[baobab] Do not use deprecated GtkStyleContext methods

[Stefano Facchini <sfacchini src gnome org>]

commit 9da230fdb63c1c1792a506b46475c7b72c6155ca
Author: Stefano Facchini <stefano facchini gmail com>
Date:   Wed Jun 10 14:51:19 2020 +0200

    Do not use deprecated GtkStyleContext methods

 src/baobab-ringschart.vala | 11 ++++++-----
 src/baobab-treemap.vala    | 14 ++++++--------
 src/baobab.css             |  7 ++++++-
 3 files changed, 18 insertions(+), 14 deletions(-)
---
diff --git a/src/baobab-ringschart.vala b/src/baobab-ringschart.vala
index 6fe2841..0a80067 100644
--- a/src/baobab-ringschart.vala
+++ b/src/baobab-ringschart.vala
@@ -198,7 +198,8 @@ namespace Baobab {
                     cr.rectangle (tooltip_rect.x + tooltip_rect.width, tooltip_rect.y, -tooltip_rect.width, 
tooltip_rect.height);
                     cr.clip ();
 
-                    var bg_color = context.get_background_color (context_state);
+                    Gdk.RGBA bg_color;
+                    context.lookup_color ("tooltip_bg_color", out bg_color);
                     cr.set_line_width (1);
                     cr.move_to (sector_center_x, sector_center_y);
                     Gdk.cairo_set_source_rgba (cr, bg_color);
@@ -239,14 +240,14 @@ namespace Baobab {
             get_allocation (out allocation);
 
             var context = get_style_context ();
-            var context_state = context.get_state ();
             context.save ();
 
             var toplevel_context = get_toplevel ().get_style_context ();
-            var toplevel_context_state = toplevel_context.get_state ();
 
-            var border_color = context.get_border_color (context_state);
-            var bg_color = toplevel_context.get_background_color (toplevel_context_state);
+            Gdk.RGBA border_color;
+            context.lookup_color ("chart_borders", out border_color);
+            Gdk.RGBA bg_color;
+            toplevel_context.lookup_color ("theme_bg_color", out bg_color);
 
             var center_x = allocation.width / 2;
             var center_y = allocation.height / 2;
diff --git a/src/baobab-treemap.vala b/src/baobab-treemap.vala
index 6db9fcf..4a63542 100644
--- a/src/baobab-treemap.vala
+++ b/src/baobab-treemap.vala
@@ -34,6 +34,10 @@ namespace Baobab {
 
     public class Treemap : Chart {
 
+        static construct {
+            set_css_name ("treemap");
+        }
+
         const int ITEM_BORDER_WIDTH = 1;
         const int ITEM_PADDING = 6;
         const int ITEM_TEXT_PADDING = 3;
@@ -59,16 +63,12 @@ namespace Baobab {
             uint border = ITEM_BORDER_WIDTH;
 
             var context = get_style_context ();
-            context.save ();
-            context.set_state (Gtk.StateFlags.NORMAL);
 
             cr.set_line_width (border);
             cr.rectangle (x + border, y + border, width - border * 2, height - border * 2);
             Gdk.cairo_set_source_rgba (cr, fill_color);
-            cr.fill_preserve ();
-            var border_color = context.get_border_color (context.get_state ());
-            Gdk.cairo_set_source_rgba (cr, border_color);
-            cr.stroke ();
+            cr.fill ();
+            context.render_frame (cr, x + 0.5, y + 0.5, width - 1, height - 1);
 
             if (show_text) {
                 var layout = create_pango_layout (null);
@@ -83,8 +83,6 @@ namespace Baobab {
                     context.render_layout (cr, x + width / 2 - rect.width / 2, y + height / 2 - rect.height 
/ 2, layout);
                 }
             }
-
-            context.restore ();
         }
 
         protected override void draw_item (Cairo.Context cr, ChartItem item, bool highlighted) {
diff --git a/src/baobab.css b/src/baobab.css
index 776a918..b246959 100644
--- a/src/baobab.css
+++ b/src/baobab.css
@@ -65,14 +65,19 @@ window infobar.error {
     border-bottom-color: @borders;
 }
 
+@define-color chart_borders darker(@borders);
 ringschart {
     padding: 13px 13px 13px 13px;
 }
 
+@define-color tooltip_bg_color rgba(0, 0, 0, 0.8);
 ringschart.subfolder-tip {
     color: white;
-    background-color: rgba(0, 0, 0, 0.8);
+    background-color: @tooltip_bg_color;
     border-radius: 3px;
     padding: 3px 3px 3px 3px;
 }
 
+treemap {
+  border: solid 1px @chart_borders;
+}