feat(renderer): support scrollEventThrottle on Android and iOS

driver/js/examples/hippy-react-demo/src/components/ViewPager/index.jsx

@@ -109,6 +109,7 @@ export default class PagerExample extends React.Component {
             onPageSelected={this.onPageSelected}
             onPageScrollStateChanged={this.onPageScrollStateChanged}
             onPageScroll={this.onPageScroll}
+            scrollEventThrottle={1000}
           >
             {
               [

renderer/native/android/src/main/java/com/tencent/mtt/hippy/views/viewpager/HippyViewPager.java

@@ -68,6 +68,8 @@ public void run() {
     // Reusable int array to be passed to method calls that mutate it in order to "return" two ints.
     private final int[] mScrollOffsetPair = new int[2];
     private int mNestedScrollOffset = 0;
+    //scroll throttle time ms
+    protected int mScrollEventThrottle = 0;
 
     private void init(Context context, boolean isVertical) {
         setCallPageChangedOnFirstLayout(true);
@@ -328,6 +330,10 @@ public void setOverflow(String overflow) {
         invalidate();
     }
 
+    public void setScrollEventThrottle(int scrollEventThrottle) {
+        mScrollEventThrottle = scrollEventThrottle;
+    }
+
     @Override
     public boolean onStartNestedScroll(@NonNull View child, @NonNull View target, int axes) {
         if (!isScrollEnabled()) {

renderer/native/android/src/main/java/com/tencent/mtt/hippy/views/viewpager/HippyViewPagerController.java

@@ -132,6 +132,11 @@ public void setOverflow(HippyViewPager pager, String overflow) {
         pager.setOverflow(overflow);
     }
 
+    @HippyControllerProps(name = "scrollEventThrottle", defaultType = HippyControllerProps.NUMBER, defaultNumber = 0)
+    public void setScrollEventThrottle(HippyViewPager pager,int scrollEventThrottle) {
+        pager.setScrollEventThrottle(scrollEventThrottle);
+    }
+
     private void resolveInvalidParams(@Nullable Promise promise) {
         if (promise != null) {
             String msg = "Invalid parameter!";

renderer/native/android/src/main/java/com/tencent/mtt/hippy/views/viewpager/ViewPagerPageChangeListener.java

@@ -16,6 +16,7 @@
 
 package com.tencent.mtt.hippy.views.viewpager;
 
+import android.os.SystemClock;
 import android.view.View;
 
 import androidx.annotation.NonNull;
@@ -34,21 +35,53 @@ public class ViewPagerPageChangeListener implements ViewPager.OnPageChangeListen
     private int mLastPageIndex = 0;
     private int mCurrPageIndex = 0;
     private final HippyViewPager mPager;
+    private long mLastScrollEventTimeStamp = -1;
+    private boolean mHasUnsentScrollEvent;
+    private int onPageScrolledPosition = 0;
+    private float onPageScrollPositionOffset = 0;
 
     public ViewPagerPageChangeListener(@NonNull HippyViewPager pager) {
         mPager = pager;
     }
 
+    /**
+     * Check whether scroll events need to be sent
+     * @return
+     */
+    protected boolean checkSendOnScrollEvent() {
+        long currTime = SystemClock.elapsedRealtime();
+        if (currTime - mLastScrollEventTimeStamp >= mPager.mScrollEventThrottle) {
+            mLastScrollEventTimeStamp = currTime;
+            return true;
+        }
+        return false;
+    }
+
     @Override
     public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
-        if (mPager != null) {
-            Map<String, Object> params = new HashMap<>();
-            params.put(PAGE_ITEM_POSITION, position);
-            params.put(PAGE_ITEM_OFFSET, positionOffset);
-            EventUtils.sendComponentEvent(mPager, EventUtils.EVENT_PAGE_SCROLL, params);
+        onPageScrolledPosition = position;
+        onPageScrollPositionOffset = positionOffset;
+        if (mPager == null) {
+            return;
+        }
+        if (!mPager.isScrollEnabled()) {
+            return;
+        }
+        if (checkSendOnScrollEvent()) {
+            sendPageScrollEvent(position, positionOffset);
+        } else {
+            mHasUnsentScrollEvent = true;
         }
     }
 
