Added custom property type layout for FImGuiKeyInfo.

Source/ImGui/ImGui.Build.cs

@@ -64,6 +64,7 @@ public class ImGui : ModuleRules
 			PrivateDependencyModuleNames.AddRange(
 				new string[]
 				{
+					"EditorStyle",
 					"Settings",
 					"UnrealEd",
 				}

Source/ImGui/Private/Editor/ImGuiEditor.cpp

@@ -6,6 +6,7 @@
 
 #include "ImGuiEditor.h"
 
+#include "ImGuiKeyInfoCustomization.h"
 #include "ImGuiSettings.h"
 
 #include <ISettingsModule.h>
@@ -22,6 +23,11 @@ namespace
 	{
 		return FModuleManager::GetModulePtr<ISettingsModule>("Settings");
 	}
+
+	FPropertyEditorModule* GetPropertyEditorModule()
+	{
+		return FModuleManager::GetModulePtr<FPropertyEditorModule>("PropertyEditor");
+	}
 }
 
 FImGuiEditor::FImGuiEditor()
@@ -56,6 +62,17 @@ void FImGuiEditor::Register()
 				GetMutableDefault<UImGuiSettings>());
 		}
 	}
+
+	if (!bCustomPropertyTypeLayoutsRegistered)
+	{
+		if (FPropertyEditorModule* PropertyModule = GetPropertyEditorModule())
+		{
+			bCustomPropertyTypeLayoutsRegistered = true;
+
+			PropertyModule->RegisterCustomPropertyTypeLayout("ImGuiKeyInfo",
+				FOnGetPropertyTypeCustomizationInstance::CreateStatic(&FImGuiKeyInfoCustomization::MakeInstance));
+		}
+	}
 }
 
 void FImGuiEditor::Unregister()
@@ -69,6 +86,16 @@ void FImGuiEditor::Unregister()
 			SettingsModule->UnregisterSettings(SETTINGS_CONTAINER);
 		}
 	}
+
+	if (bCustomPropertyTypeLayoutsRegistered)
+	{
+		bCustomPropertyTypeLayoutsRegistered = false;
+
+		if (FPropertyEditorModule* PropertyModule = GetPropertyEditorModule())
+		{
+			PropertyModule->UnregisterCustomPropertyTypeLayout("ImGuiKeyInfo");
+		}
+	}
 }
 
 void FImGuiEditor::CreateRegistrator()

Source/ImGui/Private/Editor/ImGuiEditor.h

@@ -14,7 +14,7 @@ public:
 
 private:
 
-	bool IsRegistrationCompleted() const { return bSettingsRegistered; }
+	bool IsRegistrationCompleted() const { return bSettingsRegistered && bCustomPropertyTypeLayoutsRegistered; }
 
 	void Register();
 	void Unregister();
@@ -25,6 +25,7 @@ private:
 	FDelegateHandle RegistratorHandle;
 
 	bool bSettingsRegistered = false;
+	bool bCustomPropertyTypeLayoutsRegistered = false;
 };
 
