RecyclerView - Layout_weight is ignored when it loads first time

RecyclerView - Layout_weight is ignored when it loads first time - android

I have an Activity that contains a Fragment. Fragment contains a RecyclerView, displaying CardViews.
CardView is very simple, just a TextView and a CustomView. This is the layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="100dp">
<android.support.v7.widget.CardView
android:layout_width="match_parent"
android:layout_height="100dp"
android:id="#+id/card_current_heat_cardview"
android:layout_gravity="center_vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp"
android:weightSum="4">
<TextView
android:id="#+id/card_current_heat_textview"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:textStyle="bold"
android:textColor="#000000"
android:background="#android:color/holo_red_dark"
android:gravity="center_vertical"/>
<com.amige.vm2.CurrentHeatChartView
android:id="#+id/card_current_heat_chart_view"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="3"/>
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
TextView should use 1/4 of the width, and the CustomView 3/4.
Im having trouble understanding why weights are ignored the first time the RecyclerView loads
Image of RecyclerView loaded for the first time
But if I scroll up and down, the layout works as expected for some Cards
Image of RecyclerView scrolled up and down
I also have another Activity (no fragment involved here) that has a RecyclerView and IS using this same CardView Layout and it works perfectly!!
I dont know if it has to do with the Fragment...
What am I missing?
Thanks!
EDIT
This the Adapter code
public class MainAdapter extends RecyclerView.Adapter<MyFragment.MainAdapter.ViewHolder>
{
public MainAdapter()
{
}
#Override
public MyFragment.MainAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_current_heat, parent, false);
return new MyFragment.MainAdapter.ViewHolder(v);
}
#Override
public void onBindViewHolder(MyFragment.MainAdapter.ViewHolder holder, int position)
{
if (arrayList.size() == 2)
{
if (position == 0)
{
holder.variableNameTextView.setText(“Var Name”);
holder.currentHeatChartView.reloadChartWithSamples(arrayList.get(0));
}
else
{
if ((position - 1) < arrayList.get(1).size())
{
HashMap variableHashMap = (HashMap) arrayList.get(1).get(position - 1);
holder.variableNameTextView.setText(variableHashMap.get("VarName") != null ? (String)variableHashMap.get("VarName") : "");
holder.currentHeatChartView.reloadChartWithVariableValuesAndColors(variableHashMap, colorGradientsArrayList.get((position - 1) % colorGradientsArrayList.size()));
}
}
}
}
#Override
public int getItemCount()
{
if (arrayList.size() == 2)
{
if (arrayList.get(1).size() > 0)
{
return 1 + arrayList.get(1).size();
}
else
{
return 1;
}
}
return 0;
}
public class ViewHolder extends RecyclerView.ViewHolder
{
TextView variableNameTextView;
CurrentHeatChartView currentHeatChartView;
public ViewHolder(View v)
{
super(v);
this.variableNameTextView = (TextView) v.findViewById(R.id.card_current_heat_textview);
this.currentHeatChartView = (CurrentHeatChartView) v.findViewById(R.id.card_current_heat_chart_view);
}
}
}

I found the culprit.
There was a ConstraintLayout on top of the hierarchy of the Activity containing the Fragment. Since I was working with nested layouts, ConstraintLayout was not the right way to go.
I changed it to RelativeLayout and the cards are now rendered properly.

I think your layout inflation is wrong.
View view = View.inflate(mContext, R.layout.your_layout, null);
If you do like that change your code like this.
View view = LayoutInflater.from(mContext).(R.layout.your_layout, parent, false);
Hope it helps:)

