Moved input state from SImGuiWidget to FImGuiContextProxy and modified implementation of FImGuiInputState reset functionality.

Moving input state to context proxy decouples it a bit from a particular input source and although not used right now, it allows multiple sources to send input in parallel.

Source/ImGui/Private/ImGuiContextProxy.cpp

@@ -151,10 +151,8 @@ void FImGuiContextProxy::BeginFrame(float DeltaTime)
 		ImGuiIO& IO = ImGui::GetIO();
 		IO.DeltaTime = DeltaTime;
 
-		if (InputState)
+		ImGuiInterops::CopyInput(IO, InputState);
-		{
+		InputState.ClearUpdateState();
-			ImGuiInterops::CopyInput(IO, *InputState);
-		}
 
 		ImGui::NewFrame();
 

Source/ImGui/Private/ImGuiContextProxy.h

@@ -3,7 +3,7 @@
 #pragma once
 
 #include "ImGuiDrawData.h"
-
+#include "ImGuiInputState.h"
 #include "Utilities/WorldContextIndex.h"
 
 #include <ICursor.h>
@@ -13,8 +13,6 @@
 #include <string>
 
 
-class FImGuiInputState;
-
 // Represents a single ImGui context. All the context updates should be done through this proxy. During update it
 // broadcasts draw events to allow listeners draw their controls. After update it stores draw data.
 class FImGuiContextProxy
@@ -58,13 +56,8 @@ public:
 	const TArray<FImGuiDrawList>& GetDrawData() const { return DrawLists; }
 
 	// Get input state used by this context.
-	const FImGuiInputState* GetInputState() const { return InputState; }
+	FImGuiInputState& GetInputState() { return InputState; }
-
+	const FImGuiInputState& GetInputState() const { return InputState; }
-	// Set input state to be used by this context.
-	void SetInputState(const FImGuiInputState* SourceInputState) { InputState = SourceInputState; }
-
-	// If context is currently using input state to remove then remove that binding.
-	void RemoveInputState(const FImGuiInputState* InputStateToRemove) { if (InputState == InputStateToRemove) InputState = nullptr; }
 
 	// Is this context the current ImGui context.
 	bool IsCurrentContext() const { return ImGui::GetCurrentContext() == Context.Get(); }
@@ -117,7 +110,7 @@ private:
 	bool bIsDrawEarlyDebugCalled = false;
 	bool bIsDrawDebugCalled = false;
 
-	const FImGuiInputState* InputState = nullptr;
+	FImGuiInputState InputState;
 
 	TArray<FImGuiDrawList> DrawLists;
 

Source/ImGui/Private/ImGuiInputState.cpp

@@ -46,7 +46,7 @@ namespace
 
 FImGuiInputState::FImGuiInputState()
 {
-	ResetState();
+	Reset();
 }
 
 void FImGuiInputState::AddCharacter(TCHAR Char)
@@ -82,31 +82,6 @@ void FImGuiInputState::SetMouseDown(uint32 MouseIndex, bool bIsDown)
 	}
 }
 
-void FImGuiInputState::Reset(bool bKeyboard, bool bMouse, bool bNavigation)
-{
-	if (bKeyboard)
-	{
-		ClearCharacters();
-		ClearKeys();
-	}
-
-	if (bMouse)
-	{
-		ClearMouseButtons();
-		ClearMouseAnalogue();
-	}
-
-	if (bKeyboard && bMouse)
-	{
-		ClearModifierKeys();
-	}
-
-	if (bNavigation)
-	{
-		ClearNavigationInputs();
-	}
-}
-
 void FImGuiInputState::ClearUpdateState()
 {
 	if (InputCharactersNum > 0)
@@ -132,7 +107,7 @@ void FImGuiInputState::ClearKeys()
 	using std::fill;
 	fill(KeysDown, &KeysDown[Utilities::GetArraySize(KeysDown)], false);
 
-	// Expand update range because keys array has been updated.
+	// Mark the whole array as dirty because potentially each entry could be affected.
 	KeysUpdateRange.SetFull();
 }
 
@@ -141,7 +116,7 @@ void FImGuiInputState::ClearMouseButtons()
 	using std::fill;
 	fill(MouseButtonsDown, &MouseButtonsDown[Utilities::GetArraySize(MouseButtonsDown)], false);
 
-	// Expand update range because mouse buttons array has been updated.
+	// Mark the whole array as dirty because potentially each entry could be affected.
 	MouseButtonsUpdateRange.SetFull();
 }
 

