ExpandingCollection for Android

About

This project is maintained by Ramotion, Inc.
We specialize in the designing and coding of custom UI for Mobile Apps and Websites.

Looking for developers for your project?

The Android mockup available here.

Requirements

Android 4.0 IceCreamSandwich (API lvl 14) or greater
Your favorite IDE

Installation

maven repo:

Gradle:

'com.ramotion.expandingcollection:expanding-collection:0.9.0'

SBT:

libraryDependencies += "com.ramotion.expandingcollection" % "expanding-collection" % "0.9.0"

Maven:

<dependency>
	<groupId>com.ramotion.expandingcollection</groupId>
	<artifactId>expanding-collection</artifactId>
	<version>0.9.0</version>
</dependency>

Basic usage

Add a background switcher element ECBackgroundSwitcherView and a main pager element ECPagerView to your layout. ECPagerView should always have match_parent width and wrap_content height. You can adjust the vertical position yourself using alignment/gravity or top margin. ECBackgroundSwitcherView is the dynamic background switcher, so you probably want it to be as big as its parent.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    
    <com.ramotion.expandingcollection.ECBackgroundSwitcherView
        android:id="@+id/ec_bg_switcher_element"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
        
    <com.ramotion.expandingcollection.ECPagerView
        android:id="@+id/ec_pager_element"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"/>
        
</RelativeLayout>

Tune ECPagerView: setup size of card in collapsed state and height of header in expanded state.

<com.ramotion.expandingcollection.ECPagerView xmlns:ec="http://schemas.android.com/apk/res-auto"
    android:id="@+id/ec_pager_element"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    ec:cardHeaderHeightExpanded="150dp"
    ec:cardHeight="200dp"
    ec:cardWidth="250dp" />

Expanded card contains two parts: a header part with a background (initially visible when card is collapsed) and a ListView element as content (visible only when card is expanded), so you need an xml layout for the list items.

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
    
    <TextView xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/list_item_text"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:layout_gravity="center_vertical|center_horizontal"
        android:background="@color/colorPrimary"
        android:textAlignment="center" />
        
</FrameLayout>

Also, you need to implement a custom list adapter for the list items by extending the parametrized com.ramotion.expandingcollection.ECCardContentListItemAdapter.java class, where T is type of datasource object for list items inside the card. In the example below, T is just a string object. It's a pretty straightforward implementation with a common view holder pattern.

public class CardListItemAdapter extends ECCardContentListItemAdapter<String> {

    public CardListItemAdapter(@NonNull Context context, @NonNull List<String> objects) {
        super(context, R.layout.list_item, objects);
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        ViewHolder viewHolder;
        View rowView = convertView;

        if (rowView == null) {
            LayoutInflater inflater = LayoutInflater.from(getContext());
            rowView = inflater.inflate(R.layout.list_item, null);
            viewHolder = new ViewHolder();
            viewHolder.itemText = (TextView) rowView.findViewById(R.id.list_item_text);
            rowView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) rowView.getTag();
        }

        String item = getItem(position);
        if (item != null) {
            viewHolder.itemText.setText(item);
        }
        return rowView;
    }

    static class ViewHolder {
        TextView itemText;
    }

}

Your data class must implement the com.ramotion.expandingcollection.ECCardData.java interface where T is type of datasource object for list items inside the card.

public class CardDataImpl implements ECCardData<String> {

    private String cardTitle;
    private Integer mainBackgroundResource;
    private Integer headBackgroundResource;
    private List<String> listItems;

    @Override
    public Integer getMainBackgroundResource() {
        return mainBackgroundResource;
    }

    @Override
    public Integer getHeadBackgroundResource() {
        return headBackgroundResource;
    }

    @Override
    public List<String> getListItems() {
        return listItems;
    }
}

Almost done! The last thing we need to do is provide our dataset to a pager element through a pager adapter. It's just an implementation of the abstract class com.ramotion.expandingcollection.ECPagerViewAdapter.java with one abstract method, so it can be easily implemented inside your activity.

public class MainActivity extends Activity {

   private ECPagerView ecPagerView;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       // Get pager from layout
       ecPagerView = (ECPagerView) findViewById(R.id.ec_pager_element);

       // Generate example dataset
       List<ECCardData> dataset = CardDataImpl.generateExampleData();

       // Implement and pager adapter and set it to pager view
       ecPagerView.setPagerViewAdapter(new ECPagerViewAdapter(getApplicationContext(), dataset) {
           @Override
           public void instantiateCard(LayoutInflater inflaterService, ViewGroup head, ListView list, ECCardData data) {
               // Data object for current card
               CardDataImpl cardData = (CardDataImpl) data;

               // Set adapter and items to current card content list
               list.setAdapter(new CardListItemAdapter(getApplicationContext(), cardData.getListItems()));
               // Also some visual tuning can be done here
               list.setBackgroundColor(Color.WHITE);

               // Here we can create elements for head view or inflate layout from xml using inflater service
               TextView cardTitle = new TextView(getApplicationContext());
               cardTitle.setText(cardData.getCardTitle());
               cardTitle.setTextSize(COMPLEX_UNIT_DIP, 20);
               FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(FrameLayout.LayoutParams.WRAP_CONTENT, FrameLayout.LayoutParams.WRAP_CONTENT);
               layoutParams.gravity = Gravity.CENTER;
               head.addView(cardTitle, layoutParams);

               // Card toggling by click on head element view
               head.setOnClickListener(new View.OnClickListener() {
                   @Override
                   public void onClick(final View v) {
                       ecPagerView.toggle();
                   }
               });
           }
       });

       // Add background switcher to pager view
       ecPagerView.setBackgroundSwitcherView((ECBackgroundSwitcherView) findViewById(R.id.ec_bg_switcher_element));

   }

   // Card collapse on back pressed
   @Override
   public void onBackPressed() {
       if (!ecPagerView.collapse())
           super.onBackPressed();
   }

}

You can find this and other, more complex, examples in this repository

Licence

Expanding Collection is released under the MIT license. See LICENSE for details.