Add Snackbar action observables

rxbinding-design-kotlin/src/main/kotlin/com/jakewharton/rxbinding2/support/design/widget/RxSnackbar.kt

@@ -5,6 +5,7 @@
 package com.jakewharton.rxbinding2.support.design.widget
 
 import android.support.design.widget.Snackbar
+import android.view.View
 import io.reactivex.Observable
 import kotlin.Int
 import kotlin.Suppress
@@ -16,3 +17,19 @@ import kotlin.Suppress
  * to free this reference.
  */
 inline fun Snackbar.dismisses(): Observable<Int> = RxSnackbar.dismisses(this)
+
+/**
+ * Create an observable which emits the action click events from `view`.
+ *
+ * *Warning:* The created observable keeps a strong reference to `view`. Unsubscribe
+ * to free this reference.
+ */
+inline fun Snackbar.actionClicks(resId: Int): Observable<View> = RxSnackbar.actionClicks(this, resId)
+
+/**
+ * Create an observable which emits the action click events from `view`.
+ *
+ * *Warning:* The created observable keeps a strong reference to `view`. Unsubscribe
+ * to free this reference.
+ */
+inline fun Snackbar.actionClicks(text: CharSequence): Observable<View> = RxSnackbar.actionClicks(this, text)

rxbinding-design/build.gradle

@@ -18,6 +18,7 @@ dependencies {
   androidTestCompile rootProject.ext.supportTestRunner
   androidTestCompile rootProject.ext.supportTestRules
   androidTestCompile rootProject.ext.supportTestEspresso
+  androidTestCompile rootProject.ext.supportTestEspressoContrib
   androidTestCompile rootProject.ext.rxAndroid
 }
 

rxbinding-design/src/androidTest/AndroidManifest.xml

@@ -8,5 +8,9 @@
         android:name="com.jakewharton.rxbinding2.support.design.widget.RxSwipeDismissBehaviorTestActivity"
         android:theme="@style/Theme.AppCompat"
         />
+    <activity
+        android:name="com.jakewharton.rxbinding2.support.design.widget.RxSnackbarTestActivity"
+        android:theme="@style/Theme.AppCompat"
+        />
   </application>
 </manifest>

rxbinding-design/src/androidTest/java/com/jakewharton/rxbinding2/support/design/widget/RxSnackbarTest.java

@@ -4,24 +4,51 @@
 import android.content.Context;
 import android.support.design.widget.Snackbar;
 import android.support.test.InstrumentationRegistry;
+import android.support.test.espresso.Espresso;
+import android.support.test.espresso.contrib.CountingIdlingResource;
+import android.support.test.rule.ActivityTestRule;
 import android.support.test.runner.AndroidJUnit4;
 import android.view.ContextThemeWrapper;
+import android.view.View;
 import android.widget.FrameLayout;
 import com.jakewharton.rxbinding2.RecordingObserver;
 import com.jakewharton.rxbinding2.support.design.R;
-import io.reactivex.android.schedulers.AndroidSchedulers;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import io.reactivex.android.schedulers.AndroidSchedulers;
 
 import static android.support.design.widget.Snackbar.Callback.DISMISS_EVENT_MANUAL;
 import static android.support.design.widget.Snackbar.LENGTH_SHORT;
+import static android.support.test.espresso.Espresso.onView;
+import static android.support.test.espresso.action.ViewActions.click;
+import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import static junit.framework.Assert.assertNotNull;
 import static org.junit.Assert.assertEquals;
 
 @RunWith(AndroidJUnit4.class) public final class RxSnackbarTest {
   private final Instrumentation instrumentation = InstrumentationRegistry.getInstrumentation();
   private final Context rawContext = InstrumentationRegistry.getContext();
   private final Context context = new ContextThemeWrapper(rawContext, R.style.Theme_AppCompat);
   private final FrameLayout parent = new FrameLayout(context);
+  @Rule public final ActivityTestRule<RxSnackbarTestActivity> activityRule =
+          new ActivityTestRule<>(RxSnackbarTestActivity.class);
+  private Snackbar snackbar;
+  private CountingIdlingResource idler;
+
+  @Before public void setUp() {
+    RxSnackbarTestActivity activity = activityRule.getActivity();
+    snackbar = activity.snackbar;
+
+    idler = new CountingIdlingResource("counting idler");
+    Espresso.registerIdlingResources(idler);
+  }
+
+  @After public void teardown() {
+    Espresso.unregisterIdlingResources(idler);
+  }
 
   @Test public void dismisses() {
     final Snackbar view = Snackbar.make(parent, "Hey", LENGTH_SHORT);
@@ -55,4 +82,47 @@
     });
     o.assertNoMoreEvents();
   }
+
+  @Test public void actionClicks() {
+    Snackbar.Callback callback = new Snackbar.Callback() {
+      @Override
+      public void onShown(Snackbar sb) {
+        idler.decrement();
+      }
+    };
+    snackbar.addCallback(callback);
+
+    final String actionText = "Action";
+
+    RecordingObserver<View> o = new RecordingObserver<>();
+    RxSnackbar.actionClicks(snackbar, actionText)
+            .subscribeOn(AndroidSchedulers.mainThread())
+            .subscribe(o);
+    o.assertNoMoreEvents(); // No initial value.
+
+    show();
+    onView(withText(actionText)).perform(click());
+    assertNotNull(o.takeNext());
+
+    show();
+    onView(withText(actionText)).perform(click());
+    assertNotNull(o.takeNext());
+
+    o.dispose();
+    show();
+    onView(withText(actionText)).perform(click());
+    o.assertNoMoreEvents();
+
+    snackbar.removeCallback(callback);
+  }
+
+  private void show() {
+    idler.increment();
+    instrumentation.runOnMainSync(new Runnable() {
+      @Override public void run() {
+        snackbar.show();
+      }
+    });
+    instrumentation.waitForIdleSync();
+  }
 }

rxbinding-design/src/androidTest/java/com/jakewharton/rxbinding2/support/design/widget/RxSnackbarTestActivity.java

