Develop Reference

ItemDecoration - How to create vertical dividers?

I'm trying to create multiple vertical dividers for each ViewHolder in recyclerView but can't figure out how.
Heres my code for working horizontal dividers:
#Override
public void onDrawOver(#NonNull Canvas c, #NonNull RecyclerView parent, #NonNull RecyclerView.State state) {
int left = parent.getPaddingLeft();
int right = parent.getWidth() - parent.getPaddingRight();
int count = parent.getChildCount();
for(int i = 0; i < count; 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);
}
}
drawable divider:
<?xml version="1.0" encoding="utf-8"?>
<size
android:width="10dp"
android:height="10dp" />
<solid android:color="#color/standardBlue" />

DividerItemDecoration is a RecyclerView.ItemDecoration that can be used as a divider between items of a LinearLayoutManager. It supports both HORIZONTAL and VERTICAL orientations.
Usage:
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
layoutManager.getOrientation());
recyclerView.addItemDecoration(dividerItemDecoration);
Previous answer
All ItemDecorations are drawn in the order they were added, before the item views (in onDraw()) and after the items (in onDrawOver(Canvas, RecyclerView, RecyclerView.State).
Vertical spacing ItemDecoration
Extend ItemDecoration, add custom constructor which takes space height as a
parameter and override getItemOffsets() method:
public class VerticalSpaceItemDecoration extends RecyclerView.ItemDecoration {
private final int verticalSpaceHeight;
public VerticalSpaceItemDecoration(int verticalSpaceHeight) {
this.verticalSpaceHeight = verticalSpaceHeight;
}
#Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
RecyclerView.State state) {
outRect.bottom = verticalSpaceHeight;
}
}
If you don't want to insert space below the last item, add the following condition:
if (parent.getChildAdapterPosition(view) != parent.getAdapter().getItemCount() - 1) {
outRect.bottom = verticalSpaceHeight;
}
Note: you can also modify outRect.top, outRect.left and outRect.right properties for desired effect.
Divider ItemDecoration
Extend ItemDecoration and override onDraw() method:
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
private Drawable divider;
/**
* Default divider will be used
*/
public DividerItemDecoration(Context context) {
final TypedArray styledAttributes = context.obtainStyledAttributes(ATTRS);
divider = styledAttributes.getDrawable(0);
styledAttributes.recycle();
}
/**
* Custom divider will be used
*/
public DividerItemDecoration(Context context, int resId) {
divider = 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 + divider.getIntrinsicHeight();
divider.setBounds(left, top, right, bottom);
divider.draw(c);
}
}
}
You can either call the first constructor that uses the default Android divider attributes, or the second one that uses your own drawable, for example drawable/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="#ff992900" />
</shape>
Note: if you want the divider to be drawn over your items, override onDrawOver() method instead.
Usage
To use your new class add VerticalSpaceItemDecoration or DividerSpaceItemDecoration to RecyclerView, for example in your fragment's onCreateView() method:
private static final int VERTICAL_ITEM_SPACE = 48;
private RecyclerView recyclerView;
private LinearLayoutManager linearLayoutManager;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_feed, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.fragment_home_recycler_view);
linearLayoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(linearLayoutManager);
//add ItemDecoration
recyclerView.addItemDecoration(new VerticalSpaceItemDecoration(VERTICAL_ITEM_SPACE));
//or
recyclerView.addItemDecoration(new DividerItemDecoration(getActivity()));
//or
recyclerView.addItemDecoration(
new DividerItemDecoration(getActivity(), R.drawable.divider));
recyclerView.setAdapter(...);
return rootView;
}

View not appearing at bottom of CardView?