Source/ImGui/Private/ImGuiInputState.h

@@ -151,17 +151,34 @@ public:
 	// @param bInHasGamepad - True, if gamepad is attached
 	void SetGamepad(bool bInHasGamepad) { bHasGamepad = bInHasGamepad; }
 
-	// Reset the whole state and mark as dirty.
+	// Reset the whole input state and mark it as dirty.
-	void ResetState() { Reset(true, true, true); }
+	void Reset()
+	{
+		ResetKeyboard();
+		ResetMouse();
+		ResetGamepadNavigation();
+	}
 
-	// Reset keyboard state and mark as dirty.
+	// Reset the keyboard input state and mark it as dirty.
-	void ResetKeyboardState() { Reset(true, false, false); }
+	void ResetKeyboard()
+	{
+		ClearCharacters();
+		ClearKeys();
+		ClearModifierKeys();
+	}
 
-	// Reset mouse state and mark as dirty.
+	// Reset the mouse input state and mark it as dirty.
-	void ResetMouseState() { Reset(false, true, false); }
+	void ResetMouse()
+	{
+		ClearMouseButtons();
+		ClearMouseAnalogue();
+	}
 
-	// Reset navigation state.
+	// Reset the gamepad navigation state.
-	void ResetNavigationState() { Reset(false, false, true); }
+	void ResetGamepadNavigation()
+	{
+		ClearNavigationInputs();
+	}
 
 	// Clear part of the state that is meant to be updated in every frame like: accumulators, buffers, navigation data
 	// and information about dirty parts of keys or mouse buttons arrays.
@@ -172,8 +189,6 @@ private:
 	void SetKeyDown(uint32 KeyIndex, bool bIsDown);
 	void SetMouseDown(uint32 MouseIndex, bool IsDown);
 
-	void Reset(bool bKeyboard, bool bMouse, bool bNavigation);
-
 	void ClearCharacters();
 	void ClearKeys();
 	void ClearMouseButtons();

Source/ImGui/Private/Widgets/SImGuiWidget.cpp

@@ -10,6 +10,7 @@
 #include "ImGuiImplementation.h"
 #include "ImGuiInputHandler.h"
 #include "ImGuiInputHandlerFactory.h"
+#include "ImGuiInputState.h"
 #include "ImGuiInteroperability.h"
 #include "ImGuiModuleManager.h"
 #include "ImGuiModuleSettings.h"
@@ -83,7 +84,7 @@ void SImGuiWidget::Construct(const FArguments& InArgs)
 #if IMGUI_WIDGET_DEBUG
 	ContextProxy->OnDraw().AddRaw(this, &SImGuiWidget::OnDebugDraw);
 #endif // IMGUI_WIDGET_DEBUG
-	ContextProxy->SetInputState(&InputState);
+	InputState = &ContextProxy->GetInputState();
 
 	// Register for settings change.
 	RegisterImGuiSettingsDelegates();
@@ -119,7 +120,6 @@ SImGuiWidget::~SImGuiWidget()
 #if IMGUI_WIDGET_DEBUG
 		ContextProxy->OnDraw().RemoveAll(this);
 #endif // IMGUI_WIDGET_DEBUG
-		ContextProxy->RemoveInputState(&InputState);
 	}
 
 	// Unregister from post-update notifications.
@@ -148,7 +148,7 @@ FReply SImGuiWidget::OnKeyChar(const FGeometry& MyGeometry, const FCharacterEven
 	const FImGuiInputResponse Response = InputHandler->OnKeyChar(CharacterEvent);
 	if (Response.HasProcessingRequest())
 	{
-		InputState.AddCharacter(CharacterEvent.GetCharacter());
+		InputState->AddCharacter(CharacterEvent.GetCharacter());
 	}
 
 	return ToSlateReply(Response);
@@ -158,12 +158,12 @@ FReply SImGuiWidget::OnKeyDown(const FGeometry& MyGeometry, const FKeyEvent& Key
 {
 	if (KeyEvent.GetKey().IsGamepadKey())
 	{
-		if (InputState.IsGamepadNavigationEnabled())
+		if (InputState->IsGamepadNavigationEnabled())
 		{
 			const FImGuiInputResponse Response = InputHandler->OnGamepadKeyDown(KeyEvent);
 			if (Response.HasProcessingRequest())
 			{
-				InputState.SetGamepadNavigationKey(KeyEvent, true);
+				InputState->SetGamepadNavigationKey(KeyEvent, true);
 			}
 
