CODEWITHSUNDEEP
android
Iván
Iván

Reputation: 19

Is there a way to make a recycler view show a fixed number of items?

I have an alert dialog built in a ConstraintLayout with a RecyclerView in it. My problem is that recycler view has not a fixed size and it only displays a few items (it's scrollable though, but I need it to be bigger).

This is my layout:

<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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/textView2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:fontFamily="sans-serif-light"
        android:text="@string/traces_dialog_title"
        android:textColor="@color/black_color"
        android:textSize="26sp"
        app:layout_constraintBottom_toBottomOf="@+id/view"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <View
        android:id="@+id/view"
        android:layout_width="0dp"
        android:layout_height="0.5dp"
        android:layout_marginBottom="45dp"
        android:layout_marginTop="53dp"
        android:background="@color/graySeparatorBarColor"
        app:layout_constraintBottom_toBottomOf="@+id/linearLayout"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />


    <TextView
        android:id="@+id/linearLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="4dp"
        android:fontFamily="sans-serif-light"
        android:text="@string/order_number_label"
        android:textColor="@color/black_color"
        android:textSize="20sp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <TextView
        android:id="@+id/order_number"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginStart="8dp"
        android:fontFamily="sans-serif-light"
        android:text="#12345"
        android:textColor="@color/black_color"
        android:textSize="20sp"
        app:layout_constraintBottom_toTopOf="@+id/medication_name"
        app:layout_constraintStart_toEndOf="@+id/linearLayout"
        app:layout_constraintTop_toTopOf="@+id/linearLayout" />


    <TextView
        android:id="@+id/medication_name"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="4dp"
        android:fontFamily="sans-serif"
        android:text="Ciclofosfamida 500mg"
        android:textColor="@color/black_color"
        android:textSize="24sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/linearLayout" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/traces"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:nestedScrollingEnabled="false"
        android:overScrollMode="never"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/medication_name"
        app:layout_constraintVertical_chainStyle="spread_inside"
        app:layout_constraintBottom_toTopOf="@+id/view3"
        android:layout_marginBottom="16dp">

    </android.support.v7.widget.RecyclerView>

    <View
        android:id="@+id/view3"
        android:layout_width="0dp"
        android:layout_height="0.5dp"
        android:layout_marginBottom="8dp"
        android:background="@color/graySeparatorBarColor"
        app:layout_constraintBottom_toTopOf="@+id/close"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent" />


    <TextView
        android:id="@+id/close"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:layout_marginEnd="16dp"
        android:fontFamily="sans-serif-medium"
        android:paddingBottom="@dimen/spacingTiny"
        android:paddingTop="@dimen/spacingTiny"
        android:text="@string/accept_delivery"
        android:textColor="@color/buttonColor"
        android:textSize="16sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />


</android.support.constraint.ConstraintLayout>

And this is how I open and handle the AlertDialog:

private void openTracesDialog(final Medication medication) {
        AlertDialog.Builder builder;
        final AlertDialog alertDialog;

        LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
        View layout = inflater.inflate(R.layout.show_traces_dialog, null);
        RecyclerView traceList = (RecyclerView) layout.findViewById(R.id.traces);
        TextView orderNumber = (TextView) layout.findViewById(R.id.order_number);
        TextView medicationName = (TextView) layout.findViewById(R.id.medication_name);
        medicationName.setText(medication.getName());
        orderNumber.setText("#" + order.getOrderNumber());
        traceList.setLayoutManager(new LinearLayoutManager(mContext));
        traceList.setAdapter(new RecyclerView.Adapter<TraceHolder>() {
            @Override
            public TraceHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(LAYOUT_INFLATER_SERVICE);
                View v = inflater.inflate(R.layout.item_trace, null);
                v.setLayoutParams(new RecyclerView.LayoutParams(RecyclerView.LayoutParams.MATCH_PARENT, RecyclerView.LayoutParams.WRAP_CONTENT));
                return new MedicationExtendedAdapter.TraceHolder(v);
            }

