[10/16] incubator-weex git commit: [WEEX-311] [iOS] use new layoutEngin to replace yoga

[ac...@apache.org]

http://git-wip-us.apache.org/repos/asf/incubator-weex/blob/b77b4259/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.m
----------------------------------------------------------------------
diff --git a/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.m b/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.m
deleted file mode 100644
index 585c9f3..0000000
--- a/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.m
+++ /dev/null
@@ -1,207 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-#import "WXRefreshComponent.h"
-#import "WXScrollerComponent.h"
-#import "WXLoadingIndicator.h"
-#import "WXComponent_internal.h"
-#import "WXLog.h"
-
-@interface WXRefreshComponent()
-
-@property (nonatomic) BOOL displayState;
-@property (nonatomic) BOOL initFinished;
-@property (nonatomic) BOOL refreshEvent;
-@property (nonatomic) BOOL pullingdownEvent;
-
-@property (nonatomic, weak) WXLoadingIndicator *indicator;
-
-@end
-
-@implementation WXRefreshComponent
-
-- (instancetype)initWithRef:(NSString *)ref type:(NSString *)type styles:(NSDictionary *)styles attributes:(NSDictionary *)attributes events:(NSArray *)events weexInstance:(WXSDKInstance *)weexInstance
-{
-    self = [super initWithRef:ref type:type styles:styles attributes:attributes events:events weexInstance:weexInstance];
-    if (self) {
-        _refreshEvent = NO;
-        _pullingdownEvent = NO;
-        if (attributes[@"display"]) {
-            if ([attributes[@"display"] isEqualToString:@"show"]) {
-                _displayState = YES;
-            } else if ([attributes[@"display"] isEqualToString:@"hide"]) {
-                _displayState = NO;
-            } else {
-                WXLogError(@"");
-            }
-        }
-        self.cssNode->style.position_type = CSS_POSITION_ABSOLUTE;
-    }
-    return self;
-}
-
-- (void)viewDidLoad
-{
-     _initFinished = YES;
-    
-    if (!_displayState) {
-        [_indicator.view setHidden:YES];
-    }
-}
-
-- (void)layoutDidFinish
-{
-    [self.view setFrame: (CGRect) {
-        .size = self.calculatedFrame.size,
-        .origin.x = self.calculatedFrame.origin.x,
-        .origin.y = self.view.frame.origin.y - CGRectGetHeight(self.calculatedFrame)
-    }];
-}
-
-- (void)viewWillUnload
-{
-    _displayState = NO;
-    _refreshEvent = NO;
-    _initFinished = NO;
-}
-
-- (void)refresh
-{
-    if (!_refreshEvent || _displayState) {
-        return;
-    }
-    [self fireEvent:@"refresh" params:nil];
-}
-
-- (void)pullingdown:(NSDictionary*)param
-{
-    if (!_pullingdownEvent) {
-        return ;
-    }
-    
-    [self fireEvent:@"pullingdown" params:param];
-}
-
-- (void)_insertSubcomponent:(WXComponent *)subcomponent atIndex:(NSInteger)index
-{
-    if (subcomponent) {
-        [super _insertSubcomponent:subcomponent atIndex:index];
-        if ([subcomponent isKindOfClass:[WXLoadingIndicator class]]) {
-            _indicator = (WXLoadingIndicator*)subcomponent;
-        }
-    }
-}
-
-- (void)updateAttributes:(NSDictionary *)attributes
-{
-    if (attributes[@"display"]) {
-        if ([attributes[@"display"] isEqualToString:@"show"]) {
-            _displayState = YES;
-        } else if ([attributes[@"display"] isEqualToString:@"hide"]) {
-            _displayState = NO;
-        } else {
-            WXLogError(@"");
-        }
-        [self setDisplay];
-    }
-}
-
-- (void)addEvent:(NSString *)eventName
-{
-    if ([eventName isEqualToString:@"refresh"]) {
-        _refreshEvent = YES;
-    }
-    if ([eventName isEqualToString:@"pullingdown"]) {
-        _pullingdownEvent = YES;
-    }
-}
-
-- (void)removeEvent:(NSString *)evetName
-{
-    if ([evetName isEqualToString:@"refresh"]) {
-        _refreshEvent = NO;
-    }
-    if ([evetName isEqualToString:@"pullingdown"]) {
-        _pullingdownEvent = NO;
-    }
-}
-
-- (void)setDisplay
-{
-    id<WXScrollerProtocol> scrollerProtocol = self.ancestorScroller;
-    if (scrollerProtocol == nil || !_initFinished)
-        return;
-    
-    if ([scrollerProtocol respondsToSelector:@selector(refreshType)] &&
-        [[scrollerProtocol refreshType] isEqualToString:@"refreshForAppear"]) {
-        UIEdgeInsets inset = [scrollerProtocol contentInset];
-        if (_displayState) {
-            inset.top = self.calculatedFrame.size.height;
-            if ([_indicator.view isHidden]) {
-                [_indicator.view setHidden:NO];
-            }
-            [_indicator start];
-        } else {
-            inset.top = 0;
-            [_indicator stop];
-        }
-        [scrollerProtocol setContentInset:inset];
-    } else {
-        CGPoint offset = [scrollerProtocol contentOffset];
-        if (_displayState) {
-            offset.y = -self.calculatedFrame.size.height;
-            if ([_indicator.view isHidden]) {
-                [_indicator.view setHidden:NO];
-            }
-            [_indicator start];
-        } else {
-            offset.y = 0;
-            [_indicator stop];
-        }
-        [scrollerProtocol setContentOffset:offset animated:YES];
-    }
-  
-}
-
-- (BOOL)displayState
-{
-    return _displayState;
-}
-
-- (void)setIndicatorHidden:(BOOL)hidden {
-    [_indicator.view setHidden:hidden];
-    
-    id<WXScrollerProtocol> scrollerProtocol = self.ancestorScroller;
-    if (scrollerProtocol == nil || !_initFinished)
-        return;
-    if ([scrollerProtocol respondsToSelector:@selector(refreshType)] &&
-        [[scrollerProtocol refreshType] isEqualToString:@"refreshForAppear"]) {
-        UIEdgeInsets inset = [scrollerProtocol contentInset];
-        if (!hidden) {
-            inset.top = self.calculatedFrame.size.height;
-            [_indicator start];
-        } else {
-            inset.top = 0;
-            [_indicator stop];
-        }
-        [scrollerProtocol setContentInset:inset];
-    }
-}
-
-@end

http://git-wip-us.apache.org/repos/asf/incubator-weex/blob/b77b4259/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.mm
----------------------------------------------------------------------
diff --git a/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.mm b/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.mm
new file mode 100644
index 0000000..f940e3a
--- /dev/null
+++ b/ios/sdk/WeexSDK/Sources/Component/WXRefreshComponent.mm
@@ -0,0 +1,224 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#import "WXRefreshComponent.h"
+#import "WXScrollerComponent.h"
+#import "WXLoadingIndicator.h"
+#import "WXComponent_internal.h"
+#import "WXLog.h"
+#import "WXComponent+Layout.h"
+
+@interface WXRefreshComponent()
+
+@property (nonatomic) BOOL displayState;
+@property (nonatomic) BOOL initFinished;
+@property (nonatomic) BOOL refreshEvent;
+@property (nonatomic) BOOL pullingdownEvent;
+
+@property (nonatomic, weak) WXLoadingIndicator *indicator;
+
+@end
+
+@implementation WXRefreshComponent
+
+- (instancetype)initWithRef:(NSString *)ref type:(NSString *)type styles:(NSDictionary *)styles attributes:(NSDictionary *)attributes events:(NSArray *)events weexInstance:(WXSDKInstance *)weexInstance
+{
+    self = [super initWithRef:ref type:type styles:styles attributes:attributes events:events weexInstance:weexInstance];
+    if (self) {
+        _refreshEvent = NO;
+        _pullingdownEvent = NO;
+        if (attributes[@"display"]) {
+            if ([attributes[@"display"] isEqualToString:@"show"]) {
+                _displayState = YES;
+            } else if ([attributes[@"display"] isEqualToString:@"hide"]) {
+                _displayState = NO;
+            } else {
+                WXLogError(@"");
+            }
+        }
+//#ifndef USE_FLEX
+        if (![WXComponent isUseFlex]) {
+          self.cssNode->style.position_type = CSS_POSITION_ABSOLUTE;
+        }
+//#else
+        else
+        {
+            self.flexCssNode->setStylePositionType(WeexCore::kAbsolute);
+        }
+       
+//#endif
+    }
+    return self;
+}
+
+- (void)viewDidLoad
+{
+     _initFinished = YES;
+    
+    if (!_displayState) {
+        [_indicator.view setHidden:YES];
+    }
+}
+
+- (void)layoutDidFinish
+{
+    [self.view setFrame: (CGRect) {
+        .size = self.calculatedFrame.size,
+        .origin.x = self.calculatedFrame.origin.x,
+        .origin.y = self.view.frame.origin.y - CGRectGetHeight(self.calculatedFrame)
+    }];
+}
+
+- (void)viewWillUnload
+{
+    _displayState = NO;
+    _refreshEvent = NO;
+    _initFinished = NO;
+}
+
+- (void)refresh
+{
+    if (!_refreshEvent || _displayState) {
+        return;
+    }
+#ifdef DEBUG
+    WXLogDebug(@"flexLayout -> refreshComponent : refresh ref:%@",self.ref);
+#endif
+    [self fireEvent:@"refresh" params:nil];
+}
+
+- (void)pullingdown:(NSDictionary*)param
+{
+    if (!_pullingdownEvent) {
+        return ;
+    }
+#ifdef DEBUG
+    WXLogDebug(@"flexLayout -> refreshComponent : pullingdown ,ref:%@",self.ref);
+#endif
+    
+    [self fireEvent:@"pullingdown" params:param];
+}
+
+- (void)_insertSubcomponent:(WXComponent *)subcomponent atIndex:(NSInteger)index
+{
+    if (subcomponent) {
+        [super _insertSubcomponent:subcomponent atIndex:index];
+        if ([subcomponent isKindOfClass:[WXLoadingIndicator class]]) {
+            _indicator = (WXLoadingIndicator*)subcomponent;
+        }
+    }
+}
+
+- (void)updateAttributes:(NSDictionary *)attributes
+{
+    if (attributes[@"display"]) {
+        if ([attributes[@"display"] isEqualToString:@"show"]) {
+            _displayState = YES;
+        } else if ([attributes[@"display"] isEqualToString:@"hide"]) {
+            _displayState = NO;
+        } else {
+            WXLogError(@"");
+        }
+        [self setDisplay];
+    }
+}
+
+- (void)addEvent:(NSString *)eventName
+{
+    if ([eventName isEqualToString:@"refresh"]) {
+        _refreshEvent = YES;
+    }
+    if ([eventName isEqualToString:@"pullingdown"]) {
+        _pullingdownEvent = YES;
+    }
+}
+
+- (void)removeEvent:(NSString *)evetName
+{
+    if ([evetName isEqualToString:@"refresh"]) {
+        _refreshEvent = NO;
+    }
+    if ([evetName isEqualToString:@"pullingdown"]) {
+        _pullingdownEvent = NO;
+    }
+}
+
+- (void)setDisplay
+{
+    id<WXScrollerProtocol> scrollerProtocol = self.ancestorScroller;
+    if (scrollerProtocol == nil || !_initFinished)
+        return;
+    
