diff -r ef01d2c90128 -r 473954dc6b74 ui/gtk/toolkit.c
--- a/ui/gtk/toolkit.c	Mon Jun 17 21:20:58 2024 +0200
+++ b/ui/gtk/toolkit.c	Sun Sep 29 13:32:51 2024 +0200
@@ -46,8 +46,8 @@
 
 #include <pthread.h>
 
-#ifndef UI_GTK2
-static GtkApplication *app;
+#ifdef UI_APPLICATION
+UI_APPLICATION app;
 #endif
 
 static const char *application_name;
@@ -67,22 +67,24 @@
 static int scale_factor = 1;
 
 UIEXPORT void ui_init(const char *appname, int argc, char **argv) {
+    application_name = appname;
     uic_init_global_context();
     
+#if GTK_MAJOR_VERSION >= 4
+    gtk_init();
+#else
     gtk_init(&argc, &argv);
-    application_name = appname;
+#endif
     
     ui_css_init();
-    
     uic_docmgr_init();
-    
     uic_toolbar_init();
-    
     ui_image_init();
-    
     uic_load_app_properties();
     
-#ifdef UI_SUPPORTS_SCALE
+#if GTK_MAJOR_VERSION >= 4
+    scale_factor = 1; // TODO
+#elif defined(UI_SUPPORTS_SCALE)
     scale_factor = gdk_monitor_get_scale_factor(
             gdk_display_get_primary_monitor(gdk_display_get_default()));
 #endif
@@ -121,14 +123,11 @@
 #endif
 
 void ui_main() {
-#ifndef UI_GTK2
+#ifdef UI_APPLICATION
     cxmutstr appid = cx_asprintf(
             "ui.%s",
             application_name ? application_name : "application1");
-    
-    app = gtk_application_new(
-            appid.ptr,
-            G_APPLICATION_FLAGS_NONE);
+    app = UI_APPLICATION_NEW(appid.ptr);
     g_signal_connect (app, "startup", G_CALLBACK (app_startup), NULL);
     g_signal_connect (app, "activate", G_CALLBACK (app_activate), NULL);
     g_application_run(G_APPLICATION (app), 0, NULL);
@@ -153,17 +152,22 @@
 }
 
 GtkApplication* ui_get_application() {
-    return app;
+    return GTK_APPLICATION(app);
 }
 #endif
 
 void ui_show(UiObject *obj) {
     uic_check_group_widgets(obj->ctx);
+#if GTK_MAJOR_VERSION >= 4
+    gtk_window_present(GTK_WINDOW(obj->widget));
+#elif GTK_MAJOR_VERSION <= 3
     gtk_widget_show_all(obj->widget);
+#endif
 }
 
 void ui_close(UiObject *obj) {
-    gtk_widget_destroy(obj->widget);
+    // TODO
+    //gtk_widget_destroy(obj->widget);
 }
 
 
@@ -226,24 +230,38 @@
 }
 
 void ui_set_show_all(UIWIDGET widget, int value) {
+    // TODO: gtk4
+#if GTK_MAJOR_VERSION <= 3
     gtk_widget_set_no_show_all(widget, !value);
+#endif
 }
 
 void ui_set_visible(UIWIDGET widget, int visible) {
+    // TODO: gtk4
+#if GTK_MAJOR_VERSION <= 3
     if(visible) {
         gtk_widget_set_no_show_all(widget, FALSE);
         gtk_widget_show_all(widget);
     } else {
         gtk_widget_hide(widget);
     }
+#endif
 }
 
 void ui_clipboard_set(char *str) {
+#if GTK_MAJOR_VERSION >= 4
+    // TODO: gtk4: needs widget
+#else
     GtkClipboard *cb = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
     gtk_clipboard_set_text(cb, str, strlen(str));
+#endif
 }
 
 char* ui_clipboard_get() {
+#if GTK_MAJOR_VERSION >= 4
+    // TODO: gtk4: needs widget
+    return NULL;
+#else
     GtkClipboard *cb = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
     char *str = gtk_clipboard_wait_for_text(cb);
     if(str) {
@@ -253,6 +271,7 @@
     } else {
         return NULL;
     }
+#endif
 }
 
 int ui_get_scalefactor() {
@@ -295,12 +314,44 @@
 
 static GtkCssProvider* ui_gtk_css_provider;
 
+#if GTK_MAJOR_VERSION == 4
+static const char *ui_gtk_css = 
+"#path-textfield-box {\n"
+"  background-color: alpha(currentColor, 0.1);"
+"  border-radius: 6px;"
+"  padding: 0px;"
+"}\n"
+".pathbar-extra-button {\n"
+"  border-top-right-radius: 6px;"
+"  border-bottom-right-radius: 6px;"
+"  border-top-left-radius: 0px;"
+"  border-bottom-left-radius: 0px;"
+"}\n"
+"#pathbar button {\n"
+"  margin: 3px;"
+"  border-radius: 4px;"
+"  padding-top: 0px;"
+"  padding-bottom: 0px;"
+"  padding-left: 8px;"
+"  padding-right: 8px;"
+"}\n"
+"#path-textfield-box entry {\n"
+"  background-color: #00000000;"
+"  border-top-left-radius: 6px;"
+"  border-bottom-left-radius: 6px;"
+"  border-top-right-radius: 0px;"
+"  border-bottom-right-radius: 0px;"
+"}"
+;
+
+#elif GTK_MAJOR_VERSION == 3
 static const char *ui_gtk_css = 
 "#path-textfield-box {"
 "  background-color: @theme_base_color;"
 "  border-radius: 5px;"
 "  padding: 0px;"
 "}";
+#endif
 
 void ui_css_init(void) {
     ui_gtk_css_provider = gtk_css_provider_new();
@@ -325,7 +376,7 @@
 #endif /* GTK_MINOR_VERSION < 12 */
     
     GdkDisplay *display = gdk_display_get_default();
-    gtk_style_context_add_provider_for_display(display, GTK_STYLE_PROVIDER(ui_gtk_css_provider), GTK_STYLE_PROVIDER_PRIORITY_USER);
+    gtk_style_context_add_provider_for_display(display, GTK_STYLE_PROVIDER(ui_gtk_css_provider), GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
     
 #endif /* UI_GTK4 */
 }