[studio] Add confirmation for closing file with unsaved changes

src/olympic/studio/modlib/include/studio/imguiutil.hpp

@@ -303,6 +303,34 @@ class FilePicker {
 
 };
 
+class QuestionPopup {
+ 	private:
+		enum class Stage {
+			Closed,
+			Opening,
+			Open,
+		};
+		Stage m_stage = Stage::Closed;
+		bool m_open{};
+		ox::String m_title;
+		ox::String m_question;
+
+	public:
+		ox::Signal<ox::Error(ig::PopupResponse)> response;
+
+		QuestionPopup(ox::StringParam title, ox::StringParam question) noexcept;
+
+		void open() noexcept;
+
+		void close() noexcept;
+
+		[[nodiscard]]
+		bool isOpen() const noexcept;
+
+		void draw(StudioContext &ctx, ImVec2 const &sz = {}) noexcept;
+
+};
+
 [[nodiscard]]
 bool mainWinHasFocus() noexcept;
 

src/olympic/studio/modlib/src/imguiutil.cpp

@@ -225,6 +225,59 @@ void FilePicker::show() noexcept {
 	m_show = true;
 }
 
+
+QuestionPopup::QuestionPopup(ox::StringParam title, ox::StringParam question) noexcept:
+	m_title{std::move(title)},
+	m_question{std::move(question)} {
+}
+
+void QuestionPopup::open() noexcept {
+	m_stage = Stage::Opening;
+}
+
+void QuestionPopup::close() noexcept {
+	m_stage = Stage::Closed;
+	m_open = false;
+}
+
+bool QuestionPopup::isOpen() const noexcept {
+	return m_open;
+}
+
+void QuestionPopup::draw(StudioContext &ctx, ImVec2 const &sz) noexcept {
+	switch (m_stage) {
+		case Stage::Closed:
+			break;
+		case Stage::Opening:
+			ImGui::OpenPopup(m_title.c_str());
+			m_stage = Stage::Open;
+			m_open = true;
+		[[fallthrough]];
+		case Stage::Open:
+			centerNextWindow(ctx.tctx);
+			ImGui::SetNextWindowSize(static_cast<ImVec2>(sz));
+			constexpr auto modalFlags = ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoResize;
+			if (ImGui::BeginPopupModal(m_title.c_str(), &m_open, modalFlags)) {
+				ImGui::Text("%s", m_question.c_str());
+				auto const r = PopupControlsOkCancel(m_open, "Yes", "No");
+				response.emit(r);
+				switch (r) {
+					case PopupResponse::None:
+						break;
+					case PopupResponse::OK:
+						close();
+						break;
+					case PopupResponse::Cancel:
+						close();
+						break;
+				}
+				ImGui::EndPopup();
+			}
+			break;
+	}
+}
+
+
 bool s_mainWinHasFocus{};
 bool mainWinHasFocus() noexcept {
 	return s_mainWinHasFocus;