+    if ([scrollerProtocol respondsToSelector:@selector(refreshType)] &&
+        [[scrollerProtocol refreshType] isEqualToString:@"refreshForAppear"]) {
+        UIEdgeInsets inset = [scrollerProtocol contentInset];
+        if (_displayState) {
+            inset.top = self.calculatedFrame.size.height;
+            if ([_indicator.view isHidden]) {
+                [_indicator.view setHidden:NO];
+            }
+            [_indicator start];
+        } else {
+            inset.top = 0;
+            [_indicator stop];
+        }
+        [scrollerProtocol setContentInset:inset];
+    } else {
+        CGPoint offset = [scrollerProtocol contentOffset];
+        if (_displayState) {
+            offset.y = -self.calculatedFrame.size.height;
+            if ([_indicator.view isHidden]) {
+                [_indicator.view setHidden:NO];
+            }
+            [_indicator start];
+        } else {
+            offset.y = 0;
+            [_indicator stop];
+        }
+        [scrollerProtocol setContentOffset:offset animated:YES];
+    }
+  
+}
+
+- (BOOL)displayState
+{
+    return _displayState;
+}
+
+- (void)setIndicatorHidden:(BOOL)hidden {
+    [_indicator.view setHidden:hidden];
+    
+    id<WXScrollerProtocol> scrollerProtocol = self.ancestorScroller;
+    if (scrollerProtocol == nil || !_initFinished)
+        return;
+    if ([scrollerProtocol respondsToSelector:@selector(refreshType)] &&
+        [[scrollerProtocol refreshType] isEqualToString:@"refreshForAppear"]) {
+        UIEdgeInsets inset = [scrollerProtocol contentInset];
+        if (!hidden) {
+            inset.top = self.calculatedFrame.size.height;
+            [_indicator start];
+        } else {
+            inset.top = 0;
+            [_indicator stop];
+        }
+        [scrollerProtocol setContentInset:inset];
+    }
+}
+
+@end

http://git-wip-us.apache.org/repos/asf/incubator-weex/blob/b77b4259/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.h
----------------------------------------------------------------------
diff --git a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.h b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.h
index db0c155..8f2b587 100644
--- a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.h
+++ b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.h
@@ -28,8 +28,6 @@
 
 @property (nonatomic, assign) CGSize contentSize;
 
-@property (nonatomic, readonly, assign) css_node_t *scrollerCSSNode;
-
 - (NSUInteger)childrenCountForScrollerLayout;
 
 - (void)handleAppear;

http://git-wip-us.apache.org/repos/asf/incubator-weex/blob/b77b4259/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.m
----------------------------------------------------------------------
diff --git a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.m b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.m
deleted file mode 100644
index 5f197d1..0000000
--- a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.m
+++ /dev/null
@@ -1,884 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-#import "WXScrollerComponent.h"
-#import "WXComponent_internal.h"
-#import "WXComponent.h"
-#import "WXDefine.h"
-#import "WXConvert.h"
-#import "WXSDKInstance.h"
-#import "WXUtility.h"
-#import "WXLoadingComponent.h"
-#import "WXRefreshComponent.h"
-#import "WXConfigCenterProtocol.h"
-#import "WXSDKEngine.h"
-#import "WXComponent+Events.h"
-
-@interface WXScrollerComponentView:UIScrollView
-@end
-
-@implementation WXScrollerComponentView
-- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
-{
-    if ([(id <WXScrollerProtocol>) self.wx_component respondsToSelector:@selector(requestGestureShouldStopPropagation:shouldReceiveTouch:)]) {
-        return [(id <WXScrollerProtocol>) self.wx_component requestGestureShouldStopPropagation:gestureRecognizer shouldReceiveTouch:touch];
-    }
-    else{
-        return YES;
-    }
-}
-@end
-
-@interface WXScrollToTarget : NSObject
-
-@property (nonatomic, weak)   WXComponent *target;
-@property (nonatomic, assign) BOOL hasAppear;
-
-@end
-
-@implementation WXScrollToTarget
-
-@end
-
-
-@interface WXScrollerComponent()
-
-@property (nonatomic, strong) NSMutableArray *  stickyArray;
-@property (nonatomic, strong) NSMutableArray * listenerArray;
-@property (nonatomic, weak) WXRefreshComponent *refreshComponent;
-@property (nonatomic, weak) WXLoadingComponent *loadingComponent;
-
-@end
-
-@implementation WXScrollerComponent
-{
-    CGSize _contentSize;
-    BOOL _listenLoadMore;
-    BOOL _scrollEvent;
-    BOOL _scrollStartEvent;
-    BOOL _scrollEndEvent;
-    BOOL _isScrolling;
-    CGFloat _loadMoreOffset;
-    CGFloat _previousLoadMoreContentHeight;
-    CGFloat _offsetAccuracy;
-    CGPoint _lastContentOffset;
-    CGPoint _lastScrollEventFiredOffset;
-    BOOL _scrollable;
-    NSString * _alwaysScrollableVertical;
-    NSString * _alwaysScrollableHorizontal;
-    BOOL _bounces;
-    
-    // refreshForAppear: load more when refresh component begin appear(if scroll is dragging or decelerating, should delay)
-    // refreshForWholeVisible: load more until the whole refresh component visible
-    NSString *_refreshType;
-
-    // vertical & horizontal
-    WXScrollDirection _scrollDirection;
-    // left & right & up & down
-    NSString *_direction;
-    BOOL _showScrollBar;
-    BOOL _pagingEnabled;
-    
-    BOOL _shouldNotifiAppearDescendantView;
-    BOOL _shouldRemoveScrollerListener;
-
-    css_node_t *_scrollerCSSNode;
-    
-    NSHashTable* _delegates;
-}
-
-WX_EXPORT_METHOD(@selector(resetLoadmore))
-
-- (void)resetLoadmore
-{
-    _previousLoadMoreContentHeight=0;
-}
-
-- (css_node_t *)scrollerCSSNode
-{
-    return _scrollerCSSNode;
-}
-
-- (void)_insertSubcomponent:(WXComponent *)subcomponent atIndex:(NSInteger)index
-{
-    [super _insertSubcomponent:subcomponent atIndex:index];
-    
-    if ([subcomponent isKindOfClass:[WXRefreshComponent class]]) {
-        _refreshComponent = (WXRefreshComponent*)subcomponent;
-    }
-    else if ([subcomponent isKindOfClass:[WXLoadingComponent class]]) {
-        _loadingComponent = (WXLoadingComponent*)subcomponent;
-    }
-}
-
--(instancetype)initWithRef:(NSString *)ref type:(NSString *)type styles:(NSDictionary *)styles attributes:(NSDictionary *)attributes events:(NSArray *)events weexInstance:(WXSDKInstance *)weexInstance
-{
-    self = [super initWithRef:ref type:type styles:styles attributes:attributes events:events weexInstance:weexInstance];
-    if (self) {
-        
-        _stickyArray = [NSMutableArray array];
-        _listenerArray = [NSMutableArray array];
-        _scrollEvent = NO;
-        _scrollStartEvent = NO;
-        _scrollEndEvent = NO;
-        _lastScrollEventFiredOffset = CGPointMake(0, 0);
-        _scrollDirection = attributes[@"scrollDirection"] ? [WXConvert WXScrollDirection:attributes[@"scrollDirection"]] : WXScrollDirectionVertical;
-        _showScrollBar = attributes[@"showScrollbar"] ? [WXConvert BOOL:attributes[@"showScrollbar"]] : YES;
-        
-        if (attributes[@"alwaysScrollableVertical"]) {
-            _alwaysScrollableVertical = [WXConvert NSString:attributes[@"alwaysScrollableVertical"]];
-        }
-        if (attributes[@"alwaysScrollableHorizontal"]) {
-            _alwaysScrollableHorizontal = [WXConvert NSString:attributes[@"alwaysScrollableHorizontal"]];
-        }
-        _bounces = attributes[@"bounce"]?[WXConvert BOOL:attributes[@"bounce"]]:YES;
-        _refreshType = [WXConvert NSString:attributes[@"refreshType"]]?:@"refreshForWholeVisible";
-        _pagingEnabled = attributes[@"pagingEnabled"] ? [WXConvert BOOL:attributes[@"pagingEnabled"]] : NO;
-        _loadMoreOffset = attributes[@"loadmoreoffset"] ? [WXConvert WXPixelType:attributes[@"loadmoreoffset"] scaleFactor:self.weexInstance.pixelScaleFactor] : 0;
-        _loadmoreretry = attributes[@"loadmoreretry"] ? [WXConvert NSUInteger:attributes[@"loadmoreretry"]] : 0;
-        _listenLoadMore = [events containsObject:@"loadmore"];
-        _scrollable = attributes[@"scrollable"] ? [WXConvert BOOL:attributes[@"scrollable"]] : YES;
-        _offsetAccuracy = attributes[@"offsetAccuracy"] ? [WXConvert WXPixelType:attributes[@"offsetAccuracy"] scaleFactor:self.weexInstance.pixelScaleFactor] : 0;
-        _scrollerCSSNode = new_css_node();
-        
-        // let scroller fill the rest space if it is a child component and has no fixed height & width
-        if (((_scrollDirection == WXScrollDirectionVertical &&
-            isUndefined(self.cssNode->style.dimensions[CSS_HEIGHT])) ||
-            (_scrollDirection == WXScrollDirectionHorizontal &&
-              isUndefined(self.cssNode->style.dimensions[CSS_WIDTH]))) &&
-             self.cssNode->style.flex <= 0.0) {
-            self.cssNode->style.flex = 1.0;
-        }
-        id configCenter = [WXSDKEngine handlerForProtocol:@protocol(WXConfigCenterProtocol)];
-        if ([configCenter respondsToSelector:@selector(configForKey:defaultValue:isDefault:)]) {
-            BOOL shouldNotifiAppearDescendantView = [[configCenter configForKey:@"iOS_weex_ext_config.shouldNotifiAppearDescendantView" defaultValue:@(YES) isDefault:NULL] boolValue];
-            _shouldNotifiAppearDescendantView = shouldNotifiAppearDescendantView;
-            BOOL shouldRemoveScrollerListener = [[configCenter configForKey:@"iOS_weex_ext_config.shouldRemoveScrollerListener" defaultValue:@(YES) isDefault:NULL] boolValue];
-            _shouldRemoveScrollerListener = shouldRemoveScrollerListener;
-            
-        }
-    }
-    
-    return self;
-}
-
-- (UIView *)loadView
-{
-    return [[WXScrollerComponentView alloc] init];
-}
-
-- (void)viewDidLoad
-{
-    [super viewDidLoad];
-    [self setContentSize:_contentSize];
-    WXScrollerComponentView* scrollView = (WXScrollerComponentView *)self.view;
-    scrollView.delegate = self;
-    scrollView.exclusiveTouch = YES;
-    scrollView.autoresizesSubviews = NO;
-    scrollView.clipsToBounds = YES;
-    scrollView.showsVerticalScrollIndicator = _showScrollBar;
-    scrollView.showsHorizontalScrollIndicator = _showScrollBar;
-    scrollView.scrollEnabled = _scrollable;
-    scrollView.pagingEnabled = _pagingEnabled;
-    
-    if (scrollView.bounces != _bounces) {
-        scrollView.bounces = _bounces;
-    }
-    
-    if (_alwaysScrollableHorizontal) {
-        scrollView.alwaysBounceHorizontal = [WXConvert BOOL:_alwaysScrollableHorizontal];