+    private void sendPageScrollEvent(int position, float positionOffset) {
+        mHasUnsentScrollEvent = false;
+        Map<String, Object> params = new HashMap<>();
+        params.put(PAGE_ITEM_POSITION, position);
+        params.put(PAGE_ITEM_OFFSET, positionOffset);
+        EventUtils.sendComponentEvent(mPager, EventUtils.EVENT_PAGE_SCROLL, params);
+    }
+
     @Override
     public void onPageSelected(int position) {
         if (mPager != null) {
@@ -75,6 +108,11 @@ private void onScrollStateChangeToIdle() {
         if (mPager == null || mCurrPageIndex == mLastPageIndex) {
             return;
         }
+        mLastScrollEventTimeStamp = -1;
+        // Supplementary  sending page scroll event
+        if (mHasUnsentScrollEvent) {
+            sendPageScrollEvent(onPageScrolledPosition, onPageScrollPositionOffset);
+        }
         Promise promise = mPager.getCallBackPromise();
         if (promise != null) {
             Map<String, Object> result = new HashMap<>();

renderer/native/ios/renderer/component/viewPager/NativeRenderViewPager.h

@@ -37,6 +37,7 @@ typedef void (^ViewPagerItemsCountChanged)(NSUInteger count);
 @property (nonatomic, strong) HippyDirectEventBlock onPageScrollStateChanged;
 
 @property (nonatomic, assign) NSInteger initialPage;
+@property (nonatomic, assign) double scrollEventThrottle;
 @property (nonatomic, assign) CGPoint targetOffset;
 @property (nonatomic, assign, readonly) NSUInteger pageCount;
 @property (nonatomic, copy) ViewPagerItemsCountChanged itemsChangedBlock;

renderer/native/ios/renderer/component/viewPager/NativeRenderViewPager.mm

@@ -45,7 +45,10 @@ @interface NativeRenderViewPager ()
 
 @property (nonatomic, assign) CGFloat previousStopOffset;
 @property (nonatomic, assign) NSUInteger lastPageSelectedCallbackIndex;
-
+@property (nonatomic, assign) double _lastScrollDispatchTime;
+@property (nonatomic, assign) double mHasUnsentScrollEvent;
+@property (nonatomic, assign) NSUInteger onPageScrolledPosition;
+@property (nonatomic, assign) CGFloat onPageScrollPositionOffset;
 @end
 