 #endif // WITH_EDITOR

Source/ImGui/Private/Editor/ImGuiKeyInfoCustomization.cpp

@@ -0,0 +1,211 @@
+// Distributed under the MIT License (MIT) (see accompanying LICENSE file)
+
+#include "ImGuiPrivatePCH.h"
+
+#if WITH_EDITOR
+
+#include "ImGuiKeyInfoCustomization.h"
+
+#include "ImGuiSettings.h"
+
+#include <PropertyCustomizationHelpers.h>
+#include <SKeySelector.h>
+#include <Widgets/SCompoundWidget.h>
+#include <Widgets/Input/SCheckBox.h>
+
+
+#define LOCTEXT_NAMESPACE "ImGuiEditor"
+
+
+//----------------------------------------------------------------------------------------------------
+// Helper widgets
+//----------------------------------------------------------------------------------------------------
+
+namespace
+{
+	class SPropertyKeySelector : public SCompoundWidget
+	{
+	public:
+		SLATE_BEGIN_ARGS(SPropertyKeySelector)
+		{}
+		SLATE_ARGUMENT(TSharedPtr<IPropertyHandle>, KeyHandle)
+		SLATE_ATTRIBUTE(FSlateFontInfo, Font)
+		SLATE_END_ARGS()
+
+		void Construct(const FArguments& InArgs)
+		{
+			KeyHandle = InArgs._KeyHandle;
+
+			ChildSlot
+			[
+				SNew(SKeySelector)
+				.CurrentKey(this, &SPropertyKeySelector::GetCurrentKey)
+				.OnKeyChanged(this, &SPropertyKeySelector::OnKeyChanged)
+				.Font(InArgs._Font)
+			];
+		}
+
+		TOptional<FKey> GetCurrentKey() const
+		{
+			TArray<void*> RawPtrs;
+			KeyHandle->AccessRawData(RawPtrs);
+
+			if (RawPtrs.Num())
+			{
+				FKey* KeyPtr = static_cast<FKey*>(RawPtrs[0]);
+
+				if (KeyPtr)
+				{
+					for (int32 Index = 1; Index < RawPtrs.Num(); Index++)
+					{
+						if (*static_cast<FKey*>(RawPtrs[Index]) != *KeyPtr)
+						{
+							return TOptional<FKey>();
+						}
+					}
+
+					return *KeyPtr;
+				}
+			}
+
+			return FKey();
+		}
+
+		void OnKeyChanged(TSharedPtr<FKey> SelectedKey)
+		{
+			KeyHandle->SetValueFromFormattedString(SelectedKey->ToString());
+		}
+
+	private:
+
+		TSharedPtr<IPropertyHandle> KeyHandle;
+	};
+
+	class SPropertyTriStateCheckBox : public SCompoundWidget
+	{
+	public:
+
+		using FCheckBoxStateRaw = std::underlying_type<ECheckBoxState>::type;
+
+		SLATE_BEGIN_ARGS(SPropertyTriStateCheckBox)
+		{}
+		SLATE_ARGUMENT(TSharedPtr<IPropertyHandle>, PropertyHandle)
+		SLATE_END_ARGS()
+
+		void Construct(const FArguments& InArgs)
+		{
+			PropertyHandle = InArgs._PropertyHandle;
+
+			// We are abusing SCheckBox a bit but our GetPropertyValue with custom OnCheckBoxStateChanged implementation
+			// gives a checkbox that allows to cycle between all three states.
+			ChildSlot
+			[
+				SNew(SCheckBox)
+				.IsChecked(this, &SPropertyTriStateCheckBox::GetPropertyValue)
+				.OnCheckStateChanged(this, &SPropertyTriStateCheckBox::OnCheckBoxStateChanged)
+			];
+		}
+
+		FCheckBoxStateRaw GetPropertyRawValue() const
+		{
+			FCheckBoxStateRaw Value;
+			PropertyHandle.Get()->GetValue(Value);
+			return Value;
+		}
+
+		ECheckBoxState GetPropertyValue() const
+		{
+			return static_cast<ECheckBoxState>(GetPropertyRawValue());
+		}
+
+		void OnCheckBoxStateChanged(ECheckBoxState State)
+		{
+			const FCheckBoxStateRaw PrevEnumValue = (GetPropertyRawValue() + 2) % 3;
+			PropertyHandle.Get()->SetValue(PrevEnumValue);
+		}
+
+	private:
+
+		TSharedPtr<IPropertyHandle> PropertyHandle;
+	};
+}
+
+
+//----------------------------------------------------------------------------------------------------
+// FImGuiKeyInfoCustomization implementation
+//----------------------------------------------------------------------------------------------------
+
+namespace InputConstants
+{
+	static const FMargin PropertyPadding(2.0f, 0.0f, 2.0f, 0.0f);
+}
+
+TSharedRef<IPropertyTypeCustomization> FImGuiKeyInfoCustomization::MakeInstance()
+{
+	return MakeShareable(new FImGuiKeyInfoCustomization);
+}
+
+void FImGuiKeyInfoCustomization::CustomizeHeader(TSharedRef<IPropertyHandle> InStructPropertyHandle, FDetailWidgetRow& HeaderRow, IPropertyTypeCustomizationUtils& StructCustomizationUtils)
+{
+	TSharedPtr<IPropertyHandle> KeyHandle = InStructPropertyHandle->GetChildHandle(GET_MEMBER_NAME_CHECKED(FImGuiKeyInfo, Key));
+	TSharedPtr<IPropertyHandle> ShiftHandle = InStructPropertyHandle->GetChildHandle(GET_MEMBER_NAME_CHECKED(FImGuiKeyInfo, Shift));
+	TSharedPtr<IPropertyHandle> CtrlHandle = InStructPropertyHandle->GetChildHandle(GET_MEMBER_NAME_CHECKED(FImGuiKeyInfo, Ctrl));
+	TSharedPtr<IPropertyHandle> AltHandle = InStructPropertyHandle->GetChildHandle(GET_MEMBER_NAME_CHECKED(FImGuiKeyInfo, Alt));
+	TSharedPtr<IPropertyHandle> CmdHandle = InStructPropertyHandle->GetChildHandle(GET_MEMBER_NAME_CHECKED(FImGuiKeyInfo, Cmd));
+
+#define ADD_CHECK_BOX_SLOT(Handle) \
+	+ SHorizontalBox::Slot()\
+	.Padding(InputConstants::PropertyPadding)\
+	.HAlign(HAlign_Left)\
+	.VAlign(VAlign_Center)\
+	.AutoWidth()\
+	[\
+		Handle->CreatePropertyNameWidget()\
+	]\
+	+ SHorizontalBox::Slot()\
+	.Padding(InputConstants::PropertyPadding)\
+	.HAlign(HAlign_Left)\
+	.VAlign(VAlign_Center)\
+	.AutoWidth()\
+	[\
+		SNew(SPropertyTriStateCheckBox).PropertyHandle(Handle)\
+	]
+
+	HeaderRow
+	.NameContent()
+	[
+		InStructPropertyHandle->CreatePropertyNameWidget()
+	]
+	.ValueContent()
+	.MaxDesiredWidth(400.f)
+	[
+		SNew(SHorizontalBox)
+		+ SHorizontalBox::Slot()
+		.Padding(InputConstants::PropertyPadding)
+		.AutoWidth()
+		[
+			SNew(SBox)
+			.WidthOverride(200.f)
+			[
+				SNew(SPropertyKeySelector)
+				.KeyHandle(KeyHandle)
+				.Font(StructCustomizationUtils.GetRegularFont())
+			]
+		]
+		ADD_CHECK_BOX_SLOT(ShiftHandle)
+		ADD_CHECK_BOX_SLOT(CtrlHandle)
+		ADD_CHECK_BOX_SLOT(AltHandle)
+		ADD_CHECK_BOX_SLOT(CmdHandle)
+	];
+
+#undef ADD_CHECK_BOX_SLOT
+}
+
+void FImGuiKeyInfoCustomization::CustomizeChildren(TSharedRef<IPropertyHandle> InStructPropertyHandle, IDetailChildrenBuilder& StructBuilder, IPropertyTypeCustomizationUtils& StructCustomizationUtils)
+{
+}
+
+
+#undef LOCTEXT_NAMESPACE
+
+#endif // WITH_EDITOR

