Helper to set and forget imgui style changes.

ImGuiStyleScope.h

//-------------------------------------------------------------------------------------------------
// Helper for managing style changes. Can set and forget.
// Usage 1: ImGuiStyleScope scope(ImGuiCol_Text, ImGuiColors::Red);
// Usage 2:
//	ImGuiStyleScope scope;
//	scope.Color(ImGuiCol_Text, ImGuiColors::Yellow)
//		.Style(ImGuiStyleVar_Alpha, 0.4f);
//-------------------------------------------------------------------------------------------------
class ImGuiStyleScope : GC_NonCopyable
{
public:
	ImGuiStyleScope() : myColors(0), myVars(0) {}
	ImGuiStyleScope(ImGuiCol anIndex, ImU32 aValue) : ImGuiStyleScope()
	{
		Color(anIndex, aValue);
	}
	ImGuiStyleScope(ImGuiCol anIndex, ImVec4 const& aValue) : ImGuiStyleScope()
	{
		Color(anIndex, aValue);
	}
	ImGuiStyleScope(ImGuiStyleVar anIndex, float aValue) : ImGuiStyleScope()
	{
		Style(anIndex, aValue);
	}
	ImGuiStyleScope(ImGuiStyleVar anIndex, ImVec2 const& aValue) : ImGuiStyleScope()
	{
		Style(anIndex, aValue);
	}
	~ImGuiStyleScope()
	{
		if (myColors) ImGui::PopStyleColor(myColors);
		if (myVars) ImGui::PopStyleVar(myVars);
	}

	ImGuiStyleScope& Color(ImGuiCol anIndex, ImU32 aValue)
	{
		ImGui::PushStyleColor(anIndex, aValue);
		++myColors;
		return *this;
	}
	ImGuiStyleScope& Color(ImGuiCol anIndex, ImVec4 const& aValue)
	{
		ImGui::PushStyleColor(anIndex, aValue);
		++myColors;
		return *this;
	}
	ImGuiStyleScope& Style(ImGuiStyleVar anIndex, float aValue)
	{
		ImGui::PushStyleVar(anIndex, aValue);
		++myVars;
		return *this;
	}
	ImGuiStyleScope& Style(ImGuiStyleVar anIndex, ImVec2 const& aValue)
	{
		ImGui::PushStyleVar(anIndex, aValue);
		++myVars;
		return *this;
	}

private:
	uint myColors;
	uint myVars;
};