 @implementation NativeRenderViewPager
@@ -62,6 +65,8 @@ - (instancetype)initWithFrame:(CGRect)frame {
         self.previousFrame = CGRectZero;
         self.scrollViewListener = [NSHashTable weakObjectsHashTable];
         self.lastPageIndex = NSUIntegerMax;
+        self.scrollEventThrottle = 0.0;
+        self._lastScrollDispatchTime = -1;
         self.targetContentOffsetX = CGFLOAT_MAX;
         if (@available(iOS 11.0, *)) {
             self.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
@@ -99,7 +104,7 @@ - (void)insertHippySubview:(UIView *)view atIndex:(NSInteger)atIndex {
     }
     [super insertHippySubview:view atIndex:(NSInteger)atIndex];
     [self.viewPagerItems insertObject:view atIndex:atIndex];
-    
+
     if ([view isKindOfClass:[NativeRenderViewPagerItem class]]) {
         NativeRenderViewPagerItem *item = (NativeRenderViewPagerItem *)view;
         __weak NativeRenderViewPager *weakPager = self;
@@ -117,7 +122,7 @@ - (void)insertHippySubview:(UIView *)view atIndex:(NSInteger)atIndex {
             return frame;
         };
     }
-    
+
     self.needsLayoutItems = YES;
     if (_itemsChangedBlock) {
         _itemsChangedBlock([self.viewPagerItems count]);
@@ -175,14 +180,14 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
     CGFloat currentContentOffset = self.contentOffset.x;
     CGFloat offset = currentContentOffset - self.previousStopOffset;
     CGFloat offsetRatio = offset / CGRectGetWidth(self.bounds);
-    
+
     if (offsetRatio > 1) {
         offsetRatio -= floor(offsetRatio);
     }
     if (offsetRatio < -1) {
         offsetRatio -= ceil(offsetRatio);
     }
-    
+
     NSUInteger currentPageIndex = [self currentPageIndex];
     NSInteger nextPageIndex = ceil(offsetRatio) == offsetRatio ? currentPageIndex : currentPageIndex + ceil(offsetRatio);
     if (nextPageIndex < 0) {
@@ -191,14 +196,18 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView {
     if (nextPageIndex >= [self.viewPagerItems count]) {
         nextPageIndex = [self.viewPagerItems count] - 1;
     }
-    
+
     if (self.onPageScroll) {
-        self.onPageScroll(@{
-            @"position": @(nextPageIndex),
-            @"offset": @(offsetRatio),
-        });
+        if ([self checkSendOnScrollEvent]) {
+            self.onPageScrolledPosition = nextPageIndex;
+            self.onPageScrollPositionOffset = offsetRatio;
+            [self sendOnPageScrollEvent:self.onPageScrolledPosition positionOffset:self.onPageScrollPositionOffset];
+        } else {
+            self.mHasUnsentScrollEvent = true;
+        }
+
     }
-    
+
     for (NSObject<UIScrollViewDelegate> *scrollViewListener in _scrollViewListener) {
         if ([scrollViewListener respondsToSelector:@selector(scrollViewDidScroll:)]) {
             [scrollViewListener scrollViewDidScroll:scrollView];
@@ -240,6 +249,10 @@ - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL
     if (!decelerate) {
         self.isScrolling = NO;
     }
+
+    if(!decelerate) {
+        [self onScrollIdle];
+    }
     if (self.onPageScrollStateChanged) {
         NSString *state = decelerate ? @"settling" : @"idle";
         self.onPageScrollStateChanged(@{ @"pageScrollState": state });
@@ -255,6 +268,7 @@ - (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView {
 }
 
 - (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
+    [self onScrollIdle];
     if (self.onPageScrollStateChanged) {
         self.onPageScrollStateChanged(@{ @"pageScrollState": @"idle" });
     }
@@ -490,4 +504,31 @@ - (void)autoPageDown {
     }
 }
 
+/**Check whether scroll events need to be sent*/
+- (bool)checkSendOnScrollEvent {
+    NSTimeInterval now = CACurrentMediaTime();
+    if (self.scrollEventThrottle < (now - self._lastScrollDispatchTime) * 1000) {
+        self._lastScrollDispatchTime = now;
+        return true;
+    }
+    return false;
+}
+
+- (void)sendOnPageScrollEvent: (NSUInteger)position  positionOffset:(CGFloat) positionOffset{
+    self.mHasUnsentScrollEvent = false;
+    self.onPageScroll(@{
+        @"position": @(position),
+        @"offset": @(positionOffset),
+    });
+}
+
+- (void)onScrollIdle {
+    //reset on scroll idle
+    self._lastScrollDispatchTime = -1;
+    if(self.mHasUnsentScrollEvent) {
+        self.mHasUnsentScrollEvent = false;
+        [self sendOnPageScrollEvent:self.onPageScrolledPosition positionOffset:self.onPageScrollPositionOffset];
+    }
+}
+
 @end

renderer/native/ios/renderer/component/viewPager/NativeRenderViewPagerManager.mm

@@ -35,6 +35,7 @@ - (UIView *)view {
 HIPPY_EXPORT_VIEW_PROPERTY(bounces, BOOL)
 HIPPY_EXPORT_VIEW_PROPERTY(initialPage, NSInteger)
 HIPPY_EXPORT_VIEW_PROPERTY(scrollEnabled, BOOL)
+HIPPY_EXPORT_VIEW_PROPERTY(scrollEventThrottle, double)
 
 HIPPY_EXPORT_VIEW_PROPERTY(onPageSelected, HippyDirectEventBlock)
 HIPPY_EXPORT_VIEW_PROPERTY(onPageScroll, HippyDirectEventBlock)