Added 'ImGui.SwitchInputMode' command and configurable key binding to DebugExecBindings.

Source/ImGui/Private/ImGuiInputHandler.cpp

@@ -6,6 +6,7 @@
 
 #include "ImGuiContextProxy.h"
 #include "ImGuiModuleManager.h"
+#include "ImGuiSettings.h"
 
 #include <Engine/Console.h>
 #include <Input/Events.h>
@@ -25,6 +26,13 @@ DEFINE_LOG_CATEGORY_STATIC(LogImGuiInputHandler, Warning, All);
 
 FImGuiInputResponse UImGuiInputHandler::OnKeyDown(const FKeyEvent& KeyEvent)
 {
+	// If this is an input mode switch event then handle it here and consume.
+	if (IsSwitchInputModeEvent(KeyEvent))
+	{
+		FImGuiModule::Get().ToggleInputMode();
+		return FImGuiInputResponse().RequestConsume();
+	}
+
 	// Ignore console events, so we don't block it from opening.
 	if (IsConsoleEvent(KeyEvent))
 	{
@@ -68,6 +76,28 @@ bool UImGuiInputHandler::IsStopPlaySessionEvent(const FKeyEvent& KeyEvent) const
 }
 #endif // WITH_EDITOR
 
+namespace
+{
+	bool IsMatching(ECheckBoxState CheckBoxState, bool bValue)
+	{
+		return (CheckBoxState == ECheckBoxState::Undetermined) || ((CheckBoxState == ECheckBoxState::Checked) == bValue);
+	}
+
+	bool AreModifiersMatching(const FImGuiKeyInfo& KeyInfo, const FKeyEvent& KeyEvent)
+	{
+		return IsMatching(KeyInfo.Shift, KeyEvent.IsShiftDown())
+			&& IsMatching(KeyInfo.Ctrl, KeyEvent.IsControlDown())
+			&& IsMatching(KeyInfo.Alt, KeyEvent.IsAltDown())
+			&& IsMatching(KeyInfo.Cmd, KeyEvent.IsCommandDown());
+	}
+}
+
+bool UImGuiInputHandler::IsSwitchInputModeEvent(const FKeyEvent& KeyEvent) const
+{
+	const FImGuiKeyInfo KeyInfo = GetDefault<UImGuiSettings>()->GetSwitchInputModeKey();
+	return (KeyEvent.GetKey() == KeyInfo.Key) && AreModifiersMatching(KeyInfo, KeyEvent);
+}
+
 bool UImGuiInputHandler::HasImGuiActiveItem() const
 {
 	FImGuiContextProxy* ContextProxy = ModuleManager->GetContextManager().GetContextProxy(ContextIndex);

Source/ImGui/Private/ImGuiModule.cpp

@@ -22,6 +22,21 @@ namespace CVars
 	extern TAutoConsoleVariable<int32> ShowDemo;
 }
 
+namespace Commands
+{
+	const TCHAR* SwitchInputMode = TEXT("ImGui.SwitchInputMode");
+}
+
+void SwitchImGuiInputMode()
+{
+	FImGuiModule::Get().ToggleInputMode();
+}
+
+FAutoConsoleCommand SwitchInputModeCommand = FAutoConsoleCommand(
+	Commands::SwitchInputMode,
+	TEXT("Changes ImGui input mode."),
+	FConsoleCommandDelegate::CreateStatic(SwitchImGuiInputMode));
+
 struct EDelegateCategory
 {
 	enum

Source/ImGui/Private/ImGuiSettings.cpp

@@ -3,6 +3,7 @@
 #include "ImGuiPrivatePCH.h"
 
 #include "ImGuiSettings.h"
+#include "Utilities/DebugExecBindings.h"
 
 
 UImGuiSettings::UImGuiSettings()
@@ -19,6 +20,21 @@ UImGuiSettings::~UImGuiSettings()
 #endif
 }
 
