Adjusted to be compatible with API 12.2

Author: matthew-carroll

shell/platform/darwin/ios/framework/Source/FlutterViewController.mm

@@ -32,6 +32,18 @@ @interface FlutterViewController () <FlutterBinaryMessenger>
 @property(nonatomic, readwrite, getter=isDisplayingFlutterUI) BOOL displayingFlutterUI;
 @end
 
+#if __IPHONE_OS_VERSION_MAX_ALLOWED < 130000
+typedef enum UIAccessibilityContrast : NSInteger {
+  UIAccessibilityContrastUnspecified = 0,
+  UIAccessibilityContrastNormal = 1,
+  UIAccessibilityContrastHigh = 2
+} UIAccessibilityContrast;
+
+@interface UITraitCollection(AccessibilityContrastApi)
+- (UIAccessibilityContrast)accessibilityContrast;
+@end
+#endif
+
 @implementation FlutterViewController {
   std::unique_ptr<fml::WeakPtrFactory<FlutterViewController>> _weakFactory;
   fml::scoped_nsobject<FlutterEngine> _engine;
@@ -987,7 +999,6 @@ - (NSString*)brightnessMode {
 }
 
 - (NSString*)contrastMode {
-#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
   if (@available(iOS 13, *)) {
     UIAccessibilityContrast contrast = self.traitCollection.accessibilityContrast;
 
@@ -999,9 +1010,6 @@ - (NSString*)contrastMode {
   } else {
     return @"normal";
   }
-#else
-  return @"normal";
-#endif
 }
 
 #pragma mark - Status Bar touch event handling

shell/platform/darwin/ios/framework/Source/FlutterViewControllerTest.m

@@ -15,6 +15,18 @@
 @interface FlutterViewControllerTest : XCTestCase
 @end
 
+#if __IPHONE_OS_VERSION_MAX_ALLOWED < 130000
+typedef enum UIAccessibilityContrast : NSInteger {
+  UIAccessibilityContrastUnspecified = 0,
+  UIAccessibilityContrastNormal = 1,
+  UIAccessibilityContrastHigh = 2
+} UIAccessibilityContrast;
+
+@interface UITraitCollection(AccessibilityContrastApi)
+- (UIAccessibilityContrast)accessibilityContrast;
+@end
+#endif
+
 @implementation FlutterViewControllerTest
 
 - (void)testBinaryMessenger {
@@ -80,6 +92,10 @@ - (void)testItReportsPlatformBrightnessWhenViewWillAppear {
 }
 
 - (void)testItReportsDarkPlatformBrightnessWhenTraitCollectionRequestsIt {
+  if (!@available(iOS 13, *)) {
+    return;
+  }
+  
   // Setup test.
   id engine = OCMClassMock([FlutterEngine class]);
 
@@ -121,7 +137,6 @@ - (UITraitCollection*)setupFakeUserInterfaceStyle:(UIUserInterfaceStyle)style {
 
 #pragma mark - Platform Contrast
 
-#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
 - (void)testItReportsNormalPlatformContrastByDefault {
   if (!@available(iOS 13, *)) {
     return;
@@ -221,6 +236,5 @@ - (UITraitCollection*)setupFakeTraitCollectionWithContrast:(UIAccessibilityContr
   OCMStub([mockTraitCollection accessibilityContrast]).andReturn(UIAccessibilityContrastHigh);
   return mockTraitCollection;
 }
-#endif
 
 @end