"On Close" events and handling the window close for WebView solutions

include/webui.h

@@ -519,6 +519,19 @@ WEBUI_EXPORT void webui_set_browser_folder(const char* path);
  */
 WEBUI_EXPORT bool webui_set_default_root_folder(const char* path);
 
+/**
+ * @brief Set a callback to catch the close event of the WebView window.
+ * Must return `false` to prevent the close event, `true` otherwise.
+ *
+ * @example
+ * bool myCloseEvent(size_t window) {
+ *    // Prevent WebView window close event
+ *    return false;
+ * }
+ * webui_set_close_handler(myWindow, myCloseEvent);
+ */
+WEBUI_EXPORT void webui_set_close_handler_wv(size_t window, bool (*close_handler)(size_t window));
+
 /**
  * @brief Set a custom handler to serve files. This custom handler should
  * return full HTTP header and body.

src/webui.c

@@ -373,6 +373,7 @@ typedef struct _webui_window_t {
     int x;
     int y;
     bool position_set;
+    bool (*close_handler_wv)(size_t window);
     const void*(*files_handler)(const char* filename, int* length);
     const void*(*files_handler_window)(size_t window, const char* filename, int* length);
     const void* file_handler_async_response;
@@ -641,6 +642,7 @@ static bool _webui_wv_set_position(_webui_wv_linux_t* webView, int x, int y);
 static bool _webui_wv_set_size(_webui_wv_linux_t* webView, int windowWidth, int windowHeight);
 static bool _webui_wv_show(_webui_window_t* win, char* url);
 static void _webui_wv_event_closed(void *widget, void *arg);
+static bool _webui_wv_event_on_close(void *widget, void *event, void *arg);
 static int _webui_wv_exit_schedule(void* arg);
 static bool _webui_wv_maximize(_webui_wv_linux_t* webView);
 static bool _webui_wv_minimize(_webui_wv_linux_t* webView);
@@ -775,6 +777,25 @@ void webui_run(size_t window, const char* script) {
     _webui_send_all(win, 0, WEBUI_CMD_JS_QUICK, script, js_len);
 }
 
+void webui_set_close_handler_wv(size_t window, bool(*close_handler)(size_t window)) {
+
+    // Initialization
+    _webui_init();
+
+    // Dereference
+    if (_webui_mutex_app_is_exit_now(WEBUI_MUTEX_GET_STATUS) || _webui.wins[window] == NULL)
+        return;
+
+    _webui_window_t* win = _webui.wins[window];
+
+    #ifdef WEBUI_LOG
+    printf("[User]webui_set_close_handler(%zu, %p)", window, close_handler);
+    #endif
+
+    // Set the close handler
+    win->close_handler_wv = close_handler;
+}
+
 void webui_set_file_handler(size_t window, const void*(*handler)(const char* filename, int* length)) {
 
     if (handler == NULL)
@@ -11531,13 +11552,25 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved) {
             }
             case WM_CLOSE: {
                 if (win) {
-                    // Stop the WebView thread, close the window
-                    // and free resources.
-                    if (win->webView) {
-                        win->webView->stop = true;
-                        _webui_webview_update(win);
-                    }                    
-                    _webui_wv_event_closed(win);
+                    bool can_close = true;
+                    if (win->close_handler_wv != NULL) {
+                        can_close = win->close_handler_wv(win->num);
+                        #ifdef WEBUI_LOG
+                        webui_log_debug("[Core]\t\tClose handler installed for %zu, result = %d\n", win->num, can_close);
+                        #endif
+                    }
+                    if (can_close) {
+                        // Stop the WebView thread, close the window
+                        // and free resources.
+                        if (win->webView) {
+                            win->webView->stop = true;
+                            _webui_webview_update(win);
+                        }
+                        _webui_wv_event_closed(win);
+                    } else {
+                        // Do not close the window, no default processing
+                        return 0;
+                    }
                 }
                 break;
             }
@@ -11972,6 +12005,24 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved) {
         }
     }
 
+    // Delete Event (implement on close handling)
+    static bool _webui_wv_event_on_close(void *widget, void *evt, void *arg) {
+            #ifdef WEBUI_LOG
+            printf("[Core]\t\t_webui_wv_event_on_close()\n");
+            #endif
+            _webui_window_t* win = _webui_dereference_win_ptr(arg);
+            if (win) {
+                if (win->close_handler_wv) {
+                    bool can_close = win->close_handler_wv(win->num);
+                    #ifdef WEBUI_LOG
+                    printf("[Core]\t\t_webui_wv_event_on_close() -> can_close = %d\n", can_close);
+                    #endif
+                    return !can_close;
+                }
+            }
+            return false;
+    }
+
     static bool _webui_wv_set_size(_webui_wv_linux_t* webView, int windowWidth, int windowHeight) {
         #ifdef WEBUI_LOG
         printf("[Core]\t\t_webui_wv_set_size(%d. %d)\n", windowWidth, windowHeight);
@@ -12110,6 +12161,8 @@ BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved) {
         // Events
         g_signal_connect_data(win->webView->gtk_wv, "notify::title", G_CALLBACK(
             _webui_wv_event_title), (void *)win, NULL, 0);
+        g_signal_connect_data(win->webView->gtk_win, "delete-event", G_CALLBACK(
+                   _webui_wv_event_on_close), (void *)win, NULL, 0);
         g_signal_connect_data(win->webView->gtk_win, "destroy", G_CALLBACK(
             _webui_wv_event_closed), (void *)win, NULL, 0);