+namespace Commands
+{
+	extern const TCHAR* SwitchInputMode;
+}
+
+void UImGuiSettings::PostInitProperties()
+{
+	Super::PostInitProperties();
+
+	// Instead of saving binding to input config, we manually update DebugExecBindings from here. This has an advantage
+	// that there is no ambiguity where settings are stored and more importantly, it works out of the box in packed
+	// and staged builds.  
+	DebugExecBindings::UpdatePlayerInputs(SwitchInputModeKey, Commands::SwitchInputMode);
+}
+
 #if WITH_EDITOR
 
 void UImGuiSettings::RegisterPropertyChangedDelegate()
@@ -38,13 +54,16 @@ void UImGuiSettings::OnPropertyChanged(class UObject* ObjectBeingModified, struc
 {
 	if (ObjectBeingModified == this)
 	{
-		static const FName ImGuiInputHandlerPropertyName = GET_MEMBER_NAME_CHECKED(UImGuiSettings, ImGuiInputHandlerClass);
-
 		const FName UpdatedPropertyName = PropertyChangedEvent.MemberProperty ? PropertyChangedEvent.MemberProperty->GetFName() : NAME_None;
-		if (UpdatedPropertyName == ImGuiInputHandlerPropertyName)
+
+		if (UpdatedPropertyName == GET_MEMBER_NAME_CHECKED(UImGuiSettings, ImGuiInputHandlerClass))
 		{
 			OnImGuiInputHandlerClassChanged.Broadcast();
 		}
+		else if (UpdatedPropertyName == GET_MEMBER_NAME_CHECKED(UImGuiSettings, SwitchInputModeKey))
+		{
+			DebugExecBindings::UpdatePlayerInputs(SwitchInputModeKey, Commands::SwitchInputMode);
+		}
 	}
 }
 

Source/ImGui/Private/ImGuiSettings.h

@@ -19,6 +19,31 @@
 #include "ImGuiSettings.generated.h"
 
 
+/**
+ * Struct containing key information that can be used for key binding. Using 'Undetermined' value for modifier keys
+ * means that those keys should be ignored when testing for a match.
+ */
+USTRUCT()
+struct FImGuiKeyInfo
+{
+	GENERATED_BODY()
+
+	UPROPERTY(EditAnywhere)
+	FKey Key;
+
+	UPROPERTY(EditAnywhere)
+	ECheckBoxState Shift = ECheckBoxState::Undetermined;
+
+	UPROPERTY(EditAnywhere)
+	ECheckBoxState Ctrl = ECheckBoxState::Undetermined;
+
+	UPROPERTY(EditAnywhere)
+	ECheckBoxState Alt = ECheckBoxState::Undetermined;
+
+	UPROPERTY(EditAnywhere)
+	ECheckBoxState Cmd = ECheckBoxState::Undetermined;
+};
+
 // Settings for ImGui module.
 UCLASS(config=ImGui, defaultconfig)
 class UImGuiSettings : public UObject
@@ -33,9 +58,14 @@ public:
 	// Path to custom implementation of ImGui Input Handler.
 	const FStringClassReference& GetImGuiInputHandlerClass() const { return ImGuiInputHandlerClass; }
 
+	// Get mapping for 'ImGui.SwitchInputMode' command.
+	const FImGuiKeyInfo& GetSwitchInputModeKey() const { return SwitchInputModeKey; }
+
 	// Delegate raised when ImGuiInputHandlerClass property has changed.
 	FSimpleMulticastDelegate OnImGuiInputHandlerClassChanged;
 
+	virtual void PostInitProperties() override;
+
 protected:
 
 	// Path to own implementation of ImGui Input Handler allowing to customize handling of keyboard and gamepad input.
@@ -43,8 +73,16 @@ protected:
 	UPROPERTY(EditAnywhere, config, Category = "Input", meta = (MetaClass = "ImGuiInputHandler"))
 	FStringClassReference ImGuiInputHandlerClass;
 
+	// Define a custom key binding to 'ImGui.SwitchInputMode' command. Mapping will be only set if Key property in this
+	// structure is set to a valid key. Modifier keys can be either completely ignored (Undetermined), required to be
+	// pressed (Checked) or required to be not pressed (Unchecked).
+	UPROPERTY(EditAnywhere, config, Category = "Input")
+	FImGuiKeyInfo SwitchInputModeKey;
+
 private:
 
+	void UpdateSwitchInputModeBinding();
+
 #if WITH_EDITOR
 
 	void RegisterPropertyChangedDelegate();