Related

View.GONE leaves empty space

I get 2 types of data with Firebase and with RadioButton I sort the displayed data. Everything seems to work, but still there is an empty space when one of the data types is hidden. Tell me how to hide / show data correctly.
That's what I get
Adapter:
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int
viewType) {
switch (viewType) {
case Person.PersonType.TYPE_1:
View userType1 = LayoutInflater.from(parent.getContext())
.inflate(R.layout.driver_row, parent, false);
return new PersonType1ViewHolder(userType1);
case Person.PersonType.TYPE_2:
View userType2 = LayoutInflater.from(parent.getContext())
.inflate(R.layout.fare_row, parent, false);
return new PersonType2ViewHolder(userType2);
}
return super.onCreateViewHolder(parent, viewType);
}
#Override
protected void populateViewHolder(RecyclerView.ViewHolder viewHolder,
Person model,
int position) {
if (viewHolder instanceof PersonType1ViewHolder) {
((PersonType1ViewHolder) viewHolder).time.setText("Full time: " +
model.getTime());
if (activate) {
viewHolder.itemView.setVisibility(View.GONE);
} else {
viewHolder.itemView.setVisibility(View.VISIBLE);
}
return;
}
if (viewHolder instanceof PersonType2ViewHolder) {
((PersonType2ViewHolder) viewHolder).time.setText("Full time2: " +
model.getTime());
if (activate2) {
viewHolder.itemView.setVisibility(View.GONE);
} else {
viewHolder.itemView.setVisibility(View.VISIBLE);
}
private class PersonType1ViewHolder extends RecyclerView.ViewHolder {
TextView time;
PersonType1ViewHolder(View itemView) {
super(itemView);
time = itemView.findViewById(R.id.tv_time);
}
}
private class PersonType2ViewHolder extends RecyclerView.ViewHolder {
TextView time;
PersonType2ViewHolder(View itemView) {
super(itemView);
time = itemView.findViewById(R.id.tv_time_two);
}
}
Row layouts are the same - wrap_content
<androidx.cardview.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="#+id/tv_time"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
MainActivity XML
<RelativeLayout 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"
tools:context=".MainActivity">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_trip_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#id/radio_button_group" />
<Button
android:id="#+id/add_trip"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:onClick="addTrip"
android:text="add" />
<RadioGroup
android:id="#+id/radio_button_group"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#id/add_trip"
android:layout_centerHorizontal="true"
android:orientation="horizontal">
<RadioButton
android:id="#+id/rb_all"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:checked="true"
android:text="all" />
<RadioButton
android:id="#+id/rb_driver"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="driver" />
<RadioButton
android:id="#+id/rb_fare"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="fare" />
</RadioGroup>
</RelativeLayout>

I don’t know how correct this is, but I just programmatically set the parameters
viewHolder.itemView.setLayoutParams(new RecyclerView.LayoutParams(0, 0));

I also encountered issue like this, turns out it's the problem with the override method getItemCount() in the adapter. I guess if you specified the number of getItemCount(), RecyclerView will reserve a place for the ViewHolder even if you hide it. This is the code of how i solve it.
override fun getItemViewType(position: Int): Int {
when {
!importantImages.isNullOrEmpty() && !otherImages.isNullOrEmpty() -> {
return when (position) {
0 -> Important.ordinal
else -> Other.ordinal
}
}
otherImages.isNullOrEmpty() -> {
return Important.ordinal
}
importantImages.isNullOrEmpty() -> {
return Other.ordinal
}
}
return 0
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
return when (ViewType.values()[viewType]) {
Important -> {
val layoutInflater = LayoutInflater
.from(parent.context)
.inflate(R.layout.layout_important_list, parent, false)
ImportantViewHolder(layoutInflater)
}
Other -> {
val layoutInflater = LayoutInflater
.from(parent.context)
.inflate(R.layout.layout_other_list, parent, false)
OtherViewHolder(layoutInflater)
}
}
}
override fun getItemCount(): Int = when {
!importantImages.isNullOrEmpty() && !otherImages.isNullOrEmpty() -> {
2
}
importantImages.isNullOrEmpty() && otherImages.isNullOrEmpty() -> {
0
}
else -> {
1
}
}
Hope it helps! :)

I have this problem too, I found that if add a container outside with wrap_content, then it works.
<FrameLayout 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">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/v_root"
android:layout_width="match_parent"
android:layout_height="48dp">
</androidx.constraintlayout.widget.ConstraintLayout>
</FrameLayout>
In java code:
v_root.setVisibility(View.GONE);
v_root in code means your old view root.

1.Why does it happen?
viewHolder.itemView.setVisibility(View.GONE); This will not work in RecyclerView.
itemView is a child view in RecyclerView. Unlike the other ViewGroup (FrameLayout,etc), RecyclerView ignores childen's visibility during layout process.
2.How to solve it?
Option1 Use a regular view group such as FrameLayout to wrap your real layout, and hide your real layout: findViewById(R.id.layout_to_hide).setVisibility(View.GONE)
<FrameLayout android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout android:id="#+id/layout_to_hide"
android:layout_width="match_parent"
android:layout_height="wrap_content">
//Put here your views
</LinearLayout>
</FrameLayout>
Option2 Change the itemView’s heigh to 0 so we can't see it
holder.itemView.setLayoutParams(new RecyclerView.LayoutParams(0, 0));
Option3 If this item shouldn't be in List, then simply don't let it in adapter data, or remove it.
3.Learn more
1. Why the other view group such as FrameLayout works fine with children's visibibilty?
They don't compute the child's layout params if it's GONE
2. Why RecyclerView doesn't?
RecyclerView still compute the child's layout params if it's GONE so it still occupies spaces.

