Gtk3: ROM settings: use theme background for around widgets and in un…

…used space

To avoid large white (light theme) or black (dark theme) areas we use CSS to
set the background color for the GtkListBoxes to the special `@theme_bg_color`
color.


git-svn-id: https://svn.code.sf.net/p/vice-emu/code/trunk@44968 379a1393-f5fb-40a0-bcee-ef074d9b53f7

vice/src/arch/gtk3/widgets/settings_rom.c

@@ -109,6 +109,15 @@
 #include "settings_rom.h"
 
 
+/** \brief  CSS for the GtkListBoxes used for the ROMs
+ *
+ * We use the theme background color to avoid ugly white (light theme) or
+ * black areas (dark theme) areas around the widgets and in the unused space
+ * of the GtkScrolledWindow.
+ */
+#define LISTBOX_CSS "list { background-color: @theme_bg_color; }"
+
+
 /** \brief  Array length helper
  *
  * \param[in]   arr array
@@ -267,6 +276,9 @@ static gchar *last_directory;
 /** \brief  Last filename used in a ROM set file dialog */
 static gchar *last_filename;
 
+/** \brief  CSS provided used for the GtkListBox widgets */
+static GtkCssProvider *listbox_css_provider;
+
 
 /* {{{ Event handlers */
 /** \brief  Callback for the ROM set open dialog
@@ -587,6 +599,8 @@ static GtkWidget *expandable_list_new(const char *title)
     expander = gtk_expander_new(title);
     list     = gtk_list_box_new();
 
+    vice_gtk3_css_provider_add(list, listbox_css_provider);
+
     gtk_container_add(GTK_CONTAINER(expander), list);
     gtk_container_add(GTK_CONTAINER(listrow), expander);
     return listrow;
@@ -790,12 +804,17 @@ GtkWidget *settings_rom_widget_create(GtkWidget *parent)
     size_t     i;
     int        row = 0;
 
+    listbox_css_provider  = vice_gtk3_css_provider_new(LISTBOX_CSS);
+
     grid = gtk_grid_new();
     gtk_grid_set_column_spacing(GTK_GRID(grid), 16);
     gtk_grid_set_row_spacing(GTK_GRID(grid), 8);
 
     root_list = gtk_list_box_new();
+    gtk_widget_set_vexpand(root_list, TRUE);
     scrolled  = gtk_scrolled_window_new(NULL, NULL);
+    vice_gtk3_css_provider_add(root_list, listbox_css_provider);
+
     if (machine_class == VICE_MACHINE_PET) {
         /* We add a check button and buttons to load a chargen to xpet, so the
          * scrolled window must be slightly less tall */
@@ -919,5 +938,7 @@ void settings_rom_widget_shutdown(void)
     g_free(last_directory);
     g_free(last_filename);
     last_directory = NULL;
-    last_filename = NULL;
+    last_filename  = NULL;
+    g_object_unref(listbox_css_provider);
+    listbox_css_provider  = NULL;
 }