[gtksourceview] vim: fix ctrl+y/ctrl+e movements

[Christian Hergert <chergert src gnome org>]

commit a88d46020e7fda3f0924879e61d7f18a616649b7
Author: Christian Hergert <chergert redhat com>
Date:   Mon Nov 22 06:58:26 2021 -0800

    vim: fix ctrl+y/ctrl+e movements
    
    We only want to add to count in the forward direction. This fixes the
    Ctrl+E moving two lines sometimes and the Ctrl+Y not moving at all.
    
    This was an issue in gnome-text-editor, but not test-widget due to how
    the rectangles play out (possibly due to margins).

 gtksourceview/vim/gtksourcevimstate.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)
---
diff --git a/gtksourceview/vim/gtksourcevimstate.c b/gtksourceview/vim/gtksourcevimstate.c
index c0070c0b..530e50c0 100644
--- a/gtksourceview/vim/gtksourcevimstate.c
+++ b/gtksourceview/vim/gtksourcevimstate.c
@@ -724,12 +724,17 @@ gtk_source_vim_state_scroll_line (GtkSourceVimState *self,
 
        view = gtk_source_vim_state_get_view (self);
        gtk_text_view_get_visible_rect (GTK_TEXT_VIEW (view), &rect);
-       gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (view), &top, rect.x, rect.y);
+       gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (view), &top, 0, rect.y);
        gtk_text_view_get_line_yrange (GTK_TEXT_VIEW (view), &top, &y, &height);
 
        /* Add a line is slightly visible. Works in both directions */
-       if (y < rect.y)
-               count++;
+       if (y < rect.y && (rect.y - y) > (height / 2))
+       {
+               if (count > 0)
+               {
+                       count++;
+               }
+       }
 
        if (count > 0)
                gtk_text_iter_forward_lines (&top, count);
@@ -773,7 +778,7 @@ scroll_half_page_up (GtkSourceVimState *self)
 
 void
 gtk_source_vim_state_scroll_half_page (GtkSourceVimState *self,
-                                      int                count)
+                                       int                count)
 {
        GtkSourceView *view;
        GdkRectangle rect, loc;