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Android RecyclerView add horizontal gape in beginning and in ending

I am trying to replicate a view from iOS so that user have same look and feel throughout the android application as well.
I am having a RecyclerView with LinearLayoutManager and horizontal orientation. So far so good.
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layoutManager="android.support.v7.widget.LinearLayoutManager"
tools:listitem="#layout/item_recycler_view" />
With the output design:
However, in case of iOS design we have items starting from center however the horizontal view is completely scrollable (meaning the scrolling can be done to full width even if the item loading from center).
I know there is no use of adding padding/margin or using a different view like HorizontalScrollView. How can we obtain such behaviour so that i give nearly same experience to users.
Let me know if there is anything that i can provide to clarify the problem statement.

Quick solution
Add an empty item on the beginning and one on the end of your list, and make your index access account for those two extra items. That should help you get the desired effect.
Not so quick solution
Android allows us to write our own custom Layout Managers for RecyclerView. It comes with three types that will cover most of the user cases:
LinearLayoutManger (For lists in general);
GridLayoutManager (For grids);
StaggeredGridLayoutManager (For grids with items with custom sizes).
I believe you could write one to always start placing the first item on the center of the screen. That will require more work, but it won't mess with your data indexes.
Read this, and this, on how to create custom Layout Managers. Also, take a look at the docs. That should be a good place to start.

There are two ways you could do this. The simplest by far would be to add horizontal padding to your RecyclerView and set the view to not clip based on padding. Something like this:
android:paddingLeft="100dp"
android:paddingRight="100dp"
android:clipToPadding="false"
The other way would be to create an ItemDecoration and add it to your RecyclerView. You could then override the getItemOffsets() method to add a left-hand offset to your first item and a right-hand offset to your last item.
This second approach is better because it won't affect the RecyclerView's scrollbars, but it is a little more complex. Here's an example to get you started:
private static class MyItemDecoration extends RecyclerView.ItemDecoration {
#Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int parentWidth = parent.getWidth();
int childWidth = view.getWidth();
int margin = (parentWidth - childWidth) / 2;
int position = parent.getChildAdapterPosition(view);
outRect.left = position == 0 ? margin : 0;
outRect.right = position == (parent.getAdapter().getItemCount() - 1) ? margin : 0;
}
}

I think the only way will be adding different layout for first and last position in adapter of recyclerview.
It can be done using viewType parameter in createViewHolder(ViewGroup parent, int viewType)

Horizontal RecyclerView with variable item heights not wrapping properly

What I intend to achieve
The item view should occupy the entire height of the item
It could be that the item height is lesser than the height of the tallest item in the recyclerview, in which case it should just stick to the top like in the screenshot above.
The bug I'm running into
As in the screenshot above, views are getting truncated.
What I've tried so far
Initially I went with wrap_content on the recyclerview, now that it is supported. It didn't work when none of the views visible on the screen at the time were the tallest. This makes sense in how the view hierarchy is laid out. How can the height of something which hasn't even been bound to any data yet be calculated if the height is dependent on that data?
Workaround time :S
Instead of trying a custom layoutmanager, I first went with what I felt needed to be done - laying out all item views at the beginning to figure out their height.
There's a progressbar and an animation playing in the upper part of the screen to catch the user's attention while all this happens with recyclerview visibility set to invisible. I use two things, one didn't suffice - I've attached an observer in the adapter's onViewAttached() call and I've used a scroll change listener as well. There's a LinearSnapHelper attached to the recycler view to snap to adjacent (next or previous, depending on the scroll direction) position on scroll.
In this setup,
I'm going to each position in the recyclerview using layoutManager.smoothScrollToPosition()
Getting the child view height using
View currentChildView = binding.nextRv.getChildAt(layoutManager.findFirstCompletelyVisibleItemPosition());
if (currentChildView != null) {
currentChildHeight = currentChildView.getHeight();
}
in scroll change listener on RecyclerView.SCROLL_STATE_IDLE or by passing the height to the view attached observer mentioned above in the adapter's onViewAttachedToWindow()
#Override
public void onViewAttachedToWindow(BindingViewHolder holder) {
if (mObserver != null) {
mObserver.onViewAttached(holder.binding.getRoot().getHeight());
}
}
Storing a maxHeight that changes to the max of maxHeight and new child's height.
As is evident, this is ugly. Plus it doesn't give me the current view's height - onAttached means it's only just attached, not measured and laid out. It is the recycled view, not the view bound to current data item. Which presents problems like the truncation of view illustrated above.
I've also tried wrap_content height on the recycler view and invalidating from recycler's parent till the recycler and the child on scroll coming to SCROLL_STATE_IDLE. Doesn't work.
I'm not sure how a custom layoutmanager can help here.
Can someone guide me in the right direction?

