diff --git a/DragGestureRecognizer.xcodeproj/project.pbxproj b/DragGestureRecognizer.xcodeproj/project.pbxproj
index 9ecd6ae..7c0829e 100644
--- a/DragGestureRecognizer.xcodeproj/project.pbxproj
+++ b/DragGestureRecognizer.xcodeproj/project.pbxproj
@@ -191,20 +191,23 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0800;
-				LastUpgradeCheck = 0800;
+				LastUpgradeCheck = 1010;
 				ORGANIZATIONNAME = "Wojciech Nagrodzki";
 				TargetAttributes = {
 					2EA02D081D78A64800FEB930 = {
 						CreatedOnToolsVersion = 8.0;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
 					};
 					2EA02D1C1D78A64800FEB930 = {
 						CreatedOnToolsVersion = 8.0;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
 						TestTargetID = 2EA02D081D78A64800FEB930;
 					};
 					2EA02D271D78A64800FEB930 = {
 						CreatedOnToolsVersion = 8.0;
+						LastSwiftMigration = 1010;
 						ProvisioningStyle = Automatic;
 						TestTargetID = 2EA02D081D78A64800FEB930;
 					};
@@ -328,15 +331,24 @@
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
@@ -378,15 +390,24 @@
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_DEPRECATED_OBJC_IMPLEMENTATIONS = YES;
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_DOCUMENTATION_COMMENTS = YES;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_IMPLICIT_RETAIN_SELF = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_SUSPICIOUS_MOVES = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
@@ -420,7 +441,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.DragGestureRecognizer;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Debug;
 		};
@@ -432,7 +453,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.DragGestureRecognizer;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.2;
 			};
 			name = Release;
 		};
@@ -445,7 +466,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.DragGestureRecognizerTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.2;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/DragGestureRecognizer.app/DragGestureRecognizer";
 			};
 			name = Debug;
@@ -459,7 +481,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.DragGestureRecognizerTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.2;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/DragGestureRecognizer.app/DragGestureRecognizer";
 			};
 			name = Release;
@@ -472,7 +495,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.DragGestureRecognizerUITests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.2;
 				TEST_TARGET_NAME = DragGestureRecognizer;
 			};
 			name = Debug;
@@ -485,7 +509,8 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.wnagrodzki.DragGestureRecognizerUITests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 3.0;
+				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_VERSION = 4.2;
 				TEST_TARGET_NAME = DragGestureRecognizer;
 			};
 			name = Release;
diff --git a/DragGestureRecognizer.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/DragGestureRecognizer.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 0000000..18d9810
--- /dev/null
+++ b/DragGestureRecognizer.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/DragGestureRecognizer/AppDelegate.swift b/DragGestureRecognizer/AppDelegate.swift
index e1f8305..0169909 100644
--- a/DragGestureRecognizer/AppDelegate.swift
+++ b/DragGestureRecognizer/AppDelegate.swift
@@ -30,7 +30,7 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
     var window: UIWindow?
 
 
-    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
+    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
         // Override point for customization after application launch.
         return true
     }
diff --git a/DragGestureRecognizer/DragGestureRecognizer.swift b/DragGestureRecognizer/DragGestureRecognizer.swift
index b52ccfa..b524604 100644
--- a/DragGestureRecognizer/DragGestureRecognizer.swift
+++ b/DragGestureRecognizer/DragGestureRecognizer.swift
@@ -46,7 +46,7 @@ class DragGestureRecognizer: UILongPressGestureRecognizer {
         initialTouchLocationsInViews[inView] = initialLocation
     }
     
-    override var state: UIGestureRecognizerState {
+    override var state: UIGestureRecognizer.State {
         
         didSet {