Add ability to control scroll animation duration for Android

Libraries/Components/ScrollResponder.js

@@ -405,46 +405,53 @@ const ScrollResponderMixin = {
    * This is currently used to help focus child TextViews, but can also
    * be used to quickly scroll to any element we want to focus. Syntax:
    *
-   * `scrollResponderScrollTo(options: {x: number = 0; y: number = 0; animated: boolean = true})`
+   * `scrollResponderScrollTo(options: {x: number = 0; y: number = 0; animated: boolean = true, duration: number = 0})`
    *
    * Note: The weird argument signature is due to the fact that, for historical reasons,
    * the function also accepts separate arguments as as alternative to the options object.
    * This is deprecated due to ambiguity (y before x), and SHOULD NOT BE USED.
+   *
+   * Also note "duration" is currently only supported for Android.
    */
   scrollResponderScrollTo: function(
-    x?: number | { x?: number, y?: number, animated?: boolean },
+    x?: number | { x?: number, y?: number, animated?: boolean, duration?: number },
     y?: number,
-    animated?: boolean
+    animated?: boolean,
+    duration?: number
   ) {
     if (typeof x === 'number') {
       console.warn('`scrollResponderScrollTo(x, y, animated)` is deprecated. Use `scrollResponderScrollTo({x: 5, y: 5, animated: true})` instead.');
     } else {
-      ({x, y, animated} = x || {});
+      ({x, y, animated, duration} = x || {});
     }
     UIManager.dispatchViewManagerCommand(
       nullthrows(this.scrollResponderGetScrollableNode()),
       UIManager.RCTScrollView.Commands.scrollTo,
-      [x || 0, y || 0, animated !== false],
+      [x || 0, y || 0, animated !== false, duration || 0],
     );
   },
 
   /**
    * Scrolls to the end of the ScrollView, either immediately or with a smooth
-   * animation.
+   * animation. For Android, you may specify a "duration" number instead of the
+   * "animated" boolean.
    *
    * Example:
    *
    * `scrollResponderScrollToEnd({animated: true})`
+   * or for Android, you can do:
+   * `scrollResponderScrollToEnd({duration: 500})`
    */
   scrollResponderScrollToEnd: function(
-    options?: { animated?: boolean },
+    options?: { animated?: boolean, duration?: boolean },
   ) {
     // Default to true
     const animated = (options && options.animated) !== false;
+    const duration = options ? options.duration || 0 : 0;
     UIManager.dispatchViewManagerCommand(
       this.scrollResponderGetScrollableNode(),
       UIManager.RCTScrollView.Commands.scrollToEnd,
-      [animated],
+      [animated, duration],
     );
   },
 

Libraries/Components/ScrollView/ScrollView.js

@@ -526,29 +526,33 @@ const ScrollView = createReactClass({
   },
 
   /**
-   * Scrolls to a given x, y offset, either immediately or with a smooth animation.
+   * Scrolls to a given x, y offset, either immediately, with a smooth animation, or,
+   * for Android only, a custom animation duration time.
    *
    * Example:
    *
-   * `scrollTo({x: 0, y: 0, animated: true})`
+   * `scrollTo({x: 0, y: 0, animated: true, duration: 0})`
    *
    * Note: The weird function signature is due to the fact that, for historical reasons,
    * the function also accepts separate arguments as an alternative to the options object.
    * This is deprecated due to ambiguity (y before x), and SHOULD NOT BE USED.
+   *
+   * Also note "duration" is currently only supported for Android.
    */
   scrollTo: function(
-    y?: number | { x?: number, y?: number, animated?: boolean },
+    y?: number | { x?: number, y?: number, animated?: boolean, duration?: number },
     x?: number,
-    animated?: boolean
+    animated?: boolean,
+    duration?: number
   ) {
     if (typeof y === 'number') {
       console.warn('`scrollTo(y, x, animated)` is deprecated. Use `scrollTo({x: 5, y: 5, ' +
         'animated: true})` instead.');
     } else {
-      ({x, y, animated} = y || {});
+      ({x, y, animated, duration} = y || {});
     }
     this.getScrollResponder().scrollResponderScrollTo(
-      {x: x || 0, y: y || 0, animated: animated !== false}
+      {x: x || 0, y: y || 0, animated: animated !== false, duration: duration || 0}
     );
   },
 
