debug-gui: migrate to GTK4

Global:

- Stop passing commandline arguments to gtk_init:
  https://docs.gtk.org/gtk4/migrating-3to4.html#stop-passing-commandline-arguments-to-gtk_init

window_init function:

- gtk_window_new doesn't require a type anymore

- gtk_window_iconify has been renamed to gtk_window_minimize

- gtk_container_add has been removed in favor of container specific
  APIs. Use gtk_window_set_child in this case.

- gtk_widget_show_all has been removed, widgets are now visible by
  default:
  https://docs.gtk.org/gtk4/migrating-3to4.html#widgets-are-now-visible-by-default

- gtk_widget_set_events to NULL is no longer required, widgets must set
  their event handlers explicitly now:
  https://blog.gtk.org/2020/04/29/custom-widgets-in-gtk-4-input/

window_delete_event_cb function:

- Use the new close-request event:
  https://docs.gtk.org/gtk4/migrating-3to4.html#stop-using-gtkwidget-event-signals

map_event_cb function:

- gtk_widget_set_cursor_from_name instead of gdk_window_set_cursor

- Wait until the draw area is resized to use the whole window to start
  calculating sizes

window_place_ui_elements function:

- Use gtk_widget_get_width and gtk_widget_get_height instead of
  gtk_window_get_size

Drawing:

- Use gtk_drawing_area_set_draw_func instead of the GtkWidget::draw
  signal:
  https://docs.gtk.org/gtk4/migrating-3to4.html#adapt-to-drawing-model-changes

Signed-off-by: José Expósito <jose.exposito89@gmail.com>

2 files changed, 86 insertions, 5 deletions

diff --git a/meson.build b/meson.build
index e78fafd1..9db3283f 100644
--- a/meson.build
+++ b/meson.build
@@ -550,7 +550,13 @@ executable('libinput-record',
 	   )
 
 if get_option('debug-gui')
-	dep_gtk = dependency('gtk+-3.0', version : '>= 3.20')
+	dep_gtk = dependency('gtk4', version : '>= 4.0', required : false)
+	config_h.set10('HAVE_GTK4', dep_gtk.found())
+	if not dep_gtk.found()
+		dep_gtk = dependency('gtk+-3.0', version : '>= 3.20')
+		config_h.set10('HAVE_GTK3', dep_gtk.found())
+	endif
+
 	dep_cairo = dependency('cairo')
 	dep_glib = dependency('glib-2.0')
 
diff --git a/tools/libinput-debug-gui.c b/tools/libinput-debug-gui.c
index 5bcf8a36..22afa6a8 100644
--- a/tools/libinput-debug-gui.c
+++ b/tools/libinput-debug-gui.c
@@ -792,10 +792,27 @@ draw(GtkWidget *widget, cairo_t *cr, gpointer data)
 	return TRUE;
 }
 
+#if HAVE_GTK4
+static void
+draw_gtk4(GtkDrawingArea *widget,
+	  cairo_t *cr,
+	  int width,
+	  int height,
+	  gpointer data)
+{
+	draw(GTK_WIDGET(widget), cr, data);
+}
+#endif
+
 static void
 window_place_ui_elements(GtkWidget *widget, struct window *w)
 {
+#if HAVE_GTK4
+	w->width = gtk_widget_get_width(w->area);
+	w->height = gtk_widget_get_height(w->area);
+#else
 	gtk_window_get_size(GTK_WINDOW(widget), &w->width, &w->height);
+#endif
 
 	w->pointer.x = w->width/2;
 	w->pointer.y = w->height/2;
@@ -821,6 +838,22 @@ window_place_ui_elements(GtkWidget *widget, struct window *w)
 	w->pinch.y = w->height/2;
 }
 
