FIX: Allow Copy/Paste between windows by intercepting the commands hi…

…gher up the hierarchy. (ISX-1823)

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -44,6 +44,7 @@ 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 windows not working until an item in the Action Map/Action lists was selected.
 
 ## [1.8.0-pre.2] - 2023-11-09
 

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

@@ -204,6 +204,10 @@ private static void PasteActionsFromClipboard(InputActionsEditorState state, boo
             var index = state.selectedActionIndex;
             if (addLast)
                 index = actionArray.arraySize - 1;
+
+            if (index < 0)
+                index = 0;
+
             PasteData(EditorGUIUtility.systemCopyBuffer, new[] {index}, actionArray);
         }
 
@@ -288,13 +292,14 @@ 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)
+            if (index > 0 && arrayProperty.arraySize > 0 && index - 1 < arrayProperty.arraySize)
             {
                 var currentProperty = arrayProperty.GetArrayElementAtIndex(index - 1);
                 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);
@@ -351,7 +356,7 @@ 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_MenuButtonToolbar;
         private readonly ToolbarButton m_SaveButton;
 
@@ -71,6 +74,13 @@ public InputActionsEditorView(VisualElement root, StateContainer stateContainer)
                     controlSchemes = controlSchemes,
                     selectedControlSchemeIndex = state.selectedControlSchemeIndex
                 });
+
+            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()
@@ -159,6 +169,49 @@ public class ViewState
             public IEnumerable<InputControlScheme> controlSchemes;
             public int selectedControlSchemeIndex;
         }
+
+        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))
+            {
+                // Can't paste an Action without any Action Maps for it to go to
+                if (m_ActionMapsListView.itemsSource.Count > 0)
+                    Dispatch(Commands.PasteActionsOrBindings());
+            }
+            else if (copiedType == typeof(InputBinding))
+            {
+                // Can't paste a Binding without any Actions for it to go to
+                if (m_ActionsTreeView.itemsSource.Count > 0)
+                {
+                    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