Source/ImGui/Private/Editor/ImGuiKeyInfoCustomization.h

@@ -0,0 +1,26 @@
+// Copyright 1998-2018 Epic Games, Inc. All Rights Reserved.
+
+#pragma once
+
+#if WITH_EDITOR
+
+#include <IPropertyTypeCustomization.h>
+#include <PropertyHandle.h>
+
+
+class FDetailWidgetRow;
+class IDetailChildrenBuilder;
+class IPropertyHandle;
+
+// Property type customization for FImGuiKeyInfo.
+class FImGuiKeyInfoCustomization : public IPropertyTypeCustomization
+{
+public:
+	static TSharedRef<IPropertyTypeCustomization> MakeInstance();
+
+	// IPropertyTypeCustomization interface
+	virtual void CustomizeHeader(TSharedRef<IPropertyHandle> InStructPropertyHandle, FDetailWidgetRow& HeaderRow, IPropertyTypeCustomizationUtils& StructCustomizationUtils) override;
+	virtual void CustomizeChildren(TSharedRef<IPropertyHandle> InStructPropertyHandle, IDetailChildrenBuilder& StructBuilder, IPropertyTypeCustomizationUtils& StructCustomizationUtils) override;
+};
+
+#endif // WITH_EDITOR

Source/ImGui/Private/ImGuiSettings.h

@@ -70,19 +70,19 @@ protected:
 
 	// Path to own implementation of ImGui Input Handler allowing to customize handling of keyboard and gamepad input.
 	// If not set then default handler is used.
-	UPROPERTY(EditAnywhere, config, Category = "Input", meta = (MetaClass = "ImGuiInputHandler"))
+	UPROPERTY(EditAnywhere, config, Category = "Extensions", meta = (MetaClass = "ImGuiInputHandler"))
 	FStringClassReference ImGuiInputHandlerClass;
 
-	// Define a custom key binding to 'ImGui.SwitchInputMode' command. Mapping will be only set if Key property in this
+	// Define a custom key binding to 'ImGui.SwitchInputMode' command. Binding is only set if key is valid.
-	// structure is set to a valid key. Modifier keys can be either completely ignored (Undetermined), required to be
+	// Note that modifier key properties can be set to one of the three values: undetermined means that state of the given
-	// pressed (Checked) or required to be not pressed (Unchecked).
+	// modifier is not tested, checked means that it needs to be pressed and unchecked means that it cannot be pressed.
-	UPROPERTY(EditAnywhere, config, Category = "Input")
+	//
+	// This binding is using Player Input's DebugExecBindings which only works in non-shipment builds.
+	UPROPERTY(EditAnywhere, config, Category = "Keyboard Shortcuts")
 	FImGuiKeyInfo SwitchInputModeKey;
 
 private:
 
-	void UpdateSwitchInputModeBinding();
-
 #if WITH_EDITOR
 
 	void RegisterPropertyChangedDelegate();

Source/ImGui/Public/ImGuiInputHandler.h

@@ -90,7 +90,7 @@ private:
  * Also note that input handler functions are only called when ImGui Widget is receiving input events, what can be for
  * instance suppressed by opening console.
  *
- * See @ Project Settings/Plugins/ImGui/Input/ImGuiInputHandlerClass property to set custom implementation.
+ * See @ Project Settings/Plugins/ImGui/Extensions/ImGuiInputHandlerClass property to set custom implementation.
  */
 UCLASS()
 class IMGUI_API UImGuiInputHandler : public UObject