+#if HAVE_GTK4
+static void
+map_event_cb(GtkDrawingArea *widget, int width, int height, gpointer data)
+{
+	struct window *w = data;
+
+	window_place_ui_elements(GTK_WIDGET(widget), w);
+
+	gtk_drawing_area_set_draw_func(GTK_DRAWING_AREA(w->area),
+				       draw_gtk4,
+				       w,
+				       NULL);
+
+	gtk_widget_set_cursor_from_name(w->win, "none");
+}
+#else
 static void
 map_event_cb(GtkWidget *widget, GdkEvent *event, gpointer data)
 {
@@ -851,6 +884,7 @@ map_event_cb(GtkWidget *widget, GdkEvent *event, gpointer data)
 		      NULL /* prepare_func_data */
 		     );
 }
+#endif
 
 static void
 window_quit(struct window *w)
@@ -858,6 +892,17 @@ window_quit(struct window *w)
 	g_main_loop_quit(w->event_loop);
 }
 
+#if HAVE_GTK4
+static gboolean
+window_delete_event_cb(GtkWindow *window, gpointer data)
+{
+	struct window *w = data;
+
+	window_quit(w);
+
+	return TRUE;
+}
+#else
 static void
 window_delete_event_cb(GtkWidget *widget, GdkEvent *event, gpointer data)
 {
@@ -865,28 +910,51 @@ window_delete_event_cb(GtkWidget *widget, GdkEvent *event, gpointer data)
 
 	window_quit(w);
 }
+#endif
 
 static void
 window_init(struct window *w)
 {
 	list_init(&w->evdev_devices);
 
+#if HAVE_GTK4
+	w->win = gtk_window_new();
+#else
 	w->win = gtk_window_new(GTK_WINDOW_TOPLEVEL);
-	if (getenv("LIBINPUT_RUNNING_TEST_SUITE"))
+#endif
+
+	if (getenv("LIBINPUT_RUNNING_TEST_SUITE")) {
+#if HAVE_GTK4
+		gtk_window_minimize(GTK_WINDOW(w->win));
+#else
 		gtk_window_iconify(GTK_WINDOW(w->win));
-	gtk_widget_set_events(w->win, 0);
+#endif
+	}
+
 	gtk_window_set_title(GTK_WINDOW(w->win), "libinput debugging tool");
 	gtk_window_set_default_size(GTK_WINDOW(w->win), 1024, 768);
 	gtk_window_maximize(GTK_WINDOW(w->win));
 	gtk_window_set_resizable(GTK_WINDOW(w->win), TRUE);
 	gtk_widget_realize(w->win);
+
+	w->area = gtk_drawing_area_new();
+
+#if HAVE_GTK4
+	g_signal_connect(G_OBJECT(w->area), "resize", G_CALLBACK(map_event_cb), w);
+	g_signal_connect(G_OBJECT(w->win), "close-request", G_CALLBACK(window_delete_event_cb), w);
+
+	gtk_window_set_child(GTK_WINDOW(w->win), w->area);
+	gtk_widget_show(w->win);
+#else
 	g_signal_connect(G_OBJECT(w->win), "map-event", G_CALLBACK(map_event_cb), w);
 	g_signal_connect(G_OBJECT(w->win), "delete-event", G_CALLBACK(window_delete_event_cb), w);
 
-	w->area = gtk_drawing_area_new();
+	gtk_widget_set_events(w->win, 0);
 	gtk_widget_set_events(w->area, 0);
+
 	gtk_container_add(GTK_CONTAINER(w->win), w->area);
 	gtk_widget_show_all(w->win);
+#endif
 
 	w->pad.ring.position = -1;
 	w->pad.strip.position = -1;
@@ -1618,8 +1686,15 @@ main(int argc, char **argv)
 	enum tools_backend backend = BACKEND_NONE;
 	const char *seat_or_device[2] = {"seat0", NULL};
 	bool verbose = false;
+	bool gtk_init = false;
+
+#if HAVE_GTK4
+	gtk_init = gtk_init_check();
+#else
+	gtk_init = gtk_init_check(&argc, &argv);
+#endif
 
-	if (!gtk_init_check(&argc, &argv))
+	if (!gtk_init)
 		return 77;
 
 	tools_init_options(&options);