CardView is another major element introduced in Material Design. Using CardView you can represent the information in a card manner with a drop shadow (elevation) and corner radius which looks consistent across the platform.
How to Add CardView?
To use the CardView in your app, add the CardView dependency in build.gradle and Sync the project.
dependencies {
// CardView
compile 'com.android.support:cardview-v7:23.3.+'
}
Add the <android.support.v7.widget.CardView> widget to your layout and place other UI widgets like TextViews, ImageViews inside it. You can notice that the below CardView widget contains a single TextView.<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto">
<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="250dp"
android:layout_height="250dp"
card_view:cardCornerRadius="4dp">
<TextView
android:text="Hello Card"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</android.support.v7.widget.CardView>
</LinearLayout>
Creating New Project.
Create a new project in Android Studio from File New Project. When it prompts you to select the default activity, select Empty Activity and proceed.
Add album covers and icons required for this project.
Add the below strings, colors and dimen resources to strings.xml, colors.xml and dimens.xml files.
<resources>
<string name="app_name">Card View</string>
<string name="action_settings">Settings</string>
<string name="action_add_favourite">Add to Favourites</string>
<string name="action_play_next">Play Next</string>
<string name="backdrop_title">LOVE MUSIC</string>
<string name="backdrop_subtitle">This season top 20 albums</string>
</resources>
<?xml version="1.0" encoding="utf-8"?>
<resources>
<color name="colorPrimary">#F50057</color>
<color name="colorPrimaryDark">#F50057</color>
<color name="colorAccent">#FF4081</color>
<color name="viewBg">#f1f5f8</color>
<color name="album_title">#4c4c4c</color>
</resources>
<resources>
<dimen name="activity_horizontal_margin">16dp</dimen>
<dimen name="activity_vertical_margin">16dp</dimen>
<dimen name="fab_margin">16dp</dimen>
<dimen name="item_offset">10dp</dimen>
<dimen name="detail_backdrop_height">250dp</dimen>
<dimen name="backdrop_title">30dp</dimen>
<dimen name="backdrop_subtitle">18dp</dimen>
<dimen name="card_margin">5dp</dimen>
<dimen name="card_album_radius">0dp</dimen>
<dimen name="album_cover_height">160dp</dimen>
<dimen name="album_title_padding">10dp</dimen>
<dimen name="album_title">15dp</dimen>
<dimen name="songs_count_padding_bottom">5dp</dimen>
<dimen name="songs_count">12dp</dimen>
<dimen name="ic_album_overflow_width">20dp</dimen>
<dimen name="ic_album_overflow_height">30dp</dimen>
<dimen name="ic_album_overflow_margin_top">10dp</dimen>
</resources>
Open build.gradle and add CardView, RecyclerView and Glide dependencies. RecyclerView is used to display the albums in grid manner. CardView is used to display single album item. Glide is used to display the album cover images.
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.3.0'
compile 'com.android.support:design:23.3.0'
// RecyclerView
compile 'com.android.support:recyclerview-v7:23.3.+'
// CardView
compile 'com.android.support:cardview-v7:23.3.+'
// Glide
compile 'com.github.bumptech.glide:glide:3.7.0'
}
To create instance of a single album, we need a model class denoting the album properties like name, number of songs and cover image. So create a class named Album.java and add the below code.package com.singh.cardview;
/**
* Created by Singh on 20/11/16.
