frontend: Add OBS::Canvas class

Author: dsaedtler

frontend/cmake/ui-utility.cmake

@@ -33,6 +33,8 @@ target_sources(
     utility/MultitrackVideoOutput.hpp
     utility/obf.c
     utility/obf.h
+    utility/OBSCanvas.cpp
+    utility/OBSCanvas.hpp
     utility/OBSEventFilter.hpp
     utility/OBSProxyStyle.cpp
     utility/OBSProxyStyle.hpp

frontend/utility/OBSCanvas.cpp

@@ -0,0 +1,100 @@
+/******************************************************************************
+    Copyright (C) 2025 by Dennis Sädtler <[email protected]>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+******************************************************************************/
+
+#include "OBSCanvas.hpp"
+
+#include <utility>
+
+namespace OBS {
+
+Canvas::Canvas(obs_canvas_t *canvas) : canvas(canvas) {}
+
+Canvas::Canvas(Canvas &&other) noexcept
+{
+	canvas = std::exchange(other.canvas, nullptr);
+}
+
+Canvas::~Canvas() noexcept
+{
+	if (!canvas)
+		return;
+
+	obs_canvas_remove(canvas);
+	obs_canvas_release(canvas);
+	canvas = nullptr;
+}
+
+Canvas &Canvas::operator=(Canvas &&other) noexcept
+{
+	canvas = std::exchange(other.canvas, canvas);
+
+	return *this;
+}
+
+std::optional<OBSDataAutoRelease> Canvas::Save() const
+{
+	if (!canvas)
+		return std::nullopt;
+	if (obs_data_t *saved = obs_save_canvas(canvas))
+		return saved;
+
+	return std::nullopt;
+}
+
+std::optional<Canvas> Canvas::Load(obs_data_t *data)
+{
+	if (OBSDataAutoRelease canvas_data = obs_data_get_obj(data, "info")) {
+		if (obs_canvas_t *canvas = obs_load_canvas(canvas_data)) {
+			return canvas;
+		}
+	}
+
+	return std::nullopt;
+}
+
+std::vector<Canvas> Canvas::LoadCanvases(obs_data_array_t *canvases)
+{
+	auto cb = [](obs_data_t *data, void *param) -> void {
+		auto vec = static_cast<std::vector<Canvas> *>(param);
+		if (auto canvas = Canvas::Load(data))
+			vec->emplace_back(std::move(*canvas));
+	};
+
+	std::vector<Canvas> ret;
+	obs_data_array_enum(canvases, cb, &ret);
+
+	return ret;
+}
+
+OBSDataArrayAutoRelease Canvas::SaveCanvases(const std::vector<Canvas> &canvases)
+{
+	OBSDataArrayAutoRelease savedCanvases = obs_data_array_create();
+
+	for (auto &canvas : canvases) {
+		auto canvas_data = canvas.Save();
+		if (!canvas_data)
+			continue;
+
+		OBSDataAutoRelease data = obs_data_create();
+		obs_data_set_obj(data, "info", *canvas_data);
+		obs_data_array_push_back(savedCanvases, data);
+	}
+
+	return savedCanvases;
+}
+
+} // namespace OBS

frontend/utility/OBSCanvas.hpp

@@ -0,0 +1,51 @@
+/******************************************************************************
+    Copyright (C) 2025 by Dennis Sädtler <[email protected]>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+******************************************************************************/
+
+#pragma once
+
+#include <optional>
+#include <vector>
+
+#include "obs.h"
+#include "obs.hpp"
+
+namespace OBS {
+class Canvas {
+
+public:
+	Canvas(obs_canvas_t *canvas);
+	Canvas(Canvas &&other) noexcept;
+
+	~Canvas() noexcept;
+
+	// No default or copy/move constructors
+	Canvas() = delete;
+	Canvas(Canvas &other) = delete;
+
+	Canvas &operator=(Canvas &&other) noexcept;
+
+	operator obs_canvas_t *() const { return canvas; }
+
+	[[nodiscard]] std::optional<OBSDataAutoRelease> Save() const;
+	static std::optional<Canvas> Load(obs_data_t *data);
+	static std::vector<Canvas> LoadCanvases(obs_data_array_t *canvases);
+	static OBSDataArrayAutoRelease SaveCanvases(const std::vector<Canvas> &canvases);
+
+private:
+	obs_canvas_t *canvas = nullptr;
+};
+} // namespace OBS