A highly customizable Android ViewGroup for displaying Chips (specified in the Material Design Guide).

Chips Input Layout

A highly customizable Android ViewGroup for displaying Chips (specified in the Material Design Guide)!

Here's some of the core features of this library:

• You can allow the user to filter chips as they type
• You can allow the user to enter custom chips
• You can specify if the chips show details, is deletable, or has an avatar
• You can specify how the chips are managed/stored in memory
• ChipsInputView can validate chips that are selected
• Most views (seen in screenshots) are highly customizable
• Sticks to the Material Design Guide as much as possible

Honorable Mentions:

• This was based on the design of: https://github.com/pchmn/MaterialChipsInput
• This uses a RecyclerView layout manager: https://github.com/BelooS/ChipsLayoutManager

Using the Chips Input Layout

The basic usage of this library is to allow users to input chips and for them to be displayed like in the Material Design Guide. To achieve this functionality, you'll need to use the ChipsInputLayout view.

Using in an XML layout

ChipsInputLayout can be used in any ViewGroup and supports all width and height attributes. Simple usage is shown here:

<com.tylersuehr.library.ChipsInputLayout
        android:id="@+id/chips_input"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Start typing for chips... "
        android:textColorHint="#757575"
        android:textColor="#212121"
        app:detailedChipsEnabled="true"
        app:customChipsEnabled="true"/>

Here is a table of all the XML attributes available for this view:

Using in Java code

ChipsInputLayout can be programmatically added into any ViewGroup. Simple usage in an Activity is shown here:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    
    ChipsInputLayout chipsInputLayout = new ChipsInputLayout(this);
    // Set any properties for chips input layout
    
    setContentView(chipsInputLayout);
}

Here is a table of all the accessible attributes available for this view:

Using the Chips

There are a plethora of ways you can manipulate chips in ChipsInputLayout. However, the main abilities afforded by ChipsInputLayout are that you can set a list of chips that can be filtered by user input and set a list of chips that are pre-selected. Other features are listed in the table below.

Creating a chip

Chip is the base object needed for ChipsInputLayout, and associated components in the library, to work properly. ChipsInputLayout can work with anything that is a Chip. So, that means that you can create any type of 'chip' data you want... simply inherit the Chip class and you're good to go!

Here's a small example:

public class CoolChip extends Chip {
    private final String coolName;
    private final Uri coolPic;
    
    public CoolChip(String coolName, Uri coolPic) {
        this.coolName = coolName;
        this.coolPic = coolPic;
    }
    
    Override
    public String getTitle() {
        return coolName;
    }
    
    @Override
    public Uri getAvatarUri() {
        return coolPic;
    }
    
    // ...other chip methods that are required to implement
}

Setting a filterable list of chips in ChipsInputLayout

ChipsInputLayout supports the ability to show/hide a list of chips that are filterable as the user inputs text into it. To use this feature, simply call setFilterableChipList(List) in ChipsInputLayout.

Not calling setFilterableChipList(List) will imply you don't wish to use that feature, therefore, ChipsInputLayout, will not show/hide the filterable list as the user inputs text.

Here is a simple example:

@Override
protected void onCreate(List<ContactChip> chips) {
    // ...Cool onCreate stuff in activity
    
    ChipsInputLayout chipsInput = (ChipsInputLayout)findViewById(R.id.chips_input);
    
    // ...Cool logic to acquire chips
    List<AwesomeChip> chips = getReallyCoolChips();
        
    this.chipsInput.setFilterableChipList(chips);
}

Setting a pre-selected list of chips in ChipsInputLayout

ChipsInputLayout supports the ability to set an already-selected list of chips. To use this feature, simply call setSelectedChipList(List) in ChipsInputLayout.

Here is a simple example:

@Override
protected void onCreate(List<ContactChip> chips) {
    // ...Cool onCreate stuff in activity
    
    ChipsInputLayout chipsInput = (ChipsInputLayout)findViewById(R.id.chips_input);
    
    // ...Cool logic to acquire chips
    List<TagChip> defaultChips = getDefaultTagChips();
        
    this.chipsInput.setSelectedChipList(chips);
}

Other chip manipulation methods in ChipsInputLayout

Managing the Chips

Where this library capitalizes, is how it decentralizes where and how the selected and filterable chips are stored. This makes accessing and receiving updates to data source changes from various Android components really simple.

All chips are managed by, ChipDataSource, which is an abstraction to decouple the concrete implementation of how the abstract methods manage the chips. This means that other implementations of ChipDataSource can be made at your own leisure. Simply call changeChipDataSource(ChipDataSource) in ChipsInputLayout to use your implementation of ChipDataSource.

Although not required, but definitely recommeneded, you can inherit the semi-concrete, ObservableChipDataSource, which is an implementation of ChipDataSource that handles the observer functionality for you properly so that it simplifies writing other ChipDataSource implementations.

