butterknife

Class ButterKnife

java.lang.Object

butterknife.ButterKnife

public final class ButterKnife
extends Object

Field and method binding for Android views. Use this class to simplify finding views and attaching listeners by binding them with annotations.

Finding views from your activity is as easy as:

 public class ExampleActivity extends Activity {
    @Bind(R.id.title) EditText titleView;
    @Bind(R.id.subtitle) EditText subtitleView;

    @Override protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.example_activity);
     ButterKnife.bind(this);
   }
 }
 

Binding can be performed directly on an activity, a view, or a dialog. Alternate objects to bind can be specified along with an activity, view, or dialog.

Group multiple views together into a List or array.

  @Bind({R.id.first_name, R.id.middle_name, R.id.last_name})
 List nameViews;
 

There are three convenience methods for working with view collections:

• apply(List, Action) – Applies an action to each view.
• apply(List, Setter, Object) – Applies a setter value to each view.
• apply(List, Property, Object) – Applies a property value to each view.

To bind listeners to your views you can annotate your methods:

  @OnClick(R.id.submit) void onSubmit() {
   // React to button click.
 }
 

Any number of parameters from the listener may be used on the method.

  @OnItemClick(R.id.tweet_list) void onTweetClicked(int position) {
   // React to tweet click.
 }
 

Be default, views are required to be present in the layout for both field and method bindings. If a view is optional add a @Nullable annotation such as the one in the support-annotations library.

  @Nullable @Bind(R.id.title) TextView subtitleView;
 

Resources can also be bound to fields to simplify programmatically working with views:

  @ResourceBool(R.bool.is_tablet) boolean isTablet;
  @ResourceInt(R.int.columns) int columns;
  @ResourceColor(R.color.error_red) int errorRed;
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ButterKnife.Action<T extends android.view.View> An action that can be applied to a list of views.
static class	ButterKnife.Finder DO NOT USE: Exposed for generated code.
static interface	ButterKnife.Setter<T extends android.view.View,V> A setter that can apply a value to a list of views.
static interface	ButterKnife.ViewBinder<T> DO NOT USE: Exposed for generated code.

Method Summary

Modifier and Type	Method and Description
static <T extends android.view.View> void	apply(List<T> list, ButterKnife.Action<? super T> action) Apply the specified action across the list of views.
static <T extends android.view.View,V> void	apply(List<T> list, ButterKnife.Setter<? super T,V> setter, V value) Set the value using the specified setter across the list of views.
static <T extends android.view.View,V> void	apply(List<T> list, android.util.Property<? super T,V> setter, V value) Apply the specified value across the list of views using the property.
static void	bind(android.app.Activity target) Bind annotated fields and methods in the specified Activity.
static void	bind(android.app.Dialog target) Bind annotated fields and methods in the specified Dialog.
static void	bind(Object target, android.app.Activity source) Bind annotated fields and methods in the specified target using the source Activity as the view root.
static void	bind(Object target, android.app.Dialog source) Bind annotated fields and methods in the specified target using the source Dialog as the view root.
static void	bind(Object target, android.view.View source) Bind annotated fields and methods in the specified target using the source View as the view root.
static void	bind(android.view.View target) Bind annotated fields and methods in the specified View.
static <T extends android.view.View> T	findById(android.app.Activity activity, int id) Simpler version of Activity.findViewById(int) which infers the target type.
static <T extends android.view.View> T	findById(android.app.Dialog dialog, int id) Simpler version of Dialog.findViewById(int) which infers the target type.
static <T extends android.view.View> T	findById(android.view.View view, int id) Simpler version of View.findViewById(int) which infers the target type.
static void	setDebug(boolean debug) Control whether debug logging is enabled.
static void	unbind(Object target) Reset fields annotated with @Bind to null.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

setDebug

public static void setDebug(boolean debug)

Control whether debug logging is enabled.

bind

public static void bind(android.app.Activity target)

Bind annotated fields and methods in the specified Activity. The current content view is used as the view root.

Parameters:

target - Target activity for view binding.

bind

public static void bind(android.view.View target)

Bind annotated fields and methods in the specified View. The view and its children are used as the view root.

Parameters:

target - Target view for view binding.

bind

public static void bind(android.app.Dialog target)

Bind annotated fields and methods in the specified Dialog. The current content view is used as the view root.

Parameters:

target - Target dialog for view binding.

bind

public static void bind(Object target,
                        android.app.Activity source)

Bind annotated fields and methods in the specified target using the source Activity as the view root.

Parameters:

target - Target class for view binding.

source - Activity on which IDs will be looked up.

bind

public static void bind(Object target,
                        android.view.View source)

Bind annotated fields and methods in the specified target using the source View as the view root.

Parameters:

target - Target class for view binding.

source - View root on which IDs will be looked up.

bind

public static void bind(Object target,
                        android.app.Dialog source)

Bind annotated fields and methods in the specified target using the source Dialog as the view root.

Parameters:

target - Target class for view binding.

source - Dialog on which IDs will be looked up.

unbind

public static void unbind(Object target)

Reset fields annotated with @Bind to null.

This should only be used in the onDestroyView method of a fragment.

Parameters:

target - Target class for field unbind.

apply

public static <T extends android.view.View> void apply(List<T> list,
                                                       ButterKnife.Action<? super T> action)

Apply the specified action across the list of views.

apply

public static <T extends android.view.View,V> void apply(List<T> list,
                                                         ButterKnife.Setter<? super T,V> setter,
                                                         V value)

Set the value using the specified setter across the list of views.

apply

public static <T extends android.view.View,V> void apply(List<T> list,
                                                         android.util.Property<? super T,V> setter,
                                                         V value)

Apply the specified value across the list of views using the property.

findById

public static <T extends android.view.View> T findById(android.view.View view,
                                                       int id)

Simpler version of View.findViewById(int) which infers the target type.

findById

public static <T extends android.view.View> T findById(android.app.Activity activity,
                                                       int id)

Simpler version of Activity.findViewById(int) which infers the target type.

findById

public static <T extends android.view.View> T findById(android.app.Dialog dialog,
                                                       int id)

Simpler version of Dialog.findViewById(int) which infers the target type.