@@ -0,0 +1,22 @@
+package com.jakewharton.rxbinding2.support.design.widget;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.support.design.widget.Snackbar;
+import android.widget.FrameLayout;
+
+import static android.support.design.widget.Snackbar.LENGTH_INDEFINITE;
+
+public final class RxSnackbarTestActivity extends Activity {
+
+  Snackbar snackbar;
+
+  @Override protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+
+    FrameLayout parent = new FrameLayout(this);
+    snackbar = Snackbar.make(parent, "Hey", LENGTH_INDEFINITE);
+
+    setContentView(parent);
+  }
+}

rxbinding-design/src/main/java/com/jakewharton/rxbinding2/support/design/widget/RxSnackbar.java

@@ -3,6 +3,7 @@
 import android.support.annotation.CheckResult;
 import android.support.annotation.NonNull;
 import android.support.design.widget.Snackbar;
+import android.view.View;
 import io.reactivex.Observable;
 
 import static com.jakewharton.rxbinding2.internal.Preconditions.checkNotNull;
@@ -23,6 +24,31 @@ public static Observable<Integer> dismisses(@NonNull Snackbar view) {
     return new SnackbarDismissesObservable(view);
   }
 
+  /**
+   * Create an observable which emits the action click events from {@code view}.
+   * <p>
+   * <em>Warning:</em> The created observable keeps a strong reference to {@code view}. Unsubscribe
+   * to free this reference.
+   */
+  @CheckResult @NonNull
+  public static Observable<View> actionClicks(@NonNull Snackbar view, int resId) {
+    checkNotNull(view, "view == null");
+    return new SnackbarActionObservable(view, resId);
+  }
+
+  /**
+   * Create an observable which emits the action click events from {@code view}.
+   * <p>
+   * <em>Warning:</em> The created observable keeps a strong reference to {@code view}. Unsubscribe
+   * to free this reference.
+   */
+  @CheckResult @NonNull
+  public static Observable<View> actionClicks(@NonNull Snackbar view, @NonNull CharSequence text) {
+    checkNotNull(view, "view == null");
+    checkNotNull(text, "text == null");
+    return new SnackbarActionObservable(view, text);
+  }
+
   private RxSnackbar() {
     throw new AssertionError("No instances.");
   }

rxbinding-design/src/main/java/com/jakewharton/rxbinding2/support/design/widget/SnackbarActionObservable.java

@@ -0,0 +1,74 @@
+package com.jakewharton.rxbinding2.support.design.widget;
+
+import android.support.design.widget.Snackbar;
+import android.view.View;
+import android.view.View.OnClickListener;
+import io.reactivex.Observable;
+import io.reactivex.Observer;
+import io.reactivex.android.MainThreadDisposable;
+
+import static com.jakewharton.rxbinding2.internal.Preconditions.checkMainThread;
+
+final class SnackbarActionObservable extends Observable<View> {
+  private final Snackbar view;
+  private final int resId;
+  private final CharSequence text;
+
+  SnackbarActionObservable(Snackbar view, int resId) {
+    this.view = view;
+    this.text = null;
+    this.resId = resId;
+  }
+
+  SnackbarActionObservable(Snackbar view, CharSequence text) {
+    this.view = view;
+    this.text = text;
+    this.resId = -1;
+  }
+
+  @Override protected void subscribeActual(Observer<? super View> observer) {
+    if (!checkMainThread(observer)) {
+      return;
+    }
+    Listener listener = new Listener(view, observer);
+    observer.onSubscribe(listener);
+    if (text == null) {
+      view.setAction(resId, listener.callback);
+    } else {
+      view.setAction(text, listener.callback);
+    }
+  }
+
+  final class Listener extends MainThreadDisposable {
+    private final Snackbar snackbar;
+    private final OnClickListener callback;
+
+    Listener(Snackbar snackbar, final Observer<? super View> observer) {
+      this.snackbar = snackbar;
+      this.callback = new OnClickListener() {
+        @Override
+        public void onClick(View view) {
+          if (!isDisposed()) {
+            observer.onNext(view);
+          }
+        }
+      };
+    }
+
+    @Override protected void onDispose() {
+      // Provide stub OnClickListener implementation
+      // This is necessary because Snackbar will hide Action text if setAction is called with
+      // listener set to null
+      if (text == null) {
+        snackbar.setAction(resId, new EmptyActionListener());
+      } else {
+        snackbar.setAction(text, new EmptyActionListener());
+      }
+    }
+  }
+
+  private static final class EmptyActionListener implements OnClickListener {
+    @Override public void onClick(View v) {
+    }
+  }
+}