Add get_horizontal/vertical_padding() methods

Add get_horizontal_padding() and get_vertical_padding() methods,
that return the total padding (LEFT+RIGHT or TOP+BOTTOM).

https://bugzilla.gnome.org/show_bug.cgi?id=597983

src/st/st-theme-node.c

@@ -2174,6 +2174,44 @@ st_theme_node_get_border_image (StThemeNode *node)
   return NULL;
 }
 
+/**
+ * st_theme_node_get_horizontal_padding:
+ * @node: a #StThemeNode
+ *
+ * Gets the total horizonal padding (left + right padding)
+ *
+ * Return value: the total horizonal padding
+ *   in pixels
+ */
+double
+st_theme_node_get_horizontal_padding (StThemeNode *node)
+{
+  double padding = 0.0;
+  padding += st_theme_node_get_padding (node, ST_SIDE_LEFT);
+  padding += st_theme_node_get_padding (node, ST_SIDE_RIGHT);
+
+  return padding;
+}
+
+/**
+ * st_theme_node_get_vertical_padding:
+ * @node: a #StThemeNode
+ *
+ * Gets the total vertical padding (top + bottom padding)
+ *
+ * Return value: the total vertical padding
+ *   in pixels
+ */
+double
+st_theme_node_get_vertical_padding (StThemeNode *node)
+{
+  double padding = 0.0;
+  padding += st_theme_node_get_padding (node, ST_SIDE_TOP);
+  padding += st_theme_node_get_padding (node, ST_SIDE_BOTTOM);
+
+  return padding;
+}
+
 /**
  * st_theme_node_get_shadow:
  * @node: a #StThemeNode

src/st/st-theme-node.h

@@ -129,6 +129,9 @@ void   st_theme_node_get_border_color  (StThemeNode  *node,
 double st_theme_node_get_padding       (StThemeNode  *node,
                                         StSide        side);
 
+double st_theme_node_get_horizontal_padding (StThemeNode *node);
+double st_theme_node_get_vertical_padding   (StThemeNode *node);
+
 int    st_theme_node_get_width         (StThemeNode  *node);
 int    st_theme_node_get_height        (StThemeNode  *node);
 int    st_theme_node_get_min_width     (StThemeNode  *node);