The question is not very clear.
But I can assure you that with View.GONE, the view becomes invisible without leaving spaces. While with View.INVISIBLE, the view leaves an invisible space.
If it doesn't work, it means that something is wrong with your layout.

Expandable recycler view and a textview below issue

I'm trying to implement a 2 expandable recyclerview with 2 headings.So my view has
1.
2.
3.
4.
Since my recyclerview is expandable, and when I expand the 1st recyclerview , it goes inside my 2nd textview.
ie.there is a separate scroll for my recycler view.
I want the 2nd textview and recyclerview to move down when expanding the 1st recyclerview.
activity.xml
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_marginBottom="10dp"
tools:context=".ListActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textSize="22sp"
android:text="Weightage: 40%"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.RecyclerView
android:id="#+id/recview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fafafa" />
</LinearLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textStyle="bold"
android:textSize="22sp"
android:layout_marginBottom="10dp"
android:text="Weightage: 60%"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/recview2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#fafafa" />
</LinearLayout>
</ScrollView>
the same happens with the second recyclerview. On expanding the second recycler view, recyclerview items have a separate scroll and the text above stays at a place.The overall scroll doesn't work.

You can achieve this using only one Recyclerview. Make one model class named "Model" of your data, in which add one variable like "isHeader". When you prepare your data list to show in Recyclerview make 2 model object with
'isHeader = true'
Also, make two (item_layout.xml & header_layout.xml) xml files, one for header & another for your original data item.
And in Recyclerview adapter class you have two separate ViewHolder classes for each of the above layouts. refer this for more details and example
public class MultiViewTypeAdapter extends RecyclerView.Adapter {
public static final int HEADER_VIEW = 0;
public static final int LIST_VIEW = 1;
private Resources resources;
private DownloadListener downloadListener;
public MyToursAdapter(List<Model> objects) {
super(objects);
resources = App.getApp().getResources();
}
#NonNull
#Override
public RecycleView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
if (viewType == HEADER_VIEW) {
return new SectionHeaderItemViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.header_layout, parent, false));
} else
return new ListItemViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false));
}
#Override
public void onBindViewHolder(#NonNull BaseRecycleAdapter.ViewHolder holder, int position) {
if (getItemViewType(position) == HEADER_VIEW)
((HeaderItemViewHolder) holder).bindHeaderViewHolder(objects.get(position));
else
((ListItemViewHolder) holder).bindListViewHolder(objects.get(position));
}
#Override
public int getItemViewType(int position) {
if (objects.get(position).isHeader())
return HEADER_VIEW;
else
return LIST_VIEW;
}
public class ListItemViewHolder extends BaseRecycleAdapter.ViewHolder {
//write code to show data from list object.
}
public class HeaderItemViewHolder extends BaseRecycleAdapter.ViewHolder {
//write code to show data from list object.
}
}
enter code here

How do I not recycle only the first 2 views of my recyclerview or any items?

