[ios] fix "safe-area-insets" support for css

ios/sdk/WeexSDK/Sources/Bridge/WXCoreBridge.mm

@@ -1550,6 +1550,23 @@ + (void)install
         CGFloat h = MAX(screenSize.width, screenSize.height);
         env->SetDeviceWidth(std::to_string(w));
         env->SetDeviceHeight(std::to_string(h));
+
+        __block UIEdgeInsets safeAreaInsets = UIEdgeInsetsZero;
+    #if __IPHONE_11_0
+        if (@available(iOS 11.0, *)) {
+            WXPerformBlockSyncOnMainThread(^{
+                safeAreaInsets = [UIApplication sharedApplication].windows[0].safeAreaInsets;
+            });
+        }
+    #endif
+        env->SetSafeAreaInsets(WXSafeAreaInsets{
+            .top = safeAreaInsets.top,
+            .bottom = safeAreaInsets.bottom,
+            .left = safeAreaInsets.left,
+            .right = safeAreaInsets.right
+        });
+
+
         env->AddOption("screen_width_pixels", std::to_string(w));
         env->AddOption("screen_height_pixels", std::to_string(h));
 

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

@@ -207,6 +207,16 @@ + (NSDictionary *)getEnvironment
     CGFloat deviceHeight = [self portraitScreenSize].height;
     CGFloat scale = [[UIScreen mainScreen] scale];
 
+    __block UIEdgeInsets safeAreaInsets = UIEdgeInsetsZero;
+
+#if __IPHONE_11_0
+    if (@available(iOS 11.0, *)) {
+        WXPerformBlockSyncOnMainThread(^{
+            safeAreaInsets = [UIApplication sharedApplication].windows[0].safeAreaInsets;
+        });
+    }
+#endif
+
     NSMutableDictionary *data = [NSMutableDictionary dictionaryWithDictionary:@{
                                     @"platform":platform,
                                     @"osName":platform, //osName is eaqual to platorm name in native
@@ -219,7 +229,8 @@ + (NSDictionary *)getEnvironment
                                     @"deviceHeight":@(deviceHeight * scale),
                                     @"scale":@(scale),
                                     @"layoutDirection": [self getEnvLayoutDirection] == WXLayoutDirectionRTL ? @"rtl" : @"ltr",
-                                    @"scheme": currentScheme
+                                    @"scheme": currentScheme,
+                                    @"safeArea": @{@"top":@(safeAreaInsets.top), @"bottom":@(safeAreaInsets.bottom), @"left":@(safeAreaInsets.left), @"right":@(safeAreaInsets.right)}
                                 }];
 
     if ([[[UIDevice currentDevice] systemVersion] integerValue] >= 11) {

weex_core/Source/core/common/view_utils.h

@@ -35,6 +35,9 @@ namespace WeexCore {
   constexpr char NONE[] = "none";
 
   constexpr char STATUS_BAR_HEIGHT[] = "status_bar_height";
+  constexpr char SAFE_AREA_PREFIX[] = "env(safe-area-inset-";
+  constexpr char SAFE_AREA_SURFIX[] = ")";
+
 
   template<typename T>
   inline std::string to_string(const T &n) {
@@ -108,6 +111,11 @@ namespace WeexCore {
            src.compare(src.size() - suffix.size(), suffix.size(), suffix) == 0;
   }
 
+  inline bool startWidth(const std::string &src, const std::string &suffix) {
+    return src.size() > suffix.size() &&
+           src.compare(0, suffix.size(), suffix) == 0;
+  }
+
   inline float transferWx(const std::string &stringWithWXPostfix, const float &viewport,
                           const float &device_width) {
     std::string temp = stringWithWXPostfix;
@@ -119,6 +127,25 @@ namespace WeexCore {
     return density * f * viewport / device_width;
   }
 
