[gnome-shell/issue154: 4/6] st-theme-node: Add new getter st_theme_node_get_letter_spacing

[Marco Trevisan <marcotrevi src gnome org>]

commit 695d61968dfe1945ad63f8b8fd263f4724df4eb8
Author: Mario Sanchez Prada <mario endlessm com>
Date:   Fri Apr 13 12:56:18 2018 +0100

    st-theme-node: Add new getter st_theme_node_get_letter_spacing
    
    This will be used by ClutterText-backed StWidgets to update their
    list of PangoAttributes according to the letter-spacing property.

 src/st/st-theme-node.c | 22 ++++++++++++++++++++++
 src/st/st-theme-node.h |  2 ++
 2 files changed, 24 insertions(+)
---
diff --git a/src/st/st-theme-node.c b/src/st/st-theme-node.c
index 3739b93b4..fd2cdb084 100644
--- a/src/st/st-theme-node.c
+++ b/src/st/st-theme-node.c
@@ -2545,6 +2545,28 @@ st_theme_node_get_text_align(StThemeNode *node)
   return ST_TEXT_ALIGN_LEFT;
 }
 
+/**
+ * st_theme_node_get_letter_spacing:
+ * @node: a #StThemeNode
+ *
+ * Gets the value for the letter-spacing style property, in pixels.
+ *
+ * Return value: the value of the letter-spacing property, if
+ *   found, or zero if such property has not been found.
+ */
+gdouble
+st_theme_node_get_letter_spacing (StThemeNode *node)
+{
+  gdouble spacing = 0.;
+
+  g_return_val_if_fail (ST_IS_THEME_NODE (node), spacing);
+
+  ensure_properties (node);
+
+  st_theme_node_lookup_length (node, "letter-spacing", FALSE, &spacing);
+  return spacing;
+}
+
 static gboolean
 font_family_from_terms (CRTerm *term,
                         char  **family)
diff --git a/src/st/st-theme-node.h b/src/st/st-theme-node.h
index 940b97a38..08648e68a 100644
--- a/src/st/st-theme-node.h
+++ b/src/st/st-theme-node.h
@@ -223,6 +223,8 @@ StTextDecoration st_theme_node_get_text_decoration (StThemeNode *node);
 
 StTextAlign st_theme_node_get_text_align (StThemeNode *node);
 
+double st_theme_node_get_letter_spacing (StThemeNode *node);
+
 /* Font rule processing is pretty complicated, so we just hardcode it
  * under the standard font/font-family/font-size/etc names. This means
  * you can't have multiple separate styled fonts for a single item,