I could not accept #Pradeep Kumar Kushwaha's answer because against one solution, I do not want different font sizes in the list. Consistency is a key element in design. Second alternative he gave couldn't work because with ellipsize I would need to give a "more" button of some sort for user to read the entire content and my text view is already taking a click action. Putting more some place else would again not be good design.
Changing the design with the simple compromise of resizing the recyclerview when the tallest, truncated item comes into focus, it turns into the simple use case of notifyItemChanged(). Even for the attempt I made using the view attached observer and scroll state listener, notifyItemChanged could be used but that approach is just too hacky. This I can live with in both code and design. Here goes the code required.
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
if (newState == RecyclerView.SCROLL_STATE_IDLE) {
int position = ((LinearLayoutManager) binding.nextRv.getLayoutManager())
.findFirstVisibleItemPosition();
if (position != nextSnippetAdapter.getItemCount() - 1) {
binding.nextRv.getAdapter().notifyItemRangeChanged(position, 2);
} else {
binding.nextRv.getAdapter().notifyItemChanged(position);
}
}
}
For my particular setup, calling for just these two elements works. It can further be optimized so as to call for single element at position + 1 in most cases, and checking and calling for the appropriate one in corner (literal) cases.

Inside your adapter where I can find two cards one on top and another on bottom
How I would have defined my layout is like this:
Cardview1
LinearLayout1 --> orientation vertical
cardview2 (Top card where text is written)
Linearlayout2 (where I can see icons such as like etc)-->orientation horizontal
Now fix the height of Linearlayout2 by setting it to wrap content.
And the height of cardview2 should be 0dp and add weight = 1
Now inside cardview2 add a TextView1 to matchparent in height and width.
Better inside textview1 add ellipsize to end and add max lines
If you want to show all lines try to find autoresizetextview library it can be founded here --> AutoResizeTextView
Hope it helps.

I think the recyclerview can be set to height wrap_content. And the items can be make like height to match_parent.
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layput_height="wrap_content"/>
Item as:
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
// your coode
</androidx.constraintlayout.widget.ConstraintLayout>
I had little more requirement than the question. Even my problem solved in the way.
Remember I am using:
androidx.recyclerview:recyclerview:1.0.0-beta01
dependency for the project

notifyItemChanged() make the RecyclerView scroll and jump to UP

i have a RecycleView with an adapter that show a list of servers
and the user must select one server.
when i call notifyItemChanged(previousPosition) inside the onClick() method
to make the old server unselected and the new server selected,
that's make the RecycleView list jump to up exactly in the middle of list.
and this problem happen just when i click on one of the last 2 or 3 servers inside the RecycleView list
here is the code of my RecyclerView.Adapter :
public class ServerAdapter extends RecyclerView.Adapter<ServerAdapter.ServerViewHolder> {
private List<Server> listServers = new ArrayList<>();
private int[] icons = new int[]{R.drawable.server1,R.drawable.server2,R.drawable.server3,R.drawable.server4,R.drawable.server5,R.drawable.server6,R.drawable.offline};
private int selected = 0;
private int previousSelected = 0;
public ServerAdapter(List<Server> listServers){
this.listServers = listServers;
}
#Override
public ServerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.server_relative_layout,parent,false);
return new ServerViewHolder(view);
}
#Override
public void onBindViewHolder(final ServerViewHolder holder, final int position) {
if(position == selected){
holder.getBackground().setSelected(true);
}else{
holder.getBackground().setSelected(false);
}
holder.getBackground().setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(position != selected){
previousSelected = selected;
selected = position;
holder.getBackground().setSelected(true);
notifyItemChanged(previousSelected);
}
}
});
holder.getImageServer().setImageResource(icons[position%6]);
holder.getTextNameServer().setText(listServers.get(position).getName());
holder.getTextConnected().setText(listServers.get(position).getUrl());
}
#Override
public int getItemCount() {
return listServers.size();
}
public class ServerViewHolder extends RecyclerView.ViewHolder{
private ImageView imageServer;
private TextView textNameServer;
private TextView textConnected;
private View background;
public ServerViewHolder(View itemView) {
super(itemView);
imageServer = (ImageView)itemView.findViewById(R.id.imageServer);
textNameServer = (TextView)itemView.findViewById(R.id.textNameServer);
textConnected = (TextView)itemView.findViewById(R.id.textConnected);
background = itemView;
}
public ImageView getImageServer() {
return imageServer;
}
public TextView getTextConnected() {
return textConnected;
}
public TextView getTextNameServer() {
return textNameServer;
}
public View getBackground() {
return background;
}
}
}
any solutions to solve this problem ? thanks.
The problem happened exactly when i specify the layout height and do not let it to wrap_content
<android.support.v7.widget.RecyclerView
android:layout_width="wrap_content"
android:layout_height="400dp"
android:id="#+id/serverRecyclerView"
android:layout_margin="10dp"
/>
or when i put it below something for expample like that :
<android.support.v7.widget.RecyclerView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/serverRecyclerView"
android:layout_margin="10dp"
android:layout_below="#+id/image"/>
my code exactly is :
<android.support.v7.widget.RecyclerView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/serverRecyclerView"
android:layout_margin="10dp"
android:layout_alignTop="#+id/imageBall"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:layout_toRightOf="#+id/camera"
android:layout_toEndOf="#+id/camera"/>