*/
public class Album {
private String name;
private int numOfSongs;
private int thumbnail;
public Album() {
}
public Album(String name, int numOfSongs, int thumbnail) {
this.name = name;
this.numOfSongs = numOfSongs;
this.thumbnail = thumbnail;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getNumOfSongs() {
return numOfSongs;
}
public void setNumOfSongs(int numOfSongs) {
this.numOfSongs = numOfSongs;
}
public int getThumbnail() {
return thumbnail;
}
public void setThumbnail(int thumbnail) {
this.thumbnail = thumbnail;
}
}
We also need an xml layout to display the album card. Create an xml layout named album_card.xml under res layout. Here you can notice that I have added <android.support.v7.widget.CardView> and added all the album properties like name, number of songs and cover image inside it. I also added a 3 dot icon which shows a popup menu on tapping it.<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.CardView
android:id="@+id/card_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_margin="@dimen/card_margin"
android:elevation="3dp"
card_view:cardCornerRadius="@dimen/card_album_radius">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/thumbnail"
android:layout_width="match_parent"
android:layout_height="@dimen/album_cover_height"
android:background="?attr/selectableItemBackgroundBorderless"
android:clickable="true"
android:scaleType="fitXY" />
<TextView
android:id="@+id/title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/thumbnail"
android:paddingLeft="@dimen/album_title_padding"
android:paddingRight="@dimen/album_title_padding"
android:paddingTop="@dimen/album_title_padding"
android:textColor="@color/album_title"
android:textSize="@dimen/album_title" />
<TextView
android:id="@+id/count"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/title"
android:paddingBottom="@dimen/songs_count_padding_bottom"
android:paddingLeft="@dimen/album_title_padding"
android:paddingRight="@dimen/album_title_padding"
android:textSize="@dimen/songs_count" />
<ImageView
android:id="@+id/overflow"
android:layout_width="@dimen/ic_album_overflow_width"
android:layout_height="@dimen/ic_album_overflow_height"
android:layout_alignParentRight="true"
android:layout_below="@id/thumbnail"
android:layout_marginTop="@dimen/ic_album_overflow_margin_top"
android:scaleType="centerCrop"
android:src="@drawable/ic_dots" />
</RelativeLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
Create a menu file named menu_album.xml under res menu folder. This menu will be shown as popup menu on tapping on dots icons on each album card item.<menu 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">
<item
android:id="@+id/action_add_favourite"
android:orderInCategory="100"
android:title="@string/action_add_favourite" />
<item
android:id="@+id/action_play_next"
android:orderInCategory="101"
android:title="@string/action_play_next" />
</menu>
To render the RecyclerView, we need an adapter class which inflates the album_card.xml by keeping appropriate information. Create a class named AlbumsAdapter.java and add the below content.package com.singh.cardview;
import android.content.Context;
import android.support.v7.widget.PopupMenu;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.bumptech.glide.Glide;
import java.util.List;
/**
* Created by Singh on 20/11/16.
*/
public class AlbumsAdapter extends RecyclerView.Adapter<AlbumsAdapter.MyViewHolder> {
private Context mContext;
private List<Album> albumList;
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView title, count;
public ImageView thumbnail, overflow;
public MyViewHolder(View view) {
super(view);
title = (TextView) view.findViewById(R.id.title);
count = (TextView) view.findViewById(R.id.count);
thumbnail = (ImageView) view.findViewById(R.id.thumbnail);
overflow = (ImageView) view.findViewById(R.id.overflow);
}
}
public AlbumsAdapter(Context mContext, List<Album> albumList) {
this.mContext = mContext;
this.albumList = albumList;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.album_card, parent, false);
return new MyViewHolder(itemView);
}
@Override
public void onBindViewHolder(final MyViewHolder holder, int position) {
Album album = albumList.get(position);
holder.title.setText(album.getName());
holder.count.setText(album.getNumOfSongs() + " songs");
// loading album cover using Glide library
Glide.with(mContext).load(album.getThumbnail()).into(holder.thumbnail);
holder.overflow.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
showPopupMenu(holder.overflow);
}
});
}
private void showPopupMenu(View view) {
// inflate menu
PopupMenu popup = new PopupMenu(mContext, view);
MenuInflater inflater = popup.getMenuInflater();
inflater.inflate(R.menu.menu_album, popup.getMenu());
popup.setOnMenuItemClickListener(new MyMenuItemClickListener());
popup.show();
}
/**
* Click listener for popup menu items
*/
class MyMenuItemClickListener implements PopupMenu.OnMenuItemClickListener {
public MyMenuItemClickListener() {
}
@Override
public boolean onMenuItemClick(MenuItem menuItem) {
switch (menuItem.getItemId()) {
case R.id.action_add_favourite:
Toast.makeText(mContext, "Add to favourite", Toast.LENGTH_SHORT).show();
return true;
case R.id.action_play_next:
Toast.makeText(mContext, "Play next", Toast.LENGTH_SHORT).show();
return true;
default:
}
return false;
}
}
@Override
public int getItemCount() {
return albumList.size();
}
}
Open the layout files main activity activity_main.xml and content_main.xml, add AppBarLayout, CollapsingToolbarLayout, Toolbar and RecyclerView.<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/white"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:id="@+id/appbar"
android:layout_width="match_parent"
android:layout_height="@dimen/detail_backdrop_height"
android:fitsSystemWindows="true"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:expandedTitleTextAppearance="@android:color/transparent"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/backdrop"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
android:scaleType="centerCrop"
app:layout_collapseMode="parallax" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:gravity="center_horizontal"
android:orientation="vertical">
<TextView
android:id="@+id/love_music"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/backdrop_title"
android:textColor="@android:color/white"
android:textSize="@dimen/backdrop_title" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/backdrop_subtitle"
android:textColor="@android:color/white"
android:textSize="@dimen/backdrop_subtitle" />
</LinearLayout>
</RelativeLayout>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<include layout="@layout/content_main" />
</android.support.design.widget.CoordinatorLayout>
content_main.xml?xml version="1.0" encoding="utf-8"?>
<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="match_parent"
android:background="@color/viewBg"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="info.androidhive.cardview.MainActivity"
tools:showIn="@layout/activity_main">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clipToPadding="false"
android:scrollbars="vertical" />
</RelativeLayout>
Finally open MainActivity.java and do the necessary changes.
