Added compatibility header

Summary:
- Added IGListCompatibility.h file, and imported it in the files where we need the target check.
- Ordered the project by type

In "IGListKit.h" we still have the conditional check for `#if TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR` - Did we want to make a macro or something for this check?

This is the most Obj-C I've ever done... just felt that was a worthy comment.

Closes #364

- [x] All tests pass. Demo project builds and runs.
- [x] I added tests, an experiment, or detailed why my change isn't tested.
- [x] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [x] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
Closes #369

Differential Revision: D4366344

Pulled By: jessesquires

fbshipit-source-id: f0a6168b8965ded22a641814797fbdec92ca1c36

IGListKit.xcodeproj/project.pbxproj

@@ -260,6 +260,9 @@
 		88DF89881E010F5C00B1B9B4 /* IGListDiffResultTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 294AC6311DDE4C19002FCE5D /* IGListDiffResultTests.m */; };
 		88DF89891E010F6500B1B9B4 /* IGListDiffSwiftTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 88144EE61D870EDC007C7F66 /* IGListDiffSwiftTests.swift */; };
 		88DF898A1E010F7000B1B9B4 /* IGListDiffTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 88144EE81D870EDC007C7F66 /* IGListDiffTests.m */; };
+		989317631E0ED45900DB93B3 /* IGListCompatibility.h in Headers */ = {isa = PBXBuildFile; fileRef = 989317621E0ED45900DB93B3 /* IGListCompatibility.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		989317641E0ED45900DB93B3 /* IGListCompatibility.h in Headers */ = {isa = PBXBuildFile; fileRef = 989317621E0ED45900DB93B3 /* IGListCompatibility.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		989317651E0ED45900DB93B3 /* IGListCompatibility.h in Headers */ = {isa = PBXBuildFile; fileRef = 989317621E0ED45900DB93B3 /* IGListCompatibility.h */; settings = {ATTRIBUTES = (Public, ); }; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -430,6 +433,7 @@
 		887D0B3F1D870D7F009E01F7 /* IGListKitTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = IGListKitTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		887D0B571D870E1E009E01F7 /* Info.plist */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		88DF897C1E010E6A00B1B9B4 /* IGListKit-macOSTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = "IGListKit-macOSTests.xctest"; sourceTree = BUILT_PRODUCTS_DIR; };
+		989317621E0ED45900DB93B3 /* IGListCompatibility.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = IGListCompatibility.h; sourceTree = "<group>"; };
 		C4A16046BECFD57B7EB75259 /* Pods-IGListKitTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-IGListKitTests.debug.xcconfig"; path = "Pods/Target Support Files/Pods-IGListKitTests/Pods-IGListKitTests.debug.xcconfig"; sourceTree = "<group>"; };
 		DD3152AC1DE227FA00AC9D2C /* IGListKit.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = IGListKit.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		FD40284889DE182FFC7F471E /* Pods_IGListKitTests.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_IGListKitTests.framework; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -489,34 +493,34 @@
 		0B3B927E1E08D7F5008390ED /* Source */ = {
 			isa = PBXGroup;
 			children = (
-				0B3B927F1E08D7F5008390ED /* Common */,
 				0B3B929A1E08D7F5008390ED /* IGListAdapter.h */,
-				0B3B929B1E08D7F5008390ED /* IGListAdapter.m */,
 				0B3B929C1E08D7F5008390ED /* IGListAdapterDataSource.h */,
 				0B3B929D1E08D7F5008390ED /* IGListAdapterDelegate.h */,
 				0B3B929E1E08D7F5008390ED /* IGListAdapterUpdater.h */,
-				0B3B929F1E08D7F5008390ED /* IGListAdapterUpdater.m */,
 				0B3B92A01E08D7F5008390ED /* IGListAdapterUpdaterDelegate.h */,
 				0B3B92A11E08D7F5008390ED /* IGListCollectionContext.h */,
 				0B3B92A21E08D7F5008390ED /* IGListCollectionView.h */,
-				0B3B92A31E08D7F5008390ED /* IGListCollectionView.m */,
 				0B3B92A41E08D7F5008390ED /* IGListDisplayDelegate.h */,
 				0B3B92A51E08D7F5008390ED /* IGListGridCollectionViewLayout.h */,
-				0B3B92A61E08D7F5008390ED /* IGListGridCollectionViewLayout.m */,
 				0B3B92A71E08D7F5008390ED /* IGListReloadDataUpdater.h */,
-				0B3B92A81E08D7F5008390ED /* IGListReloadDataUpdater.m */,
 				0B3B92A91E08D7F5008390ED /* IGListScrollDelegate.h */,
