Adds lazy creation of gesture subjects.

JakeWharton · Sep 9, 2015 · 40840ad · 40840ad
1 parent ab17425
commit 40840ad
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Showing 2 changed files with 75 additions and 20 deletions.
diff --git a/rxbinding/src/main/java/com/jakewharton/rxbinding/view/ObservableGestureListener.java b/rxbinding/src/main/java/com/jakewharton/rxbinding/view/ObservableGestureListener.java
@@ -4,52 +4,107 @@
 import android.view.MotionEvent;
 import android.view.View;
 
+import rx.Observable;
 import rx.subjects.PublishSubject;
 
 final class ObservableGestureListener implements GestureDetector.OnGestureListener {
 
     final View view;
 
-    PublishSubject<ViewGestureEvent> downGestureObservable = PublishSubject.create();
-    PublishSubject<ViewGestureEvent> showPressGestureObservable = PublishSubject.create();
-    PublishSubject<ViewGestureEvent> singleTapUpGestureObservable = PublishSubject.create();
-    PublishSubject<ViewGestureScrollEvent> scrollGestureObservable = PublishSubject.create();
-    PublishSubject<ViewGestureEvent> longPressGestureObservable = PublishSubject.create();
-    PublishSubject<ViewGestureFlingEvent> flingGestureObservable = PublishSubject.create();
+    private PublishSubject<ViewGestureEvent> downGestureObservable;
+    private PublishSubject<ViewGestureEvent> showPressGestureObservable;
+    private PublishSubject<ViewGestureEvent> singleTapUpGestureObservable;
+    private PublishSubject<ViewGestureScrollEvent> scrollGestureObservable;
+    private PublishSubject<ViewGestureEvent> longPressGestureObservable;
+    private PublishSubject<ViewGestureFlingEvent> flingGestureObservable;
 
     ObservableGestureListener(View view) {
         this.view = view;
     }
 
+    public Observable<ViewGestureEvent> downObservable() {
+        if (downGestureObservable == null) {
+            downGestureObservable = PublishSubject.create();
+        }
+        return downGestureObservable;
+    }
+
+    public Observable<ViewGestureEvent> showPressObservable() {
+        if (showPressGestureObservable == null) {
+            showPressGestureObservable = PublishSubject.create();
+        }
+        return showPressGestureObservable;
+    }
+
+    public Observable<ViewGestureEvent> singleTapUpObservable() {
+        if (singleTapUpGestureObservable == null) {
+            singleTapUpGestureObservable = PublishSubject.create();
+        }
+        return singleTapUpGestureObservable;
+    }
+
+    public Observable<ViewGestureScrollEvent> scrollObservable() {
+        if (scrollGestureObservable == null) {
+            scrollGestureObservable = PublishSubject.create();
+        }
+        return scrollGestureObservable;
+    }
+
+    public Observable<ViewGestureEvent> longPressObservable() {
+        if (longPressGestureObservable == null) {
+            longPressGestureObservable = PublishSubject.create();
+        }
+        return longPressGestureObservable;
+    }
+
+    public Observable<ViewGestureFlingEvent> flingObservable() {
+        if (flingGestureObservable == null) {
+            flingGestureObservable = PublishSubject.create();
+        }
+        return flingGestureObservable;
+    }
+
     @Override public boolean onDown(MotionEvent e) {
-        downGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        if (downGestureObservable != null) {
+            downGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        }
         return false;
     }
 
     @Override public void onShowPress(MotionEvent e) {
-        showPressGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        if (showPressGestureObservable != null) {
+            showPressGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        }
     }
 
     @Override public boolean onSingleTapUp(MotionEvent e) {
-        singleTapUpGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        if (singleTapUpGestureObservable != null) {
+            singleTapUpGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        }
         return false;
     }
 
     @Override
     public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
-        scrollGestureObservable.onNext(
-                ViewGestureScrollEvent.create(view, e1, e2, distanceX, distanceY));
+        if (scrollGestureObservable != null) {
+            scrollGestureObservable.onNext(
+                    ViewGestureScrollEvent.create(view, e1, e2, distanceX, distanceY));
+        }
         return false;
     }
 
     @Override public void onLongPress(MotionEvent e) {
-        longPressGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        if (longPressGestureObservable != null) {
+            longPressGestureObservable.onNext(ViewGestureEvent.create(view, e));
+        }
     }
 
     @Override
     public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
-        flingGestureObservable.onNext(
-                ViewGestureFlingEvent.create(view, e1, e2, velocityX, velocityY));
+        if (flingGestureObservable != null) {
+            flingGestureObservable.onNext(
+                    ViewGestureFlingEvent.create(view, e1, e2, velocityX, velocityY));
+        }
         return false;
     }
 }
diff --git a/rxbinding/src/main/java/com/jakewharton/rxbinding/view/RxGestures.java b/rxbinding/src/main/java/com/jakewharton/rxbinding/view/RxGestures.java
@@ -69,42 +69,42 @@ private RxGestures(View view, Observable<MotionEvent> motionEventObservable) {
      * Create an observable of down gestures.
      */
     public Observable<ViewGestureEvent> down() {
-        return gestureListener.downGestureObservable;
+        return gestureListener.downObservable();
     }
 
     /**
      * Create an observable of show press gestures.
      */
     public Observable<ViewGestureEvent> showPress() {
-        return gestureListener.showPressGestureObservable;
+        return gestureListener.showPressObservable();
     }
 
     /**
      * Create an observable of single tap up gestures.
      */
     public Observable<ViewGestureEvent> singleTapUp() {
-        return gestureListener.singleTapUpGestureObservable;
+        return gestureListener.singleTapUpObservable();
     }
 
     /**
      * Create an observable of scroll gestures.
      */
     public Observable<ViewGestureScrollEvent> scroll() {
-        return gestureListener.scrollGestureObservable;
+        return gestureListener.scrollObservable();
     }
 
     /**
      * Create an observable of long press gestures.
      */
     public Observable<ViewGestureEvent> longPress() {
-        return gestureListener.longPressGestureObservable;
+        return gestureListener.longPressObservable();
     }
 
     /**
      * Create an observable of fling gestures.
      */
     public Observable<ViewGestureFlingEvent> fling() {
-        return gestureListener.flingGestureObservable;
+        return gestureListener.flingObservable();
     }
 
 }