Improved number editing control for ImGui

iminputvalue.cpp

// WARNING: Revision 5+ Requires unreleased code from imgui, stick to 3 or 2 for now (don't look at revision 4)

#define IMGUI_DEFINE_MATH_OPERATORS
#include <imgui.h>
#include <imgui_internal.h>
#include "iminputvalue.h"

namespace ImGui
{
  //-------------------------------------------------------------------------------------------------
	// Customized number box with mouse drag support and condensed arrow buttons
	//-------------------------------------------------------------------------------------------------
	template <typename T>
	bool InputValue(T& aValue, T aStep, ImGuiDataType aType, char const* aFormat, ImGuiInputTextFlags aFlags)
	{
		float width = CalcItemWidth();
		float height = GetFrameHeight();

		BeginGroup();

		// Only show buttons if there's enough space
		bool hasButtons = width > height * 4;
		int buttonStep = 0;
		if (hasButtons)
		{
			width -= height;
			PushItemWidth(width);
		}

		bool changed = InputScalar("", aType, &aValue, nullptr, nullptr, aFormat, aFlags);
		ImGuiID id = GetItemID();

		SetActiveItemUsesMouseWheel(id);

		if (hasButtons)
		{
			PopItemWidth();

			PushStyleVar(ImGuiStyleVar_FramePadding, { 0, 0 });
			PushStyleVar(ImGuiStyleVar_ItemSpacing, { 0, 0 });

			SameLine();

			BeginGroup();

			if (ButtonEx("###up", { height, height / 2 }, ImGuiButtonFlags_NoNavFocus))
			{
				buttonStep = 1;
			}

			SetActiveItemUsesMouseWheel(id);

			float offset = height - GetFontSize();
			ImVec2 pos = GetItemRectMin();
			RenderArrow(GetWindowDrawList(), { pos.x + offset / 2, pos.y + offset / 4 }, GetColorU32(ImGuiCol_Text), ImGuiDir_Up, 0.5f);

			if (ButtonEx("###down", { height, height / 2 + 1 }, ImGuiButtonFlags_NoNavFocus))
			{
				buttonStep = -1;
			}

			SetActiveItemUsesMouseWheel(id);

			pos = ImGui::GetItemRectMin();
			RenderArrow(GetWindowDrawList(), { pos.x + offset / 2, pos.y + 1 }, GetColorU32(ImGuiCol_Text), ImGuiDir_Down, 0.5f);

			EndGroup();

			PopStyleVar(2);
		}

		EndGroup();

		if (buttonStep)
		{
			if (ApplyStep(aValue, aStep, aType, buttonStep))
			{
				changed = true;
				SetKeyboardFocusHere(-1);
			}
		}

		// Drag support
		{
			GC_MouseDragHelper& helper = ImGuiHelpers::GetStorageSlot()->GetOrCreate<GC_MouseDragHelper>(true);

			if (helper.HasMouse() || IsItemHovered())
			{
				if (helper.Update(GetIO().KeyShift ? GC_MouseKey::Left : GC_MouseKey::Middle))
					SetKeyboardFocusHere(-1);
			}

			if (helper.HasMouse())
			{
				GC_Vector2i delta = GC_InputMouse::Instance().Movement();
				if (ApplyStep(aValue, aStep, aType, delta.x - delta.y))
				{
					changed = true;
					if (GImGui->InputTextState.ID == id)
						GImGui->InputTextState.Reinitialize = true;
				}
			}
		}

		// Mouse wheel support
		{
			if (IsItemHovered() && IsItemActive())
			{
				if (float scroll = GetIO().InputCurrentFrame->MouseWheel)
				{
					if (ApplyStep(aValue, aStep, aType, scroll))
					{
						changed = true;
						if (GImGui->InputTextState.ID == id)
							GImGui->InputTextState.Reinitialize = true;
					}
				}
			}
		}

		return changed;
	}
	//-------------------------------------------------------------------------------------------------
	template <typename T>
	bool InputValues(char const* label, int components, ImGuiDataType data_type, T* aValue, T const* aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		ImGuiWindow* window = GetCurrentWindow();
		if (window->SkipItems)
			return false;

		ImGuiContext& g = *GImGui;
		bool value_changed = false;
		BeginGroup();
		PushID(label);
		PushMultiItemsWidths(components, CalcItemWidth());
		for (int i = 0; i < components; i++)
		{
			PushID(i);
			if (i > 0)
				SameLine(0, g.Style.ItemInnerSpacing.x);
			value_changed |= InputValue(aValue[i], aStep[i], data_type, aFormat, aFlags);
			PopID();
			PopItemWidth();
		}
		PopID();

		const char* label_end = FindRenderedTextEnd(label);
		if (label != label_end)
		{
			SameLine(0.0f, g.Style.ItemInnerSpacing.x);
			TextEx(label, label_end);
		}

		EndGroup();
		return value_changed;
	}

	//-------------------------------------------------------------------------------------------------
	// All the value hooks into the custom edit box
	//-------------------------------------------------------------------------------------------------
	bool Input(char const* aName, float& aValue, float aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_Float, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, double& aValue, double aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_Double, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, s8& aValue, s8 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_S8, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, s16& aValue, s16 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_S16, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, s32& aValue, s32 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_S32, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, s64& aValue, s64 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_S64, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, u8& aValue, u8 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_U8, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, u16& aValue, u16 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_U16, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, u32& aValue, u32 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_U32, &aValue, &aStep, aFlags, aFormat);
	}

	bool Input(char const* aName, u64& aValue, u64 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 1, ImGuiDataType_U64, &aValue, &aStep, aFlags, aFormat);
	}

	// Example for vector/math types
	bool Input(char const* aName, Vector3<float>& aValue, u64 aStep, ImGuiInputTextFlags aFlags, char const* aFormat)
	{
		return InputValues(aName, 3, ImGuiDataType_Float, &aValue, &aStep, aFlags, aFormat);
	}
}

iminputvalue.h

// WARNING: Revision 5+ Requires unreleased code from imgui, stick to 3 or 2 for now (don't look at revision 4)
namespace ImGui
{
	//-------------------------------------------------------------------------------------------------
	// All the value hooks into the custom edit box
	//-------------------------------------------------------------------------------------------------
	bool Input(char const* aName, float& aValue, float aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, double& aValue, double aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, s8& aValue, s8 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, s16& aValue, s16 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, s32& aValue, s32 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, s64& aValue, s64 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, u8& aValue, u8 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, u16& aValue, u16 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, u32& aValue, u32 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	bool Input(char const* aName, u64& aValue, u64 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
	
	// Example for vector/math types
	bool Input(char const* aName, Vector3<float>& aValue, u64 aStep, ImGuiInputTextFlags aFlags, char const* aFormat);
}