@@ -558,15 +562,19 @@ const ScrollView = createReactClass({
    *
    * Use `scrollToEnd({animated: true})` for smooth animated scrolling,
    * `scrollToEnd({animated: false})` for immediate scrolling.
+   * For Android, you may specify a duration, e.g. `scrollToEnd({duration: 500})`
+   * for a controlled duration scroll.
    * If no options are passed, `animated` defaults to true.
    */
   scrollToEnd: function(
-    options?: { animated?: boolean },
+    options?: { animated?: boolean, duration?: number },
   ) {
     // Default to true
     const animated = (options && options.animated) !== false;
+    const duration = options ? options.duration || 0 : 0;
     this.getScrollResponder().scrollResponderScrollToEnd({
       animated: animated,
+      duration: duration
     });
   },
 

React/Views/ScrollView/RCTScrollViewManager.m

@@ -147,7 +147,9 @@ - (UIView *)view
 RCT_EXPORT_METHOD(scrollTo:(nonnull NSNumber *)reactTag
                   offsetX:(CGFloat)x
                   offsetY:(CGFloat)y
-                  animated:(BOOL)animated)
+                  animated:(BOOL)animated
+                  // TODO(dannycochran) Use the duration here for a ScrollView.
+                  duration:(CGFloat __unused)duration)
 {
   [self.bridge.uiManager addUIBlock:
    ^(__unused RCTUIManager *uiManager, NSDictionary<NSNumber *, UIView *> *viewRegistry){
@@ -162,7 +164,9 @@ - (UIView *)view
 }
 
 RCT_EXPORT_METHOD(scrollToEnd:(nonnull NSNumber *)reactTag
-                  animated:(BOOL)animated)
+                  animated:(BOOL)animated
+                  // TODO(dannycochran) Use the duration here for a ScrollView.
+                  duration:(CGFloat __unused)duration)
 {
   [self.bridge.uiManager addUIBlock:
    ^(__unused RCTUIManager *uiManager, NSDictionary<NSNumber *, UIView *> *viewRegistry){

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java

@@ -9,8 +9,10 @@
 
 package com.facebook.react.views.scroll;
 
+import android.animation.ObjectAnimator;
 import android.graphics.Color;
 import android.util.DisplayMetrics;
+
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.module.annotations.ReactModule;
 import com.facebook.react.uimanager.DisplayMetricsHolder;
@@ -43,6 +45,7 @@ public class ReactHorizontalScrollViewManager
   };
 
   private @Nullable FpsListener mFpsListener = null;
+  private @Nullable ObjectAnimator mAnimator = null;
 
   public ReactHorizontalScrollViewManager() {
     this(null);
@@ -138,8 +141,8 @@ public void flashScrollIndicators(ReactHorizontalScrollView scrollView) {
   @Override
   public void scrollTo(
       ReactHorizontalScrollView scrollView, ReactScrollViewCommandHelper.ScrollToCommandData data) {
-    if (data.mAnimated) {
-      scrollView.smoothScrollTo(data.mDestX, data.mDestY);
+    if (data.mDuration > 0) {
+      animateScroll(scrollView, data.mDestX, data.mDestY, data.mDuration);
     } else {
       scrollView.scrollTo(data.mDestX, data.mDestY);
     }
@@ -152,8 +155,8 @@ public void scrollToEnd(
     // ScrollView always has one child - the scrollable area
     int right =
       scrollView.getChildAt(0).getWidth() + scrollView.getPaddingRight();
-    if (data.mAnimated) {
-      scrollView.smoothScrollTo(right, scrollView.getScrollY());
+    if (data.mDuration > 0) {
+      animateScroll(scrollView, right, scrollView.getScrollY(), data.mDuration);
     } else {
       scrollView.scrollTo(right, scrollView.getScrollY());
     }
@@ -217,4 +220,11 @@ public void setBorderColor(ReactHorizontalScrollView view, int index, Integer co
     float alphaComponent = color == null ? YogaConstants.UNDEFINED : (float) ((int)color >>> 24);
     view.setBorderColor(SPACING_TYPES[index], rgbComponent, alphaComponent);
   }
+
+  private void animateScroll(ReactHorizontalScrollView view, int mDestX, int mDestY, int mDuration) {
+    if (mAnimator != null) {
+      mAnimator.cancel();
+    }
+    mAnimator = ReactScrollViewHelper.animateScroll(view, mDestX, mDestY, mDuration);
+  }
 }