 				0B3B92AA1E08D7F5008390ED /* IGListSectionController.h */,
-				0B3B92AB1E08D7F5008390ED /* IGListSectionController.m */,
 				0B3B92AC1E08D7F5008390ED /* IGListSectionType.h */,
 				0B3B92AD1E08D7F5008390ED /* IGListSingleSectionController.h */,
-				0B3B92AE1E08D7F5008390ED /* IGListSingleSectionController.m */,
 				0B3B92AF1E08D7F5008390ED /* IGListStackedSectionController.h */,
-				0B3B92B01E08D7F5008390ED /* IGListStackedSectionController.m */,
 				0B3B92B11E08D7F5008390ED /* IGListSupplementaryViewSource.h */,
 				0B3B92B21E08D7F5008390ED /* IGListUpdatingDelegate.h */,
 				0B3B92B31E08D7F5008390ED /* IGListWorkingRangeDelegate.h */,
+				0B3B929B1E08D7F5008390ED /* IGListAdapter.m */,
+				0B3B929F1E08D7F5008390ED /* IGListAdapterUpdater.m */,
+				0B3B92A31E08D7F5008390ED /* IGListCollectionView.m */,
+				0B3B92A61E08D7F5008390ED /* IGListGridCollectionViewLayout.m */,
+				0B3B92A81E08D7F5008390ED /* IGListReloadDataUpdater.m */,
+				0B3B92AB1E08D7F5008390ED /* IGListSectionController.m */,
+				0B3B92AE1E08D7F5008390ED /* IGListSingleSectionController.m */,
+				0B3B92B01E08D7F5008390ED /* IGListStackedSectionController.m */,
 				0B3B92B41E08D7F5008390ED /* Info.plist */,
+				0B3B927F1E08D7F5008390ED /* Common */,
 				0B3B92B51E08D7F5008390ED /* Internal */,
 			);
 			path = Source;
@@ -527,26 +531,27 @@
 			children = (
 				0B3B92801E08D7F5008390ED /* IGListAssert.h */,
 				0B3B92811E08D7F5008390ED /* IGListBatchUpdateData.h */,
-				0B3B92821E08D7F5008390ED /* IGListBatchUpdateData.mm */,
+				989317621E0ED45900DB93B3 /* IGListCompatibility.h */,
 				0B3B92831E08D7F5008390ED /* IGListDiff.h */,
-				0B3B92841E08D7F5008390ED /* IGListDiff.mm */,
 				0B3B92851E08D7F5008390ED /* IGListDiffable.h */,
 				0B3B92861E08D7F5008390ED /* IGListExperiments.h */,
 				0B3B92871E08D7F5008390ED /* IGListIndexPathResult.h */,
-				0B3B92881E08D7F5008390ED /* IGListIndexPathResult.m */,
 				0B3B92891E08D7F5008390ED /* IGListIndexSetResult.h */,
-				0B3B928A1E08D7F5008390ED /* IGListIndexSetResult.m */,
 				0B3B928B1E08D7F5008390ED /* IGListKit.h */,
 				0B3B928C1E08D7F5008390ED /* IGListMacros.h */,
 				0B3B928D1E08D7F5008390ED /* IGListMoveIndex.h */,
-				0B3B928E1E08D7F5008390ED /* IGListMoveIndex.m */,
 				0B3B928F1E08D7F5008390ED /* IGListMoveIndexPath.h */,
-				0B3B92901E08D7F5008390ED /* IGListMoveIndexPath.m */,
-				0B3B92911E08D7F5008390ED /* Internal */,
 				0B3B92961E08D7F5008390ED /* NSNumber+IGListDiffable.h */,
-				0B3B92971E08D7F5008390ED /* NSNumber+IGListDiffable.m */,
 				0B3B92981E08D7F5008390ED /* NSString+IGListDiffable.h */,
+				0B3B92881E08D7F5008390ED /* IGListIndexPathResult.m */,
+				0B3B928A1E08D7F5008390ED /* IGListIndexSetResult.m */,
+				0B3B928E1E08D7F5008390ED /* IGListMoveIndex.m */,
+				0B3B92901E08D7F5008390ED /* IGListMoveIndexPath.m */,
+				0B3B92971E08D7F5008390ED /* NSNumber+IGListDiffable.m */,
 				0B3B92991E08D7F5008390ED /* NSString+IGListDiffable.m */,
+				0B3B92821E08D7F5008390ED /* IGListBatchUpdateData.mm */,
+				0B3B92841E08D7F5008390ED /* IGListDiff.mm */,
+				0B3B92911E08D7F5008390ED /* Internal */,
 			);
 			path = Common;
 			sourceTree = "<group>";
@@ -725,6 +730,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				989317641E0ED45900DB93B3 /* IGListCompatibility.h in Headers */,
 				0B3B92FB1E08D7F5008390ED /* IGListAdapterDataSource.h in Headers */,
 				0B3B92E91E08D7F5008390ED /* IGListIndexSetResultInternal.h in Headers */,
 				0B3B930B1E08D7F5008390ED /* IGListDisplayDelegate.h in Headers */,
@@ -776,6 +782,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				989317631E0ED45900DB93B3 /* IGListCompatibility.h in Headers */,
 				0B3B92FA1E08D7F5008390ED /* IGListAdapterDataSource.h in Headers */,
 				0B3B92E81E08D7F5008390ED /* IGListIndexSetResultInternal.h in Headers */,
 				0B3B930A1E08D7F5008390ED /* IGListDisplayDelegate.h in Headers */,
@@ -827,6 +834,7 @@
 			isa = PBXHeadersBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				989317651E0ED45900DB93B3 /* IGListCompatibility.h in Headers */,
 				0B3B934D1E08D839008390ED /* IGListBatchUpdateData.h in Headers */,
 				0B3B934B1E08D82E008390ED /* IGListMoveIndexPathInternal.h in Headers */,
 				0B3B93521E08D839008390ED /* IGListIndexSetResult.h in Headers */,