-    }
-    if (_alwaysScrollableVertical) {
-        scrollView.alwaysBounceVertical = [WXConvert BOOL:_alwaysScrollableVertical];
-    }
-    
-    if (@available(iOS 11.0, *)) {
-        if ([scrollView respondsToSelector:@selector(setContentInsetAdjustmentBehavior:)]) {
-            scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
-        }
-    } else {
-        // Fallback on earlier versions
-    }
-    
-    if (self.ancestorScroller) {
-        scrollView.scrollsToTop = NO;
-    } else {
-        scrollView.scrollsToTop = YES;
-    }
-}
-
-- (void)layoutDidFinish
-{
-    if ([self isViewLoaded]) {
-        [self setContentSize:_contentSize];
-        [self adjustSticky];
-        [self handleAppear];
-    }
-    
-    [_loadingComponent resizeFrame];
-}
-
-- (void)viewWillUnload
-{
-    ((UIScrollView *)_view).delegate = nil;
-}
-
-- (void)dealloc
-{
-    ((UIScrollView *)_view).delegate = nil;
-    [self.stickyArray removeAllObjects];
-    [self.listenerArray removeAllObjects];
-    
-    free(_scrollerCSSNode);
-}
-
-- (void)updateAttributes:(NSDictionary *)attributes
-{
-    if (attributes[@"showScrollbar"]) {
-        _showScrollBar = [WXConvert BOOL:attributes[@"showScrollbar"]];
-        ((UIScrollView *)self.view).showsHorizontalScrollIndicator = _showScrollBar;
-        ((UIScrollView *)self.view).showsVerticalScrollIndicator = _showScrollBar;
-    }
-    
-    if (attributes[@"pagingEnabled"]) {
-        _pagingEnabled = [WXConvert BOOL:attributes[@"pagingEnabled"]];
-        ((UIScrollView *)self.view).pagingEnabled = _pagingEnabled;
-    }
-    
-    if (attributes[@"loadmoreoffset"]) {
-        _loadMoreOffset = [WXConvert WXPixelType:attributes[@"loadmoreoffset"] scaleFactor:self.weexInstance.pixelScaleFactor];
-    }
-    if (attributes[@"bounce"]) {
-        _bounces = [WXConvert BOOL:attributes[@"bounce"]];
-        ((UIScrollView *)self.view).bounces = _bounces;
-    }
-    
-    if (attributes[@"loadmoreretry"]) {
-        NSUInteger loadmoreretry = [WXConvert NSUInteger:attributes[@"loadmoreretry"]];
-        if (loadmoreretry != _loadmoreretry) {
-            _previousLoadMoreContentHeight = 0;
-        }
-        self.loadmoreretry = loadmoreretry;
-    }
-    if (attributes[@"scrollable"]) {
-        _scrollable = attributes[@"scrollable"] ? [WXConvert BOOL:attributes[@"scrollable"]] : YES;
-        ((UIScrollView *)self.view).scrollEnabled = _scrollable;
-    }
-    if (attributes[@"alwaysScrollableHorizontal"]) {
-        _alwaysScrollableHorizontal = [WXConvert NSString:attributes[@"alwaysScrollableHorizontal"]];
-        ((UIScrollView*)self.view).alwaysBounceHorizontal = [WXConvert BOOL:_alwaysScrollableHorizontal];
-    }
-    
-    if (attributes[@"alwaysScrollableVertical"]) {
-        _alwaysScrollableVertical = [WXConvert NSString:attributes[@"alwaysScrollableVertical"]];
-        ((UIScrollView*)self.view).alwaysBounceVertical = [WXConvert BOOL:_alwaysScrollableVertical];
-    }
-    
-    if (attributes[@"refreshType"]) {
-        _refreshType = [WXConvert NSString:attributes[@"refreshType"]];
-    }
-    
-    if (attributes[@"offsetAccuracy"]) {
-        _offsetAccuracy = [WXConvert WXPixelType:attributes[@"offsetAccuracy"] scaleFactor:self.weexInstance.pixelScaleFactor];
-    }
-    
-    if (attributes[@"scrollDirection"]) {
-        _scrollDirection = attributes[@"scrollDirection"] ? [WXConvert WXScrollDirection:attributes[@"scrollDirection"]] : WXScrollDirectionVertical;
-    }
-}
-
-- (void)addEvent:(NSString *)eventName
-{
-    if ([eventName isEqualToString:@"loadmore"]) {
-        _listenLoadMore = YES;
-    }
-    if ([eventName isEqualToString:@"scroll"]) {
-        _scrollEvent = YES;
-    }
-    if ([eventName isEqualToString:@"scrollstart"]) {
-        _scrollStartEvent = YES;
-    }
-    if ([eventName isEqualToString:@"scrollend"]) {
-        _scrollEndEvent = YES;
-    }
-}
-
-- (void)removeEvent:(NSString *)eventName
-{
-    if ([eventName isEqualToString:@"loadmore"]) {
-        _listenLoadMore = NO;
-    }
-    if ([eventName isEqualToString:@"scroll"]) {
-        _scrollEvent = NO;
-    }
-    if ([eventName isEqualToString:@"scrollstart"]) {
-        _scrollStartEvent = NO;
-    }
-    if ([eventName isEqualToString:@"scrollend"]) {
-        _scrollEndEvent = NO;
-    }
-}
-
-#pragma mark WXScrollerProtocol
-
-- (void)addStickyComponent:(WXComponent *)sticky
-{
-    if(![self.stickyArray containsObject:sticky]) {
-        [self.stickyArray addObject:sticky];
-        [self adjustSticky];
-    }
-}
-
-- (void)removeStickyComponent:(WXComponent *)sticky
-{
-    if([self.stickyArray containsObject:sticky]) {
-        [self.stickyArray removeObject:sticky];
-        [self adjustSticky];
-    }
-}
-
-- (void)adjustSticky
-{
-    if (![self isViewLoaded]) {
-        return;
-    }
-    CGFloat scrollOffsetY = ((UIScrollView *)self.view).contentOffset.y;
-    for(WXComponent *component in self.stickyArray) {
-        if (isnan(component->_absolutePosition.x) && isnan(component->_absolutePosition.y)) {
-            component->_absolutePosition = [component.supercomponent.view convertPoint:component.view.frame.origin toView:self.view];
-        }
-        CGPoint relativePosition = component->_absolutePosition;
-        if (isnan(relativePosition.y)) {
-            continue;
-        }
-        
-        WXComponent *supercomponent = component.supercomponent;
-        if(supercomponent != self && component.view.superview != self.view) {
-            [component.view removeFromSuperview];
-            [self.view addSubview:component.view];
-        } else {
-            [self.view bringSubviewToFront:component.view];
-        }
-        
-        CGFloat relativeY = relativePosition.y;
-        BOOL needSticky = NO;
-        
-        if (scrollOffsetY >= relativeY) {
-            needSticky = YES;
-        } else {
-            // important: reset views' frame
-            component.view.frame = CGRectMake(relativePosition.x, relativePosition.y, component.calculatedFrame.size.width, component.calculatedFrame.size.height);
-        }
-        
-        if (!needSticky) {
-            continue;
-        }
-        
-        // The minimum Y sticky view can reach is its original position
-        CGFloat minY = relativeY;
-        CGPoint superRelativePosition = supercomponent == self ? CGPointZero : [supercomponent.supercomponent.view convertPoint:supercomponent.view.frame.origin toView:self.view];
-        CGFloat maxY = superRelativePosition.y + supercomponent.calculatedFrame.size.height - component.calculatedFrame.size.height;
-        
-        CGFloat stickyY = scrollOffsetY;
-        if (stickyY < minY) {
-            stickyY = minY;
-        } else if (stickyY > maxY && ![supercomponent conformsToProtocol:@protocol(WXScrollerProtocol)]) {
-            // Sticky component can not go beyond its parent's bounds when its parent is not scroller;
-            stickyY = maxY;
-        }
-        
-        UIView *stickyView = component.view;
-        CGPoint origin = stickyView.frame.origin;
-        origin.y = stickyY;
-        stickyView.frame = (CGRect){origin,stickyView.frame.size};
-    }
-}
-
-- (void)addScrollToListener:(WXComponent *)target
-{
-    BOOL has = NO;
-    NSMutableArray *listenerArray = [self.listenerArray copy];
-    for (WXScrollToTarget *targetData in listenerArray) {
-        if (targetData.target == target) {
-            has = YES;
-            break;
-        }
-    }
-    if (!has) {
-        WXScrollToTarget *scrollTarget = [[WXScrollToTarget alloc] init];
-        scrollTarget.target = target;
-        scrollTarget.hasAppear = NO;
-        [self.listenerArray addObject:scrollTarget];
-    }
-}
-
-- (void)removeScrollToListener:(WXComponent *)target
-{
-    if (_shouldRemoveScrollerListener) {
-        WXScrollToTarget *targetData = nil;
-        NSMutableArray *listenerArray = [self.listenerArray copy];
-        for (WXScrollToTarget *targetDataTemp in listenerArray) {
-            if (targetDataTemp.target == target) {
-                targetData = targetDataTemp;
-                break;
-            }
-        }
-        if(targetData) {
-            [self.listenerArray removeObject:targetData];
-        }
-    }
-}
-
-- (void)scrollToComponent:(WXComponent *)component withOffset:(CGFloat)offset animated:(BOOL)animated
-{
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-
-    CGPoint contentOffset = scrollView.contentOffset;
-    CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
-    
-    if (_scrollDirection == WXScrollDirectionHorizontal) {
-        CGFloat contentOffetX = [component.supercomponent.view convertPoint:component.view.frame.origin toView:self.view].x;
-        contentOffetX += offset * scaleFactor;
-        
-        if (scrollView.contentSize.width >= scrollView.frame.size.width && contentOffetX > scrollView.contentSize.width - scrollView.frame.size.width) {
-            contentOffset.x = scrollView.contentSize.width - scrollView.frame.size.width;
-        } else {
-            contentOffset.x = contentOffetX;
-        }
-    } else {
-        CGFloat contentOffetY = [component.supercomponent.view convertPoint:component.view.frame.origin toView:self.view].y;
-        contentOffetY += offset * scaleFactor;
-        
-        if (scrollView.contentSize.height >= scrollView.frame.size.height && contentOffetY > scrollView.contentSize.height - scrollView.frame.size.height) {
-            contentOffset.y = scrollView.contentSize.height - scrollView.frame.size.height;
-        } else {
-            contentOffset.y = contentOffetY;
-        }
-    }
-    
-    [scrollView setContentOffset:contentOffset animated:animated];
-}
-
-- (BOOL)isNeedLoadMore
-{
-    if (WXScrollDirectionVertical == _scrollDirection) {
-        if (_loadMoreOffset >= 0.0 && ((UIScrollView *)self.view).contentOffset.y >= 0) {
-            return _previousLoadMoreContentHeight != ((UIScrollView *)self.view).contentSize.height && ((UIScrollView *)self.view).contentSize.height - ((UIScrollView *)self.view).contentOffset.y -  self.view.frame.size.height <= _loadMoreOffset;
-        }
-    } else if (WXScrollDirectionHorizontal == _scrollDirection) {
-        if (_loadMoreOffset >= 0.0 && ((UIScrollView *)self.view).contentOffset.x >= 0) {
