[gtksourceview] SpaceDrawer: improve space_needs_drawing() readability

[Sébastien Wilmet <swilmet src gnome org>]

commit 2d295d75175ef446ace0abf8b5bf2962e9d7559f
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Fri Jul 22 23:48:47 2016 +0200

    SpaceDrawer: improve space_needs_drawing() readability

 gtksourceview/gtksourcespacedrawer.c |   82 +++++++++++++++++----------------
 1 files changed, 42 insertions(+), 40 deletions(-)
---
diff --git a/gtksourceview/gtksourcespacedrawer.c b/gtksourceview/gtksourcespacedrawer.c
index 9fb053f..9eb68ae 100644
--- a/gtksourceview/gtksourcespacedrawer.c
+++ b/gtksourceview/gtksourcespacedrawer.c
@@ -396,53 +396,68 @@ space_needs_drawing_according_to_tag (const GtkTextIter *iter,
 }
 
 static gboolean
-check_location (GtkSourceSpaceDrawer *drawer,
-               const GtkTextIter    *iter,
-               const GtkTextIter    *leading,
-               const GtkTextIter    *trailing)
+space_needs_drawing_according_to_location (GtkSourceSpaceDrawer *drawer,
+                                          const GtkTextIter    *iter,
+                                          const GtkTextIter    *leading_end,
+                                          const GtkTextIter    *trailing_start)
 {
-       gint flags = 0;
-       gint location = drawer->priv->flags & (GTK_SOURCE_DRAW_SPACES_LEADING |
-                                              GTK_SOURCE_DRAW_SPACES_TEXT |
-                                              GTK_SOURCE_DRAW_SPACES_TRAILING);
+       gint iter_locations = 0;
+       gint allowed_locations = drawer->priv->flags & (GTK_SOURCE_DRAW_SPACES_LEADING |
+                                                       GTK_SOURCE_DRAW_SPACES_TEXT |
+                                                       GTK_SOURCE_DRAW_SPACES_TRAILING);
 
        /* Draw all by default */
-       if (location == 0)
+       if (allowed_locations == 0)
        {
                return TRUE;
        }
 
-       if (gtk_text_iter_compare (iter, trailing) >= 0)
+       if (gtk_text_iter_compare (iter, leading_end) < 0)
        {
-               flags |= GTK_SOURCE_DRAW_SPACES_TRAILING;
+               iter_locations |= GTK_SOURCE_DRAW_SPACES_LEADING;
        }
 
-       if (gtk_text_iter_compare (iter, leading) < 0)
+       if (gtk_text_iter_compare (trailing_start, iter) <= 0)
        {
-               flags |= GTK_SOURCE_DRAW_SPACES_LEADING;
+               iter_locations |= GTK_SOURCE_DRAW_SPACES_TRAILING;
        }
 
-       if (flags == 0)
+       /* Neither leading nor trailing, must be in text */
+       if (iter_locations == 0)
        {
-               /* Neither leading nor trailing, must be in text */
-               return location & GTK_SOURCE_DRAW_SPACES_TEXT;
-       }
-       else
-       {
-               return location & flags;
+               iter_locations = GTK_SOURCE_DRAW_SPACES_TEXT;
        }
+
+       return (iter_locations & allowed_locations) != 0;
+}
+
+static gboolean
+space_needs_drawing_according_to_whitespace_type (GtkSourceSpaceDrawer *drawer,
+                                                 const GtkTextIter    *iter)
+{
+       gint flags;
+       gunichar c;
+
+       flags = drawer->priv->flags;
+       c = gtk_text_iter_get_char (iter);
+
+       return ((flags & GTK_SOURCE_DRAW_SPACES_TAB && c == '\t') ||
+               (flags & GTK_SOURCE_DRAW_SPACES_NBSP &&
+                g_unichar_break_type (c) == G_UNICODE_BREAK_NON_BREAKING_GLUE) ||
+               (flags & GTK_SOURCE_DRAW_SPACES_SPACE &&
+                g_unichar_type (c) == G_UNICODE_SPACE_SEPARATOR) ||
+               (flags & GTK_SOURCE_DRAW_SPACES_NEWLINE &&
+                gtk_text_iter_ends_line (iter) && !gtk_text_iter_is_end (iter)));
 }
 
 static gboolean
 space_needs_drawing (GtkSourceSpaceDrawer *drawer,
                     const GtkTextIter    *iter,
-                    const GtkTextIter    *leading,
-                    const GtkTextIter    *trailing)
+                    const GtkTextIter    *leading_end,
+                    const GtkTextIter    *trailing_start)
 {
        gboolean has_tag;
        gboolean needs_drawing;
-       gint flags;
-       gunichar c;
 
        /* Check the GtkSourceTag:draw-spaces property */
 
@@ -452,23 +467,10 @@ space_needs_drawing (GtkSourceSpaceDrawer *drawer,
                return needs_drawing;
        }
 
-       /* Check the GtkSourceView:draw-spaces property */
-
-       if (!check_location (drawer, iter, leading, trailing))
-       {
-               return FALSE;
-       }
-
-       flags = drawer->priv->flags;
-       c = gtk_text_iter_get_char (iter);
+       /* Check the flags */
 
-       return ((flags & GTK_SOURCE_DRAW_SPACES_TAB && c == '\t') ||
-               (flags & GTK_SOURCE_DRAW_SPACES_NBSP &&
-                g_unichar_break_type (c) == G_UNICODE_BREAK_NON_BREAKING_GLUE) ||
-               (flags & GTK_SOURCE_DRAW_SPACES_SPACE &&
-                g_unichar_type (c) == G_UNICODE_SPACE_SEPARATOR) ||
-               (flags & GTK_SOURCE_DRAW_SPACES_NEWLINE &&
-                gtk_text_iter_ends_line (iter) && !gtk_text_iter_is_end (iter)));
+       return (space_needs_drawing_according_to_location (drawer, iter, leading_end, trailing_start) &&
+               space_needs_drawing_according_to_whitespace_type (drawer, iter));
 }
 
 static void