[iOS] Set overflow to hidden by default on iOS to conform to Android. (…

…#2521)

ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m

@@ -517,6 +517,9 @@ - (BOOL)_handleConfigCenter
     if ([configCenter respondsToSelector:@selector(configForKey:defaultValue:isDefault:)]) {		
         BOOL enableRTLLayoutDirection = [[configCenter configForKey:@"iOS_weex_ext_config.enableRTLLayoutDirection" defaultValue:@(YES) isDefault:NULL] boolValue];
         [WXUtility setEnableRTLLayoutDirection:enableRTLLayoutDirection];
+
+        BOOL overflowHiddenByDefault = [[configCenter configForKey:@"iOS_weex_ext_config.overflowHiddenByDefault" defaultValue:@(YES) isDefault:NULL] boolValue];
+        [WXUtility setOverflowHiddenByDefault:overflowHiddenByDefault];
     }
     return NO;
 }

ios/sdk/WeexSDK/Sources/Utility/WXUtility.h

@@ -494,9 +494,11 @@ BOOL WXFloatGreaterThanWithPrecision(CGFloat a,CGFloat b,double precision);
 + (NSData *_Nonnull)base64DictToData:(NSDictionary *_Nullable)base64Dict;
 
 + (void)setEnableRTLLayoutDirection:(BOOL)value;
-
 + (BOOL)enableRTLLayoutDirection;
 
++ (void)setOverflowHiddenByDefault:(BOOL)value;
++ (BOOL)overflowHiddenByDefault;
+
 + (long) getUnixFixTimeMillis;
 
 + (NSArray<NSString *> *_Nullable)extractPropertyNamesOfJSValueObject:(JSValue *_Nullable)jsvalue;

ios/sdk/WeexSDK/Sources/Utility/WXUtility.m

@@ -43,6 +43,7 @@
 #define KEY_USERNAME_PASSWORD  @"com.taobao.Weex.weex123456"
 
 static BOOL enableRTLLayoutDirection = YES;
+static BOOL overflowHiddenByDefault = YES;
 
 void WXPerformBlockOnMainThread(void (^ _Nonnull block)(void))
 {
@@ -770,6 +771,18 @@ + (BOOL)enableRTLLayoutDirection
     return enableRTLLayoutDirection;
 }
 
+# pragma mark - Overflow
+
++ (void)setOverflowHiddenByDefault:(BOOL)value
+{
+    overflowHiddenByDefault = value;
+}
+
++ (BOOL)overflowHiddenByDefault
+{
+    return overflowHiddenByDefault;
+}
+
 #pragma mark - get deviceID
 + (NSString *)getDeviceID {
     NSMutableDictionary *usernamepasswordKVPairs = (NSMutableDictionary *)[self load:KEY_USERNAME_PASSWORD];

ios/sdk/WeexSDK/Sources/View/WXComponent+ViewManagement.mm

@@ -177,7 +177,15 @@ - (void)_initViewPropertyWithStyles:(NSDictionary *)styles
     _backgroundColor = styles[@"backgroundColor"] ? [WXConvert UIColor:styles[@"backgroundColor"]] : [UIColor clearColor];
     _backgroundImage = styles[@"backgroundImage"] ? [WXConvert NSString:styles[@"backgroundImage"]]: nil;
     _opacity = styles[@"opacity"] ? [WXConvert CGFloat:styles[@"opacity"]] : 1.0;
-    _clipToBounds = styles[@"overflow"] ? [WXConvert WXClipType:styles[@"overflow"]] : NO;
+    if ([WXUtility overflowHiddenByDefault]) {
+        /* If we enable overflow:hidden by default, we cannot use original "overflow" style value.
+         Unless js explicitly define "ios-overflow: visible", we disable clipToBounds.
+         */
+        _clipToBounds = styles[@"iosOverflow"] ? [WXConvert WXClipType:styles[@"iosOverflow"]] : YES;
+    }
+    else {
+        _clipToBounds = styles[@"overflow"] ? [WXConvert WXClipType:styles[@"overflow"]] : NO;
+    }
     _visibility = styles[@"visibility"] ? [WXConvert WXVisibility:styles[@"visibility"]] : WXVisibilityShow;
     _positionType = styles[@"position"] ? [WXConvert WXPositionType:styles[@"position"]] : WXPositionTypeRelative;
     _transform = styles[@"transform"] || styles[@"transformOrigin"] ?
@@ -227,9 +235,17 @@ - (void)_updateViewStyles:(NSDictionary *)styles
         _layer.opacity = _opacity;
     }
 
-    if (styles[@"overflow"]) {
-        _clipToBounds = [WXConvert WXClipType:styles[@"overflow"]];
-        _view.clipsToBounds = _clipToBounds;
+    if ([WXUtility overflowHiddenByDefault]) {
+        if (styles[@"iosOverflow"]) {
+            _clipToBounds = [WXConvert WXClipType:styles[@"iosOverflow"]];
+            _view.clipsToBounds = _clipToBounds;
+        }
+    }
+    else {
+        if (styles[@"overflow"]) {
+            _clipToBounds = [WXConvert WXClipType:styles[@"overflow"]];
+            _view.clipsToBounds = _clipToBounds;
+        }
     }
 
     if (styles[@"position"]) {

ios/sdk/WeexSDKTests/WXComponentTests.m

@@ -71,7 +71,6 @@ - (void)testDefaultProperties
      *  View
      */
     XCTAssertEqual(component->_backgroundColor, [UIColor clearColor]);
-    XCTAssertEqual(component->_clipToBounds, NO);
     XCTAssertNil(component->_view);
     XCTAssertEqual(component->_opacity, 1.0);
     XCTAssertEqual(component->_visibility, WXVisibilityShow);