[android] How to add dividers and spaces between items in RecyclerView?



14 Answers

Might I direct your attention to this particular file on Github by Alex Fu: https://gist.github.com/alexfu/0f464fc3742f134ccd1e

It's the DividerItemDecoration.java example file "pulled straight from the support demos".(https://plus.google.com/103498612790395592106/posts/VVEB3m7NkSS)

I was able to get divider lines nicely after importing this file in my project and add it as an item decoration to the recycler view.

Here's how my onCreateView look like in my fragment containing the Recyclerview:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_recycler_view, container, false);

    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
    mRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST));

    mRecyclerView.setHasFixedSize(true);
    mLayoutManager = new LinearLayoutManager(getActivity());
    mRecyclerView.setLayoutManager(mLayoutManager);
    mRecyclerView.setItemAnimator(new DefaultItemAnimator());

    return rootView;
}

I'm sure additional styling can be done, but it's a starting point. :)

Question

This is an example of how it could have been done previously in the ListView class, using the divider and dividerHeight parameters:

<ListView
    android:id="@+id/activity_home_list_view"
    android:layout_width="match_parent" 
    android:layout_height="match_parent"
    android:divider="@android:color/transparent"
    android:dividerHeight="8dp"/>

However, I don't see such possibility in the RecyclerView class.

<android.support.v7.widget.RecyclerView
    android:id="@+id/activity_home_recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"/>

In that case, is it ok to define margins and/or add a custom divider view directly into a list item's layout or is there a better way to achieve my goal?




Add a margin to your view, it worked for me.

android:layout_marginTop="10dp"

If you just want to add equal spacing and want to do it in XML, just set padding to your RecyclerView and equal amount of layoutMargin to the item you inflate into your RecyclerView, and let the background color determine the spacing color.




You can add with programaticly easily.

If your Layout Manager is Linearlayout then you can use:

DividerItemDecoration is a RecyclerView.ItemDecoration that can be used as a divider between items of a LinearLayoutManager. It supports both HORIZONTAL and VERTICAL orientations.

 mDividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
         mLayoutManager.getOrientation());
 recyclerView.addItemDecoration(mDividerItemDecoration);

source




I forked the DividerItemDecoration from an older gist and simplified it to fit my use case, and I also modified it to draw the dividers the way they are drawn in ListView, including a divider after the last list item. This will also handle vertical ItemAnimator animations:

1) Add this class to your project:

public class DividerItemDecoration extends RecyclerView.ItemDecoration {
    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
    private Drawable divider;

    public DividerItemDecoration(Context context) {
        try {
            final TypedArray a = context.obtainStyledAttributes(ATTRS);
            divider = a.getDrawable(0);
            a.recycle();
        } catch (Resources.NotFoundException e) {
            // TODO Log or handle as necessary.
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        if (divider == null) return;
        if (parent.getChildAdapterPosition(view) < 1) return;

        if (getOrientation(parent) == LinearLayoutManager.VERTICAL)
            outRect.top = divider.getIntrinsicHeight();
        else
            throw new IllegalArgumentException("Only usable with vertical lists");
    }

    @Override
    public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
        if (divider == null) {
            super.onDrawOver(c, parent, state);
            return;
        }

        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();
        final int childCount = parent.getChildCount();

        for (int i = 0; i < childCount; ++i) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
            final int size = divider.getIntrinsicHeight();
            final int top = (int) (child.getTop() - params.topMargin - size + child.getTranslationY());
            final int bottom = top + size;
            divider.setBounds(left, top, right, bottom);
            divider.draw(c);

            if (i == childCount - 1) {
                final int newTop = (int) (child.getBottom() + params.bottomMargin + child.getTranslationY());
                final int newBottom = newTop + size;
                divider.setBounds(left, newTop, right, newBottom);
                divider.draw(c);
            }
        }
    }

    private int getOrientation(RecyclerView parent) {
        if (!(parent.getLayoutManager() instanceof LinearLayoutManager))
            throw new IllegalStateException("Layout manager must be an instance of LinearLayoutManager");
        return ((LinearLayoutManager) parent.getLayoutManager()).getOrientation();
    }
}

2) Add the decorator to your RecylerView:

recyclerView.addItemDecoration(new DividerItemDecoration(getActivity()));



We can decorate the items using various decorators attached to the recyclerview such as the DividerItemDecoration:

Simply use the following ...taken from the answer by EyesClear

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

private Drawable mDivider;

/**
 * Default divider will be used
 */
public DividerItemDecoration(Context context) {
    final TypedArray styledAttributes = context.obtainStyledAttributes(ATTRS);
    mDivider = styledAttributes.getDrawable(0);
    styledAttributes.recycle();
}

