CHANGE: Remove code to support Unity versions older than 2021.3 (#2267)

Author: K-Tone

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -13,6 +13,7 @@ however, it has to be formatted properly to pass verification tests.
 ### Changed
 - Replaced "Look" rebinding button for "Keyboard" control scheme with a mouse sensitivity slider in `RebindingUISample` to illustrate how to support customizing scaling of mouse deltas and how to reapply the persisted setting between runs.
 - Changed: Input System no longer depends the obsolete com.unity.modules.vr package.
+- Removed code that had to do with Unity versions older than Unity 2021.3 LTS.
 
 ### Added
 - Added an example of how to swap two similar controls to the `RebindingUISample`. This is accessible via a button with two arrows at the right hand-side of the screen. Pressing the button allows swapping the current bindings of the "Move" and "Look" gamepad bindings via the new `RebindActionUI.SwapBinding(RebindActionUI other)` method.

Packages/com.unity.inputsystem/InputSystem/Controls/InputControlExtensions.cs

@@ -1931,12 +1931,7 @@ public void Finish()
                 }
 
                 device.m_ButtonControlsCheckingPressState = new List<ButtonControl>(i);
-                #if UNITY_2020_1_OR_NEWER
                 device.m_UpdatedButtons = new HashSet<int>(i);
-                #else
-                // 2019 is too old to support setting HashSet capacity
-                device.m_UpdatedButtons = new HashSet<int>();
-                #endif
 
                 device.isSetupFinished = true;
             }

Packages/com.unity.inputsystem/InputSystem/Devices/InputDeviceBuilder.cs

@@ -75,12 +75,7 @@ public InputDevice Finish()
             }
 
             device.m_ButtonControlsCheckingPressState = new List<ButtonControl>(i);
-            #if UNITY_2020_1_OR_NEWER
             device.m_UpdatedButtons = new HashSet<int>(i);
-            #else
-            // 2019 is too old to support setting HashSet capacity
-            device.m_UpdatedButtons = new HashSet<int>();
-            #endif
 
             // Kill off our state.
             Reset();

Packages/com.unity.inputsystem/InputSystem/Editor/AssetImporter/InputActionAssetEditor.cs

@@ -247,14 +247,8 @@ private static void Process(string[] assets, ICollection<string> target)
                 }
             }
 
-            // Note: Callback prior to Unity 2021.2 did not provide a boolean indicating domain relaod.
-#if UNITY_2021_2_OR_NEWER
             private static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets,
                 string[] movedAssets, string[] movedFromAssetPaths, bool didDomainReload)
-#else
-            private static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets,
-                string[] movedAssets, string[] movedFromAssetPaths)
-#endif
             {
                 Process(importedAssets, s_Imported);
                 Process(deletedAssets, s_Deleted);

Packages/com.unity.inputsystem/InputSystem/Editor/AssetImporter/InputActionImporter.cs

@@ -4,11 +4,7 @@
 using System.IO;
 using System.Linq;
 using UnityEditor;
-#if UNITY_2020_2_OR_NEWER
 using UnityEditor.AssetImporters;
-#else
-using UnityEditor.Experimental.AssetImporters;
-#endif
 using UnityEngine.InputSystem.Utilities;
 
 ////FIXME: The importer accesses icons through the asset db (which EditorGUIUtility.LoadIcon falls back on) which will
@@ -381,14 +377,8 @@ private static bool ContainsInputActionAssetPath(string[] assetPaths)
         // the name will no longer be a mismatch and the cycle will be aborted.
         private class InputActionJsonNameModifierAssetProcessor : AssetPostprocessor
         {
-            // Note: Callback prior to Unity 2021.2 did not provide a boolean indicating domain relaod.
-#if UNITY_2021_2_OR_NEWER
             private static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets,
                 string[] movedAssets, string[] movedFromAssetPaths, bool didDomainReload)
-#else
-            private static void OnPostprocessAllAssets(string[] importedAssets, string[] deletedAssets,
-                string[] movedAssets, string[] movedFromAssetPaths)
-#endif
             {
                 var needToInvalidate = false;
                 foreach (var assetPath in importedAssets)

Packages/com.unity.inputsystem/InputSystem/Editor/AssetImporter/InputActionImporterEditor.cs

@@ -3,11 +3,7 @@
 using System.IO;
 using UnityEngine.InputSystem.Utilities;
 using UnityEditor;
-#if UNITY_2020_2_OR_NEWER
 using UnityEditor.AssetImporters;
-#else
-using UnityEditor.Experimental.AssetImporters;
-#endif
 
 ////TODO: support for multi-editing
 

Packages/com.unity.inputsystem/InputSystem/Editor/DeviceSimulator/InputSystemPlugin.cs

@@ -1,4 +1,4 @@
-#if UNITY_EDITOR && UNITY_2021_1_OR_NEWER
+#if UNITY_EDITOR
 
 using System;
 using System.Collections.Generic;

Packages/com.unity.inputsystem/InputSystem/Editor/InputSystemPackageControl.cs

@@ -1,4 +1,4 @@
-#if UNITY_EDITOR && UNITY_2020_2_OR_NEWER
+#if UNITY_EDITOR
 using System;
 using System.Collections.ObjectModel;
 using UnityEditor;

Packages/com.unity.inputsystem/InputSystem/Editor/InputSystemPluginControl.cs

@@ -1,4 +1,4 @@
-#if ((UNITY_EDITOR && UNITY_2021_1_OR_NEWER) || PACKAGE_DOCS_GENERATION)
+#if (UNITY_EDITOR || PACKAGE_DOCS_GENERATION)
 using System;
 using System.Collections.Generic;
 using UnityEditor;

Packages/com.unity.inputsystem/InputSystem/Editor/Internal/EditorHelpers.cs

@@ -129,12 +129,7 @@ internal static bool SaveAsset(string assetPath, string text)
         // Maps path into a physical path.
         public static string GetPhysicalPath(string path)
         {
-            // Note that we can only get physical path for 2021.2 or newer
-#if UNITY_2021_2_OR_NEWER
             return FileUtil.GetPhysicalPath(path);
-#else
-            return path;
-#endif
         }
     }
 }