Hi I have a simple CardView where I want to show a divider between each Cardview. The issue is, my View that I use as a divider never gets shown on the last CardView in my RecyclerView. Here is my attempt:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:fresco="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="100dp"
card_view:cardElevation="0dp"
android:id="#+id/cv_news_feed">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp">
...Content...
</RelativeLayout>
</LinearLayout>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#color/material_color_grey_300" />
</android.support.v7.widget.CardView>
The divider shows up for every CardView except for the last for whatever reason and I'm not sure why this is occurring. Any help would be appreciated, thanks!
EDIT: Image posted:

Remove following view from your item
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#color/material_color_grey_300" />
and try to use ItemDecoration as follows
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(
Utility.ItemDecorationConst);
recyclerView.addItemDecoration(5);
DividerItemDecoration.java
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private int space;
public DividerItemDecoration(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.top = space;
outRect.bottom = space;
}
}

CardView is an extension of FrameLayout which means that your divider is not in the bottom of your CardView but in the top.
Place your divider in your LinearLayout instead.

Add layout_gravity attribute to the View:
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_gravity="bottom"
android:background="#color/material_color_grey_300" />

You can try to this code , hope this can help you
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:fresco="http://schemas.android.com/tools"
android:id="#+id/cv_news_feed"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minHeight="100dp"
card_view:cardElevation="0dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp">
...Content...
</RelativeLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_below="#+id/cv_news_feed"
android:layout_marginTop="5dp"
android:background="#android:color/holo_red_dark" />
</RelativeLayout>

Create a class DividerItemDecoration:
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
/**
* Created by Lincoln on 30/10/15.
*/
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{
android.R.attr.listDivider
};
public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;
public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;
private Drawable mDivider;
private int mOrientation;
public DividerItemDecoration(Context context, int orientation) {
final TypedArray a = context.obtainStyledAttributes(ATTRS);
mDivider = a.getDrawable(0);
a.recycle();
setOrientation(orientation);
}
public void setOrientation(int orientation) {
if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) {
throw new IllegalArgumentException("invalid orientation");
}
mOrientation = orientation;
}
#Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST) {
drawVertical(c, parent);
} else {
drawHorizontal(c, parent);
}
}
public void drawVertical(Canvas c, RecyclerView parent) {
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 top = child.getBottom() + params.bottomMargin;
final int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
public void drawHorizontal(Canvas c, RecyclerView parent) {
final int top = parent.getPaddingTop();
final int bottom = parent.getHeight() - parent.getPaddingBottom();
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 left = child.getRight() + params.rightMargin;
final int right = left + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
#Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
if (mOrientation == VERTICAL_LIST) {
outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
} else {
outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
}
}
}
Then set the item decoration using addItemDecoration() method before setting the adapter.
recyclerView.addItemDecoration(new DividerItemDecoration(this, LinearLayoutManager.VERTICAL));
// set the adapter
recyclerView.setAdapter(mAdapter);
N.B. Remove the view that you are using in cardview layout to show the divider.

Try to put your divider into LinearLayout,i.e.:

You should use like this
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp">
...Content...
</RelativeLayout>
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:background="#color/material_color_grey_300" />
</LinearLayout>
Because CardView extends FrameLayout so your devider will be behind LinearLayout content.

RecyclerView ItemDecoration: Spacing AND Divider

Below is how I'm doing the spacing for RecyclerView items. It's designed to work with both grids and lists. The spacing works.
What I can't figure out is how to insert a divider line as well. Any help doing so would be greatly appreciated.
SIDE NOTE: if you have a better way to implement the spacing than what I'm currently doing, I'd be very grateful as well :)
public class ItemOffsetDecoration extends RecyclerView.ItemDecoration {
private int numOfColumns;
private int listSize;
private int offsetInDp;
private boolean isGridView;
private boolean canScrollHorizontally;
private boolean isBottomRow = false;
public ItemOffsetDecoration(RecyclerView.LayoutManager manager, int listSize, int offsetInDp) {
this(manager, 1, listSize, offsetInDp);
}
public ItemOffsetDecoration(RecyclerView.LayoutManager manager, int numOfColumns, int listSize, int offsetInDp) {
this.numOfColumns = numOfColumns;
this.listSize = listSize;
this.offsetInDp = PixelConversionUtils.dpToPx(offsetInDp);
this.isGridView = manager instanceof GridLayoutManager;
this.canScrollHorizontally = manager.canScrollHorizontally();
}
#Override
public void getItemOffsets(Rect outRect, View view,
RecyclerView parent, RecyclerView.State state) {
// only do left/right spacing if grid or horizontal list
if (isGridView || canScrollHorizontally) {
outRect.left = offsetInDp;
outRect.right = offsetInDp;
}
// only do top/bottom spacing if grid or vertical list
if (isGridView || !canScrollHorizontally) {
int pos = parent.getChildAdapterPosition(view);
boolean isNotTopRow = pos >= numOfColumns;
// Don't add top spacing to top row
if (isNotTopRow) {
outRect.top = offsetInDp;
}
int columnIndex = ((GridLayoutManager.LayoutParams) view.getLayoutParams()).getSpanIndex();
if (pos >= (listSize - numOfColumns) && columnIndex == 0) {
isBottomRow = true;
}
// Don't add bottom spacing to bottom row
if (!isBottomRow && pos < (listSize - numOfColumns)) {
outRect.bottom = offsetInDp;
}
}
}
}
here's a quick visual of what I'm looking to do:
here's what I have:
here's what I want:

You can achieve desired look this way:
first, create a divider Drawable, for this example I've used a simple shape, but you could use default line divider or any other drawable:
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size android:height="2dp" />
<size android:width="2dp" />
<solid android:color="#000000" />
</shape>
second, in your ItemOffsetDecoration declare Drawable and initialize it:
public class ItemOffsetDecoration extends RecyclerView.ItemDecoration {
private Drawable mDivider;
...
public ItemOffsetDecoration(...) {
mDivider = ContextCompat.getDrawable(context, R.drawable.item_divider);
}
}
third, override onDrawOver() method:
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
if (isGridView) {
drawVerticalDivider(c, parent);
} else {
drawVerticalDivider(c, parent);
drawHorizontalDivider(c, parent);
}
}
where drawVerticalDivider() & drawHorizontalDivider() are (might be a good idea to refactor them into the single method and control direction of the divider via parameter):
public void drawVerticalDivider(Canvas c, RecyclerView parent) {
if (parent.getChildCount() == 0) return;
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
View child = parent.getChildAt(i);
RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) child.getLayoutParams();
int left = child.getLeft() - params.leftMargin - offsetInDp;
int right = child.getRight() + params.rightMargin + offsetInDp;
int top = child.getBottom() + params.bottomMargin + offsetInDp;
int bottom = top + mDivider.getIntrinsicHeight();
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
public void drawHorizontalDivider(Canvas c, RecyclerView parent) {
final int childCount = parent.getChildCount();
for (int i = 0; i < childCount; i++) {
View child = parent.getChildAt(i);
RecyclerView.LayoutParams params =
(RecyclerView.LayoutParams) child.getLayoutParams();
int left = child.getRight() + params.rightMargin + offsetInDp;
int right = left + mDivider.getIntrinsicWidth();
int top = child.getTop() - params.topMargin - offsetInDp;
int bottom = child.getBottom() + params.bottomMargin + offsetInDp;
mDivider.setBounds(left, top, right, bottom);
mDivider.draw(c);
}
}
Result for the Linear and Grid LayoutManagers:

Try placing the following XML snippet to get a divider:
<View android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginLeft="72dp"
android:layout_marginRight="16dp"
android:background="123e4152"/>
You can put this in the recyclerView's item layout beneath your items. Also Play around with the margins and background to suit your list.

haha……actualy,i had try like this for Divider ,although with a bit funny : first make you recycleview backgroud with Deep color,and make item_view backgroud white,then marginbottom for every item -> I'm serious, do not vote down :)
<?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">
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_marginBottom="2dp"
android:layout_height="wrap_content">
<TextView
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content" />
<TextView
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="match_parent" />
</LinearLayout>

How do I show dividers in a PreferenceFragment?