/**
 * Custom divider will be used
 */
public DividerItemDecoration(Context context, int resId) {
    mDivider = ContextCompat.getDrawable(context, resId);
}

@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
    int left = parent.getPaddingLeft();
    int right = parent.getWidth() - parent.getPaddingRight();

    int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        View child = parent.getChildAt(i);

        RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

        int top = child.getBottom() + params.bottomMargin;
        int bottom = top + mDivider.getIntrinsicHeight();

        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(c);
    }
}

} and then use the above as follows

RecyclerView.ItemDecoration itemDecoration = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST);
recyclerView.addItemDecoration(itemDecoration);

This will display dividers between each item within the list as shown below:

And for those of who are looking for more details can check out this guide Using the RecyclerView _ CodePath Android Cliffnotes

Some answers here suggest the use of margins but the catch is that : If you add both top and bottom margins, they will appear both added between items and they will be too large. If you only add either, there will be no margin either at the top or the bottom of the whole list. If you add half of the distance at the top, half at the bottom, the outer margins will be too small.

Thus, the only aesthetically correct solution is the divider that the system knows where to apply properly: between items but not above or below items.

Please let me know of any doubts in the comments below :)




1.One of the Way is by using cardview and recycler view together we can easily add effect like divider. ex.https://developer.android.com/training/material/lists-cards.html

2.and other is by adding view as divider to list_item_layout of recycler view.

        <View
            android:id="@+id/view1"
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="@color/colorAccent" />



Since there is no right way to implement this yet properly using Material Design, I just did the following trick to add a divider on the list item directly:

<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="@color/dividerColor"/>



This is simple, you don't need such complicated code

    DividerItemDecoration divider = new 
    DividerItemDecoration(mRVMovieReview.getContext(), 
    DividerItemDecoration.VERTICAL);
    divider.setDrawable(ContextCompat.getDrawable(getBaseContext(), 
       R.drawable.line_divider));
    mRVMovieReview.addItemDecoration(divider);

Add this in your drawable : line_divider.xml

   <?xml version="1.0" encoding="utf-8"?>
   <shape xmlns:android="http://schemas.android.com/apk/res/android" 
    android:shape="rectangle">
        <size android:height="1dp" />
        <solid android:color="@android:color/black" />
    </shape>



Simple ItemDecoration implementation for equal spaces between all items.

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
    private int space;

    public SpacesItemDecoration(int space) {
        this.space = space;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.left = space;
        outRect.right = space;
        outRect.bottom = space;

        // Add top margin only for the first item to avoid double space between items
        if(parent.getChildAdapterPosition(view) == 0) {
            outRect.top = space;
        }
    }
}



I think using simple divider will help you

To add divider to each item:
1- Add this to drawable directory line_divider.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size
    android:width="1dp"
    android:height="1dp" />
<solid android:color="#999999" />
</shape>

2- Create SimpleDividerItemDecoration class
I used this example to define this class:
https://gist.github.com/polbins/e37206fbc444207c0e92

package com.example.myapp;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import com.example.myapp.R;

public class SimpleDividerItemDecoration extends RecyclerView.ItemDecoration{
private Drawable mDivider;

public SimpleDividerItemDecoration(Resources resources) {
    mDivider = resources.getDrawable(R.drawable.line_divider);
}

public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
    int left = parent.getPaddingLeft();
    int right = parent.getWidth() - parent.getPaddingRight();

    int childCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        View child = parent.getChildAt(i);

        RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

        int top = child.getBottom() + params.bottomMargin;
        int bottom = top + mDivider.getIntrinsicHeight();

        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(c);
    }
  }
}


3- In activity or fragment that using RecyclerView, inside onCreateView add this:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
 RecyclerView myRecyclerView = (RecyclerView) layout.findViewById(R.id.my_recycler_view);
 myRecyclerView.addItemDecoration(new SimpleDividerItemDecoration(getResources()));
 ....
 }


4- To add spacing between Items
you just need to add padding property to your item view

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:padding="4dp"
>
..... item structure
</RelativeLayout>



public class VerticalItemDecoration extends RecyclerView.ItemDecoration {

private boolean verticalOrientation = true;
private int space = 10;

public VerticalItemDecoration(int value, boolean verticalOrientation) {
    this.space = value;
    this.verticalOrientation = verticalOrientation;
}

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
                           RecyclerView.State state) {
    //skip first item in the list
    if (parent.getChildAdapterPosition(view) != 0) {
        if (verticalOrientation) {
            outRect.set(space, 0, 0, 0);
        } else if (!verticalOrientation) {
            outRect.set(0, space, 0, 0);
        }
    }
}
}

mCompletedShippingRecyclerView.addItemDecoration(new VerticalItemDecoration(20,false)); 



This doesn't actually solve the problem, but as a temporary workaround, you can set the useCompatPadding property on the card in your XML layout to make it measure the same as it does on pre-Lollipop versions.

card_view:cardUseCompatPadding="true"



The RecyclerView is a bit different from the ListView. Actually, the RecyclerView needs a ListView like structure in it. For example, a LinearLayout. The LinearLayout has parameters for the dividing each element. In the code below I have a RecyclerView comprised of CardView objects within a LinearLayout with a "padding" that will put some space between items. Make that space really small and you get a line.