Looks like this is a bug: https://code.google.com/p/android/issues/detail?id=203574
The best workaround seems to be Bart's answer to set the RecyclerView's LinearLayoutManager's AutoMeasure property to false.
LinearLayoutManager llm = new LinearLayoutManager(context);
llm.setAutoMeasureEnabled(false);
recyclerView.setLayoutManager(llm);
The set FixedSize to true solution had way too many side-effects...
RecyclerView.setHasFixedSize(true)

I don't know why, but I used:
RecyclerView.setHasFixedSize(true)
This worked for me. I hope it can help.

android:descendantFocusability="blocksDescendants"
android:descendantFocusability="blocksDescendants"
this attr solve my bug

RecyclerView.ItemAnimator animator = myRecyclerListView.getItemAnimator();
if (animator instanceof SimpleItemAnimator) {
((SimpleItemAnimator)animator).setSupportsChangeAnimations(false);
}

My RecyclerView was inside ConstraintLayout, and I also had such problem and calling setAutoMeasureEnabled(false) of RecyclerView's LayoutManager did not fix the issue for me, furthermore this method is deprecated in 28.0.0 version. What I did is that, I wrapped my RecyclerView with RelativeLayout and now it works like a charm. As mentioned in bugtracker, this "issue" is intented behaviour in LinearLayout and is not going to be fixed. So if it is possible, just wrap your RecyclerView something like this:
<RelativeLayout
android:id="#+id/container_messages_list"
android:layout_width="match_parent"
android:layout_height="0dp"
android:background="#drawable/chat_back_pattern"
app:layout_constraintBottom_toTopOf="#+id/bottom_view"
app:layout_constraintTop_toBottomOf="#+id/toolbar">
<android.support.v7.widget.RecyclerView
android:id="#+id/messages_list"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</RelativeLayout>

for anyone who stumbles upon this issue, try using
yourRecyclerView.notifyItemChanged(int position, Object payload);
This one did the trick for me.
Using
setAutoMeasureEnabled(false);
also worked but in some edge cases recycler view was acting weird. Good luck!

RecyclerView can perform several optimizations if it can know in advance that RecyclerView's size is not affected by the adapter contents. RecyclerView can still change its size based on other factors (e.g. its parent's size) but this size calculation cannot depend on the size of its children or contents of its adapter (except the number of items in the adapter).
If your use of RecyclerView falls into this category, set this to true. It will allow RecyclerView to avoid invalidating the whole layout when its adapter contents change.
If we have a RecyclerView with match_parent as height/width, we should add setHasFixedSize(true) since the size of the RecyclerView itself does not change inserting or deleting items into it.
setHasFixedSize should be false if we have a RecyclerView with wrap_content as height/width because each element inserted by the adapter could change the size of the RecyclerView depending on the items inserted/deleted, so, the size of the RecyclerView will be different each time we add/delete items.
recyclerView.setHasFixedSize(true);
true if adapter changes cannot affect the size of the RecyclerView.
References
Android Developers Reference - RecyclerView
Understanding RecyclerView setHasFixedSize - Gastón Saillén

I came across the similar problem, just take care of the xml layout file.
Do not use the layout_below , layout_above or others similar properties in RecyclerView or RecyclerView's parent view.
You can use LinearLayout weight , layout_marginBottom or sth to achieve
layout_below or other.

The late answer better than nothing, if you're using NestedScrollView as the parent view of RecyclerView you should delete it.

