added Application; implemented event handling

Application.cpp

@@ -0,0 +1,57 @@
+//
+// Application.cpp
+// libscgui
+//
+// Created by Bob Polis at 2020-10-23
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#include "Application.hpp"
+#include "Window.hpp"
+
+using namespace sc::gui;
+
+Application Application::app;
+
+void Application::run() {
+    bool quit {false};
+    while (!quit) {
+        SDL_Event event;
+        if (SDL_PollEvent(&event)) {
+            switch (event.type) {
+                case SDL_QUIT:
+                    quit = true;
+                    break;
+                case SDL_WINDOWEVENT:
+                    quit = Window::handle_window_event(event);
+                    break;
+                default:
+                    quit = handle_event(event);
+            }
+        }
+        for (const Window& window : Window::windows()) {
+            window.update();
+        }
+    }
+}
+
+void Application::add_event_handler(EventHandler handler, SDL_EventType event) {
+    auto it = _event_handlers.find(event);
+    if (it != _event_handlers.end()) {
+        it->second.push_back(handler);
+    } else {
+        std::vector<EventHandler> handlers {handler};
+        _event_handlers.emplace(event, handlers);
+    }
+}
+
+bool Application::handle_event(const SDL_Event& event) {
+    bool quit {false};
+    auto it  = _event_handlers.find(static_cast<SDL_EventType>(event.type));
+    if (it != _event_handlers.end()) {
+        for (EventHandler handler : it->second) {
+            quit |= handler(event);
+        }
+    }
+    return quit;
+}

Application.hpp

@@ -0,0 +1,49 @@
+//
+// Application.hpp
+// libscgui
+//
+// Created by Bob Polis at 2020-10-23
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#ifndef _Application_H_
+#define _Application_H_
+
+#include <SDL2/SDL.h>
+#include <map>
+#include <vector>
+
+namespace sc {
+    namespace gui {
+        using EventHandler = bool(*)(const SDL_Event&);
+
+        class Application {
+            public:
+                static Application& instance() { return app; }
+
+                Application() = default;
+                ~Application() = default;
+
+                // prohibit copying and moving
+                Application(const Application&) = delete;
+                Application& operator=(const Application&) = delete;
+                Application(Application&&) = delete;
+                Application& operator=(Application&&) = delete;
+
+                void run();
+                void add_event_handler(EventHandler handler, SDL_EventType event);
+
+            private:
+                static Application app;
+
+                std::map<SDL_EventType, std::vector<EventHandler>> _event_handlers;
+
+                bool handle_event(const SDL_Event& event);
+        };
+
+        // convenience function
+        Application& app() { return Application::instance(); }
+    }
+}
+
+#endif // _Application_H_

Window.cpp

@@ -8,15 +8,78 @@
 
 #include <SDL2/SDL_image.h>
 #include <cmath>
+#include <algorithm>
 #include "Window.hpp"
 
 using namespace sc::gui;
 
-Window::Window(const char* title) : _path {title} {
+std::vector<Window> Window::_windows;
+std::map<SDL_WindowEventID, std::vector<WindowEventHandler>> Window::_global_event_handlers;
+
+Window* Window::from_sdl(Uint32 window_id) {
+    SDL_Window* w {SDL_GetWindowFromID(window_id)};
+    if (w) {
+        auto it = std::find_if(_windows.begin(), _windows.end(), [w](Window& win) {
+            return win.get_window() == w;
+        });
+        if (it != _windows.end()) {
+            return &*it;
+        }
+    }
+    return nullptr;
+}
+
+bool Window::handle_window_event(const SDL_Event& event) {
+    bool quit {handle_global_event(event)};
+    Window* w {from_sdl(event.window.windowID)};
+    if (w) {
+        return w->handle_event(event, quit);
+    }
+    return quit;
+}
+
+bool Window::handle_global_event(const SDL_Event& event) {
+    bool quit {false};
+    auto iter = _global_event_handlers.find(static_cast<SDL_WindowEventID>(event.window.event));
+    if (iter != _global_event_handlers.end()) {
+        for (WindowEventHandler handler : iter->second) {
+            quit = handler(event, quit);
+        }
+    }
+    switch (event.window.event) {
+        case SDL_WINDOWEVENT_CLOSE: {
+            // remove window from window list
+            SDL_Window* w {SDL_GetWindowFromID(event.window.windowID)};
+            auto it = std::remove_if(_windows.begin(), _windows.end(), [w](Window& win) {
+                return win.get_window() == w;
+            });
+            _windows.erase(it, _windows.end());
+            if (_windows.size() == 0) {
+                quit = true;
+            }
+            break;
+        }
+        default:
+            break;
+    }
+    return quit;
+}
+
+void Window::add_global_event_handler(WindowEventHandler handler, SDL_WindowEventID type) {
+    auto it = _global_event_handlers.find(type);
+    if (it != _global_event_handlers.end()) {
+        it->second.push_back(handler);
+    } else {
+        std::vector<WindowEventHandler> handlers {handler};
+        _global_event_handlers.emplace(type, handlers);
+    }
+}
+
+Window::Window(const char* title) : _title {title} {
     SDL_Window* win = SDL_CreateWindow(title,
-                                     SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
-                                     900, 540,
-                                     SDL_WINDOW_RESIZABLE);
+                                       SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+                                       900, 540,
+                                       SDL_WINDOW_RESIZABLE);
     _w.reset(win);
     _r.reset(SDL_CreateRenderer(win, -1, 0));
 }
@@ -33,7 +96,7 @@ void Window::update() const {
 
