FIX: Allow Copy/Paste between windows (ISX-1823).

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -48,6 +48,7 @@ however, it has to be formatted properly to pass verification tests.
 - Fixed InputManager.asset file growing in size on each Reset call.
 - Fixed Opening InputDebugger throws 'Action map must have state at this point' error.
 - Fixed Cut/Paste behaviour to match Editor - Cut items will now be cleared from clipboard after pasting.
+- Fixed Pasting items between Input Action Editor windows having no effect until an item in the Action Map/Action lists was selected.
 - Fixed InputAction asset appearing dirty after rename [ISXB-695](https://issuetracker.unity3d.com/product/unity/issues/guid/ISXB-749).
 - Fixed Error logged when InputActionEditor window opened without a valid asset.
 - Fixed ArgumentNullExceptions thrown when deleting items quickly in the UITK Editor.

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/InputActionsEditorWindow.cs

@@ -250,6 +250,12 @@ private bool HasAssetChanged(SerializedObject serializedAsset)
             return newAssetJson != m_AssetJson;
         }
 
+        private void OnFocus()
+        {
+            // Apply focus here so that Paste works when users tab into the window (handled in InputActionsEditorView)
+            rootVisualElement.Focus();
+        }
+
         private void OnLostFocus()
         {
             // Auto-save triggers on focus-lost instead of on every change

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/ActionMapsView.cs

@@ -211,7 +211,8 @@ private void OnPointerDown(PointerDownEvent evt)
             if (evt.button == (int)MouseButton.RightMouse && evt.clickCount == 1)
             {
                 var actionMap = (evt.target as VisualElement).GetFirstAncestorOfType<InputActionMapsTreeViewItem>();
-                m_ListView.SetSelection(actionMap.parent.IndexOf(actionMap));
+                if (actionMap != null)
+                    m_ListView.SetSelection(actionMap.parent.IndexOf(actionMap));
             }
         }
 

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/CopyPasteHelper.cs

@@ -214,6 +214,9 @@ private static void PasteActionsFromClipboard(InputActionsEditorState state, boo
             var index = state.selectedActionIndex;
             if (addLast)
                 index = actionArray.arraySize - 1;
+
+            index = Math.Clamp(index, 0, actionArray.arraySize - 1);
+
             PasteData(EditorGUIUtility.systemCopyBuffer, new[] {index}, actionArray);
         }
 
@@ -222,6 +225,11 @@ private static void PasteBindingsFromClipboard(InputActionsEditorState state)
             var actionMap = Selectors.GetSelectedActionMap(state)?.wrappedProperty;
             var bindingsArray = actionMap?.FindPropertyRelative(nameof(InputActionMap.m_Bindings));
             var actions = actionMap?.FindPropertyRelative(nameof(InputActionMap.m_Actions));
+
+            // Don't do anything if there's no valid array to paste into.
+            if (state.selectedActionIndex == -1 || actions == null || bindingsArray == null)
+                return;
+
             var index = state.selectionType == SelectionType.Action ? Selectors.GetBindingIndexBeforeAction(actions, state.selectedActionIndex, bindingsArray) : state.selectedBindingIndex;
             PasteData(EditorGUIUtility.systemCopyBuffer, new[] {index}, bindingsArray);
         }
@@ -298,13 +306,16 @@ private static void PasteAction(SerializedProperty arrayProperty, string jsonToI
         private static int PasteBindingOrComposite(SerializedProperty arrayProperty, string json, int index, string actionName, bool createCompositeParts = true)
         {
             var pastePartOfComposite = IsPartOfComposite(json);
-            if (index > 0)
+            var currentPropertyIndex = index - 1;
+            // We don't care about these checks if the array index is invalid
+            if (currentPropertyIndex >= 0 && currentPropertyIndex < arrayProperty.arraySize)
             {
-                var currentProperty = arrayProperty.GetArrayElementAtIndex(index - 1);
+                var currentProperty = arrayProperty.GetArrayElementAtIndex(currentPropertyIndex);
                 var currentIsComposite = IsComposite(currentProperty) || IsPartOfComposite(currentProperty);
                 if (pastePartOfComposite && !currentIsComposite) //prevent pasting part of composite into non-composite
                     return index;
             }
+
             index = pastePartOfComposite || s_State.selectionType == SelectionType.Action ? index : Selectors.GetSelectedBindingIndexAfterCompositeBindings(s_State) + 1;
             if (json.Contains(k_BindingData)) //copied data is composite with bindings - only true for directly copied composites, not for composites from copied actions
                 return PasteCompositeFromJson(arrayProperty, json, index, actionName);
@@ -361,7 +372,7 @@ private static bool IsPartOfComposite(string json)
         private static SerializedProperty AddElement(SerializedProperty arrayProperty, string name, int index = -1)
         {
             var uniqueName = InputActionSerializationHelpers.FindUniqueName(arrayProperty, name);
-            if (index < 0)
+            if (index < 0 || index > arrayProperty.arraySize)
                 index = arrayProperty.arraySize;
 
             arrayProperty.InsertArrayElementAtIndex(index);