-            return _previousLoadMoreContentHeight != ((UIScrollView *)self.view).contentSize.width && ((UIScrollView *)self.view).contentSize.width - ((UIScrollView *)self.view).contentOffset.x -  self.view.frame.size.width <= _loadMoreOffset;
-        }
-    }
-    
-    return NO;
-}
-
-- (void)loadMore
-{
-    [self fireEvent:@"loadmore" params:nil];
-    
-    if (WXScrollDirectionVertical == _scrollDirection) {
-        _previousLoadMoreContentHeight = ((UIScrollView *)self.view).contentSize.height;
-    } else if (WXScrollDirectionHorizontal == _scrollDirection) {
-        _previousLoadMoreContentHeight = ((UIScrollView *)self.view).contentSize.width;
-    }
-}
-
-- (CGPoint)contentOffset
-{
-    CGPoint rtv = CGPointZero;
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-    if (scrollView) {
-        rtv = scrollView.contentOffset;
-    }
-    return rtv;
-}
-
-- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated
-{
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-    [scrollView setContentOffset:contentOffset animated:animated];
-}
-
-- (CGSize)contentSize
-{
-    return ((UIScrollView *)self.view).contentSize;
-}
-
-- (void)setContentSize:(CGSize)size
-{
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-    scrollView.contentSize = size;
-}
-
-- (UIEdgeInsets)contentInset
-{
-    UIEdgeInsets rtv = UIEdgeInsetsZero;
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-    if (scrollView) {
-        rtv = scrollView.contentInset;
-    }
-    return rtv;
-}
-
-- (void)setContentInset:(UIEdgeInsets)contentInset
-{
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-    [scrollView setContentInset:contentInset];
-}
-
-- (void)addScrollDelegate:(id<UIScrollViewDelegate>)delegate
-{
-    if (delegate) {
-        if (!_delegates) {
-            _delegates = [NSHashTable hashTableWithOptions:NSPointerFunctionsWeakMemory];
-        }
-        [_delegates addObject:delegate];
-    }
-}
-
-- (void)removeScrollDelegate:(id<UIScrollViewDelegate>)delegate
-{
-    if (delegate) {
-        [_delegates removeObject:delegate];
-    }
-}
-
-- (WXScrollDirection)scrollDirection
-{
-    return _scrollDirection;
-}
-
-- (NSString*)refreshType
-{
-    return _refreshType;
-}
-- (BOOL)requestGestureShouldStopPropagation:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
-{
-    return [self gestureShouldStopPropagation:gestureRecognizer shouldReceiveTouch:touch];
-}
-
-#pragma mark UIScrollViewDelegate
-- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
-{
-    if ([_refreshType isEqualToString:@"refreshForAppear"] && _refreshComponent) {
-        [_refreshComponent setIndicatorHidden:NO];
-    }
-    
-    if (_scrollStartEvent) {
-        CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
-        NSDictionary *contentSizeData = @{@"width":[NSNumber numberWithFloat:scrollView.contentSize.width / scaleFactor],@"height":[NSNumber numberWithFloat:scrollView.contentSize.height / scaleFactor]};
-        NSDictionary *contentOffsetData = @{@"x":[NSNumber numberWithFloat:-scrollView.contentOffset.x / scaleFactor],@"y":[NSNumber numberWithFloat:-scrollView.contentOffset.y / scaleFactor]};
-        [self fireEvent:@"scrollstart" params:@{@"contentSize":contentSizeData,@"contentOffset":contentOffsetData} domChanges:nil];
-    }
-}
-
-- (void)scrollViewDidScroll:(UIScrollView *)scrollView
-{
-    //apply block which are registered
-    WXSDKInstance *instance = self.weexInstance;
-    if ([self.ref isEqualToString:WX_SDK_ROOT_REF] &&
-        [self isKindOfClass:[WXScrollerComponent class]]) {
-        if (instance.onScroll) {
-            instance.onScroll(scrollView.contentOffset);
-        }
-    }
-    
-    if (_lastContentOffset.x > scrollView.contentOffset.x) {
-        _direction = @"right";
-    } else if (_lastContentOffset.x < scrollView.contentOffset.x) {
-        _direction = @"left";
-        if (WXScrollDirectionHorizontal == _scrollDirection) {
-            [self handleLoadMore];
-        }
-    } else if(_lastContentOffset.y > scrollView.contentOffset.y) {
-        _direction = @"down";
-    } else if(_lastContentOffset.y < scrollView.contentOffset.y) {
-        _direction = @"up";
-        if (WXScrollDirectionVertical == _scrollDirection) {
-            [self handleLoadMore];
-        }
-    }
-    
-    CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
-    [_refreshComponent pullingdown:@{
-             REFRESH_DISTANCE_Y: @(fabs((scrollView.contentOffset.y - _lastContentOffset.y)/scaleFactor)),
-             REFRESH_VIEWHEIGHT: @(_refreshComponent.view.frame.size.height/scaleFactor),
-             REFRESH_PULLINGDISTANCE: @(scrollView.contentOffset.y/scaleFactor),
-             @"type":@"pullingdown"
-    }];
-    _lastContentOffset = scrollView.contentOffset;
-    // check sticky
-    [self adjustSticky];
-    [self handleAppear];
-    
-    if (self.onScroll) {
-        self.onScroll(scrollView);
-    }
-    if (_scrollEvent) {
-        NSDictionary *contentSizeData = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithFloat:scrollView.contentSize.width / scaleFactor],@"width",[NSNumber numberWithFloat:scrollView.contentSize.height / scaleFactor],@"height", nil];
-        //contentOffset values are replaced by (-contentOffset.x,-contentOffset.y) ,in order to be consistent with Android client.
-        NSDictionary *contentOffsetData = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithFloat:-scrollView.contentOffset.x / scaleFactor],@"x",[NSNumber numberWithFloat:-scrollView.contentOffset.y / scaleFactor],@"y", nil];
-        CGFloat distance = 0;
-        if (_scrollDirection == WXScrollDirectionHorizontal) {
-            distance = scrollView.contentOffset.x - _lastScrollEventFiredOffset.x;
-        } else {
-            distance = scrollView.contentOffset.y - _lastScrollEventFiredOffset.y;
-        }
-        if (fabs(distance) >= _offsetAccuracy) {
-            [self fireEvent:@"scroll" params:@{@"contentSize":contentSizeData,@"contentOffset":contentOffsetData} domChanges:nil];
-            _lastScrollEventFiredOffset = scrollView.contentOffset;
-        }
-    }
-    NSHashTable *delegates = [_delegates copy];
-    for (id<UIScrollViewDelegate> delegate in delegates) {
-        if ([delegate respondsToSelector:@selector(scrollViewDidScroll:)]) {
-            [delegate scrollViewDidScroll:scrollView];
-        }
-    }
-}
-
-- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView
-{
-    UIEdgeInsets inset = [scrollView contentInset];
-    
-//  currently only set contentInset when loading
-//    if ([_refreshComponent displayState]) {
-//        inset.top = _refreshComponent.view.frame.size.height;
-//    }
-//    else {
-//        inset.top = 0;
-//    }
-    
-    if ([_loadingComponent displayState]) {
-        inset.bottom = _loadingComponent.view.frame.size.height;
-    } else {
-        inset.bottom = 0;
-    }
-    [scrollView setContentInset:inset];
-}
-
-- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
-{
-    if (_scrollEndEvent) {
-        if (!_isScrolling) {
-            CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
-            NSDictionary *contentSizeData = @{@"width":[NSNumber numberWithFloat:scrollView.contentSize.width / scaleFactor],@"height":[NSNumber numberWithFloat:scrollView.contentSize.height / scaleFactor]};
-            NSDictionary *contentOffsetData = @{@"x":[NSNumber numberWithFloat:-scrollView.contentOffset.x / scaleFactor],@"y":[NSNumber numberWithFloat:-scrollView.contentOffset.y / scaleFactor]};
-            [self fireEvent:@"scrollend" params:@{@"contentSize":contentSizeData,@"contentOffset":contentOffsetData} domChanges:nil];
-        }
-    }
-}
-
-- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
-{
-    if ([_refreshType isEqualToString:@"refreshForAppear"]) {
-        if(targetContentOffset == nil)
-            return;
-        CGPoint offset = *targetContentOffset;
-        if(velocity.y <= 0) {
-            // drop down
-            if( offset.y <= _refreshComponent.calculatedFrame.size.height ) {
-                [self loadMoreIfNeed];
-            }
-        } else if (velocity.y > 0) {
-            // drop up
-        }
-    }
-}
-
-- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
-{
-    [_loadingComponent.view setHidden:NO];
-    [_refreshComponent.view setHidden:NO];
-    
-    //refresh
-    if ([_refreshType isEqualToString:@"refreshForWholeVisible"]) {
-        if (_refreshComponent && scrollView.contentOffset.y < 0 && scrollView.contentOffset.y + _refreshComponent.calculatedFrame.size.height < _refreshComponent.calculatedFrame.origin.y) {
-            [_refreshComponent refresh];
-        }
-    }
-    
-    //loading
-    if (_loadingComponent && scrollView.contentOffset.y > 0 &&
-        scrollView.contentOffset.y + scrollView.frame.size.height > _loadingComponent.view.frame.origin.y + _loadingComponent.calculatedFrame.size.height) {
-        [_loadingComponent loading];
-    }
-    if (!decelerate) {
-        _isScrolling = NO;
-        [self performSelector:@selector(scrollViewDidEndDecelerating:) withObject:nil afterDelay:0.1];
-    }
-}
-
-- (void)loadMoreIfNeed
-{
-    WXScrollerComponentView* scrollView = (WXScrollerComponentView *)self.view;
-    if (scrollView.isDragging || scrollView.isTracking || scrollView.isDecelerating) {
-        [self performSelector:@selector(loadMoreIfNeed) withObject:nil afterDelay:0.1];
-        return;
-    }
-    [_refreshComponent refresh];
-}
-
-- (void)handleAppear
-{
-    if (![self isViewLoaded]) {
-        return;
-    }
-    UIScrollView *scrollView = (UIScrollView *)self.view;
-    CGFloat vx = scrollView.contentInset.left + scrollView.contentOffset.x;
-    CGFloat vy = scrollView.contentInset.top + scrollView.contentOffset.y;
-    CGFloat vw = scrollView.frame.size.width - scrollView.contentInset.left - scrollView.contentInset.right;
-    CGFloat vh = scrollView.frame.size.height - scrollView.contentInset.top - scrollView.contentInset.bottom;
-    CGRect scrollRect = CGRectMake(vx, vy, vw, vh);;
-    
-    // notify action for appear
-    NSArray *listenerArrayCopy = [self.listenerArray copy];
-    for(WXScrollToTarget *target in listenerArrayCopy){
-        if (_shouldNotifiAppearDescendantView) {
-            // if target component is descendant of scrollerview, it should notify the appear event handler, or here will skip this appear calculation.