 void Window::load_image() {
     // load image from file into surface
-    SDL_Surface* loaded = IMG_Load(_path.c_str());
+    SDL_Surface* loaded = IMG_Load(_title.c_str());
     if (!loaded) throw std::runtime_error(IMG_GetError());
     std::unique_ptr<SDL_Surface, void(*)(SDL_Surface*)> loaded_ {loaded, SDL_FreeSurface};
 
@@ -64,3 +127,23 @@ void Window::load_image() {
     }
     set_size(w, h);
 }
+
+void Window::add_event_handler(WindowEventHandler handler, SDL_WindowEventID type) {
+    auto it = _event_handlers.find(type);
+    if (it != _event_handlers.end()) {
+        it->second.push_back(handler);
+    } else {
+        std::vector<WindowEventHandler> handlers {handler};
+        _event_handlers.emplace(type, handlers);
+    }
+}
+
+bool Window::handle_event(const SDL_Event& event, bool quit) {
+    auto it = _event_handlers.find(static_cast<SDL_WindowEventID>(event.window.event));
+    if (it != _event_handlers.end()) {
+        for (WindowEventHandler handler : it->second) {
+            quit = handler(event, quit);
+        }
+    }
+    return quit;
+}

Window.hpp

@@ -13,13 +13,26 @@
 #include <string>
 #include <memory>
 #include <stdexcept>
+#include <vector>
+#include <map>
 
 namespace sc {
     namespace gui {
+        using WindowEventHandler = bool(*)(const SDL_Event&, bool quit);
+
         class Window {
             public:
+                static std::vector<Window>& windows() { return _windows; }
+                static bool handle_window_event(const SDL_Event& event);
+                static bool handle_global_event(const SDL_Event& event);
+                static void add_global_event_handler(WindowEventHandler handler, SDL_WindowEventID type);
+                static Window* from_sdl(Uint32 window_id);
+
                 Window(const char* title);
 
+                void add_event_handler(WindowEventHandler handler, SDL_WindowEventID type);
+                bool handle_event(const SDL_Event& event, bool quit);
+
                 SDL_Window* get_window() const { return _w.get(); }
                 void set_size(int w, int h);
 
@@ -27,10 +40,14 @@ namespace sc {
                 void load_image();
 
             private:
-                std::string _path;
+                static std::vector<Window> _windows;
+                static std::map<SDL_WindowEventID, std::vector<WindowEventHandler>> _global_event_handlers;
+
+                std::string _title;
                 std::unique_ptr<SDL_Window,   void(*)(SDL_Window*)>   _w {nullptr, SDL_DestroyWindow};
                 std::unique_ptr<SDL_Renderer, void(*)(SDL_Renderer*)> _r {nullptr, SDL_DestroyRenderer};
                 std::unique_ptr<SDL_Texture,  void(*)(SDL_Texture*)>  _t {nullptr, SDL_DestroyTexture};
+                std::map<SDL_WindowEventID, std::vector<WindowEventHandler>> _event_handlers;
         };
     }
 }