I am using a recyclerview for displaying and broadcasting videos of users. However, when I scroll through the recycler view, I see my first view, which has my video gets recycled hence why it's not visible to other users. Is there a way I can make sure that the first view is not recycled so I dont have to worry about my video view getting resetrecycled every single time I scroll through my list?
Here's my code :
In my fragment...
...
<android.support.v7.widget.RecyclerView
android:id="#+id/videoList"
android:layout_width="0dp"
android:layout_height="0dp"
android:visibility="invisible"
app:layout_constraintBottom_toTopOf="#+id/myButtonContainer"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="#+id/myoldContainer">
...
and the corresponding adapter...
public class GroupAdapter extends RecyclerView.Adapter<GroupAdapter.myViewHolder> {
private CopyOnWriteArrayList<Person> persons;
private Context mContext;
public GroupAdapter(#NonNull final CopyOnWriteArrayList<Person> persons , Context context) {
this.persons = persons;
this.mContext= context;
for (Person person : this.persons) {
//get names
}
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
final View layout = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_person, parent, false);
final MyViewHolder viewHolder = new MyViewHolder(layout);
return viewHolder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
final Person person = person.get(position);
final Participant participant = person.getParticipant();
if (person.getName() != null) {
holder.personName.setText(person.getName());
}
if (person.getImage() != null) {
holder.personImage.setImageBitmap(person.getImage());
} else {
holder.personImage.setImageResource(R.drawable.default_profile);
}
holder.personImage.setVisibility(View.INVISIBLE);
holder.personImage.setVisibility(View.VISIBLE);
final VideoView videoView;
if (participant.isMe) {
videoView = participant.videoStreamer.videoView;
} else {
videoView = participant.videoPlayer.videoView;
}
if (holder.personVideo.getChildCount() != 0) {
holder.personVideo.removeAllViews();
}
if (videoView.getParent() != null) {
ViewGroup parent = (ViewGroup) videoView.getParent();
parent.removeView(videoView);
}
holder.personVideo.addView(videoView, myViewHolder.videoLayoutParams);
if (person.isVideoPaused()) {
holder.personVideo.setVisibility(View.INVISIBLE);
holder.personImage.setVisibility(View.VISIBLE);
} else {
holder.personVideo.setVisibility(View.VISIBLE);
holder.personImage.setVisibility(View.INVISIBLE);
}
}
#Override
public int getItemCount() {
return persons.size();
}
public static final class MyViewHolder extends RecyclerView.ViewHolder {
#BindView(R.id.personVideo)
public ViewGroup personVideo;
#BindView(R.id.personImage)
public ImageView personImage;
#BindView(R.id.personName)
public TextView personName;
protected static FrameLayout.LayoutParams videoLayoutParams = new FrameLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT
);
public MyViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
}
Here's how I am setting it in my fragment:
LinearLayoutManager manager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
videoAdapter = new VideoAdapter(myHelper.getPeople(), getContext());
videoList.setLayoutManager(manager);
videoList.setAdapter(videoAdapter);
item_person:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_marginTop="0dp"
android:background="#drawable/person_border"
xmlns:app="http://schemas.android.com/apk/res-auto">
<RelativeLayout
android:id="#+id/personContainer"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintDimensionRatio="1:1"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent">
<FrameLayout
android:id="#+id/personVideo"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black" />
<ImageView
android:id="#+id/personImage"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/black"
android:src="#drawable/default_profile" />
<TextView
android:id="#+id/personName"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#AA555555"
android:gravity="center_horizontal|bottom"
android:textColor="#color/green"
android:textSize="12sp"
android:lines="1"
android:ellipsize="end"
tools:text="androiduser#gmail.com"
android:layout_alignParentBottom="true" />
</RelativeLayout>
</android.support.constraint.ConstraintLayout>
fragment with recycle view: xml
<android.support.constraint.ConstraintLayout 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">
<RelativeLayout>
....
</RelativeLayout>
<include containers>...</include>
...
<android.support.v7.widget.RecyclerView
android:id="#+id/personList"
android:layout_width="0dp"
android:layout_height="0dp"
android:visibility="invisible"
>
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>

I don't think that "not recycling" the video view will actually stop it from being destroyed when you scroll. It's not the recycling is the problem but the view unbinding.
I think such complex component such as VideoView should not be inside the RecyclerView at all.. You can try adding it as a static content on top, which most likely will solve the issue. You can use a NestedScrollView for that. Take a look here: Recyclerview inside scrollview- How to scroll whole content?
If you still think you want to keep it in the RecyclerView and disable the recycling, do the following.
Create a separate view type for your video view items. Here is an example:
https://stackoverflow.com/a/26573338/3086818. Treat your video view item as a header view from the example.
Once you do this, there is a RecycledViewPool class which manages the recycling of items inside a RecyclerView. You can tell it which views to recycle and which not. By default it recycles all views. To disable recycling for your video view items use your new view type like this:
recyclerView.getRecycledViewPool().setMaxRecycledViews(TYPE_VIDEO_VIEW, 0);
where TYPE_VIDEO_VIEW is the new type that you created using the previous example. The number 0 tells the RecyclerView how many items to recycle - in this case it's 0, meaning "do not recycle". More info about this here: https://stackoverflow.com/a/36313437/3086818.
I hope this helps.. Good luck!