-            if ([target.target isViewLoaded] && [target.target.view isDescendantOfView:self.view]) {
-                [self scrollToTarget:target scrollRect:scrollRect];
-            }
-        } else {
-            [self scrollToTarget:target scrollRect:scrollRect];
-        }
-    }
-}
-
-- (CGPoint)absolutePositionForComponent:(WXComponent *)component
-{
-    return [component->_view.superview convertPoint:component->_view.frame.origin toView:_view];
-}
-
-#pragma mark  Private Methods
-
-- (void)scrollToTarget:(WXScrollToTarget *)target scrollRect:(CGRect)rect
-{
-    WXComponent *component = target.target;
-    if (![component isViewLoaded]) { 
-        return;
-    }
-    
-    CGFloat ctop;
-    if (component && component->_view && component->_view.superview) {
-        ctop = [self absolutePositionForComponent:component].y;
-    } else {
-        ctop = 0.0;
-    }
-    CGFloat cbottom = ctop + CGRectGetHeight(component.calculatedFrame);
-    CGFloat cleft;
-    if (component && component->_view && component->_view.superview) {
-        cleft = [self absolutePositionForComponent:component].x;
-    } else {
-        cleft = 0.0;
-    }
-    CGFloat cright = cleft + CGRectGetWidth(component.calculatedFrame);
-    
-    CGFloat vtop = CGRectGetMinY(rect), vbottom = CGRectGetMaxY(rect), vleft = CGRectGetMinX(rect), vright = CGRectGetMaxX(rect);
-    if(cbottom > vtop && ctop <= vbottom && cleft <= vright && cright > vleft){
-        if(!target.hasAppear && component){
-            target.hasAppear = YES;
-            if (component->_appearEvent) {
-//                NSLog(@"appear:%@, %.2f", component, ctop);
-                [component fireEvent:@"appear" params:_direction ? @{@"direction":_direction} : nil];
-            }
-        }
-    } else {
-        if(target.hasAppear && component){
-            target.hasAppear = NO;
-            if(component->_disappearEvent){
-//                NSLog(@"disappear:%@", component);
-                [component fireEvent:@"disappear" params:_direction ? @{@"direction":_direction} : nil];
-            }
-        }
-    }
-}
-
-- (void)handleLoadMore
-{
-    if (_listenLoadMore && [self isNeedLoadMore]) {
-        [self loadMore];
-    }
-}
-
-#pragma mark Layout
-
-- (NSUInteger)_childrenCountForLayout;
-{
-    return 0;
-}
-
-- (NSUInteger)childrenCountForScrollerLayout
-{
-    return [super _childrenCountForLayout];
-}
-
-- (void)_calculateFrameWithSuperAbsolutePosition:(CGPoint)superAbsolutePosition
-                          gatherDirtyComponents:(NSMutableSet<WXComponent *> *)dirtyComponents
-{
-    /**
-     *  Pretty hacky way
-     *  layout from root to scroller to get scroller's frame,
-     *  layout from children to scroller to get scroller's contentSize
-     */
-    if ([self needsLayout]) {
-        memcpy(_scrollerCSSNode, self.cssNode, sizeof(css_node_t));
-        _scrollerCSSNode->children_count = (int)[self childrenCountForScrollerLayout];
-        
-        _scrollerCSSNode->style.position[CSS_LEFT] = 0;
-        _scrollerCSSNode->style.position[CSS_TOP] = 0;
-        
-        if (_scrollDirection == WXScrollDirectionVertical) {
-            _scrollerCSSNode->style.flex_direction = CSS_FLEX_DIRECTION_COLUMN;
-            _scrollerCSSNode->style.dimensions[CSS_WIDTH] = _cssNode->layout.dimensions[CSS_WIDTH];
-            _scrollerCSSNode->style.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
-        } else {
-            _scrollerCSSNode->style.flex_direction = CSS_FLEX_DIRECTION_ROW;
-            _scrollerCSSNode->style.dimensions[CSS_HEIGHT] = _cssNode->layout.dimensions[CSS_HEIGHT];
-            _scrollerCSSNode->style.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
-        }
-        
-        _scrollerCSSNode->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
-        _scrollerCSSNode->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
-        
-        layoutNode(_scrollerCSSNode, CSS_UNDEFINED, CSS_UNDEFINED, CSS_DIRECTION_INHERIT);
-        if ([WXLog logLevel] >= WXLogLevelDebug) {
-            print_css_node(_scrollerCSSNode, CSS_PRINT_LAYOUT | CSS_PRINT_STYLE | CSS_PRINT_CHILDREN);
-        }
-        CGSize size = {
-            WXRoundPixelValue(_scrollerCSSNode->layout.dimensions[CSS_WIDTH]),
-            WXRoundPixelValue(_scrollerCSSNode->layout.dimensions[CSS_HEIGHT])
-        };
-
-        if (!CGSizeEqualToSize(size, _contentSize)) {
-            // content size
-            _contentSize = size;
-            [dirtyComponents addObject:self];
-        }
-        
-        _scrollerCSSNode->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
-        _scrollerCSSNode->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
-    }
-    
-    [super _calculateFrameWithSuperAbsolutePosition:superAbsolutePosition gatherDirtyComponents:dirtyComponents];
-}
-
-@end

http://git-wip-us.apache.org/repos/asf/incubator-weex/blob/b77b4259/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
----------------------------------------------------------------------
diff --git a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
new file mode 100644
index 0000000..215d9ff
--- /dev/null
+++ b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
@@ -0,0 +1,951 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#import "WXScrollerComponent.h"
+#import "WXComponent_internal.h"
+#import "WXComponent.h"
+#import "WXDefine.h"
+#import "WXConvert.h"
+#import "WXSDKInstance.h"
+#import "WXUtility.h"
+#import "WXLoadingComponent.h"
+#import "WXRefreshComponent.h"
+#import "WXConfigCenterProtocol.h"
+#import "WXSDKEngine.h"
+#import "WXComponent+Events.h"
+#import "WXScrollerComponent+Layout.h"
+#import "WXCoreLayout.h"
+
+@interface WXScrollerComponentView:UIScrollView
+@end
+
+@implementation WXScrollerComponentView
+- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
+{
+    if ([(id <WXScrollerProtocol>) self.wx_component respondsToSelector:@selector(requestGestureShouldStopPropagation:shouldReceiveTouch:)]) {
+        return [(id <WXScrollerProtocol>) self.wx_component requestGestureShouldStopPropagation:gestureRecognizer shouldReceiveTouch:touch];
+    }
+    else{
+        return YES;
+    }
+}
+@end
+
+@interface WXScrollToTarget : NSObject
+
+@property (nonatomic, weak)   WXComponent *target;
+@property (nonatomic, assign) BOOL hasAppear;
+
+@end
+
+@implementation WXScrollToTarget
+
+@end
+
+
+@interface WXScrollerComponent()
+
+@property (nonatomic, strong) NSMutableArray *  stickyArray;
+@property (nonatomic, strong) NSMutableArray * listenerArray;
+@property (nonatomic, weak) WXRefreshComponent *refreshComponent;
+@property (nonatomic, weak) WXLoadingComponent *loadingComponent;
+
+@end
+
+@implementation WXScrollerComponent
+{
+    CGSize _contentSize;
+    BOOL _listenLoadMore;
+    BOOL _scrollEvent;
+    BOOL _scrollStartEvent;
+    BOOL _scrollEndEvent;
+    BOOL _isScrolling;
+    CGFloat _loadMoreOffset;
+    CGFloat _previousLoadMoreContentHeight;
+    CGFloat _offsetAccuracy;
+    CGPoint _lastContentOffset;
+    CGPoint _lastScrollEventFiredOffset;
+    BOOL _scrollable;
+    NSString * _alwaysScrollableVertical;
+    NSString * _alwaysScrollableHorizontal;
+    BOOL _bounces;
+    
+    // refreshForAppear: load more when refresh component begin appear(if scroll is dragging or decelerating, should delay)
+    // refreshForWholeVisible: load more until the whole refresh component visible
+    NSString *_refreshType;
+
+    // vertical & horizontal
+    WXScrollDirection _scrollDirection;
+    // left & right & up & down
+    NSString *_direction;
+    BOOL _showScrollBar;
+    BOOL _pagingEnabled;
+    
+    BOOL _shouldNotifiAppearDescendantView;
+    BOOL _shouldRemoveScrollerListener;
+
+    //css_node_t *_scrollerCSSNode;
+    
+    NSHashTable* _delegates;
+}
+
+WX_EXPORT_METHOD(@selector(resetLoadmore))
+
+- (void)resetLoadmore
+{
+    _previousLoadMoreContentHeight=0;
+}
+
+- (void)_insertSubcomponent:(WXComponent *)subcomponent atIndex:(NSInteger)index
+{
+    [super _insertSubcomponent:subcomponent atIndex:index];
+    
+    if ([subcomponent isKindOfClass:[WXRefreshComponent class]]) {
+        _refreshComponent = (WXRefreshComponent*)subcomponent;
+    }
+    else if ([subcomponent isKindOfClass:[WXLoadingComponent class]]) {
+        _loadingComponent = (WXLoadingComponent*)subcomponent;
+    }
+}
+
+-(instancetype)initWithRef:(NSString *)ref type:(NSString *)type styles:(NSDictionary *)styles attributes:(NSDictionary *)attributes events:(NSArray *)events weexInstance:(WXSDKInstance *)weexInstance
+{
+    self = [super initWithRef:ref type:type styles:styles attributes:attributes events:events weexInstance:weexInstance];
+    if (self) {
+        
+        _stickyArray = [NSMutableArray array];
+        _listenerArray = [NSMutableArray array];
+        _scrollEvent = NO;
+        _scrollStartEvent = NO;
+        _scrollEndEvent = NO;
+        _lastScrollEventFiredOffset = CGPointMake(0, 0);
+        _scrollDirection = attributes[@"scrollDirection"] ? [WXConvert WXScrollDirection:attributes[@"scrollDirection"]] : WXScrollDirectionVertical;
+        _showScrollBar = attributes[@"showScrollbar"] ? [WXConvert BOOL:attributes[@"showScrollbar"]] : YES;
+        
+        if (attributes[@"alwaysScrollableVertical"]) {
+            _alwaysScrollableVertical = [WXConvert NSString:attributes[@"alwaysScrollableVertical"]];
+        }
+        if (attributes[@"alwaysScrollableHorizontal"]) {
+            _alwaysScrollableHorizontal = [WXConvert NSString:attributes[@"alwaysScrollableHorizontal"]];
+        }
+        _bounces = attributes[@"bounce"]?[WXConvert BOOL:attributes[@"bounce"]]:YES;
+        _refreshType = [WXConvert NSString:attributes[@"refreshType"]]?:@"refreshForWholeVisible";
