How can I implement this kind of UI, where we have two recyclerViews. One scrolls horizontally and the second one vertically. when the second one scrolls first one also scrolls top together.
I tried to implement using NestedScrollView, but I had to make second recyclerView height wrap content which causes recyclerView not recycle.
The second way that I tried was having one recyclerView. And adding horizontal recyclerview as a header. The problem was to save header recyclerview scroll state when navigation. And there had been crashes when loading next page (paging 3) in header recyclerView.
The question is: Is there any optimal solution for this kind of ui?
In cases, Like this, you don't have to use 2 RecyclerView and you also have to avoid using RecyclerView insideScrollView. instead of this you have to use one vertical RecyclerView with multitype view Adapter.
in this way, you are going to have 2 different ViewHolder one of them is a horizontal recyclerView (your top item) and the other one is your other items.
for learning multitype adapter you can see this:
How to create RecyclerView with multiple view types
and for a horizontal recyclerView inside a vertical RecyclerView you can see this :
https://medium.com/#ashishkudale/android-list-inside-list-using-recyclerview-73cff2c4ea95
you have to combine these 2.
I could not understand the meaning of "header" where you said "adding horizontal recyclerview as a header" but if you did what I told and the problem is the state of inner Horizontal recyclerView, I think probably you are calling setAdapter method of horizontal RecyclerView in OnBind() method of your vertical recycler view, it is a common mistake that I have seen in many tutorials.
if you have done this mistake , try to call setAdapter of your inner recyclerView in the constructor of its viewHolder and just update the list using yourHorizontalAdapter.notifyDataSetChanged() in onBind() method of VerticalRecylerView,
and if its not the case and your recyclerView is completely destroying see this link :How to save RecyclerView's scroll position using RecyclerView.State?
Related
I have two RecyclerView inside the NestedScrollView and I need track viewed items of my RecyclerViews. But problem that using nestedScrollView the recycler pattern doesn’t work and all the views will be loaded at once because wrap_content needs the height of complete RecyclerView so it will draw all child Views at once.
Is there any way to track of the viewed items with this approach? Please help me.
never use RecyclerView inside NestedScrollView because your ViewHolders will not be recycled and you will be in danger of OutOfMemoeryExceptions, it may work for lists with small sizes but as the list size increases it becomes worse,
instead of using one ScrollView and 2 RecyclerView as child
you have to completely remove ScrollView and instead of that, use one RecyclerView with multitype ViewHolders, in other words you need to combine those 2 RecyclerView in on RecyclerView .
To achieving this you can combine those adapters manually or you can use ConcatAdapter that depends on what you want, this link may also help you if you want to use ConcatAdapter but that is not necessary.
then you can have different approaches to track the visibility of viewHolders like layoutManager.findFirstVisibleItemPosition() and etc.
I'm trying to design a row list using RecyclerView like Android TV ↳ android.support.v17.leanback.widget.ListRow. I'm able to design list with title but not row list. Can anyone help me?
Please Follow this Link for
Recycer view like play store
Use Two RecyclerView Outer Recycler is vertical and Second horizontal recycler is item of first recycler View
All you need is to call mInnerRecycler.setNestedScrollingEnabled(false); on your inner RecyclerViews and use Horizontal scrollview as root of mInnerRecyclerView
Explanation:
RecyclerView has support for nested scrolling introduced in API 21 through implementing the NestedScrollingChild interface. This is a valuable feature when you have a scrolling view inside another one that scrolls in the same direction and you want to scroll the inner View only when focused.
In any case, RecyclerView by default calls RecyclerView.setNestedScrollingEnabled(true); on itself when initializing. Now, back to the problem, since both of your RecyclerViews are within the same ViewPager that has the AppBarBehavior, the CoordinateLayout has to decide which scroll to respond to when you scroll from your inner RecyclerView; when your inner RecyclerView's nested scrolling is enabled, it gets the scrolling focus and the CoordinateLayout will choose to respond to its scrolling over the outer RecyclerView's scrolling. The thing is that, since your inner RecyclerViews don't scroll vertically, there is no vertical scroll change (from the CoordinateLayout's point of view), and if there is no change, the AppBarLayout doesn't change either.
In your case, because your inner RecyclerViews are scrolling in a different direction, you can disable it, thus causing the CoordinateLayout to disregard its scrolling and respond to the outer RecyclerView's scrolling.
Notice:
The xml attribute android:nestedScrollingEnabled="boolean" is not intended for use with the RecyclerView, and an attempt to use android:nestedScrollingEnabled="false" will result in a java.lang.NullPointerException so, at least for now, you will have to do it in code.
RecyclerView can check View Type for return header or item. And use layout manager for manage how to item scrolling direction.
RecyclerView (vertical scrolling)
- item -> RecyclerView (horizontal scrolling) check view type is header or item with condition example : is object has type header
Ref : Google play store like interface using recycler view
I created an activity with a ListView. That is a Friend ListView.