 			return ToSlateReply(Response);
@@ -180,7 +180,7 @@ FReply SImGuiWidget::OnKeyDown(const FGeometry& MyGeometry, const FKeyEvent& Key
 		const FImGuiInputResponse Response = InputHandler->OnKeyDown(KeyEvent);
 		if (Response.HasProcessingRequest())
 		{
-			InputState.SetKeyDown(KeyEvent, true);
+			InputState->SetKeyDown(KeyEvent, true);
 			CopyModifierKeys(KeyEvent);
 		}
 
@@ -192,10 +192,10 @@ FReply SImGuiWidget::OnKeyUp(const FGeometry& MyGeometry, const FKeyEvent& KeyEv
 {
 	if (KeyEvent.GetKey().IsGamepadKey())
 	{
-		if (InputState.IsGamepadNavigationEnabled())
+		if (InputState->IsGamepadNavigationEnabled())
 		{
 			// Always handle key up events to protect from leaving accidental keys not cleared in ImGui input state.
-			InputState.SetGamepadNavigationKey(KeyEvent, false);
+			InputState->SetGamepadNavigationKey(KeyEvent, false);
 
 			return ToSlateReply(InputHandler->OnGamepadKeyUp(KeyEvent));
 		}
@@ -209,7 +209,7 @@ FReply SImGuiWidget::OnKeyUp(const FGeometry& MyGeometry, const FKeyEvent& KeyEv
 		UpdateCanvasControlMode(KeyEvent);
 
 		// Always handle key up events to protect from leaving accidental keys not cleared in ImGui input state.
-		InputState.SetKeyDown(KeyEvent, false);
+		InputState->SetKeyDown(KeyEvent, false);
 		CopyModifierKeys(KeyEvent);
 
 		return ToSlateReply(InputHandler->OnKeyUp(KeyEvent));
@@ -218,12 +218,12 @@ FReply SImGuiWidget::OnKeyUp(const FGeometry& MyGeometry, const FKeyEvent& KeyEv
 
 FReply SImGuiWidget::OnAnalogValueChanged(const FGeometry& MyGeometry, const FAnalogInputEvent& AnalogInputEvent)
 {
-	if (AnalogInputEvent.GetKey().IsGamepadKey() && InputState.IsGamepadNavigationEnabled())
+	if (AnalogInputEvent.GetKey().IsGamepadKey() && InputState->IsGamepadNavigationEnabled())
 	{
 		const FImGuiInputResponse Response = InputHandler->OnGamepadAxis(AnalogInputEvent);
 		if (Response.HasProcessingRequest())
 		{
-			InputState.SetGamepadNavigationAxis(AnalogInputEvent, AnalogInputEvent.GetAnalogValue());
+			InputState->SetGamepadNavigationAxis(AnalogInputEvent, AnalogInputEvent.GetAnalogValue());
 		}
 
 		return ToSlateReply(Response);
@@ -236,32 +236,32 @@ FReply SImGuiWidget::OnAnalogValueChanged(const FGeometry& MyGeometry, const FAn
 
 FReply SImGuiWidget::OnMouseButtonDown(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
 {
-	InputState.SetMouseDown(MouseEvent, true);
+	InputState->SetMouseDown(MouseEvent, true);
 	return FReply::Handled();
 }
 
 FReply SImGuiWidget::OnMouseButtonDoubleClick(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
 {
-	InputState.SetMouseDown(MouseEvent, true);
+	InputState->SetMouseDown(MouseEvent, true);
 	return FReply::Handled();
 }
 
 FReply SImGuiWidget::OnMouseButtonUp(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
 {
-	InputState.SetMouseDown(MouseEvent, false);
+	InputState->SetMouseDown(MouseEvent, false);
 	return FReply::Handled();
 }
 
 FReply SImGuiWidget::OnMouseWheel(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
 {
-	InputState.AddMouseWheelDelta(MouseEvent.GetWheelDelta());
+	InputState->AddMouseWheelDelta(MouseEvent.GetWheelDelta());
 	return FReply::Handled();
 }
 