The answer is yes, you can actually do that.
Since you said "The first item" so you simply add a check.
if(position == 0)
{
holder.setIsRecyclable(false); //This line prevents the row from recycling
}

scrollTo() for horizontalScrollView not working

I inflate another layout to appear below some view in my current layout.
This is done like this:
LayoutInflater vi = (LayoutInflater) getActivity().getApplicationContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rootView = vi.inflate(R.layout.horizontal_scroll_view, null);
horizontalScrollView = (HorizontalScrollView) rootView.findViewById(R.id.hsv_suggestions_scroll_view);
LinearLayout suggestionsContainer = (LinearLayout) horizontalScrollView.findViewById(R.id.ll_suggestions_container);
and I can confirm that it appears in the right place since I add some Views in it after a while and they all appear.
The layout I inflate is :
<HorizontalScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/hsv_suggestions_scroll_view"
android:scrollbars="none" android:layout_gravity="center_horizontal"
android:paddingTop="16dp" android:fillViewport="true"
android:layout_width="match_parent" android:layout_height="wrap_content">
<LinearLayout
android:id="#+id/ll_suggestions_container"
android:gravity="center_horizontal" android:orientation="horizontal"
android:layout_width="wrap_content" android:layout_height="wrap_content">
</LinearLayout>
just a HorizontalScrollView with a LinearLayout as a child.
The Views I add later are all of them TextViews.
Now after a user action (write some text on an editText) I'm trying to scroll to that View and highlight it. Highlight works. What does not work is scroll.
I have tried :
horizontalScrollView.postDelayed(new Runnable() {
#Override
public void run() {
horizontalScrollView.smoothScrollTo(scrollTo, 0);
}
}, 300);
where variable scrollTo is what I get when I apply getLeft() to the View I wanna scroll to. I can confirm that it takes various values.
Anyone can help me with that ?

Got a similar issue.
I guess the root cause is that the UI was not yet rendered at that moment, causing the scroll not to work properly.
I just had to wrap my call to smoothScrollTo into .post as follows:
mScrollView.post(new Runnable() {
#Override
public void run() {
mScrollView.smoothScrollTo(xxx, yyy);
}
});
Notice that I do a post directly on the scrollView to make sure it is executed after it is being rendered. For example, doing a getActivity().runOnUIThread() would not work in my case.

Switch to using a RecyclerView with a LinearLayoutManager with orientation set to Horizontal. Like this:
scroll_view.xml
<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/scrollView"
android:scrollbars="none"
android:layout_gravity="center_horizontal"
android:paddingTop="16dp"
android:fillViewport="true"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layoutManager="android.support.v7.widget.LinearLayoutManager"
android:orientation="horizontal">
<LinearLayout
android:id="#+id/scrollContainer"
android:gravity="center_horizontal"
android:orientation="horizontal"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</android.support.v7.widget.RecyclerView>
Note: the layoutManager tag is required here for the layout to inflate. After it's inflated, we're going to set it programatically as well because otherwise we'll get an exception because the RecyclerView basically disposes of it before it's done with it.
OptionAdapter.java
public class OptionAdapter extends RecyclerView.Adapter<OptionAdapter.OptionHolder> {
private Context context;
private LayoutInflater inflater;
private ArrayList<String> options;
public OptionAdapter(Context context) {
this.context = context;
this.inflater = LayoutInflater.from(context);
options = new ArrayList<>();
}
#Override
public OptionHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new OptionHolder(inflater.inflate(R.layout.textview, parent, false));
}
#Override
public void onBindViewHolder(OptionHolder holder, int position) {
String option = options.get(position);
((TextView) holder.itemView).setText(option);
}
#Override
public int getItemCount() {
return options != null ? options.size() : 0;
}
public ArrayList<String> getOptions() {
return options;
}
public void addOption(String option, Integer index) {
if (index != null && index <= options.size()) {
options.add(index, option);
} else {
options.add(option);
}
notifyDataSetChanged();
}
public class OptionHolder extends RecyclerView.ViewHolder {
public OptionHolder(View itemView) {
super(itemView);
}
}
}
text_view.xml
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_marginLeft="8dp"
android:layout_marginRight="8dp"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="match_parent" />
Setting everything up
final LayoutInflater inflater = LayoutInflater.from(this);
final RecyclerView scrollView = (RecyclerView) inflater.inflate(R.layout.scroll_view, container, false);
scrollView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
final OptionAdapter adapter = new OptionAdapter(this);
scrollView.setAdapter(adapter);
container here is whatever view is going to be holding the RecyclerView. In my code, I've got it in a LinearLayout.
Adding a view to the list
adapter.addOption("The Added One", null);
Or if you want to add it to a specific position in the list.
adapter.addOption("The Added One", position);
Scrolling to a specific position
scrollView.smoothScrollToPosition(position);
Scrolling to a specific item in the list
scrollView.smoothScrollToPosition(adapter.getOptions().indexOf("ItemText"));
Hope it works for you!

