v1.17.21 [work-arounds]compatible for iPhoneX for issue #312

work-arounds 方案，解决 iOS12.1上，iPhoneX 位置跳动的问题。

CYLTabBarController.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "CYLTabBarController"
-  s.version      = "1.17.20"
+  s.version      = "1.17.21"
   s.summary      = "Highly customizable tabBar and tabBarController for iOS"
   s.description  = "CYLTabBarController is iPad and iPhone compatible. Supports landscape and portrait orientations and can be used inside UINavigationController."
   s.homepage     = "https://github.com/ChenYilong/CYLTabBarController"

CYLTabBarController/CYLTabBar.m

@@ -12,6 +12,8 @@
 #import "CYLConstants.h"
 #import <objc/runtime.h>
 
+static void *const CYLTabBarContext = (void*)&CYLTabBarContext;
+
 /**
  *  用 block 重写某个 class 的指定方法
  *  @param targetClass 要重写的 class
@@ -30,9 +32,6 @@
     return YES;
 }
 
-
-static void *const CYLTabBarContext = (void*)&CYLTabBarContext;
-
 @interface CYLTabBar ()
 
 /** 发布按钮 */
@@ -49,23 +48,30 @@ @implementation CYLTabBar
 #pragma mark -
 #pragma mark - LifeCycle Method
 
+static CGFloat const CYLIPhoneXTabbarButtonHeight = 48;
+static CGFloat const CYLIPhoneXTabbarButtonSafeAreaHeight = 35;
+
 + (void)load {
-    /* 这个问题是 iOS 12.1 Beta 2 的问题，只要 UITabBar 是磨砂的，并且 push viewController 时 hidesBottomBarWhenPushed = YES 则手势返回的时候就会触发。
-     
-     出现这个现象的直接原因是 tabBar 内的按钮 UITabBarButton 被设置了错误的 frame，frame.size 变为 (0, 0) 导致的。如果12.1正式版Apple修复了这个bug可以移除调这段代码(来源于QMUIKit的处理方式)*/
+    /* 这个问题是 iOS 12.1 的问题，只要 UITabBar 是磨砂的，并且 push viewController 时 hidesBottomBarWhenPushed = YES 则手势返回的时候就会触发。(来源于QMUIKit的处理方式)*/
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
         if (@available(iOS 12.1, *)) {
             OverrideImplementation(NSClassFromString(@"UITabBarButton"), @selector(setFrame:), ^id(__unsafe_unretained Class originClass, SEL originCMD, IMP originIMP) {
                 return ^(UIView *selfObject, CGRect firstArgv) {
-
                     if ([selfObject isKindOfClass:originClass]) {
+
                         // 如果发现即将要设置一个 size 为空的 frame，则屏蔽掉本次设置
                         if (!CGRectIsEmpty(selfObject.frame) && CGRectIsEmpty(firstArgv)) {
                             return;
                         }
+
+                        // 兼容 iOS 12 的 iPhoneX
+                        CGFloat tabBarHeight = firstArgv.size.height;
+                        CGFloat realTabBarHeight = CYLTabBarHeight ? (CYLTabBarHeight - CYLIPhoneXTabbarButtonSafeAreaHeight): CYLIPhoneXTabbarButtonHeight;
+                        if (CYL_IS_IPHONE_X && (tabBarHeight != realTabBarHeight)) {
+                            firstArgv.size.height = realTabBarHeight;
+                        }
                     }
-
                     // call super
                     void (*originSelectorIMP)(id, SEL, CGRect);
                     originSelectorIMP = (void (*)(id, SEL, CGRect))originIMP;

CYLTabBarController/CYLTabBarController.h

@@ -24,6 +24,7 @@ FOUNDATION_EXTERN NSUInteger CYLTabbarItemsCount;
 FOUNDATION_EXTERN NSUInteger CYLPlusButtonIndex;
 FOUNDATION_EXTERN CGFloat CYLPlusButtonWidth;
 FOUNDATION_EXTERN CGFloat CYLTabBarItemWidth;
+FOUNDATION_EXTERN CGFloat CYLTabBarHeight;
 
 @protocol CYLTabBarControllerDelegate <NSObject>
 @optional

CYLTabBarController/CYLTabBarController.m

@@ -20,6 +20,8 @@
 NSUInteger CYLTabbarItemsCount = 0;
 NSUInteger CYLPlusButtonIndex = 0;
 CGFloat CYLTabBarItemWidth = 0.0f;
+CGFloat CYLTabBarHeight = 0.0f;
+
 NSString *const CYLTabBarItemWidthDidChangeNotification = @"CYLTabBarItemWidthDidChangeNotification";
 static void * const CYLTabImageViewDefaultOffsetContext = (void*)&CYLTabImageViewDefaultOffsetContext;
 
@@ -86,6 +88,11 @@ - (void)viewWillLayoutSubviews {
     });
 }
 
+- (void)setTabBarHeight:(CGFloat)tabBarHeight {
+    _tabBarHeight = tabBarHeight;
+    CYLTabBarHeight = tabBarHeight;
+}
+
 - (UIInterfaceOrientationMask)supportedInterfaceOrientations {
     UIViewController *controller = self.selectedViewController;
     if ([controller isKindOfClass:[UINavigationController class]]) {

Example/MainTabBarController.m

@@ -170,7 +170,9 @@ - (void)customizeTabBarAppearance:(CYLTabBarController *)tabBarController {
     // 设置背景图片
     UITabBar *tabBarAppearance = [UITabBar appearance];
 
-    //FIXED: #196
+    //FIXED:  https://github.com/ChenYilong/CYLTabBarController/issues/312
+    [UITabBar appearance].translucent = NO;
+    //FIXED: https://github.com/ChenYilong/CYLTabBarController/issues/196
     NSString *tabBarBackgroundImageName = @"tabbarBg";
     UIImage *tabBarBackgroundImage = [UIImage imageNamed:tabBarBackgroundImageName];
     UIImage *scanedTabBarBackgroundImage = [[self class] scaleImage:tabBarBackgroundImage];