 FReply SImGuiWidget::OnMouseMove(const FGeometry& MyGeometry, const FPointerEvent& MouseEvent)
 {
 	const FSlateRenderTransform ImGuiToScreen = ImGuiTransform.Concatenate(MyGeometry.GetAccumulatedRenderTransform());
-	InputState.SetMousePosition(ImGuiToScreen.Inverse().TransformPoint(MouseEvent.GetScreenSpacePosition()));
+	InputState->SetMousePosition(ImGuiToScreen.Inverse().TransformPoint(MouseEvent.GetScreenSpacePosition()));
 	return FReply::Handled();
 }
 
@@ -300,7 +300,7 @@ void SImGuiWidget::OnMouseEnter(const FGeometry& MyGeometry, const FPointerEvent
 	{
 		for (const FKey& Button : { EKeys::LeftMouseButton, EKeys::MiddleMouseButton, EKeys::RightMouseButton, EKeys::ThumbMouseButton, EKeys::ThumbMouseButton2 })
 		{
-			InputState.SetMouseDown(Button, MouseEvent.IsMouseButtonDown(Button));
+			InputState->SetMouseDown(Button, MouseEvent.IsMouseButtonDown(Button));
 		}
 	}
 
@@ -375,9 +375,9 @@ void SImGuiWidget::UnregisterImGuiSettingsDelegates()
 
 void SImGuiWidget::CopyModifierKeys(const FInputEvent& InputEvent)
 {
-	InputState.SetControlDown(InputEvent.IsControlDown());
+	InputState->SetControlDown(InputEvent.IsControlDown());
-	InputState.SetShiftDown(InputEvent.IsShiftDown());
+	InputState->SetShiftDown(InputEvent.IsShiftDown());
-	InputState.SetAltDown(InputEvent.IsAltDown());
+	InputState->SetAltDown(InputEvent.IsAltDown());
 }
 
 bool SImGuiWidget::IsConsoleOpened() const
@@ -493,10 +493,10 @@ void SImGuiWidget::UpdateInputEnabled()
 
 	if (bInputEnabled)
 	{
-		InputState.SetKeyboardNavigationEnabled(ModuleManager && ModuleManager->GetProperties().IsKeyboardNavigationEnabled());
+		InputState->SetKeyboardNavigationEnabled(ModuleManager && ModuleManager->GetProperties().IsKeyboardNavigationEnabled());
-		InputState.SetGamepadNavigationEnabled(ModuleManager && ModuleManager->GetProperties().IsGamepadNavigationEnabled());
+		InputState->SetGamepadNavigationEnabled(ModuleManager && ModuleManager->GetProperties().IsGamepadNavigationEnabled());
 		const auto& Application = FSlateApplication::Get().GetPlatformApplication();
-		InputState.SetGamepad(Application.IsValid() && Application->IsGamepadAttached());
+		InputState->SetGamepad(Application.IsValid() && Application->IsGamepadAttached());
 	}
 }
 
@@ -516,18 +516,18 @@ void SImGuiWidget::UpdateInputMode(bool bHasKeyboardFocus, bool bHasMousePointer
 		// mouse-only input mode.
 		if (NewInputMode == EInputMode::None)
 		{
-			InputState.ResetState();
+			InputState->Reset();
 		}
 		else if (InputMode == EInputMode::Full)
 		{
-			InputState.ResetKeyboardState();
+			InputState->ResetKeyboard();
-			InputState.ResetNavigationState();
+			InputState->ResetGamepadNavigation();
 		}
 
 		InputMode = NewInputMode;
 	}
 
-	InputState.SetMousePointer(bUseSoftwareCursor && bHasMousePointer);
+	InputState->SetMousePointer(bUseSoftwareCursor && bHasMousePointer);
 }
 
 void SImGuiWidget::UpdateCanvasControlMode(const FInputEvent& InputEvent)
@@ -537,11 +537,6 @@ void SImGuiWidget::UpdateCanvasControlMode(const FInputEvent& InputEvent)
 
 void SImGuiWidget::OnPostImGuiUpdate()
 {
-	if (InputMode != EInputMode::None)
-	{
-		InputState.ClearUpdateState();
-	}
-
 	ImGuiRenderTransform = ImGuiTransform;
 }
 
@@ -780,7 +775,7 @@ void SImGuiWidget::OnDebugDraw()
 			{
 				TwoColumns::Value("Input Enabled", bInputEnabled);
 				TwoColumns::Value("Input Mode", TEXT_INPUT_MODE(InputMode));
-				TwoColumns::Value("Input Has Mouse Pointer", InputState.HasMousePointer());
+				TwoColumns::Value("Input Has Mouse Pointer", InputState->HasMousePointer());
 			});
 
