new UI system

interfaces/Crafter.Graphics-UIScene.cppm

@@ -0,0 +1,111 @@
+/*
+Crafter®.Graphics
+Copyright (C) 2026 Catcrafts®
+catcrafts.net
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License version 3.0 as published by the Free Software Foundation;
+
+This library 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
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+*/
+module;
+#include "vulkan/vulkan.h"
+export module Crafter.Graphics:UIScene;
+import std;
+import :Window;
+import :Types;
+import :DescriptorHeapVulkan;
+import Crafter.Event;
+import :UIWidget;
+import :UIWidgets;
+import :UILayout;
+import :UIDrawList;
+import :UIRenderer;
+import :UIHit;
+
+export namespace Crafter::UI {
+    // The single user-facing wrapper that ties the widget tree to the
+    // window's frame loop. Owns the renderer + draw list, optionally
+    // owns a default descriptor heap, registers itself as a RenderPass on
+    // the window, and routes mouse clicks through the hit tester.
+    //
+    // Typical usage:
+    //
+    //     Crafter::Window  window(1280, 720, "Demo");
+    //     window.StartInit(); window.FinishInit();
+    //     Crafter::UI::UIScene scene;
+    //     scene.Initialize(window);
+    //     scene.Root(VStack{}.children(
+    //         Button{"Play"}.onClick([&]{ ... }),
+    //         ...
+    //     ));
+    //     window.Render();
+    //     window.StartUpdate();   // continuous rendering
+    //     window.StartSync();
+    class UIScene {
+    public:
+        UIRenderer renderer;
+        DrawList   drawList;
+
+        UIScene() = default;
+        UIScene(const UIScene&) = delete;
+        UIScene& operator=(const UIScene&) = delete;
+        ~UIScene();
+
+        void Initialize(Window& window,
+                        const std::filesystem::path& spvPath = "ui.comp.spv");
+
+        // Replace the widget tree. Takes ownership and clears focus
+        // (the previously-focused widget will be destroyed with the
+        // old tree).
+        template<typename W>
+            requires std::derived_from<std::remove_cvref_t<W>, Widget>
+        void Root(W&& root) {
+            SetFocus(nullptr);
+            using T = std::remove_cvref_t<W>;
+            auto p = std::make_unique<T>(std::move(root));
+            p->parent = nullptr;
+            root_ = std::move(p);
+        }
+
+        // Focus management. Calling with nullptr blurs whatever was focused.
+        void SetFocus(Widget* w);
+        Widget* Focused() const { return focused_; }
+
+        // Optional surface-clearing colour. The swapchain image is
+        // STORAGE-only (can't be vkCmdClearColorImage'd), so we paint a
+        // full-surface rect at the start of every frame's draw list when
+        // this is set.
+        UIScene& background(Color c) { background_ = c; return *this; }
+
+        Widget* root() { return root_.get(); }
+        const Widget* root() const { return root_.get(); }
+
+    private:
+        Window* window_ = nullptr;
+        std::unique_ptr<Widget> root_;
+        std::optional<Color> background_;
+
+        // Auto-allocated heap for UI-only apps. If the user already attached
+        // a heap to the window, we leave it alone and don't own one.
+        DescriptorHeapVulkan ownedHeap_;
+        bool ownsHeap_ = false;
+
+        std::unique_ptr<EventListener<void>>             mouseListener_;
+        std::unique_ptr<EventListener<FrameTime>>        updateListener_;
+        std::unique_ptr<EventListener<const std::string_view>> textListener_;
+        std::unique_ptr<EventListener<CrafterKeys>>      keyListener_;
+        Widget* focused_ = nullptr;
+
+        float WindowScale() const;
+        void  RebuildFrame();
+    };
+}