[nostalgia/studio] Start on ImGui version of Studio

src/nostalgia/studio/filedialogmanager.cpp

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2016 - 2021 gary@drinkingtea.net
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <imgui.h>
+
+#include <nostalgia/core/gfx.hpp>
+
+#include "filedialogmanager.hpp"
+
+namespace nostalgia {
+
+studio::TaskState FileDialogManager::update(core::Context *ctx) noexcept {
+	switch (m_state) {
+		case UpdateProjectPathState::EnableSystemCursor: {
+			// switch to system cursor in this update and open file dialog in the next
+			// the cursor state has to be set before the ImGui frame starts
+			auto &io = ImGui::GetIO();
+			io.MouseDrawCursor = false;
+			m_state = UpdateProjectPathState::RunFileDialog;
+			break;
+		}
+		case UpdateProjectPathState::RunFileDialog: {
+			// switch to system cursor
+			auto [path, err] = studio::chooseDirectory();
+			// Mac file dialog doesn't restore focus to main window when closed...
+			core::focusWindow(ctx);
+			if (!err) {
+				err = pathChosen.emitCheckError(path);
+				oxAssert(err, "Path chosen response failed");
+			}
+			auto &io = ImGui::GetIO();
+			io.MouseDrawCursor = true;
+			m_state = UpdateProjectPathState::None;
+			return nostalgia::studio::TaskState::Done;
+		}
+		case UpdateProjectPathState::None:
+			break;
+	}
+	return nostalgia::studio::TaskState::Running;
+}
+
+}