Improve positioning of menu icons

Shift them into the area reserved for toggles (check/radio items).
See also "reserve-toggle-size" property of GtkMenu.

1 files changed, 64 insertions, 9 deletions

diff --git a/src/ui/interface.cpp b/src/ui/interface.cpp
index f644aa174..fc8b4032e 100644
--- a/src/ui/interface.cpp
+++ b/src/ui/interface.cpp
@@ -19,6 +19,7 @@
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
+#include <gtkmm/cssprovider.h>
 #include <gtkmm/icontheme.h>
 #include <gtkmm/radiomenuitem.h>
 #include <gtkmm/separatormenuitem.h>
@@ -446,6 +447,64 @@ sp_ui_dialog_title_string(Inkscape::Verb *verb, gchar *c)
         g_free(key);
     }
 }
+               
+/* install CSS to shift icons into the space reserved for toggles (i.e. check and radio items) */
+void shift_icons(GtkWidget *menu, gpointer /* user_data */)
+{
+    static auto provider = Gtk::CssProvider::create();
+    static bool provider_added = false;
+
+    Gtk::MenuItem *menuitem = nullptr;
+    Gtk::Box *content = nullptr;
+    Gtk::Image *icon = nullptr;
+
+    static int current_shift = 0;
+    int calculated_shift = 0;
+
+    // install CssProvider for our custom styles
+    if (!provider_added) {
+        auto const screen = Gdk::Screen::get_default();
+        Gtk::StyleContext::add_provider_for_screen(screen, provider, GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+        provider_added = true;
+    }
+
+    // get the first MenuItem with an image (i.e. "ImageMenuItem" as named below)
+    std::vector<Gtk::Widget*> children = Glib::wrap(GTK_MENU(menu))->get_children();
+    for (auto child: children) {
+        if (child->get_name() == "ImageMenuItem") {
+            menuitem = static_cast<Gtk::MenuItem *>(child);
+            content = static_cast<Gtk::Box *>(menuitem->get_child());
+            icon = static_cast<Gtk::Image *>(content->get_children()[0]);
+            break;
+        }
+    }
+
+    // calculate how far we have to shift the icon to fit it into the empty space between menuitem and its content
+    if (icon) {
+        auto allocation_menuitem = menuitem->get_allocation();
+        auto allocation_icon = icon->get_allocation();
+
+        if (menuitem->get_direction() == Gtk::TEXT_DIR_RTL) {
+            calculated_shift = allocation_menuitem.get_width() - allocation_icon.get_x() - allocation_icon.get_width();
+        } else {
+            calculated_shift = -allocation_icon.get_x();
+        }
+    }
+
+    // install CSS to shift icon, use a threshold to avoid overly frequent updates
+    // (gtk's own calculations for the reserved space are off by a few pixels if there is no check/radio item in a menu)
+    if (calculated_shift && std::abs(current_shift - calculated_shift) > 2) {
+        current_shift = calculated_shift;
+
+        std::string css_str;
+        if (menuitem->get_direction() == Gtk::TEXT_DIR_RTL) {
+            css_str = "#ImageMenuItem image {margin-right:" + std::to_string(-calculated_shift) + "px;}";
+        } else {
+            css_str = "#ImageMenuItem image {margin-left:" + std::to_string(calculated_shift) + "px;}";
+        }
+        provider->load_from_data(css_str);
+    }
+}
 
 /**
  * Appends a custom menu UI from a verb.
@@ -511,18 +570,13 @@ static GtkWidget *sp_ui_menu_append_item_from_verb(GtkMenu                  *men
         sp_shortcut_add_accelerator(item->gobj(), sp_shortcut_get_primary(verb));
         gtk_accel_label_set_accel_widget(GTK_ACCEL_LABEL(label), item->gobj());
 
-        GtkWidget *icon;
-
-        // If there is an image associated with the action, then we can add it as an
-        // icon for the menu item.  If not, give the label a bit more space
+        // If there is an image associated with the action, then we can add it as an icon for the menu item.
         if(show_icon && action->image) {
-            icon = GTK_WIDGET(sp_get_icon_image(action->image, GTK_ICON_SIZE_MENU)->gobj());
-        }
-        else {
-            icon = gtk_label_new(nullptr); // A fake icon just to act as a placeholder
+            GtkWidget *icon = GTK_WIDGET(sp_get_icon_image(action->image, GTK_ICON_SIZE_MENU)->gobj());
+            gtk_box_pack_start(GTK_BOX(box), icon, FALSE, FALSE, 0);
+            item->set_name("ImageMenuItem");
         }
 
-        gtk_box_pack_start(GTK_BOX(box), icon, FALSE, TRUE, 0);
         gtk_box_pack_start(GTK_BOX(box), label, TRUE, TRUE, 0);
 
         // Finally, pack all the widgets into the menu item
@@ -867,6 +921,7 @@ static void sp_ui_build_dyn_menus(Inkscape::XML::Node *menus, GtkWidget *menu, I
             sp_ui_build_dyn_menus(menu_pntr->firstChild(), submenu, view);
             gtk_menu_item_set_submenu(GTK_MENU_ITEM(mitem), GTK_WIDGET(submenu));
             gtk_menu_shell_append(GTK_MENU_SHELL(menu), mitem);
+            g_signal_connect(submenu, "map", G_CALLBACK(shift_icons), NULL);
             continue;
         }
         if (!strcmp(menu_pntr->name(), "verb")) {