+        _pagingEnabled = attributes[@"pagingEnabled"] ? [WXConvert BOOL:attributes[@"pagingEnabled"]] : NO;
+        _loadMoreOffset = attributes[@"loadmoreoffset"] ? [WXConvert WXPixelType:attributes[@"loadmoreoffset"] scaleFactor:self.weexInstance.pixelScaleFactor] : 0;
+        _loadmoreretry = attributes[@"loadmoreretry"] ? [WXConvert NSUInteger:attributes[@"loadmoreretry"]] : 0;
+        _listenLoadMore = [events containsObject:@"loadmore"];
+        _scrollable = attributes[@"scrollable"] ? [WXConvert BOOL:attributes[@"scrollable"]] : YES;
+        _offsetAccuracy = attributes[@"offsetAccuracy"] ? [WXConvert WXPixelType:attributes[@"offsetAccuracy"] scaleFactor:self.weexInstance.pixelScaleFactor] : 0;
+        
+//#ifndef USE_FLEX
+        if(![WXComponent isUseFlex])
+        {
+            _scrollerCSSNode = new_css_node();
+            
+            // let scroller fill the rest space if it is a child component and has no fixed height & width
+            if (((_scrollDirection == WXScrollDirectionVertical &&
+                  isUndefined(self.cssNode->style.dimensions[CSS_HEIGHT])) ||
+                 (_scrollDirection == WXScrollDirectionHorizontal &&
+                  isUndefined(self.cssNode->style.dimensions[CSS_WIDTH]))) &&
+                self.cssNode->style.flex <= 0.0) {
+                self.cssNode->style.flex = 1.0;
+            }
+        }
+//#else
+        else
+        {
+            _flexScrollerCSSNode = new WeexCore::WXCoreLayoutNode();
+            // let scroller fill the rest space if it is a child component and has no fixed height & width
+            if (((_scrollDirection == WXScrollDirectionVertical &&
+                  flexIsUndefined(self.flexCssNode->getStyleHeight())) ||
+                 (_scrollDirection == WXScrollDirectionHorizontal &&
+                  flexIsUndefined(self.flexCssNode->getStyleWidth()))) &&
+                self.flexCssNode->getFlex() <= 0.0) {
+                self.flexCssNode->setFlex(1.0);
+            }
+        }
+//#endif
+        id configCenter = [WXSDKEngine handlerForProtocol:@protocol(WXConfigCenterProtocol)];
+        if ([configCenter respondsToSelector:@selector(configForKey:defaultValue:isDefault:)]) {
+            BOOL shouldNotifiAppearDescendantView = [[configCenter configForKey:@"iOS_weex_ext_config.shouldNotifiAppearDescendantView" defaultValue:@(YES) isDefault:NULL] boolValue];
+            _shouldNotifiAppearDescendantView = shouldNotifiAppearDescendantView;
+            BOOL shouldRemoveScrollerListener = [[configCenter configForKey:@"iOS_weex_ext_config.shouldRemoveScrollerListener" defaultValue:@(YES) isDefault:NULL] boolValue];
+            _shouldRemoveScrollerListener = shouldRemoveScrollerListener;
+            
+        }
+    }
+    
+    return self;
+}
+
+- (UIView *)loadView
+{
+    return [[WXScrollerComponentView alloc] init];
+}
+
+- (void)viewDidLoad
+{
+    [super viewDidLoad];
+    [self setContentSize:_contentSize];
+    WXScrollerComponentView* scrollView = (WXScrollerComponentView *)self.view;
+    scrollView.delegate = self;
+    scrollView.exclusiveTouch = YES;
+    scrollView.autoresizesSubviews = NO;
+    scrollView.clipsToBounds = YES;
+    scrollView.showsVerticalScrollIndicator = _showScrollBar;
+    scrollView.showsHorizontalScrollIndicator = _showScrollBar;
+    scrollView.scrollEnabled = _scrollable;
+    scrollView.pagingEnabled = _pagingEnabled;
+    
+    if (scrollView.bounces != _bounces) {
+        scrollView.bounces = _bounces;
+    }
+    
+    if (_alwaysScrollableHorizontal) {
+        scrollView.alwaysBounceHorizontal = [WXConvert BOOL:_alwaysScrollableHorizontal];
+    }
+    if (_alwaysScrollableVertical) {
+        scrollView.alwaysBounceVertical = [WXConvert BOOL:_alwaysScrollableVertical];
+    }
+    
+    if (@available(iOS 11.0, *)) {
+        if ([scrollView respondsToSelector:@selector(setContentInsetAdjustmentBehavior:)]) {
+            scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
+        }
+    } else {
+        // Fallback on earlier versions
+    }
+    
+    if (self.ancestorScroller) {
+        scrollView.scrollsToTop = NO;
+    } else {
+        scrollView.scrollsToTop = YES;
+    }
+}
+
+- (void)layoutDidFinish
+{
+
+    
+    if ([self isViewLoaded]) {
+        [self setContentSize:_contentSize];
+        [self adjustSticky];
+        [self handleAppear];
+    }
+    
+    [_loadingComponent resizeFrame];
+}
+
+- (void)viewWillUnload
+{
+    ((UIScrollView *)_view).delegate = nil;
+}
+
+- (void)dealloc
+{
+    ((UIScrollView *)_view).delegate = nil;
+    [self.stickyArray removeAllObjects];
+    [self.listenerArray removeAllObjects];
+//#ifndef USE_FLEX
+    if (![WXComponent isUseFlex]) {
+         free(_scrollerCSSNode);
+    }
+//#else
+    else
+    {
+        if(_flexScrollerCSSNode){
+            delete _flexScrollerCSSNode;
+            
+            //WeexCore::WXCoreLayoutNode::freeNodeTree(_flexScrollerCSSNode);
+            
+            _flexScrollerCSSNode=nullptr;
+        }
+    }
+//#endif
+}
+
+- (void)updateAttributes:(NSDictionary *)attributes
+{
+    if (attributes[@"showScrollbar"]) {
+        _showScrollBar = [WXConvert BOOL:attributes[@"showScrollbar"]];
+        ((UIScrollView *)self.view).showsHorizontalScrollIndicator = _showScrollBar;
+        ((UIScrollView *)self.view).showsVerticalScrollIndicator = _showScrollBar;
+    }
+    
+    if (attributes[@"pagingEnabled"]) {
+        _pagingEnabled = [WXConvert BOOL:attributes[@"pagingEnabled"]];
+        ((UIScrollView *)self.view).pagingEnabled = _pagingEnabled;
+    }
+    
+    if (attributes[@"loadmoreoffset"]) {
+        _loadMoreOffset = [WXConvert WXPixelType:attributes[@"loadmoreoffset"] scaleFactor:self.weexInstance.pixelScaleFactor];
+    }
+    if (attributes[@"bounce"]) {
+        _bounces = [WXConvert BOOL:attributes[@"bounce"]];
+        ((UIScrollView *)self.view).bounces = _bounces;
+    }
+    
+    if (attributes[@"loadmoreretry"]) {
+        NSUInteger loadmoreretry = [WXConvert NSUInteger:attributes[@"loadmoreretry"]];
+        if (loadmoreretry != _loadmoreretry) {
+            _previousLoadMoreContentHeight = 0;
+        }
+        self.loadmoreretry = loadmoreretry;
+    }
+    if (attributes[@"scrollable"]) {
+        _scrollable = attributes[@"scrollable"] ? [WXConvert BOOL:attributes[@"scrollable"]] : YES;
+        ((UIScrollView *)self.view).scrollEnabled = _scrollable;
+    }
+    if (attributes[@"alwaysScrollableHorizontal"]) {
+        _alwaysScrollableHorizontal = [WXConvert NSString:attributes[@"alwaysScrollableHorizontal"]];
+        ((UIScrollView*)self.view).alwaysBounceHorizontal = [WXConvert BOOL:_alwaysScrollableHorizontal];
+    }
+    
+    if (attributes[@"alwaysScrollableVertical"]) {
+        _alwaysScrollableVertical = [WXConvert NSString:attributes[@"alwaysScrollableVertical"]];
+        ((UIScrollView*)self.view).alwaysBounceVertical = [WXConvert BOOL:_alwaysScrollableVertical];
+    }
+    
+    if (attributes[@"refreshType"]) {
+        _refreshType = [WXConvert NSString:attributes[@"refreshType"]];
+    }
+    
+    if (attributes[@"offsetAccuracy"]) {
+        _offsetAccuracy = [WXConvert WXPixelType:attributes[@"offsetAccuracy"] scaleFactor:self.weexInstance.pixelScaleFactor];
+    }
+    
+    if (attributes[@"scrollDirection"]) {
+        _scrollDirection = attributes[@"scrollDirection"] ? [WXConvert WXScrollDirection:attributes[@"scrollDirection"]] : WXScrollDirectionVertical;
+    }
+}
+
+- (void)addEvent:(NSString *)eventName
+{
+    if ([eventName isEqualToString:@"loadmore"]) {
+        _listenLoadMore = YES;
+    }
+    if ([eventName isEqualToString:@"scroll"]) {
+        _scrollEvent = YES;
+    }
+    if ([eventName isEqualToString:@"scrollstart"]) {
+        _scrollStartEvent = YES;
+    }
+    if ([eventName isEqualToString:@"scrollend"]) {
+        _scrollEndEvent = YES;
+    }
+}
+
+- (void)removeEvent:(NSString *)eventName
+{
+    if ([eventName isEqualToString:@"loadmore"]) {
+        _listenLoadMore = NO;
+    }
+    if ([eventName isEqualToString:@"scroll"]) {
+        _scrollEvent = NO;
+    }
+    if ([eventName isEqualToString:@"scrollstart"]) {
+        _scrollStartEvent = NO;
+    }
+    if ([eventName isEqualToString:@"scrollend"]) {
+        _scrollEndEvent = NO;
+    }
+}
+
+#pragma mark WXScrollerProtocol
+
+- (void)addStickyComponent:(WXComponent *)sticky
+{
+    if(![self.stickyArray containsObject:sticky]) {
+        [self.stickyArray addObject:sticky];
+        [self adjustSticky];
+    }
+}
+
+- (void)removeStickyComponent:(WXComponent *)sticky
+{
+    if([self.stickyArray containsObject:sticky]) {
+        [self.stickyArray removeObject:sticky];
+        [self adjustSticky];
+    }
+}
+
+- (void)adjustSticky
+{
+    if (![self isViewLoaded]) {
+        return;
+    }
+    CGFloat scrollOffsetY = ((UIScrollView *)self.view).contentOffset.y;
+    for(WXComponent *component in self.stickyArray) {
+        if (isnan(component->_absolutePosition.x) && isnan(component->_absolutePosition.y)) {
+            component->_absolutePosition = [component.supercomponent.view convertPoint:component.view.frame.origin toView:self.view];
+        }
+        CGPoint relativePosition = component->_absolutePosition;
+        if (isnan(relativePosition.y)) {
+            continue;
+        }
+        
+        WXComponent *supercomponent = component.supercomponent;
+        if(supercomponent != self && component.view.superview != self.view) {
+            [component.view removeFromSuperview];
+            [self.view addSubview:component.view];
+        } else {
+            [self.view bringSubviewToFront:component.view];
+        }
+        
+        CGFloat relativeY = relativePosition.y;
+        BOOL needSticky = NO;
+        
+        if (scrollOffsetY >= relativeY) {