            @Override
            public void onBindViewHolder(TraceHolder holder, int position) {
                int tracePosition = position+1;
                holder.mTraceLabel.setText("TRAZA "+tracePosition);
                holder.mTraceNumber.setText(medication.getTraces().get(position));
            }

            @Override
            public int getItemCount() {
                return medication.getTraces().size();
            }
        });

        builder = new AlertDialog.Builder(mContext);
        builder.setView(layout);
        alertDialog = builder.create();

        TextView closeButton = (TextView) layout.findViewById(R.id.close);
        closeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                alertDialog.dismiss();
            }
        });

        alertDialog.show();
    }

Upvotes: 1

Views: 2615

Answers (6)

Oussema Smaoui
Oussema Smaoui

Reputation: 97

you can change the return of this method 

 @Override
 public int getItemCount() {
       return medication.getTraces().size();
 }

to a fixed number 

 @Override
 public int getItemCount() {
       return YOUR_FIXED_NUMBER;
 }

but you should take care if the size of your list is inferior than YOUR_FIXED_NUMBER you will have crashes so you should add a test for this, like that:

 @Override
 public int getItemCount() {
    if(medication.getTraces().size() > YOUR_FIXED_NUMBER)
        return YOUR_FIXED_NUMBER;
    else
        return medication.getTraces().size(); //or any lower number depends on your need

 }

Upvotes: 1

Iv&#225;n
Iv&#225;n

Reputation: 19

Already fixed this. What I did was to set a fixed height depending on the screen to make the Dialog bigger. As all elements are constrainted, making Dialog higher makes the RecyclerView higher also.

 ConstraintLayout popUpLayout = (ConstraintLayout) layout.findViewById(R.id.constraint);
 popUpLayout.setMinHeight((int) (mContext.getResources().getDisplayMetrics().heightPixels * 0.75));

Upvotes: 1

Joshua
Joshua

Reputation: 651

Change your:

@Override
            public int getItemCount() {
                return medication.getTraces().size();
            }

to:

@Override
            public int getItemCount() {
                return 100;
            }

or whatever value you want.

Upvotes: 1

JSharma
JSharma

Reputation: 113

You should override the layoutmanager of your recycleview for this. This way it will only disable scrolling.

   public class CustomGridLayoutManager extends LinearLayoutManager {
   private boolean isScrollEnabled = true; // create boolean variable here

   public CustomGridLayoutManager(Context context) {
   super(context);
   }
   // create method to enable or disable scrolling
   public void setScrollEnabled(boolean flag) {
   this.isScrollEnabled = flag;
   }

   @Override
   public boolean canScrollVertically() {
   //Similarly you can customize "canScrollHorizontally()" for managing 
   //horizontal scroll
   return isScrollEnabled && super.canScrollVertically();
  }
}

now add your custom layout manager to your recyclerview now you can disable and enable scrolling functionality of your recyclerview 

 linearLayoutManager = new LinearLayoutManager(context) {
   @Override
   public boolean canScrollVertically() {
    return false;
    }
 };

Upvotes: 0

JavadBadirkhanly
JavadBadirkhanly

Reputation: 645

If RecyclerView has children (items) that has fixed width and height. For allowing the RecyclerView to optimize better by figuring out the exact height and width of the entire list based on the your adapter, use this line:

recyclerView.setHasFixedSize(true)

Upvotes: 0

Darish
Darish

Reputation: 11491

Is there a way to make a recycler view show a fixed number of items?

Using the default AlertDialog, it is not possible. Why you really need to change the default behaviour?

Anyway you can create your own custom fragment layout instead of the default DialogFragment or AlertDialog with transparent background so that you can assign it to any height you want. Then show/hide that fragment whenever you want instead of showing an alert dialog.

Upvotes: 1

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