SCROLL_STATE_IDLE){
// Do something
//slideDown(party_view);
Log.e("SCROLL_STATE_IDLE","SCROLL_STATE_IDLE");
}
}
});
complete example with UI synchronization
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(#NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
Handler handler = new Handler(getMainLooper());
if (newState == 0) {
handler.removeCallbacks(MainActivity.this::hideFab);
handler.postDelayed(MainActivity.this::showFab, 400);
} else {
handler.removeCallbacks(MainActivity.this::showFab);
handler.postDelayed(MainActivity.this::hideFab, 100);
}
}
});
private void hideFab() {
addFile.hide();
addText.hide();
camera.hide();
}
private void showFab() {
addFile.show();
addText.show();
camera.show();
}
I want to implement pagination with recyclerView, for this I add addOnScrollListener to the recyclerView but I am having trouble with RecyclerView.OnScrollListener not working when I set rvGridExplore.setNestedScrollingEnabled(false);
But when I remove rvGridExplore.setNestedScrollingEnabled(false); it is working fine,
I don't know how to handle this.
Here is code:
rvGridExplore = (RecyclerView) view.findViewById(R.id.rvGridExplore);
final GridLayoutManager glm = new GridLayoutManager(context,2);
// rvGridExplore.setNestedScrollingEnabled(false);
rvGridExplore.setLayoutManager(glm);
// final int visibleItemCount,totalCount,pastVisibleItems;
rvGridExplore.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
Log.v("scrollll","state changed");
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (dy > 0) {
int totalCount = glm.getItemCount();
int visibleItemCount = glm.getChildCount();
int pastVisibleItems = glm.findFirstVisibleItemPosition();
if (loading) {
if ((visibleItemCount + pastVisibleItems) >= totalCount) {
Log.v("scroll","scrolled"+pastVisibleItems);
}
}
}
}
});
Do add setOnScrollChangeListner to your NestedScrollView
nestedScrollview.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {
#Override
public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
if (scrollY == (v.getChildAt(0).getMeasuredHeight() - v.getMeasuredHeight())) {
if(loading)
onClick();
loading=false;
}
}
});
after loading data from server set boolean loading=true.
This question may be old, but to help others who stumbled upon this problem, i would like to share what i did. I had to implement onScroll Listener to recyclerview to load data from server and to make some UI changes. And also needed swipeRefresh Layout for refreshing data.
This was my xml file structure,
-RelativeLayout
-SwipeRefreshLayout
-NestedScrollView
-LinearLayout(Vertical)
-Multiple views required
After this, to detect up and down scrolling i implemented setOnScrollListener to the NestedScrollView.
Normal usage of SwipeRefreshLayout to refresh data.
And to load more data i implemented the logic inside onScrollListener of NestedScrollingView.
if (scrollY == (v.getChildAt(0).getMeasuredHeight() - v.getMeasuredHeight())) {
// Load More Data
}
If you are recyclerView is embedded in any of the NestedScrollView, then you are supposed to attach the onScrollListener to NestedScrollView.
This will work!
if (recyclerView.getLayoutManager() instanceof GridLayoutManager) {
final GridLayoutManager gridLayoutManager = (GridLayoutManager) recyclerView.getLayoutManager();
nestedScrollView.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {
#Override
public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
if (scrollY == (v.getChildAt(0).getMeasuredHeight() - v.getMeasuredHeight())) {
totalItemCount = gridLayoutManager.getItemCount();
lastVisibleItem = gridLayoutManager.findLastVisibleItemPosition();
if (!loading
&& totalItemCount <= (lastVisibleItem + visibleThreshold)) {
// End has been reached
// Do something
if (onLoadMoreListener != null) {
onLoadMoreListener.onLoadMore();
}
loading = true;
}
}
}
});
}
You said in a comment to your question "
it is under NestedScrollView which is under coordinator layout, if i remove this, Toolbar is not scrolling up". This is a mistake.
I have found that you cannot have it both ways, the CoordinatorLayout behaviour breaks when you have a RecyclerView inside a NestedScrollView to which you've added the behaviour. You need to use one or the other.
When you have a RecyclerView inside a NestedScrollView it will work as long as you set RecyclerView.setNestedScrollingEnabled(false), but as you found out this means that the OnScrollListener is not called.
The only way for all components to work correctly is to remove the NestedScrollView, make sure you do not set nesting scroll to false and work from there. Otherwise the RecyclerView.OnScrollListener events will not fire correctly.
Step 1 : Create EndlessRecyclerOnScrollListener
public abstract class EndlessRecyclerOnScrollListener extends RecyclerView.OnScrollListener {
public static String TAG = EndlessRecyclerOnScrollListener.class.getSimpleName();
// use your LayoutManager instead
private LinearLayoutManager llm;
public EndlessRecyclerOnScrollListener(LinearLayoutManager sglm) {
this.llm = llm;
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (!recyclerView.canScrollVertically(1)) {
onScrolledToEnd();
}
}
public abstract void onScrolledToEnd();
}
Step 2: Apply scroll listener to recycler view.
recyclerview.addOnScrollListener(new EndlessRecyclerOnScrollListener(mLayoutManager) {
#Override
public void onScrolledToEnd() {
Log.e("Position", "Last item reached");
if (loadMore == true) {
// put your Load more code
// add 10 by 10 to tempList then notify changing in data
}
}
});
remove the nested scroll view use linear or relative layout instead of it as root element then you can write recyclerview.setNestedScrollEnabled(false);
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.
}
}
};