#include <gtk/gtk.h> static gboolean overlay_get_child_position (GtkOverlay *overlay, GtkWidget *child, GdkRectangle *allocation, gpointer user_data) { GtkWidget *custom_child = user_data; GtkRequisition req; if (child != custom_child) return FALSE; gtk_widget_get_preferred_size (child, NULL, &req); allocation->x = 120; allocation->y = 0; allocation->width = req.width; allocation->height = req.height; return TRUE; } int main (int argc, char *argv[]) { GtkWidget *win, *overlay, *grid, *main_child, *child, *label, *sw; GtkCssProvider *provider; gchar *str; gtk_init (); provider = gtk_css_provider_new (); gtk_css_provider_load_from_data (provider, "label { border: 3px solid black; border-radius: 5px; padding: 2px; }" ".top { border-top-style: none; border-top-right-radius: 0px; border-top-left-radius: 0px; }" ".bottom { border-bottom-style: none; border-bottom-right-radius: 0px; border-bottom-left-radius: 0px; }" ".left { border-left-style: none; border-top-left-radius: 0px; border-bottom-left-radius: 0px; }" ".right { border-right-style: none; border-top-right-radius: 0px; border-bottom-right-radius: 0px; }", -1); gtk_style_context_add_provider_for_display (gdk_display_get_default (), GTK_STYLE_PROVIDER (provider), GTK_STYLE_PROVIDER_PRIORITY_APPLICATION); win = gtk_window_new (); gtk_window_set_default_size (GTK_WINDOW (win), 600, 600); grid = gtk_grid_new (); label = gtk_label_new ("Out of overlay"); gtk_widget_set_hexpand (label, TRUE); gtk_widget_set_vexpand (label, TRUE); gtk_grid_attach (GTK_GRID (grid), label, 0, 0, 1, 1); overlay = gtk_overlay_new (); sw = gtk_scrolled_window_new (); gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw), GTK_POLICY_ALWAYS, GTK_POLICY_ALWAYS); gtk_overlay_set_child (GTK_OVERLAY (overlay), sw); main_child = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0); gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), main_child); gtk_widget_set_hexpand (main_child, TRUE); gtk_widget_set_vexpand (main_child, TRUE); label = gtk_label_new ("Main child"); gtk_widget_set_halign (label, GTK_ALIGN_CENTER); gtk_widget_set_valign (label, GTK_ALIGN_CENTER); gtk_box_append (GTK_BOX (main_child), label); child = gtk_label_new (NULL); str = g_strdup_printf ("%p", child); gtk_label_set_text (GTK_LABEL (child), str); g_free (str); g_print ("Bottom/Right child: %p\n", child); gtk_widget_set_halign (child, GTK_ALIGN_END); gtk_widget_set_valign (child, GTK_ALIGN_END); gtk_overlay_add_overlay (GTK_OVERLAY (overlay), child); child = gtk_label_new (NULL); str = g_strdup_printf ("%p", child); gtk_label_set_text (GTK_LABEL (child), str); g_free (str); g_print ("Left/Top child: %p\n", child); gtk_widget_set_halign (child, GTK_ALIGN_START); gtk_widget_set_valign (child, GTK_ALIGN_START); gtk_overlay_add_overlay (GTK_OVERLAY (overlay), child); child = gtk_label_new (NULL); str = g_strdup_printf ("%p", child); gtk_label_set_text (GTK_LABEL (child), str); g_free (str); g_print ("Right/Center child: %p\n", child); gtk_widget_set_halign (child, GTK_ALIGN_END); gtk_widget_set_valign (child, GTK_ALIGN_CENTER); gtk_overlay_add_overlay (GTK_OVERLAY (overlay), child); child = gtk_label_new (NULL); str = g_strdup_printf ("%p", child); gtk_label_set_text (GTK_LABEL (child), str); g_free (str); gtk_widget_set_margin_start (child, 55); gtk_widget_set_margin_top (child, 4); g_print ("Left/Top margined child: %p\n", child); gtk_widget_set_halign (child, GTK_ALIGN_START); gtk_widget_set_valign (child, GTK_ALIGN_START); gtk_overlay_add_overlay (GTK_OVERLAY (overlay), child); child = gtk_label_new (NULL); str = g_strdup_printf ("%p", child); gtk_label_set_text (GTK_LABEL (child), str); g_free (str); g_print ("Custom get-child-position child: %p\n", child); gtk_widget_set_halign (child, GTK_ALIGN_START); gtk_widget_set_valign (child, GTK_ALIGN_START); gtk_overlay_add_overlay (GTK_OVERLAY (overlay), child); g_signal_connect (overlay, "get-child-position", G_CALLBACK (overlay_get_child_position), child); gtk_grid_attach (GTK_GRID (grid), overlay, 1, 0, 1, 3); gtk_window_set_child (GTK_WINDOW (win), grid); g_print ("\n"); gtk_widget_show (win); while (TRUE) g_main_context_iteration (NULL, TRUE); return 0; }