Here's the Recycler view in recyclerview_layout.xml

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".ToDoList">

    <!-- A RecyclerView with some commonly used attributes -->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/todo_recycler_view"
        android:scrollbars="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</RelativeLayout>

And here is what each item looks like (and it shows as divided due to the android:padding in the LinearLayout that surrounds everything.) in another file: cards_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    **android:padding="@dimen/activity_vertical_margin"**>
    <!-- A CardView that contains a TextView -->
    <android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_gravity="center"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:elevation="30dp"
        card_view:cardElevation="3dp">
            <TextView
                android:id="@+id/info_text"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                />
    </android.support.v7.widget.CardView>
</LinearLayout>



Taken from a google search, add this ItemDecoration to your RecyclerView:

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

private Drawable mDivider;
private boolean mShowFirstDivider = false;
private boolean mShowLastDivider = false;


public DividerItemDecoration(Context context, AttributeSet attrs) {
    final TypedArray a = context
            .obtainStyledAttributes(attrs, new int[]{android.R.attr.listDivider});
    mDivider = a.getDrawable(0);
    a.recycle();
}

public DividerItemDecoration(Context context, AttributeSet attrs, boolean showFirstDivider,
        boolean showLastDivider) {
    this(context, attrs);
    mShowFirstDivider = showFirstDivider;
    mShowLastDivider = showLastDivider;
}

public DividerItemDecoration(Drawable divider) {
    mDivider = divider;
}

public DividerItemDecoration(Drawable divider, boolean showFirstDivider,
        boolean showLastDivider) {
    this(divider);
    mShowFirstDivider = showFirstDivider;
    mShowLastDivider = showLastDivider;
}

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
        RecyclerView.State state) {
    super.getItemOffsets(outRect, view, parent, state);
    if (mDivider == null) {
        return;
    }
    if (parent.getChildPosition(view) < 1) {
        return;
    }

    if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
        outRect.top = mDivider.getIntrinsicHeight();
    } else {
        outRect.left = mDivider.getIntrinsicWidth();
    }
}

@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
    if (mDivider == null) {
        super.onDrawOver(c, parent, state);
        return;
    }

    // Initialization needed to avoid compiler warning
    int left = 0, right = 0, top = 0, bottom = 0, size;
    int orientation = getOrientation(parent);
    int childCount = parent.getChildCount();

    if (orientation == LinearLayoutManager.VERTICAL) {
        size = mDivider.getIntrinsicHeight();
        left = parent.getPaddingLeft();
        right = parent.getWidth() - parent.getPaddingRight();
    } else { //horizontal
        size = mDivider.getIntrinsicWidth();
        top = parent.getPaddingTop();
        bottom = parent.getHeight() - parent.getPaddingBottom();
    }

    for (int i = mShowFirstDivider ? 0 : 1; i < childCount; i++) {
        View child = parent.getChildAt(i);
        RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

        if (orientation == LinearLayoutManager.VERTICAL) {
            top = child.getTop() - params.topMargin;
            bottom = top + size;
        } else { //horizontal
            left = child.getLeft() - params.leftMargin;
            right = left + size;
        }
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(c);
    }

    // show last divider
    if (mShowLastDivider && childCount > 0) {
        View child = parent.getChildAt(childCount - 1);
        RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();
        if (orientation == LinearLayoutManager.VERTICAL) {
            top = child.getBottom() + params.bottomMargin;
            bottom = top + size;
        } else { // horizontal
            left = child.getRight() + params.rightMargin;
            right = left + size;
        }
        mDivider.setBounds(left, top, right, bottom);
        mDivider.draw(c);
    }
}

private int getOrientation(RecyclerView parent) {
    if (parent.getLayoutManager() instanceof LinearLayoutManager) {
        LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
        return layoutManager.getOrientation();
    } else {
        throw new IllegalStateException(
                "DividerItemDecoration can only be used with a LinearLayoutManager.");
    }
}
}



I have added a line in list item like below

<View
android:id="@+id/divider"
android:layout_width="match_parent"
android:layout_height="1px"
android:background="@color/dividerColor"/>

1px will draw the thin line.

If you want to hide the divider for the last row then divider.setVisiblity(View.GONE); on the onBindViewHolder for the last list Item.




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