I wanna let it choose to add it to another View.
I don't know which View to choose is the best. Recyclerview or ScrollView?
Like this
Basic difference between RecyclerView and ListView are the below.
ListView is simple to implement. Default Adapters available.
But ViewHolder pattern and finding views using ID's used to give slow performance.
Now in RecyclerView , the above problems are attended using RecyclerView.ViewHolder.
For RecyclerView adapter, this ViewHolder is mandatory. While comparing to list view this is kinda complex, but solves performance issues in ListView.
Difference LayoutManagers are available while using RecyclerView.
LinearLayoutManager
StaggeredGridLayoutManager
GridLayoutManager
Major improvement of RecyclerView performance while comparing to ListView would be this according to developer.android.com
The RecyclerView creates only as many view holders as are needed to
display the on-screen portion of the dynamic content, plus a few
extra. As the user scrolls through the list, the RecyclerView takes
the off-screen views and rebinds them to the data which is scrolling
onto the screen
To sumup, RecyclerView is preferable than ListView (when UI is having same widgets repeating according to your data)
Now when to use ScrollView:
Your UI elements may not show completely in small device screens. But in bigger screen sizes it may!
Elements may not be necessarily only list / grid. It can have combinations of any UI widgets.
Eg:- TextViews vertically , with RadioButton and Button at last for user action.
This cannot be included in ListView/ RecyclerView , now you can add ScrollView which will have a LinearLayout/RelativeLayout . Inside which all other elements can be added.
Now you can
I recommend to user always RecyclerView and never a ListView. Use RecyclerView for element list and scrollview for static views.
Seeing your image Scrollview inside RecyclerView or ListView have problems with drag.
Use a vertical RecyclerView in all page and horizontal RecyclerView each row.
I suggest you to use RecyclerView because you will load lots of images and if you use ScrollView eventually you will use so much memory. Also it is recommended to use RecyclerView when you have dynamic data. You can look the definition of the RecyclerView in the Android Documentation as follow
RecyclerView is a view for efficiently displaying large data sets by
providing a limited window of data items.
You can use nested RecyclerView for creating such hierarchal view.
You can also checkout this example for nested RecyclerView usage.
Also you can further read:
Android Recyclerview vs ListView with Viewholder
RecyclerView vs. ListView
Should we use RecyclerView to replace ListView?
I hope this helps.
Structure of my Android app is forcing me to create Vertical Nested RecyclerView inside Vertical Nested RecyclerView because of the pre-drawing all nested items inside every RootRecyclerView. The View of RootRecyclerView has approximately 5 - 10 views and the View of InsideRecyclerView consists also from 5-10 views. There is not necessarity for scrolling this ChildRecyclerView, because all scrolling is handled by RootRecyclerView (same term as Nested RecyclerView)
I have two options:
1. ChildRecyclerView, that will predraw all child items when the root item will reached the screen (it lags, but the result looks good under the 30 child rows)
2. Join the Root+Child View, remove Child RecyclerView and the all logic will be handled in the Root RecyclerView. - i tried this, also used ConstraintLayout, so the whole layout was only 1-LEVEL, but it was still laggy, even if I set Visibility of half of the views in this layout. I also setup setHasFixedSize(true), tried to use Cache methods of RecyclerView, initialCacheItemSize and so on.
So do you have any ideas, how to solve this problem? Did somebody of you met with this kind of problem? You could also imagine the case of ChildRecyclerView inside another ChildRecyclerView that is inside RootRecyclerView.
I want Horizontal scrollable items in vertical recyclerView. horizontal items will not be more than 10 in any case.
I thought of two approaches
1) Horizontal Recyclerview as item in vertical RecyclerView
2) Custom horizontalScrollView as an item in vertical RecyclerView
I have implemented first one facing some issues in scrolling but I think I will manage that.
My question is, why not second approach. I have seen all related question on SO and most of them trying to do with first approach. Why is it so?
What is disadvantage? specially I you have limited number in horizontal view.
Any pointer would be great help.
Why do we use RecyclerView instead of LinearLayout?
Because if we use a LinearLayout consisting of (let's say 50 items) they will be all rendered on screen (50 Views) and this will lead to very very bad performance issues and scalability issues. RecyclerView does initialize the views that appears on screen only ,let's say 7 views, and they will be recycled in every new row that comes.
Why do we use Horizontal Recyclerview instead of Horizontal ScrollView?
This is not usually the case. If you have multiple items in every row that needs to be recycled then you should use Horizontal RecyclerView otherwise it won't matter at all.
To summarize,
The views in the vertical RecyclerView will got recycled whether it has another horizonal RecyclerView or Horizontal ScrollView, but the views inside the Horizontal ScrollView will not get recycled and the views inside the Horizontal RecyclerView will got recycled as it's a RecyclerView.
If you don't have multiple items in your Horizontal RecyclerView, you shall use Horizontal ScrollView instead.