+  inline float transferSafeArea(const std::string &stringWithSafeArea, const float &viewport,
+                        const float &device_width) {
+      std::string flag = stringWithSafeArea.substr(strlen(SAFE_AREA_PREFIX), stringWithSafeArea.size() - strlen(SAFE_AREA_PREFIX) - strlen(SAFE_AREA_SURFIX));
+      float f = 0;
+
+      if (flag.compare("top") == 0) {
+          f = WXCoreEnvironment::getInstance()->SafeAreaInsets().top;
+      } else if (flag.compare("bottom") == 0) {
+          f = WXCoreEnvironment::getInstance()->SafeAreaInsets().bottom;
+      } else if (flag.compare("left") == 0) {
+          f = WXCoreEnvironment::getInstance()->SafeAreaInsets().left;
+      } else if (flag.compare("right") == 0) {
+          f = WXCoreEnvironment::getInstance()->SafeAreaInsets().right;
+      }
+
+      float density = getFloat(WXCoreEnvironment::getInstance()->GetOption(SCALE).c_str());
+      return density * f * viewport / device_width;
+}
+
   inline static float getFloatByViewport(std::string src, const float &viewport,
           const float &device_width, const bool &round_off_deviation) {
     float ret = NAN;
@@ -133,7 +160,12 @@ namespace WeexCore {
       ret = getFloat(transferWx(src, viewport, device_width), viewport,  device_width, round_off_deviation);
     } else if (endWidth(src, PX)) {
       ret = getFloat(src.substr(0, src.size() - strlen(PX)), viewport, device_width, round_off_deviation);
-    } else {
+    }
+    else if (startWidth(src, SAFE_AREA_PREFIX) && endWidth(src, SAFE_AREA_SURFIX)) {
+        ret = getFloat(transferSafeArea(src, viewport, device_width), viewport,  device_width, round_off_deviation);
+    }
+
+    else {
       ret = getFloat(src, viewport, device_width, round_off_deviation);
     }
     return ret;

weex_core/Source/core/config/core_environment.cpp

@@ -62,6 +62,11 @@ namespace WeexCore {
     return true;
   }
 
+  bool WXCoreEnvironment::SetSafeAreaInsets(WXSafeAreaInsets insets) {
+      mSafeAreaInsets = insets;
+      return true;
+  }
+
   const float WXCoreEnvironment::DeviceWidth() {
     return mDeviceWidth;
   }
@@ -70,6 +75,10 @@ namespace WeexCore {
     return mDeviceHeight;
   }
 
+  const WXSafeAreaInsets WXCoreEnvironment::SafeAreaInsets() {
+    return mSafeAreaInsets;
+  }
+
   const std::string WXCoreEnvironment::GetOption(const std::string &key) {
     std::map<std::string, std::string>::iterator iter = mOptions.find(key);
     if (iter != mOptions.end()) {

weex_core/Source/core/config/core_environment.h

@@ -24,6 +24,13 @@
 
 namespace WeexCore {
 
+struct WXSafeAreaInsets {
+    double top;
+    double bottom;
+    double left;
+    double right;
+};
+
   class WX_EXPORT WXCoreEnvironment {
 
   private:
@@ -51,6 +58,8 @@ namespace WeexCore {
     float mDeviceWidth;
 
     float mDeviceHeight;
+
+    WXSafeAreaInsets mSafeAreaInsets;
 
     std::map<std::string, std::string> mOptions;
 
@@ -73,6 +82,8 @@ namespace WeexCore {
     bool SetDeviceWidth(const std::string &width);
 
     bool SetDeviceHeight(const std::string &height);
+
+    bool SetSafeAreaInsets(WXSafeAreaInsets insets);
 
     inline void set_device_height(float height) {
         mDeviceHeight = height;
@@ -89,6 +100,8 @@ namespace WeexCore {
     const float DeviceWidth();
 
     const float DeviceHeight();
+
+    const WXSafeAreaInsets SafeAreaInsets();
 
     const std::string GetOption(const std::string &key);