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/InputActionsEditorView.cs

@@ -1,4 +1,5 @@
 #if UNITY_EDITOR && UNITY_INPUT_SYSTEM_PROJECT_WIDE_ACTIONS
+using CmdEvents = UnityEngine.InputSystem.Editor.InputActionsEditorConstants.CommandEvents;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -14,6 +15,8 @@ internal class InputActionsEditorView : ViewBase<InputActionsEditorView.ViewStat
         private const string autoSaveToggleId = "auto-save-toolbar-toggle";
         private const string menuButtonId = "asset-menu";
 
+        private readonly TreeView m_ActionsTreeView;
+        private readonly ListView m_ActionMapsListView;
         private readonly ToolbarMenu m_ControlSchemesToolbar;
         private readonly ToolbarMenu m_DevicesToolbar;
         private readonly ToolbarButton m_SaveButton;
@@ -86,6 +89,13 @@ public InputActionsEditorView(VisualElement root, StateContainer stateContainer,
                     selectedControlSchemeIndex = state.selectedControlSchemeIndex,
                     selectedDeviceIndex = state.selectedDeviceRequirementIndex
                 });
+
+            m_ActionsTreeView = root.Q<TreeView>("actions-tree-view");
+            m_ActionMapsListView = root.Q<ListView>("action-maps-list-view");
+
+            root.RegisterCallback<ValidateCommandEvent>(OnValidateCommand);
+            root.RegisterCallback<ExecuteCommandEvent>(OnExecuteCommand);
+            root.focusable = true; // Required for CommandEvents to work
         }
 
         private void OnReset()
@@ -221,6 +231,43 @@ public class ViewState
             public int selectedControlSchemeIndex;
             public int selectedDeviceIndex;
         }
+
+        void OnExecuteCommand(ExecuteCommandEvent evt)
+        {
+            if (evt.commandName != CmdEvents.Paste)
+                return;
+
+            var copiedType = CopyPasteHelper.GetCopiedClipboardType();
+
+            if (copiedType == typeof(InputActionMap))
+            {
+                Dispatch(Commands.PasteActionMaps());
+            }
+            else if (copiedType == typeof(InputAction))
+            {
+                Dispatch(Commands.PasteActionsOrBindings());
+            }
+            else if (copiedType == typeof(InputBinding))
+            {
+                var oldSelectedBinding = stateContainer.GetState().selectedBindingIndex;
+                Dispatch(Commands.PasteActionsOrBindings());
+
+                // If paste succeeded, expand the relevant Action to show the new binding.
+                if (stateContainer.GetState().selectedBindingIndex != oldSelectedBinding)
+                    m_ActionsTreeView.ExpandItem(m_ActionsTreeView.GetIdForIndex(stateContainer.GetState().selectedActionIndex));
+            }
+        }
+
+        void OnValidateCommand(ValidateCommandEvent evt)
+        {
+            // Mark commands as supported for Execute by stopping propagation of the event
+            switch (evt.commandName)
+            {
+                case CmdEvents.Paste:
+                    evt.StopPropagation();
+                    break;
+            }
+        }
     }
 
     internal static partial class Selectors

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/Views/Selectors.cs

@@ -79,7 +79,7 @@ public static int GetSelectedBindingIndexAfterCompositeBindings(InputActionsEdit
             var item = new SerializedInputBinding(bindings?.GetArrayElementAtIndex(state.selectedBindingIndex));
             var index = state.selectedBindingIndex + (item.isComposite || item.isPartOfComposite ? 1 : 0);
             var toSkip = 0;
-            while (new SerializedInputBinding(bindings?.GetArrayElementAtIndex(index)).isPartOfComposite)
+            while (index < bindings.arraySize && new SerializedInputBinding(bindings?.GetArrayElementAtIndex(index)).isPartOfComposite)
             {
                 toSkip++;
                 index++;