Source/ImGui/Private/Utilities/DebugExecBindings.cpp

@@ -0,0 +1,95 @@
+// Distributed under the MIT License (MIT) (see accompanying LICENSE file)
+
+#include "ImGuiPrivatePCH.h"
+
+#include "DebugExecBindings.h"
+#include "ImGuiSettings.h"
+
+#include <GameFramework/PlayerInput.h>
+
+
+namespace
+{
+	FKeyBind CreateKeyBind(const FImGuiKeyInfo& KeyInfo, const FString& Command)
+	{
+		FKeyBind KeyBind;
+		KeyBind.Command = Command;
+		KeyBind.Key = KeyInfo.Key;
+		KeyBind.bDisabled = false;
+
+#define FILL_MODIFIER_DATA(KeyInfoProperty, BindProperty, BindIgnoreProperty)\
+			if (KeyInfo.KeyInfoProperty == ECheckBoxState::Undetermined)\
+			{\
+				KeyBind.BindProperty = KeyBind.BindIgnoreProperty = false;\
+			}\
+			else\
+			{\
+				KeyBind.BindProperty = (KeyInfo.KeyInfoProperty == ECheckBoxState::Checked);\
+				KeyBind.BindIgnoreProperty = !KeyBind.BindProperty;\
+			}
+
+		FILL_MODIFIER_DATA(Shift, Shift, bIgnoreShift);
+		FILL_MODIFIER_DATA(Ctrl, Control, bIgnoreCtrl);
+		FILL_MODIFIER_DATA(Alt, Alt, bIgnoreAlt);
+		FILL_MODIFIER_DATA(Cmd, Cmd, bIgnoreCmd);
+
+#undef FILL_MODIFIER_DATA
+
+		return KeyBind;
+	}
+
+	bool IsBindable(const FKey& Key)
+	{
+		return Key.IsValid() && Key != EKeys::AnyKey && !Key.IsFloatAxis() && !Key.IsVectorAxis()
+			&& !Key.IsGamepadKey() && !Key.IsModifierKey() && !Key.IsMouseButton();
+	}
+
+	void UpdatePlayerInput(UPlayerInput* PlayerInput, const FKeyBind& KeyBind)
+	{
+		const int32 Index = PlayerInput->DebugExecBindings.IndexOfByPredicate([&](const FKeyBind& PlayerKeyBind)
+		{
+			return PlayerKeyBind.Command.Equals(KeyBind.Command, ESearchCase::IgnoreCase);
+		});
+
+		if (IsBindable(KeyBind.Key))
+		{
+			if (Index != INDEX_NONE)
+			{
+				PlayerInput->DebugExecBindings[Index] = KeyBind;
+			}
+			else
+			{
+				PlayerInput->DebugExecBindings.Add(KeyBind);
+			}
+		}
+		else
+		{
+			if (Index != INDEX_NONE)
+			{
+				PlayerInput->DebugExecBindings.RemoveAt(Index);
+			}
+		}
+	}
+}
+
+namespace DebugExecBindings
+{
+	void UpdatePlayerInputs(const FImGuiKeyInfo& KeyInfo, const FString& Command)
+	{
+		checkf(!Command.IsEmpty(), TEXT("Empty command."));
+
+		const FKeyBind KeyBind = CreateKeyBind(KeyInfo, Command);
+
+		// Update default player input, so changes will be visible in all PIE sessions created after this point.
+		if (UPlayerInput* DefaultPlayerInput = GetMutableDefault<UPlayerInput>())
+		{
+			UpdatePlayerInput(DefaultPlayerInput, KeyBind);
+		}
+
+		// Update all existing player inputs to see changes in running PIE session.
+		for (TObjectIterator<UPlayerInput> It; It; ++It)
+		{
+			UpdatePlayerInput(*It, KeyBind);
+		}
+	}
+}

Source/ImGui/Private/Utilities/DebugExecBindings.h

@@ -0,0 +1,10 @@
+// Distributed under the MIT License (MIT) (see accompanying LICENSE file)
+
+#pragma once
+
+struct FImGuiKeyInfo;
+
+namespace DebugExecBindings
+{
+	void UpdatePlayerInputs(const FImGuiKeyInfo& KeyInfo, const FString& Command);
+}

Source/ImGui/Public/ImGuiInputHandler.h

@@ -158,7 +158,7 @@ protected:
 	 * Checks whether this is a key event that can open console.
 	 *
 	 * @param KeyEvent - Key event to test.
-	 * @returns True, if this key event can open console. 
+	 * @returns True, if this key event can open console.
 	 */
 	bool IsConsoleEvent(const FKeyEvent& KeyEvent) const;
 
@@ -172,6 +172,14 @@ protected:
 	bool IsStopPlaySessionEvent(const FKeyEvent& KeyEvent) const;
 #endif
 
+	/**
+	 * Checks whether this key event can switch ImGui input mode (as defined in settings).
+	 *
+	 * @param KeyEvent - Key event to test.
+	 * @returns True, if this key is bound to 'ImGui.SwitchInputMode' command that switches ImGui input mode.
+	 */
+	bool IsSwitchInputModeEvent(const FKeyEvent& KeyEvent) const;
+
 	/**
 	 * Checks whether corresponding ImGui context has an active item (holding cursor focus).
 	 *