I had a similar problem and I tryed all solutions listed above, but noone worked.
I was already padding the "Payloads" to "notifyItemChanged(position, payloads)" because I just needed to "upload" a checkbox value so I was passing the value inside "Payloads" without recalling the update of the entire viewholder.
This solution worked for all view holders in my recycler view except for the last one (and probably for all "recycled" ones, I mean those who recall the "onBindViewHolder" by "recycling" an existing view).
I think using "notifyItemChanged" will works if you have only the recyclerview and I also think that this problem of "auto-scrolling" is raised by nested scroll views & recycler views.
I was in the case exposed by "raed", so "ScroolView -> RecyclerView -> "n" x RecyclerView". I have a scroolview wich contains a recyclerview whose viewholders can contains a recycler views.
Delete the parent ScrollView is a really weird solution and I couldn't use it, so I setted the "onStopNestedScroll" inside the "ScrollView" and not inside the RecyclerView.
Personally I used it programmatically before the code part which calls the "notifyItemChanged" method by doing:
msvContainer.onStopNestedScroll(mRecyclerView);
Where "msvContainer" is my ScrollView which contains the RecyclerView, and "mRecyclerView" is my RecyclerView contained by the ScrollView.
This way worked 99% because the first time I call "notifyItemChanged" the view scroll up only for the ScrollView, so it hides a button inside my ScrollView which is below my RecyclerView but it doesn't scroll the RecyclerView items. After the first call "notifyItemChanged" works properly.
I found that calling:
msvContainer.stopNestedScroll();
works too. But i suggest to use the first method with the target view if you have multiple nested scroll views.
Anyway you should call "startNestedScroll" after you ran out of the critical part of re-updating your view holder because the targeted view, so in my case the RecyclerView, won't scroll until you call this method so it won't recycler his view holders too.
(In my case that I have multiple Recycler View inside a parent Recycler View inside a parent Scroll View if I was in need to call "notifyItemChanged" inside the most inner Recycler View i would use the "stopNestedScroll" method for every parent view and then re-activated the scroll after the scroll-critical part)
Hope this is helpful, have a nice coding!
Bye

In my case, all I did was to set the height of the recyclerview to "match_parent". Then in your MainActivity, do;
recyclerView.smoothScrollToPosition(yourAdapter.getItemCount()-1);
Thats all...

Android NestedScrollView has wrong size after app:layout_behavior

Since Google has published the design support library for android, there are many nice things that can be done without implementing custom code. While i've tested the custom views in this lib, i have found a worse thing, and i didn't know if this is a bug or not.
I have found the cheesesquare project on github. In the activity_detail.xml(layout file) there are 3 CardViews inside the NestedScrollView. If you delete 2 of them, you can see that the NestedScrollView doesn't have the full size of the parent(match_parent). The NestedScrollView is bound to the bottom of the parent view. http://i.stack.imgur.com/BXl7w.png
The NestedScrollView get's his full size when i remove the app:layout_behavior="#string/appbar_scrolling_view_behavior".
But when i remove the layout behavior, the toolbar is not collapsing.
Is there any fix for this? Example layout file can be found here: https://github.com/Smove/cheesesquare/blob/stackoverflow/app/src/main/res/layout/activity_detail.xml
You can build the cheesesquare apk from my github branch stackoverflow

I had this problem and fixed adding:
android:layout_gravity="fill_vertical"
to the NestedScrollView. Then it starts behaving correctly, as I explained here also. Of course the NestedScrollView needs some kind of child (i.e. it must not be empty), otherwise the toolbar won't collapse.
Update
While this works well with small content, I noticed it has some problems showing longer contents, e.g. like the full activity_detail.xml above. The problem is that you can't scroll to the very bottom part of the content - it is unreachable at the bottom.
From my tests I could find that the missing part is as big as the collapsed toolbar (or at least that's what it looks to me). To fix this is issue, and having a solution reliable for both small and big contents, you should add a layout_marginBottom to the ScrollView, so that it gets measured and releases the missing bottom part. Thus:
android:layout_gravity="fill_vertical"
android:layout_marginBottom="?attr/actionBarSize"
or whatever size you gave to the Toolbar.
But still
Scrolling with small contents with this solution, even if the content is justly aligned at the top, isn't really smooth as scrolling with large contents. I'll use until a library fix comes.
Update2
Looks like this was fixed in v22.2.1 .