+            needSticky = YES;
+        } else {
+            // important: reset views' frame
+            component.view.frame = CGRectMake(relativePosition.x, relativePosition.y, component.calculatedFrame.size.width, component.calculatedFrame.size.height);
+        }
+        
+        if (!needSticky) {
+            continue;
+        }
+        
+        // The minimum Y sticky view can reach is its original position
+        CGFloat minY = relativeY;
+        CGPoint superRelativePosition = supercomponent == self ? CGPointZero : [supercomponent.supercomponent.view convertPoint:supercomponent.view.frame.origin toView:self.view];
+        CGFloat maxY = superRelativePosition.y + supercomponent.calculatedFrame.size.height - component.calculatedFrame.size.height;
+        
+        CGFloat stickyY = scrollOffsetY;
+        if (stickyY < minY) {
+            stickyY = minY;
+        } else if (stickyY > maxY && ![supercomponent conformsToProtocol:@protocol(WXScrollerProtocol)]) {
+            // Sticky component can not go beyond its parent's bounds when its parent is not scroller;
+            stickyY = maxY;
+        }
+        
+        UIView *stickyView = component.view;
+        CGPoint origin = stickyView.frame.origin;
+        origin.y = stickyY;
+        stickyView.frame = (CGRect){origin,stickyView.frame.size};
+    }
+}
+
+- (void)addScrollToListener:(WXComponent *)target
+{
+    BOOL has = NO;
+    NSMutableArray *listenerArray = [self.listenerArray copy];
+    for (WXScrollToTarget *targetData in listenerArray) {
+        if (targetData.target == target) {
+            has = YES;
+            break;
+        }
+    }
+    if (!has) {
+        WXScrollToTarget *scrollTarget = [[WXScrollToTarget alloc] init];
+        scrollTarget.target = target;
+        scrollTarget.hasAppear = NO;
+        [self.listenerArray addObject:scrollTarget];
+    }
+}
+
+- (void)removeScrollToListener:(WXComponent *)target
+{
+    if (_shouldRemoveScrollerListener) {
+        WXScrollToTarget *targetData = nil;
+        NSMutableArray *listenerArray = [self.listenerArray copy];
+        for (WXScrollToTarget *targetDataTemp in listenerArray) {
+            if (targetDataTemp.target == target) {
+                targetData = targetDataTemp;
+                break;
+            }
+        }
+        if(targetData) {
+            [self.listenerArray removeObject:targetData];
+        }
+    }
+}
+
+- (void)scrollToComponent:(WXComponent *)component withOffset:(CGFloat)offset animated:(BOOL)animated
+{
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+
+    CGPoint contentOffset = scrollView.contentOffset;
+    CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
+    
+    if (_scrollDirection == WXScrollDirectionHorizontal) {
+        CGFloat contentOffetX = [component.supercomponent.view convertPoint:component.view.frame.origin toView:self.view].x;
+        contentOffetX += offset * scaleFactor;
+        
+        if (scrollView.contentSize.width >= scrollView.frame.size.width && contentOffetX > scrollView.contentSize.width - scrollView.frame.size.width) {
+            contentOffset.x = scrollView.contentSize.width - scrollView.frame.size.width;
+        } else {
+            contentOffset.x = contentOffetX;
+        }
+    } else {
+        CGFloat contentOffetY = [component.supercomponent.view convertPoint:component.view.frame.origin toView:self.view].y;
+        contentOffetY += offset * scaleFactor;
+        
+        if (scrollView.contentSize.height >= scrollView.frame.size.height && contentOffetY > scrollView.contentSize.height - scrollView.frame.size.height) {
+            contentOffset.y = scrollView.contentSize.height - scrollView.frame.size.height;
+        } else {
+            contentOffset.y = contentOffetY;
+        }
+    }
+    
+    [scrollView setContentOffset:contentOffset animated:animated];
+}
+
+- (BOOL)isNeedLoadMore
+{
+    if (WXScrollDirectionVertical == _scrollDirection) {
+        if (_loadMoreOffset >= 0.0 && ((UIScrollView *)self.view).contentOffset.y >= 0) {
+            return _previousLoadMoreContentHeight != ((UIScrollView *)self.view).contentSize.height && ((UIScrollView *)self.view).contentSize.height - ((UIScrollView *)self.view).contentOffset.y -  self.view.frame.size.height <= _loadMoreOffset;
+        }
+    } else if (WXScrollDirectionHorizontal == _scrollDirection) {
+        if (_loadMoreOffset >= 0.0 && ((UIScrollView *)self.view).contentOffset.x >= 0) {
+            return _previousLoadMoreContentHeight != ((UIScrollView *)self.view).contentSize.width && ((UIScrollView *)self.view).contentSize.width - ((UIScrollView *)self.view).contentOffset.x -  self.view.frame.size.width <= _loadMoreOffset;
+        }
+    }
+    
+    return NO;
+}
+
+- (void)loadMore
+{
+    [self fireEvent:@"loadmore" params:nil];
+    
+    if (WXScrollDirectionVertical == _scrollDirection) {
+        _previousLoadMoreContentHeight = ((UIScrollView *)self.view).contentSize.height;
+    } else if (WXScrollDirectionHorizontal == _scrollDirection) {
+        _previousLoadMoreContentHeight = ((UIScrollView *)self.view).contentSize.width;
+    }
+}
+
+- (CGPoint)contentOffset
+{
+    CGPoint rtv = CGPointZero;
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+    if (scrollView) {
+        rtv = scrollView.contentOffset;
+    }
+    return rtv;
+}
+
+- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated
+{
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+    [scrollView setContentOffset:contentOffset animated:animated];
+}
+
+- (CGSize)contentSize
+{
+    return ((UIScrollView *)self.view).contentSize;
+}
+
+- (void)setContentSize:(CGSize)size
+{
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+    scrollView.contentSize = size;
+}
+
+- (UIEdgeInsets)contentInset
+{
+    UIEdgeInsets rtv = UIEdgeInsetsZero;
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+    if (scrollView) {
+        rtv = scrollView.contentInset;
+    }
+    return rtv;
+}
+
+- (void)setContentInset:(UIEdgeInsets)contentInset
+{
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+    [scrollView setContentInset:contentInset];
+}
+
+- (void)addScrollDelegate:(id<UIScrollViewDelegate>)delegate
+{
+    if (delegate) {
+        if (!_delegates) {
+            _delegates = [NSHashTable hashTableWithOptions:NSPointerFunctionsWeakMemory];
+        }
+        [_delegates addObject:delegate];
+    }
+}
+
+- (void)removeScrollDelegate:(id<UIScrollViewDelegate>)delegate
+{
+    if (delegate) {
+        [_delegates removeObject:delegate];
+    }
+}
+
+- (WXScrollDirection)scrollDirection
+{
+    return _scrollDirection;
+}
+
+- (NSString*)refreshType
+{
+    return _refreshType;
+}
+- (BOOL)requestGestureShouldStopPropagation:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
+{
+    return [self gestureShouldStopPropagation:gestureRecognizer shouldReceiveTouch:touch];
+}
+
+#pragma mark UIScrollViewDelegate
+- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
+{
+    if ([_refreshType isEqualToString:@"refreshForAppear"] && _refreshComponent) {
+        [_refreshComponent setIndicatorHidden:NO];
+    }
+    
+    if (_scrollStartEvent) {
+        CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
+        NSDictionary *contentSizeData = @{@"width":[NSNumber numberWithFloat:scrollView.contentSize.width / scaleFactor],@"height":[NSNumber numberWithFloat:scrollView.contentSize.height / scaleFactor]};
+        NSDictionary *contentOffsetData = @{@"x":[NSNumber numberWithFloat:-scrollView.contentOffset.x / scaleFactor],@"y":[NSNumber numberWithFloat:-scrollView.contentOffset.y / scaleFactor]};
+        [self fireEvent:@"scrollstart" params:@{@"contentSize":contentSizeData,@"contentOffset":contentOffsetData} domChanges:nil];
+    }
+}
+
+- (void)scrollViewDidScroll:(UIScrollView *)scrollView
+{
+    //apply block which are registered
+    WXSDKInstance *instance = self.weexInstance;
+    if ([self.ref isEqualToString:WX_SDK_ROOT_REF] &&
+        [self isKindOfClass:[WXScrollerComponent class]]) {
+        if (instance.onScroll) {
+            instance.onScroll(scrollView.contentOffset);
+        }
+    }
+    
+    if (_lastContentOffset.x > scrollView.contentOffset.x) {
+        _direction = @"right";
+    } else if (_lastContentOffset.x < scrollView.contentOffset.x) {
+        _direction = @"left";
+        if (WXScrollDirectionHorizontal == _scrollDirection) {
+            [self handleLoadMore];
+        }
+    } else if(_lastContentOffset.y > scrollView.contentOffset.y) {
+        _direction = @"down";
+    } else if(_lastContentOffset.y < scrollView.contentOffset.y) {
+        _direction = @"up";
+        if (WXScrollDirectionVertical == _scrollDirection) {
+            [self handleLoadMore];
+        }
+    }
+    
+    CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
+    [_refreshComponent pullingdown:@{
+             REFRESH_DISTANCE_Y: @(fabs((scrollView.contentOffset.y - _lastContentOffset.y)/scaleFactor)),
+             REFRESH_VIEWHEIGHT: @(_refreshComponent.view.frame.size.height/scaleFactor),
+             REFRESH_PULLINGDISTANCE: @(scrollView.contentOffset.y/scaleFactor),
+             @"type":@"pullingdown"
+    }];
+    _lastContentOffset = scrollView.contentOffset;
+    // check sticky
+    [self adjustSticky];
+    [self handleAppear];
+    
+    if (self.onScroll) {
+        self.onScroll(scrollView);
+    }
+    if (_scrollEvent) {
+        NSDictionary *contentSizeData = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithFloat:scrollView.contentSize.width / scaleFactor],@"width",[NSNumber numberWithFloat:scrollView.contentSize.height / scaleFactor],@"height", nil];
+        //contentOffset values are replaced by (-contentOffset.x,-contentOffset.y) ,in order to be consistent with Android client.