initCollapsingToolbar() Shows or hides the toolbar title when the toolbar is collapsed or expanded.
prepareAlbums() Adds sample albums data required for the recycler view.
GridLayoutManager is used to display the RecyclerView in Grid manner instead of list.
GridSpacingItemDecoration is used to give equal margins around RecyclerView grid items.
AlbumsAdapter instance is created and assigned to RecyclerView which renders the CardView albums in grid fashion.
package com.singh.cardview;
import android.content.res.Resources;
import android.graphics.Rect;
import android.os.Bundle;
import android.support.design.widget.AppBarLayout;
import android.support.design.widget.CollapsingToolbarLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.TypedValue;
import android.view.View;
import android.widget.ImageView;
import com.bumptech.glide.Glide;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private AlbumsAdapter adapter;
private List<Album> albumList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
initCollapsingToolbar();
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
albumList = new ArrayList<>();
adapter = new AlbumsAdapter(this, albumList);
RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(this, 2);
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.addItemDecoration(new GridSpacingItemDecoration(2, dpToPx(10), true));
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(adapter);
prepareAlbums();
try {
Glide.with(this).load(R.drawable.cover).into((ImageView) findViewById(R.id.backdrop));
} catch (Exception e) {
e.printStackTrace();
}
}
private void initCollapsingToolbar() {
final CollapsingToolbarLayout collapsingToolbar =
(CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar);
collapsingToolbar.setTitle(" ");
AppBarLayout appBarLayout = (AppBarLayout) findViewById(R.id.appbar);
appBarLayout.setExpanded(true);
// hiding & showing the title when toolbar expanded & collapsed
appBarLayout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
boolean isShow = false;
int scrollRange = -1;
@Override
public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
if (scrollRange == -1) {
scrollRange = appBarLayout.getTotalScrollRange();
}
if (scrollRange + verticalOffset == 0) {
collapsingToolbar.setTitle(getString(R.string.app_name));
isShow = true;
} else if (isShow) {
collapsingToolbar.setTitle(" ");
isShow = false;
}
}
});
}
/**
* Adding albums for testing
*/
private void prepareAlbums() {
int[] covers = new int[]{
R.drawable.album1,
R.drawable.album2,
R.drawable.album3,
R.drawable.album4,
R.drawable.album5,
R.drawable.album6};
Album a = new Album("Album", 6, covers[0]);
albumList.add(a);
a = new Album("Album", 10, covers[1]);
albumList.add(a);
a = new Album("Album", 4, covers[2]);
albumList.add(a);
a = new Album("Album", 2, covers[3]);
albumList.add(a);
a = new Album("Album", 11, covers[4]);
albumList.add(a);
a = new Album("Album", 9, covers[5]);
albumList.add(a);
adapter.notifyDataSetChanged();
}
/**
* RecyclerView item decoration - give equal margin around grid item
*/
public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {
private int spanCount;
private int spacing;
private boolean includeEdge;
public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
this.spanCount = spanCount;
this.spacing = spacing;
this.includeEdge = includeEdge;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
int position = parent.getChildAdapterPosition(view); // item position
int column = position % spanCount; // item column
if (includeEdge) {
outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)
if (position < spanCount) { // top edge
outRect.top = spacing;
}
outRect.bottom = spacing; // item bottom
} else {
outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
if (position >= spanCount) {
outRect.top = spacing; // item top
}
}
}
}
/**
* Converting dp to pixel
*/
private int dpToPx(int dp) {
Resources r = getResources();
return Math.round(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, r.getDisplayMetrics()));
}
}
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