[gtk+] Adwaita: Update treeview drop target styling

[Matthias Clasen <matthiasc src gnome org>]

commit 4ae057f07b18a9e078623931f66233d6402c5a2f
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Mar 20 19:41:31 2016 -0400

    Adwaita: Update treeview drop target styling
    
    This reinstates the between-the-rows highlight that was lost
    at some point.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=763808

 gtk/theme/Adwaita/_common.scss           |   12 +++++++++++-
 gtk/theme/Adwaita/gtk-contained-dark.css |   10 +++++++++-
 gtk/theme/Adwaita/gtk-contained.css      |   10 +++++++++-
 3 files changed, 29 insertions(+), 3 deletions(-)
---
diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index c0bea68..dc6a3ea 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -1606,7 +1606,17 @@ treeview.view {
     border-top: $backdrop_bg_color;
   }
 
-  &.dnd {
+  &.before:drop(active) {
+    border-style: solid none none none;
+    border-width: 1px;
+    border-color: mix($fg_color, $selected_bg_color, 50%);
+  }
+  &.after:drop(active) {
+    border-style: none none solid none;
+    border-width: 1px;
+    border-color: mix($fg_color, $selected_bg_color, 50%);
+  }
+  &:drop(active) {
     border-style: solid none;
     border-width: 1px;
     border-color: mix($fg_color, $selected_bg_color, 50%);
diff --git a/gtk/theme/Adwaita/gtk-contained-dark.css b/gtk/theme/Adwaita/gtk-contained-dark.css
index 56e2cc5..443f688 100644
--- a/gtk/theme/Adwaita/gtk-contained-dark.css
+++ b/gtk/theme/Adwaita/gtk-contained-dark.css
@@ -1991,7 +1991,15 @@ treeview.view {
   treeview.view:backdrop {
     border-left-color: #676b6b;
     border-top: #393f3f; }
-  treeview.view.dnd {
+  treeview.view.before:drop(active) {
+    border-style: solid none none none;
+    border-width: 1px;
+    border-color: #88a6c4; }
+  treeview.view.after:drop(active) {
+    border-style: none none solid none;
+    border-width: 1px;
+    border-color: #88a6c4; }
+  treeview.view:drop(active) {
     border-style: solid none;
     border-width: 1px;
     border-color: #88a6c4; }
diff --git a/gtk/theme/Adwaita/gtk-contained.css b/gtk/theme/Adwaita/gtk-contained.css
index 1d94570..de708a6 100644
--- a/gtk/theme/Adwaita/gtk-contained.css
+++ b/gtk/theme/Adwaita/gtk-contained.css
@@ -1998,7 +1998,15 @@ treeview.view {
   treeview.view:backdrop {
     border-left-color: #babbbb;
     border-top: #e8e8e7; }
-  treeview.view.dnd {
+  treeview.view.before:drop(active) {
+    border-style: solid none none none;
+    border-width: 1px;
+    border-color: #3c6288; }
+  treeview.view.after:drop(active) {
+    border-style: none none solid none;
+    border-width: 1px;
+    border-color: #3c6288; }
+  treeview.view:drop(active) {
     border-style: solid none;
     border-width: 1px;
     border-color: #3c6288; }