+        NSDictionary *contentOffsetData = [[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithFloat:-scrollView.contentOffset.x / scaleFactor],@"x",[NSNumber numberWithFloat:-scrollView.contentOffset.y / scaleFactor],@"y", nil];
+        CGFloat distance = 0;
+        if (_scrollDirection == WXScrollDirectionHorizontal) {
+            distance = scrollView.contentOffset.x - _lastScrollEventFiredOffset.x;
+        } else {
+            distance = scrollView.contentOffset.y - _lastScrollEventFiredOffset.y;
+        }
+        if (fabs(distance) >= _offsetAccuracy) {
+            [self fireEvent:@"scroll" params:@{@"contentSize":contentSizeData,@"contentOffset":contentOffsetData} domChanges:nil];
+            _lastScrollEventFiredOffset = scrollView.contentOffset;
+        }
+    }
+    NSHashTable *delegates = [_delegates copy];
+    for (id<UIScrollViewDelegate> delegate in delegates) {
+        if ([delegate respondsToSelector:@selector(scrollViewDidScroll:)]) {
+            [delegate scrollViewDidScroll:scrollView];
+        }
+    }
+}
+
+- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView
+{
+    UIEdgeInsets inset = [scrollView contentInset];
+    
+//  currently only set contentInset when loading
+//    if ([_refreshComponent displayState]) {
+//        inset.top = _refreshComponent.view.frame.size.height;
+//    }
+//    else {
+//        inset.top = 0;
+//    }
+    
+    if ([_loadingComponent displayState]) {
+        inset.bottom = _loadingComponent.view.frame.size.height;
+    } else {
+        inset.bottom = 0;
+    }
+    [scrollView setContentInset:inset];
+}
+
+- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
+{
+    if (_scrollEndEvent) {
+        if (!_isScrolling) {
+            CGFloat scaleFactor = self.weexInstance.pixelScaleFactor;
+            NSDictionary *contentSizeData = @{@"width":[NSNumber numberWithFloat:scrollView.contentSize.width / scaleFactor],@"height":[NSNumber numberWithFloat:scrollView.contentSize.height / scaleFactor]};
+            NSDictionary *contentOffsetData = @{@"x":[NSNumber numberWithFloat:-scrollView.contentOffset.x / scaleFactor],@"y":[NSNumber numberWithFloat:-scrollView.contentOffset.y / scaleFactor]};
+            [self fireEvent:@"scrollend" params:@{@"contentSize":contentSizeData,@"contentOffset":contentOffsetData} domChanges:nil];
+        }
+    }
+}
+
+- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset
+{
+    if ([_refreshType isEqualToString:@"refreshForAppear"]) {
+        if(targetContentOffset == nil)
+            return;
+        CGPoint offset = *targetContentOffset;
+        if(velocity.y <= 0) {
+            // drop down
+            if( offset.y <= _refreshComponent.calculatedFrame.size.height ) {
+                [self loadMoreIfNeed];
+            }
+        } else if (velocity.y > 0) {
+            // drop up
+        }
+    }
+}
+
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
+{
+    [_loadingComponent.view setHidden:NO];
+    [_refreshComponent.view setHidden:NO];
+    
+    //refresh
+    if ([_refreshType isEqualToString:@"refreshForWholeVisible"]) {
+        if (_refreshComponent && scrollView.contentOffset.y < 0 && scrollView.contentOffset.y + _refreshComponent.calculatedFrame.size.height < _refreshComponent.calculatedFrame.origin.y) {
+            [_refreshComponent refresh];
+        }
+    }
+    
+    //loading
+    if (_loadingComponent && scrollView.contentOffset.y > 0 &&
+        scrollView.contentOffset.y + scrollView.frame.size.height > _loadingComponent.view.frame.origin.y + _loadingComponent.calculatedFrame.size.height) {
+        [_loadingComponent loading];
+    }
+    if (!decelerate) {
+        _isScrolling = NO;
+        [self performSelector:@selector(scrollViewDidEndDecelerating:) withObject:nil afterDelay:0.1];
+    }
+}
+
+- (void)loadMoreIfNeed
+{
+    WXScrollerComponentView* scrollView = (WXScrollerComponentView *)self.view;
+    if (scrollView.isDragging || scrollView.isTracking || scrollView.isDecelerating) {
+        [self performSelector:@selector(loadMoreIfNeed) withObject:nil afterDelay:0.1];
+        return;
+    }
+    [_refreshComponent refresh];
+}
+
+- (void)handleAppear
+{
+    if (![self isViewLoaded]) {
+        return;
+    }
+    UIScrollView *scrollView = (UIScrollView *)self.view;
+    CGFloat vx = scrollView.contentInset.left + scrollView.contentOffset.x;
+    CGFloat vy = scrollView.contentInset.top + scrollView.contentOffset.y;
+    CGFloat vw = scrollView.frame.size.width - scrollView.contentInset.left - scrollView.contentInset.right;
+    CGFloat vh = scrollView.frame.size.height - scrollView.contentInset.top - scrollView.contentInset.bottom;
+    CGRect scrollRect = CGRectMake(vx, vy, vw, vh);;
+    
+    // notify action for appear
+    NSArray *listenerArrayCopy = [self.listenerArray copy];
+    for(WXScrollToTarget *target in listenerArrayCopy){
+        if (_shouldNotifiAppearDescendantView) {
+            // if target component is descendant of scrollerview, it should notify the appear event handler, or here will skip this appear calculation.
+            if ([target.target isViewLoaded] && [target.target.view isDescendantOfView:self.view]) {
+                [self scrollToTarget:target scrollRect:scrollRect];
+            }
+        } else {
+            [self scrollToTarget:target scrollRect:scrollRect];
+        }
+    }
+}
+
+- (CGPoint)absolutePositionForComponent:(WXComponent *)component
+{
+    return [component->_view.superview convertPoint:component->_view.frame.origin toView:_view];
+}
+
+#pragma mark  Private Methods
+
+- (void)scrollToTarget:(WXScrollToTarget *)target scrollRect:(CGRect)rect
+{
+    WXComponent *component = target.target;
+    if (![component isViewLoaded]) { 
+        return;
+    }
+    
+    CGFloat ctop;
+    if (component && component->_view && component->_view.superview) {
+        ctop = [self absolutePositionForComponent:component].y;
+    } else {
+        ctop = 0.0;
+    }
+    CGFloat cbottom = ctop + CGRectGetHeight(component.calculatedFrame);
+    CGFloat cleft;
+    if (component && component->_view && component->_view.superview) {
+        cleft = [self absolutePositionForComponent:component].x;
+    } else {
+        cleft = 0.0;
+    }
+    CGFloat cright = cleft + CGRectGetWidth(component.calculatedFrame);
+    
+    CGFloat vtop = CGRectGetMinY(rect), vbottom = CGRectGetMaxY(rect), vleft = CGRectGetMinX(rect), vright = CGRectGetMaxX(rect);
+    if(cbottom > vtop && ctop <= vbottom && cleft <= vright && cright > vleft){
+        if(!target.hasAppear && component){
+            target.hasAppear = YES;
+            if (component->_appearEvent) {
+//                NSLog(@"appear:%@, %.2f", component, ctop);
+                [component fireEvent:@"appear" params:_direction ? @{@"direction":_direction} : nil];
+            }
+        }
+    } else {
+        if(target.hasAppear && component){
+            target.hasAppear = NO;
+            if(component->_disappearEvent){
+//                NSLog(@"disappear:%@", component);
+                [component fireEvent:@"disappear" params:_direction ? @{@"direction":_direction} : nil];
+            }
+        }
+    }
+}
+
+- (void)handleLoadMore
+{
+    if (_listenLoadMore && [self isNeedLoadMore]) {
+        [self loadMore];
+    }
+}
+
+#pragma mark Layout
+
+- (NSUInteger)_childrenCountForLayout;
+{
+    return 0;
+}
+
+- (NSUInteger)childrenCountForScrollerLayout
+{
+    return [super _childrenCountForLayout];
+}
+
+- (void)_calculateFrameWithSuperAbsolutePosition:(CGPoint)superAbsolutePosition
+                          gatherDirtyComponents:(NSMutableSet<WXComponent *> *)dirtyComponents
+{
+    /**
+     *  Pretty hacky way
+     *  layout from root to scroller to get scroller's frame,
+     *  layout from children to scroller to get scroller's contentSize
+     */
+    if ([self needsLayout]) {
+//#ifndef USE_FLEX
+        if (![WXComponent isUseFlex]) {
+            memcpy(_scrollerCSSNode, self.cssNode, sizeof(css_node_t));
+            _scrollerCSSNode->children_count = (int)[self childrenCountForScrollerLayout];
+            
+            _scrollerCSSNode->style.position[CSS_LEFT] = 0;
+            _scrollerCSSNode->style.position[CSS_TOP] = 0;
+            
+            if (_scrollDirection == WXScrollDirectionVertical) {
+                _scrollerCSSNode->style.flex_direction = CSS_FLEX_DIRECTION_COLUMN;
+                _scrollerCSSNode->style.dimensions[CSS_WIDTH] = _cssNode->layout.dimensions[CSS_WIDTH];
+                _scrollerCSSNode->style.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
+            } else {
+                _scrollerCSSNode->style.flex_direction = CSS_FLEX_DIRECTION_ROW;
+                _scrollerCSSNode->style.dimensions[CSS_HEIGHT] = _cssNode->layout.dimensions[CSS_HEIGHT];
+                _scrollerCSSNode->style.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
+            }
+            
+            _scrollerCSSNode->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
+            _scrollerCSSNode->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
+            
+            layoutNode(_scrollerCSSNode, CSS_UNDEFINED, CSS_UNDEFINED, CSS_DIRECTION_INHERIT);
+            if ([WXLog logLevel] >= WXLogLevelDebug) {
+                print_css_node(_scrollerCSSNode, (css_print_options_t)(CSS_PRINT_LAYOUT | CSS_PRINT_STYLE | CSS_PRINT_CHILDREN));
+            }
+            CGSize size = {
+                WXRoundPixelValue(_scrollerCSSNode->layout.dimensions[CSS_WIDTH]),
+                WXRoundPixelValue(_scrollerCSSNode->layout.dimensions[CSS_HEIGHT])
+            };
+            
+            if (!CGSizeEqualToSize(size, _contentSize)) {
+                _contentSize = size;
+                [dirtyComponents addObject:self];
+            }
+            
+            _scrollerCSSNode->layout.dimensions[CSS_WIDTH] = CSS_UNDEFINED;
+            _scrollerCSSNode->layout.dimensions[CSS_HEIGHT] = CSS_UNDEFINED;
+        }
+      
+//#else
+        else
+        {
+            _flexScrollerCSSNode->copyStyle(_flexCssNode);
+            _flexScrollerCSSNode->copyMeasureFunc(_flexCssNode);
+            
+            if (_scrollDirection == WXScrollDirectionVertical) {
+                _flexScrollerCSSNode->setFlexDirection(WeexCore::kFlexDirectionColumn,NO);
+                _flexScrollerCSSNode->setStyleWidth(self.flexCssNode->getLayoutWidth(),NO);
+                _flexScrollerCSSNode->setStyleHeight(FlexUndefined);
+            } else {
+                _flexScrollerCSSNode->setFlexDirection(WeexCore::kFlexDirectionRow,NO);
+                _flexScrollerCSSNode->setStyleHeight(self.flexCssNode->getLayoutHeight());
+                _flexScrollerCSSNode->setStyleWidth(FlexUndefined,NO);
+            }
+            _flexScrollerCSSNode->markDirty();
+            std::pair<float, float> renderPageSize;
+            renderPageSize.first = self.weexInstance.frame.size.width;
+            renderPageSize.second = self.weexInstance.frame.size.height;
+            _flexScrollerCSSNode->calculateLayout(renderPageSize);
+            CGSize size = {
+                WXRoundPixelValue(_flexScrollerCSSNode->getLayoutWidth()),
+                WXRoundPixelValue(_flexScrollerCSSNode->getLayoutHeight())
+            };
+            
+            if (!CGSizeEqualToSize(size, _contentSize)) {
+                // content size
+                _contentSize = size;
+                [dirtyComponents addObject:self];
+            }
+        }
+//#endif
+    }
+    
+    [super _calculateFrameWithSuperAbsolutePosition:superAbsolutePosition gatherDirtyComponents:dirtyComponents];
+}
+
+@end