[gtk/wip/jimmac/dropdown-styling] Adwaita: dropdown styling

[Jakub Steiner <jimmac src gnome org>]

commit d7da0ddcea4a2ed49babaa30505130194703cd20
Author: Jakub Steiner <jimmac gmail com>
Date:   Mon Jun 15 15:18:04 2020 +0200

    Adwaita: dropdown styling
    
    - selected item color
    - offset dropdown form the parent control
    - FIXME: special styling for the top search entry
    
    Fixes (eventually) https://gitlab.gnome.org/GNOME/gtk/-/issues/2846

 gtk/theme/Adwaita/_common.scss | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index dca44ed351..5c7455f1d5 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -1171,12 +1171,29 @@ combobox {
 
     button.combo { @extend %button_basic_drop_active; }
   }
-}
 
-dropdown > popover listview > row {
-  padding: 6px;
+  // newstyle
+  popover {
+   margin-top: 6px;
+   padding: 0;
+
+    listview>row {
+    padding: 6px;
+
+    &:selected {
+        outline-color: $alt_focus_border_color;
+        color: $text-color;
+        background-color: $menu_selected_color;
+      }
+    }
+    .search { //drodowns with searchboxes on top
+      border-radius: $popover_radius $popover_radius 0 0;
+      margin: -6px 0 0 0; // FIXME: kill top margin
+    }
+  }
 }
 
+
 // the combo is a composite widget so the way we do button linking doesn't
 // work, special case needed. See
 // https://bugzilla.gnome.org/show_bug.cgi?id=733979