add drag and drop callback

include/game_window.h

@@ -41,6 +41,7 @@ class GameWindow {
     using TouchEndCallback = std::function<void (int, double, double)>;
     using KeyboardCallback = std::function<void (KeyCode, KeyAction)>;
     using KeyboardTextCallback = std::function<void (std::string const&)>;
+    using DropCallback = std::function<void (std::string const&)>;
     using PasteCallback = std::function<void (std::string const&)>;
     using GamepadStateCallback = std::function<void (int, bool)>;
     using GamepadButtonCallback = std::function<void (int, GamepadButtonId, bool)>;
@@ -58,6 +59,7 @@ class GameWindow {
     TouchEndCallback touchEndCallback;
     KeyboardCallback keyboardCallback;
     KeyboardTextCallback keyboardTextCallback;
+    DropCallback dropCallback;
     PasteCallback pasteCallback;
     GamepadStateCallback gamepadStateCallback;
     GamepadButtonCallback gamepadButtonCallback;
@@ -131,6 +133,8 @@ class GameWindow {
 
     void setKeyboardTextCallback(KeyboardTextCallback callback) { keyboardTextCallback = std::move(callback); }
 
+    void setDropCallback(DropCallback callback) { dropCallback = std::move(callback); }
+
     void setPasteCallback(PasteCallback callback) { pasteCallback = std::move(callback); }
 
     // Used when the cursor is disabled
@@ -191,6 +195,11 @@ class GameWindow {
         if (keyboardTextCallback != nullptr)
             keyboardTextCallback(c);
     }
+    void onDrop(std::string const& path) {
+        if (dropCallback != nullptr) {
+            dropCallback(path);
+        }
+    }
     void onPaste(std::string const& c) {
         if (pasteCallback != nullptr)
             pasteCallback(c);

src/window_eglut.cpp

@@ -36,6 +36,7 @@ EGLUTWindow::EGLUTWindow(const std::string& title, int width, int height, Graphi
     eglutTouchUpdateFunc(_eglutTouchUpdateFunc);
     eglutTouchEndFunc(_eglutTouchEndFunc);
     eglutKeyboardFunc(_eglutKeyboardFunc);
+    eglutDropFunc(_eglutDropFunc);
     eglutSpecialFunc(_eglutKeyboardSpecialFunc);
     eglutPasteFunc(_eglutPasteFunc);
     eglutFocusFunc(_eglutFocusFunc);
@@ -243,6 +244,12 @@ void EGLUTWindow::_eglutKeyboardFunc(char str[5], int action) {
     }
 }
 
+void EGLUTWindow::_eglutDropFunc(const char* path) {
+    if (currentWindow == nullptr)
+        return;
+    currentWindow->onDrop(path);
+}
+
 KeyCode EGLUTWindow::getKeyMinecraft(int keyCode) {
     if (keyCode >= XK_A && keyCode <= XK_Z)
         return (KeyCode) (keyCode - XK_A + (int) KeyCode::A);

src/window_eglut.h

@@ -38,6 +38,7 @@ class EGLUTWindow : public WindowWithLinuxJoystick {
     static void _eglutTouchUpdateFunc(int id, double x, double y);
     static void _eglutTouchEndFunc(int id, double x, double y);
     static void _eglutKeyboardFunc(char str[5], int action);
+    static void _eglutDropFunc(const char* path);
     static void _eglutKeyboardSpecialFunc(int key, int action);
     static void _eglutPasteFunc(const char* str, int len);
     static void _eglutFocusFunc(int action);

src/window_glfw.cpp

@@ -50,6 +50,7 @@ GLFWGameWindow::GLFWGameWindow(const std::string& title, int width, int height,
     glfwSetWindowCloseCallback(window, _glfwWindowCloseCallback);
     glfwSetKeyCallback(window, _glfwKeyCallback);
     glfwSetCharCallback(window, _glfwCharCallback);
+    glfwSetDropCallback(window, _glfwDropCallback);
     glfwSetWindowFocusCallback(window, _glfwWindowFocusCallback);
     glfwSetWindowContentScaleCallback(window, _glfwWindowContentScaleCallback);
     glfwMakeContextCurrent(window);
@@ -428,6 +429,13 @@ void GLFWGameWindow::_glfwCharCallback(GLFWwindow* window, unsigned int ch) {
     user->onKeyboardText(cvt.to_bytes(ch));
 }
 
+void GLFWGameWindow::_glfwDropCallback(GLFWwindow* window, int count, const char** paths) {
+    GLFWGameWindow* user = (GLFWGameWindow*) glfwGetWindowUserPointer(window);
+    for (int i = 0; i < count; i++) {
+        user->onDrop(std::string(paths[i]));
+    }
+}
+
 void GLFWGameWindow::_glfwWindowCloseCallback(GLFWwindow* window) {
     GLFWGameWindow* user = (GLFWGameWindow*) glfwGetWindowUserPointer(window);
     glfwSetWindowShouldClose(window, GLFW_FALSE);

src/window_glfw.h

@@ -45,6 +45,7 @@ class GLFWGameWindow : public GameWindow {
     static void _glfwScrollCallback(GLFWwindow* window, double x, double y);
     static void _glfwKeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods);
     static void _glfwCharCallback(GLFWwindow* window, unsigned int ch);
+    static void _glfwDropCallback(GLFWwindow* window, int count, const char** paths);
     static void _glfwWindowCloseCallback(GLFWwindow* window);
     static void _glfwWindowFocusCallback(GLFWwindow* window, int focused);
     static void _glfwWindowContentScaleCallback(GLFWwindow* window, float scalex, float scaley);

src/window_sdl3.cpp

@@ -272,6 +272,9 @@ void SDL3GameWindow::pollEvents() {
         case SDL_EVENT_TEXT_INPUT:
             onKeyboardText(ev.text.text ? ev.text.text : "");
             break;
+        case SDL_EVENT_DROP_FILE:
+            onDrop(ev.drop.data);
+            break;
         case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
             onClose();
             break;