using the answer by #natario If you instead set a padding for the child (LinearLayout in my case) it will look better:
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_gravity="fill_vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="?attr/actionBarSize">
<!--Rest of the code-->
Or in Kotlin you can do something like this:
coordinator.doOnLayout {
nestedScrollView.minimumHeight = resources.displayMetrics.heightPixels - with(TypedValue().also {theme.resolveAttribute(android.R.attr.actionBarSize, it, true)}) {
TypedValue.complexToDimensionPixelSize(data, resources.displayMetrics)}
}

add android:minHeight="?attr/actionBarSize" to CollapsingToolbarLayout

Workaround
Before showing my NestedScrollView and after binding the data to the NestedScrollView content, I call the method fullScroll(int direction) of my NestedScrollView instance with the View.FOCUS_UP direction as argument.
Code example for a fragment:
NestedScrollView scrollView = (NestedScrollView) getActivity().findViewById(R.id.scroll_view);
scrollView.fullScroll(View.FOCUS_UP);

use RecyclerView replace NestedScrollView fix this bug
set item count 1,that ViewHolder return your real contentView;
my code:
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
// 添加分割线
recyclerView.addItemDecoration(new DividerItemDecoration(getApplicationContext()));
recyclerView.setAdapter(new Adapter<ViewHolder>() {
#Override
public int getItemCount() {
return 1;
}
#Override
public void onBindViewHolder(ViewHolder holder, int arg1) {
WebView view = (WebView) holder.itemView;
view.getSettings().setJavaScriptEnabled(true);
view.loadUrl("http://www.baidu.com");
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup arg0, int arg1) {
return new ViewHolder(inflater.inflate(R.layout.webview, arg0, false)) {
};
}
});

Dynamically Setting RelativeLayout.LayoutParams.addRule

I have this issue where I have a relative layout that has two child relative layouts (leftpanel and rightpanel). They're inside a custom layout for listview items and each item is updated from a json response from the server. So the size depends on what the server provides.
Issue: I want to have each panel's height to match each other, but it seems that setting layout_height to match_parent doesn't work (actually, if this can be resolved, then no more problems).
What I did: I programmatically set the align top and bottom of each panel to each other -- if the other's bigger, adjust the other one and vice versa. So what I did was to have a view (rightpanel) to listen to rightPanel.getViewTreeObserver().addOnScrollChangedListener(), and call the method below everytime there's a scroll change:
private void updateLayoutAlignmentParams(ViewHolder viewHolder) {
RelativeLayout.LayoutParams leftPanelLayoutParams = (RelativeLayout.LayoutParams)viewHolder.leftPanel.getLayoutParams();
RelativeLayout.LayoutParams rightPanelLayoutParams = (RelativeLayout.LayoutParams)viewHolder.rightPanel.getLayoutParams();
int leftPanelHeight = viewHolder.leftPanel.getHeight();
int rightPanelHeight = viewHolder.rightPanel.getHeight();
if(leftPanelHeight > rightPanelHeight) {
rightPanelLayoutParams.addRule(RelativeLayout.ALIGN_BOTTOM, 0);
rightPanelLayoutParams.addRule(RelativeLayout.ALIGN_TOP, 0);
leftPanelLayoutParams.addRule(RelativeLayout.ALIGN_BOTTOM, viewHolder.rightPanel.getId());
leftPanelLayoutParams.addRule(RelativeLayout.ALIGN_TOP, viewHolder.rightPanel.getId());
} else {
leftPanelLayoutParams.addRule(RelativeLayout.ALIGN_BOTTOM, 0);
leftPanelLayoutParams.addRule(RelativeLayout.ALIGN_TOP, 0);
rightPanelLayoutParams.addRule(RelativeLayout.ALIGN_BOTTOM, viewHolder.leftPanel.getId());
rightPanelLayoutParams.addRule(RelativeLayout.ALIGN_TOP, viewHolder.leftPanel.getId());
}
}
What happens: not all the views get updated while scrolling; so I get a lop-sided listview item where one is bigger than the other vertically but some do adjust well. Odd thing is, when the item gets out of view, it's lop-sided, then gets corrected consistently.
Note: I also tried
addOnDrawListener() - every item is updated but I get an ArrayList out of bounds index but doesn't point to any line in my code. Wouldn't be the best solution anyway as I need to support devices with API < 16.
setOnGlobalLayoutListener() - Nothing happens.
Please let me know if you know why or have a better solution.

Finally [kindof] fixed it! Replaced the whole method with the code below:
private void updateLayoutAlignmentParams(ViewHolder viewHolder) {
viewHolder.rightPanel.setMinimumHeight(viewHolder.leftPanel.getHeight());
viewHolder.leftPanel.setMinimumHeight(viewHolder.rightPanel.getHeight());
}
Although, I was able to achieve having the left and right panel aligned with each other using the code above. I'm now having issues where the previous view's height and width are retained when I switch views. :(
Edit:
Okay, I ended up using LinearLayout to wrap the whole listview item. Not really sure why RelativeLayout isn't complying with match_parent, though.