[gtksourceview] SpaceDrawer: take into account implicit trailing newline

[Sébastien Wilmet <swilmet src gnome org>]

commit 49cc347f824cb100994885efeeb03a89f92c3857
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Jul 23 09:10:19 2016 +0200

    SpaceDrawer: take into account implicit trailing newline
    
    This starts to become interesting.

 gtksourceview/gtksourcespacedrawer.c |   26 ++++++++++++++++++--------
 tests/test-space-drawing.c           |    8 ++++++++
 2 files changed, 26 insertions(+), 8 deletions(-)
---
diff --git a/gtksourceview/gtksourcespacedrawer.c b/gtksourceview/gtksourcespacedrawer.c
index fc0edbc..af3a508 100644
--- a/gtksourceview/gtksourcespacedrawer.c
+++ b/gtksourceview/gtksourcespacedrawer.c
@@ -194,11 +194,19 @@ is_space (gunichar ch)
        return g_unichar_type (ch) == G_UNICODE_SPACE_SEPARATOR;
 }
 
-static inline gboolean
+static gboolean
 is_newline (const GtkTextIter *iter)
 {
-       /* TODO take into account implicit trailing newline. */
-       return gtk_text_iter_ends_line (iter) && !gtk_text_iter_is_end (iter);
+       if (gtk_text_iter_is_end (iter))
+       {
+               GtkSourceBuffer *buffer;
+
+               buffer = GTK_SOURCE_BUFFER (gtk_text_iter_get_buffer (iter));
+
+               return gtk_source_buffer_get_implicit_trailing_newline (buffer);
+       }
+
+       return gtk_text_iter_ends_line (iter);
 }
 
 static inline gboolean
@@ -649,17 +657,20 @@ _gtk_source_space_drawer_draw (GtkSourceSpaceDrawer *drawer,
                gunichar ch = gtk_text_iter_get_char (&iter);
                gint ly;
 
-               if (is_whitespace (ch) &&
+               /* Allow end iter, to draw implicit trailing newline. */
+               if ((is_whitespace (ch) || gtk_text_iter_is_end (&iter)) &&
                    space_needs_drawing (drawer, &iter, &leading_end, &trailing_start))
                {
                        draw_whitespace_at_iter (text_view, &iter, cr);
                }
 
-               if (!gtk_text_iter_forward_char (&iter))
+               if (gtk_text_iter_is_end (&iter))
                {
                        break;
                }
 
+               gtk_text_iter_forward_char (&iter);
+
                if (gtk_text_iter_compare (&iter, &line_end) > 0)
                {
                        if (gtk_text_iter_compare (&iter, &end) > 0)
@@ -670,10 +681,9 @@ _gtk_source_space_drawer_draw (GtkSourceSpaceDrawer *drawer,
                        /* Move to the first iter in the exposed area of the
                         * next line.
                         */
-                       if (!gtk_text_iter_starts_line (&iter) &&
-                           !gtk_text_iter_forward_line (&iter))
+                       if (!gtk_text_iter_starts_line (&iter))
                        {
-                               break;
+                               gtk_text_iter_forward_line (&iter);
                        }
 
                        gtk_text_view_get_line_yrange (text_view, &iter, &ly, NULL);
diff --git a/tests/test-space-drawing.c b/tests/test-space-drawing.c
index 747fbab..5f010aa 100644
--- a/tests/test-space-drawing.c
+++ b/tests/test-space-drawing.c
@@ -75,6 +75,7 @@ create_window (void)
        GtkWidget *gsv_checkbutton;
        GtkWidget *tag_set_checkbutton;
        GtkWidget *tag_checkbutton;
+       GtkWidget *implicit_trailing_newline_checkbutton;
        GtkSourceView *view;
        GtkSourceBuffer *buffer;
        GtkTextTag *tag;
@@ -136,6 +137,13 @@ create_window (void)
                                tag, "draw-spaces",
                                G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
 
+       implicit_trailing_newline_checkbutton = gtk_check_button_new_with_label ("Implicit trailing newline");
+       gtk_widget_set_margin_top (implicit_trailing_newline_checkbutton, 12);
+       gtk_container_add (GTK_CONTAINER (panel_grid), implicit_trailing_newline_checkbutton);
+       g_object_bind_property (buffer, "implicit-trailing-newline",
+                               implicit_trailing_newline_checkbutton, "active",
+                               G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
+
        scrolled_window = gtk_scrolled_window_new (NULL, NULL);
        gtk_container_add (GTK_CONTAINER (scrolled_window), GTK_WIDGET (view));
        gtk_container_add (GTK_CONTAINER (hgrid), scrolled_window);