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewCommandHelper.java

@@ -26,6 +26,15 @@ public class ReactScrollViewCommandHelper {
   public static final int COMMAND_SCROLL_TO_END = 2;
   public static final int COMMAND_FLASH_SCROLL_INDICATORS = 3;
 
+  /**
+   * Prior to users being able to specify a duration when calling "scrollTo",
+   * they could specify an "animate" boolean, which would use Android's
+   * "smoothScrollTo" method, which defaulted to a 250 millisecond
+   * animation:
+   * https://developer.android.com/reference/android/widget/Scroller.html#startScroll
+   */
+  public static final int LEGACY_ANIMATION_DURATION = 250;
+
   public interface ScrollCommandHandler<T> {
     void scrollTo(T scrollView, ScrollToCommandData data);
     void scrollToEnd(T scrollView, ScrollToEndCommandData data);
@@ -34,22 +43,21 @@ public interface ScrollCommandHandler<T> {
 
   public static class ScrollToCommandData {
 
-    public final int mDestX, mDestY;
-    public final boolean mAnimated;
+    public final int mDestX, mDestY, mDuration;
 
-    ScrollToCommandData(int destX, int destY, boolean animated) {
+    ScrollToCommandData(int destX, int destY, int duration) {
       mDestX = destX;
       mDestY = destY;
-      mAnimated = animated;
+      mDuration = duration;
     }
   }
 
   public static class ScrollToEndCommandData {
 
-    public final boolean mAnimated;
+    public final int mDuration;
 
-    ScrollToEndCommandData(boolean animated) {
-      mAnimated = animated;
+    ScrollToEndCommandData(int duration) {
+      mDuration = duration;
     }
   }
 
@@ -75,13 +83,30 @@ public static <T> void receiveCommand(
       case COMMAND_SCROLL_TO: {
         int destX = Math.round(PixelUtil.toPixelFromDIP(args.getDouble(0)));
         int destY = Math.round(PixelUtil.toPixelFromDIP(args.getDouble(1)));
-        boolean animated = args.getBoolean(2);
-        viewManager.scrollTo(scrollView, new ScrollToCommandData(destX, destY, animated));
+
+        // TODO(dannycochran) If the duration argument is specified and non-zero, use it,
+        // otherwise use the legacy "animated" boolean. Eventually this can be removed
+        // in favor of just looking at "duration".
+        int duration = 0;
+        if (args.size() == 4 && args.getDouble(3) > 0) {
+          duration = (int) Math.round(args.getDouble(3));
+        } else if (args.getBoolean(2)) {
+          duration = LEGACY_ANIMATION_DURATION;
+        }
+        viewManager.scrollTo(scrollView, new ScrollToCommandData(destX, destY, duration));
         return;
       }
       case COMMAND_SCROLL_TO_END: {
-        boolean animated = args.getBoolean(0);
-        viewManager.scrollToEnd(scrollView, new ScrollToEndCommandData(animated));
+        // TODO(dannycochran) If the duration argument is specified and non-zero, use it,
+        // otherwise use the legacy "animated" boolean. Eventually this can be removed
+        // in favor of just looking at "duration".
+        int duration = 0;
+        if (args.size() == 2 && args.getDouble(1) > 0) {
+          duration = (int) Math.round(args.getDouble(1));
+        } else if (args.getBoolean(0)) {
+          duration = LEGACY_ANIMATION_DURATION;
+        }
+        viewManager.scrollToEnd(scrollView, new ScrollToEndCommandData(duration));
         return;
       }
       case COMMAND_FLASH_SCROLL_INDICATORS:

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewHelper.java

@@ -9,6 +9,10 @@
 
 package com.facebook.react.views.scroll;
 
+import android.animation.ObjectAnimator;
+import android.animation.PropertyValuesHolder;
+
+import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -96,4 +100,28 @@ public static int parseOverScrollMode(String jsOverScrollMode) {
       throw new JSApplicationIllegalArgumentException("wrong overScrollMode: " + jsOverScrollMode);
     }
   }
+
+  /**
+   * Helper method for animating to a ScrollView position with a given duration,
+   * instead of using "smoothScrollTo", which does not expose a duration argument.
+   */
+  public static ObjectAnimator animateScroll(final ViewGroup scrollView, int mDestX, int mDestY, int mDuration) {
+    PropertyValuesHolder scrollX = PropertyValuesHolder.ofInt("scrollX", mDestX);
+    PropertyValuesHolder scrollY = PropertyValuesHolder.ofInt("scrollY", mDestY);
+
+    final ObjectAnimator animator = ObjectAnimator.ofPropertyValuesHolder(scrollView, scrollX, scrollY);
+
+    // Cancel the animation if a user interacts with the ScrollView.
+    scrollView.setOnTouchListener(new View.OnTouchListener() {
+      @Override
+      public boolean onTouch(View v, MotionEvent event) {
+        scrollView.setOnTouchListener(null);
+        animator.cancel();
+        return false;
+      }
+    });
+
+    animator.setDuration(mDuration).start();
+    return animator;
+  }
 }

ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollViewManager.java

@@ -9,8 +9,10 @@
 
 package com.facebook.react.views.scroll;
 
+import android.animation.ObjectAnimator;
 import android.annotation.TargetApi;
 import android.graphics.Color;
+
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.common.MapBuilder;
 import com.facebook.react.module.annotations.ReactModule;
@@ -45,6 +47,7 @@ public class ReactScrollViewManager
   };
 
   private @Nullable FpsListener mFpsListener = null;
+  private @Nullable ObjectAnimator mAnimator = null;
 
   public ReactScrollViewManager() {
     this(null);
@@ -144,8 +147,8 @@ public void flashScrollIndicators(ReactScrollView scrollView) {
   @Override
   public void scrollTo(
       ReactScrollView scrollView, ReactScrollViewCommandHelper.ScrollToCommandData data) {
-    if (data.mAnimated) {
-      scrollView.smoothScrollTo(data.mDestX, data.mDestY);
+    if (data.mDuration > 0) {
+      animateScroll(scrollView, data.mDestX, data.mDestY, data.mDuration);
     } else {
       scrollView.scrollTo(data.mDestX, data.mDestY);
     }
@@ -205,8 +208,8 @@ public void scrollToEnd(
     // ScrollView always has one child - the scrollable area
     int bottom =
       scrollView.getChildAt(0).getHeight() + scrollView.getPaddingBottom();
-    if (data.mAnimated) {
-      scrollView.smoothScrollTo(scrollView.getScrollX(), bottom);
+    if (data.mDuration > 0) {
+      animateScroll(scrollView, scrollView.getScrollX(), bottom, data.mDuration);
     } else {
       scrollView.scrollTo(scrollView.getScrollX(), bottom);
     }
@@ -226,4 +229,11 @@ public static Map<String, Object> createExportedCustomDirectEventTypeConstants()
         .put(ScrollEventType.MOMENTUM_END.getJSEventName(), MapBuilder.of("registrationName", "onMomentumScrollEnd"))
         .build();
   }
+
+  private void animateScroll(ReactScrollView view, int mDestX, int mDestY, int mDuration) {
+    if (mAnimator != null) {
+      mAnimator.cancel();
+    }
+    mAnimator = ReactScrollViewHelper.animateScroll(view, mDestX, mDestY, mDuration);
+  }
 }