Source/Common/IGListBatchUpdateData.mm

@@ -8,14 +8,7 @@
  */
 
 #import "IGListBatchUpdateData.h"
-
-#import <TargetConditionals.h>
-
-#if TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR
-#import <UIKit/UIKit.h>
-#else
-#import <Cocoa/Cocoa.h>
-#endif
+#import <IGListKit/IGListCompatibility.h>
 
 #import <unordered_map>
 

Source/Common/IGListCompatibility.h

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2016-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <TargetConditionals.h>
+
+#if TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR
+#import <UIKit/UIKit.h>
+#else
+#import <Cocoa/Cocoa.h>
+#endif

Source/Common/IGListDiff.mm

@@ -13,14 +13,7 @@
 #import <unordered_map>
 #import <vector>
 
-#import <TargetConditionals.h>
-
-#if TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR
-#import <UIKit/UIKit.h>
-#else
-#import <Cocoa/Cocoa.h>
-#endif
-
+#import <IGListKit/IGListCompatibility.h>
 #import <IGListKit/IGListMacros.h>
 #import <IGListKit/IGListExperiments.h>
 

Source/Common/IGListKit.h

@@ -7,13 +7,7 @@
  * of patent rights can be found in the PATENTS file in the same directory.
  */
 
-#import <TargetConditionals.h>
-
-#if TARGET_OS_EMBEDDED || TARGET_OS_SIMULATOR
-#import <UIKit/UIKit.h>
-#else
-#import <Cocoa/Cocoa.h>
-#endif
+#import <IGListKit/IGListCompatibility.h>
 
 /**
  * Project version number for IGListKit.