 			TwoColumns::CollapsingGroup("Widget", [&]()
@@ -837,7 +832,7 @@ void SImGuiWidget::OnDebugDraw()
 						{
 							const FKey& Key = Keys[Idx];
 							const uint32 KeyIndex = ImGuiInterops::GetKeyIndex(Key);
-							Styles::TextHighlight(InputState.GetKeys()[KeyIndex], [&]()
+							Styles::TextHighlight(InputState->GetKeys()[KeyIndex], [&]()
 							{
 								TwoColumns::Value(*Key.GetDisplayName().ToString(), KeyIndex);
 							});
@@ -852,9 +847,9 @@ void SImGuiWidget::OnDebugDraw()
 
 			Columns::CollapsingGroup("Modifier Keys", 4, [&]()
 			{
-				Styles::TextHighlight(InputState.IsShiftDown(), [&]() { ImGui::Text("Shift"); }); ImGui::NextColumn();
+				Styles::TextHighlight(InputState->IsShiftDown(), [&]() { ImGui::Text("Shift"); }); ImGui::NextColumn();
-				Styles::TextHighlight(InputState.IsControlDown(), [&]() { ImGui::Text("Control"); }); ImGui::NextColumn();
+				Styles::TextHighlight(InputState->IsControlDown(), [&]() { ImGui::Text("Control"); }); ImGui::NextColumn();
-				Styles::TextHighlight(InputState.IsAltDown(), [&]() { ImGui::Text("Alt"); }); ImGui::NextColumn();
+				Styles::TextHighlight(InputState->IsAltDown(), [&]() { ImGui::Text("Alt"); }); ImGui::NextColumn();
 				ImGui::NextColumn();
 			});
 
@@ -877,7 +872,7 @@ void SImGuiWidget::OnDebugDraw()
 						{
 							const FKey& Button = Buttons[Idx];
 							const uint32 MouseIndex = ImGuiInterops::GetMouseIndex(Button);
-							Styles::TextHighlight(InputState.GetMouseButtons()[MouseIndex], [&]()
+							Styles::TextHighlight(InputState->GetMouseButtons()[MouseIndex], [&]()
 							{
 								TwoColumns::Value(*Button.GetDisplayName().ToString(), MouseIndex);
 							});
@@ -892,9 +887,9 @@ void SImGuiWidget::OnDebugDraw()
 
 			Columns::CollapsingGroup("Mouse Axes", 4, [&]()
 			{
-				TwoColumns::Value("Position X", InputState.GetMousePosition().X);
+				TwoColumns::Value("Position X", InputState->GetMousePosition().X);
-				TwoColumns::Value("Position Y", InputState.GetMousePosition().Y);
+				TwoColumns::Value("Position Y", InputState->GetMousePosition().Y);
-				TwoColumns::Value("Wheel Delta", InputState.GetMouseWheelDelta());
+				TwoColumns::Value("Wheel Delta", InputState->GetMouseWheelDelta());
 				ImGui::NextColumn(); ImGui::NextColumn();
 			});
 

Source/ImGui/Private/Widgets/SImGuiWidget.h

@@ -2,7 +2,6 @@
 
 #pragma once
 
-#include "ImGuiInputState.h"
 #include "ImGuiModuleDebug.h"
 #include "ImGuiModuleSettings.h"
 
@@ -12,6 +11,7 @@
 // Hide ImGui Widget debug in non-developer mode.
 #define IMGUI_WIDGET_DEBUG IMGUI_MODULE_DEVELOPER
 
+class FImGuiInputState;
 class FImGuiModuleManager;
 class SImGuiCanvasControl;
 class UImGuiInputHandler;
@@ -37,9 +37,6 @@ public:
 	// Get index of the context that this widget is targeting.
 	int32 GetContextIndex() const { return ContextIndex; }
 
-	// Get input state associated with this widget.
-	const FImGuiInputState& GetInputState() const { return InputState; }
-
 	//----------------------------------------------------------------------------------------------------
 	// SWidget overrides
 	//----------------------------------------------------------------------------------------------------
@@ -137,7 +134,7 @@ private:
 
 	int32 ContextIndex = 0;
 
-	FImGuiInputState InputState;
+	FImGuiInputState* InputState;
 
 	EInputMode InputMode = EInputMode::None;
 	bool bInputEnabled = false;