Instead of smoothScrollTo(), try using scrollTo().
Make sure that your getLeft() is really returning a value > 0;

Recycler view showing single item

I am facing a strange error where recyclerview is showing only a single item. Below is code for my recyclerview adapter :
public class ChatAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
List<chat> chats;
String username;
final int My=0,Their=1;
public ChatAdapter(List<chat> chats) {
this.chats = chats;
this.username = PushApp.getApp().getSPF().getStringData(Constants.ANAME);
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder viewHolder;
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
switch (viewType) {
case My:
View v1 = inflater.inflate(R.layout.my_chat_child, parent, false);
viewHolder = new MyChatHolder(v1);
break;
case Their:
View v2 = inflater.inflate(R.layout.their_chat_child, parent, false);
viewHolder = new TheirMessageHolder(v2);
break;
default:
View v = inflater.inflate(R.layout.my_chat_child, parent, false);
viewHolder = new MyChatHolder(v);
break;
}
return viewHolder;
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
switch (holder.getItemViewType()) {
case My:
MyChatHolder myChatHolder = (MyChatHolder) holder;
myChatHolder.setMyMessage(chats.get(position).getMessage());
break;
case Their:
TheirMessageHolder theirMessageHolder = (TheirMessageHolder) holder;
theirMessageHolder.setTheirChat(chats.get(position).getFrom(), chats.get(position).getMessage());
break;
}
}
#Override
public int getItemViewType(int position) {
if(username.equalsIgnoreCase(chats.get(position).getFrom()))
return My;
return Their;
}
#Override
public int getItemCount() {
return chats.size();
}}
I have already used this code in other app and its working perfectly. I have checked the chats data which is also perfect.
Here's link to git repo layout files:
layout files

Don't use match_parent for height for your item view. One item fills whole screen vertically so you don't see another.

when you are creating row.xml for recyclerview should follow these things:
Always use "wrap_content" for the height of the row otherwise in "match_parent" it will occupy the whole screen for a single row.
You can also take the height in dp.

My mistake was I accidentally used:
LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
instead of:
LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)

content_main.xml as follows
android:layout_width="match_parent"
android:layout_height="match_parent"
IN row_list.xml file make following changes
android:layout_width="match_parent"
android:layout_height="wrap_content"
I make above changes it runs.

Try changing the layout used in your item view to FrameLayout. Here is an example.
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/item"
android:layout_width="match_parent"
android:layout_height="?listPreferredItemHeight"
android:clickable="true"
android:focusable="true"
android:foreground="?selectableItemBackground">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="8dp"/>
</FrameLayout>

After checking the log make sure multiple items are added in the list but in UI its showing only 1 item means check this properties.
In item_xml file change property to
Correct Approach
android:layout_width="match_parent"
android:layout_height="wrap_content"
wrong Approach
android:layout_width="match_parent"
android:layout_height="match_parent"

I have this issue today, and after 1001 minutes, I find out this come from this line inside RecyclerView:
android:layout_marginTop="10dp"
My RecyclerView was put inside NestedScrollView, I think that is the indirect cause.
So I put here for anyone else meet the same issue. here the image

1) if your recyclerview is vertical then set height of recyclerview match_parent and row_item.xml height also match_parent
2) if your recyclerview is horizontal then set Width of recyclerview match_parent and row_item.xml Width also match_parent
for ex:-
Horizontal RecyclerView
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="60dp"
android:layout_marginRight="60dp" />
row_item.xml
<TextView
android:layout_width="match_parent"
android:layout_height="180dp"
android:layout_marginBottom="5dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="5dp"
android:background="#drawable/rect"
android:gravity="center"
android:maxLines="2"
android:padding="10dp"
android:textColor="#color/white"
android:textSize="25sp" />

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

RecyclerView - Layout_weight is ignored when it loads first time - android

I found the culprit. There was a ConstraintLayout on top of the hierarchy of the Activity containing the Fragment. Since I was working with nested layouts, ConstraintLayout was not the right way to go. I changed it to RelativeLayout and the cards are now rendered properly.

I think your layout inflation is wrong. View view = View.inflate(mContext, R.layout.your_layout, null); If you do like that change your code like this. View view = LayoutInflater.from(mContext).(R.layout.your_layout, parent, false); Hope it helps:)

Related

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Expandable recycler view and a textview below issue

How do I not recycle only the first 2 views of my recyclerview or any items?

scrollTo() for horizontalScrollView not working

Recycler view showing single item

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