By default, ChipsInputLayout will automatically use ListChipDataSource; which is out-of-the-box really good at being processing and memory efficient, and it relies on the ArrayList to manage chips.

Observing chip selection changes

ChipDataSource has the ability to notify observers that want to observe specific chip selection events in ChipDataSource. The observers will be notified if a chip has been selected or unselected from the selected chip list in ChipDataSource. Both selection and deselection events will afford the chip that was selected or deselected respectively.

To use this functionality, you'll want to implement the ChipSelectionObserver and register it on ChipDataSource. Be sure to manage unregistering the observer, if need be, as well.

Since components outside of the library cannot, and should not, directly access ChipDataSouce, you'll use ChipsInputLayout to set the observer; using its setChipSelectionObserver(ChipSelectionObserver) method.

Here is a simple example:

public class CoolActivity extends AppCompatActivity implements ChipSelectionObserver {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cool);
        
        // Get the ChipsInputLayout from the layout file
        ChipsInputLayout chipsInput = (ChipsInputLayout)findViewById(R.id.chips);
        chipsInput.setChipSelectionObserver(this);
    }
    
    @Override
    public void onChipSelected(Chip selectedChip) {
        // Cool chip selection stuff here...
    }
    
    @Override
    public void onChipUnselected(Chip unselectedChip) {
        // Cool chip unselection stuff here...
    }
}

Observing any change to the chip data source

ChipDataSource has the ability to notify observers that want to observe any type of change to the data in ChipDataSource. The observers will be notified if a chip has been added or removed from either the selected or filtered lists in the ChipDataSource; however, there's no information about the event though.

This is used internally by the library to trigger UI updates on RecyclerView adapters when the data has changed.

Currently, ChipsInputLayout, does not have a method to set this type of observer on the ChipDataSource because this is for internal components of the library. However, this may be an addition to the library, if needed\requested, in the future.

To use this functionality, you'll want to implement the ChipChangedObserver and register it on ChipDataSource. Be sure to manage unregistering the observer, if need be, as well.

Here is a simple example:

public class CoolAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements ChipChangedObserver {
    public CoolAdapter(ChipDataSource dataSource) {
        dataSource.addChipChangedObserver(this);
    }
    
    // adapter implementation to do really cool adapter stuff...
    
    @Override
    public void onChipDataSourceChanged() {
        // This example would just update the Recycler when the chip data source changes
        notifyDataSetChanged();
    }
}

Chip Validation

This library also affords the ability to validate chips. Chip validtion can be used for a plethora of reasons or use-cases. Validation can be done on the selected chips or on a single chip itself.

Validation is abstracted by the ChipValidator interface. This allows you to provide your own implementation of chip validation for whatever purpose you want or need it for. By default, there is no implementation of ChipValidator set or provided by this library.

Creating a chip validator

ChipValidator must be implemented in order to write your own chip validation logic. ChipValidator has one method only, validate(Chip), and it is used to determine when a single given chip should be considered valid.

Here's a small example:

public class CustomChipValidator implements ChipsInputLayout.ChipValidator {
    @Override
    public boolean validate(Chip chip) {
        // This example will make the chip valid if the chip's title contains the letter "T"
        return chip.getTitle().toLowerCase().contains("t");
    }
}

Setting a chip validator

A custom implementation of ChipValidator can be set using the ChipsInputLayout. Simply call the setChipValidator(ChipValidator) method in ChipsInputLayout.

Here's a simple example:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_cool);
    
    // Find out chips input layout in xml layout
    ChipsInputLayout chipsInput = (ChipsInputLayout)findViewById(R.id.chips_input);
    
    // Set an instance of chip validator in chips input layout
    chipsInput.setChipValidator(new MyCoolChipValidator());
}

Using a chip validator

Using a chip validator is really easy! After setting a chip validator in ChipsInputLayout, you can validate a single given chip or all the selected chips.

Validating a single given chip can be done by calling, validateChip(Chip), in ChipsInputLayout. Validating all the selected chips can be done by calling, validateSelectedChips(), in ChipsInputLayout. When you call either of those methods without having set a chip validator, it will simply return true.

Here's a simple example:

public class CoolActivity extends AppCompatActivity {
    private ChipsInputLayout chipsInput;
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_cool);
        
        // Find chips input layout in XML layout
        this.chipsInput = (ChipsInputLayout)findViewById(R.id.chips_input);
        
        // Set custom chip validator
        this.chipsInput.setChipValidator(new MyCoolChipValidator());
    }
    
    public void onCoolButtonClicked(View v) {
        // Example to show selected chip validation
        if (chipsInput.validateSelectedChips()) {
            Toast.makeText(this, "Selected chips are valid!", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(this, "Selected chips are NOT valid!", Toast.LENGTH_SHORT).show();
        }
    }
}