I'm using PreferenceFragmentCompat from the v7 support library to display a few settings. My preferences.xml file is as follows -
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<EditTextPreference
android:defaultValue="#string/temp_url_default"
android:key="temp_edit_preference_key"
android:title="#string/temp_url_setting_title" />
<EditTextPreference
android:defaultValue=""
android:key="username_preference_key"
android:title="#string/username_setting_title" />
<EditTextPreference
android:defaultValue=""
android:key="password_preference_key"
android:title="#string/password_setting_title" />
<ListPreference
android:key="reset_preference_key"
android:title="#string/reset_setting_title" />
</PreferenceScreen>
Java code -
public class SettingsFragment extends PreferenceFragmentCompat {
#Override
public void onCreatePreferences(Bundle bundle, String s) {
addPreferencesFromResource(R.xml.preferences);
}
}
The theme I'm using for preferences is -
<style name="AppTheme.Base" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="preferenceTheme">#style/AppTheme.Preference</item>
</style>
<style name="AppTheme.Preference" parent="#style/PreferenceThemeOverlay">
<item name="android:textColorPrimary">#android:color/holo_blue_dark</item>
</style>
The four settings are just displayed one below the other, without any divider in between. How do I show a divider in between two items ?

For a few revision the com.android.support:preference-v7 support library uses the RecyclerView in order to display the settings now. Out of the box the RecyclerView doesn't have a divider but adding an ItemDecoration to the RecyclerView will work:
public class YourPreferenceFragment extends PreferenceFragmentCompat {
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
RecyclerView recyclerView = (RecyclerView) getView().findViewById(R.id.list);
recyclerView.addItemDecoration(
new DividerItemDecorationPreferences(
getActivity(),
getResources().getDimensionPixelSize(R.dimen.row_preferences_margin_horizontal),
getResources().getDimensionPixelSize(R.dimen.row_preferences_margin_horizontal)));
}
}
Obviously you can use whatever Divider you like. As for myself use the following class:
public class DividerItemDecorationPreferences extends RecyclerView.ItemDecoration {
private Drawable mDivider;
private int paddingLeft = 0;
private int paddingRight = 0;
public DividerItemDecorationPreferences(Context context, int paddingLeft, int paddingRight) {
mDivider = ContextCompat.getDrawable(context, R.drawable.divider_recycler_view);
this.paddingLeft = paddingLeft;
this.paddingRight = paddingRight;
}
#Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
int left = paddingLeft;
int right = parent.getWidth() - paddingRight;
int childCount = parent.getChildCount();
boolean lastIteration = false;
for (int i = 0; i < childCount; i++) {
if (i == childCount - 1)
lastIteration = true;
View child = parent.getChildAt(i);
if (!lastIteration) {
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);
}
}
}
}
divider_recycler_view.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="#1F000000" />
</shape>

GridView to make square board

I'm trying to make a square board with 5 x 5 grid using gridview. Here is my code:
<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:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<GridView
android:id="#+id/squareBoard"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:numColumns="5"
/>
</RelativeLayout>
This is the Adapter I used:
private class TextViewAdapter extends BaseAdapter {
private Context mContext;
private int mWidth, mHeight;
public TextViewAdapter(Context c, int width, int height) {
mContext = c;
mWidth = width;
mHeight = height;
}
public int getCount() {
return mWidth * mHeight;
}
public TextView getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
TextView tv = null;
if (convertView == null) { // if it's not recycled, initialize some attributes
tv = new TextView(mContext);
tv.setText("" + position);
tv.setGravity(Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL);
tv.setLayoutParams(new GridView.LayoutParams(100, 100));
tv.setWidth(100);
tv.setBackground(getResources().getDrawable(R.drawable.letter_box));
} else {
tv = (TextView) convertView;
}
return tv;
}
}
and this is the letter_box.xml of the textview background
<shape
xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle" >
<solid
android:color="#android:color/white" >
</solid>
<stroke
android:width="1dp"
android:color="#android:color/black" >
</stroke>
</shape>
So far, i managed to display boxes, but there's always horizontal space between columns. I want them to be like a chess board.
Can anyone help me?

Create your own class MyGridView which extends GridView.
Override its onMeasure(...) method and set height == width, like so:
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, widthMeasureSpec);
}
Then, create your own GridViewItem extending a View subclass e.g. TextView or ImageView etc. Override its onMeasure(...) method in the same way.
MyGridViewand its items will all appear square.

On your GridView, you can set the vertical spacing and the horizontal spacing that is between two items. Try setting those to 0dp.
<GridView
android:id="#+id/squareBoard"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:verticalSpacing="0dp"
android:horizontalSpacing="0dp"
android:numColumns="5"
/>