[gnome-builder/wip/gtk4-port: 786/1774] plugins/omni-gutter: improve line number positioning

[Christian Hergert <chergert src gnome org>]

commit aaea21251e622003efe3cee829f15ef2d1421815
Author: Christian Hergert <chergert redhat com>
Date:   Wed Apr 27 16:45:09 2022 -0700

    plugins/omni-gutter: improve line number positioning
    
    So that we can place things without too much extra calculations such as
    cell alignment. This just places in the middle, which isn't my favorite,
    but it is relatively fast.

 src/plugins/omni-gutter/gbp-omni-gutter-renderer.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)
---
diff --git a/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c 
b/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c
index 6d5262ede..f4d068c2c 100644
--- a/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c
+++ b/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c
@@ -145,6 +145,7 @@ struct _GbpOmniGutterRenderer
    * for us (as necessary).
    */
   int number_width;
+  int number_height;
 
   /*
    * Calculated size for diagnostics, to be a nearest icon-size based
@@ -152,9 +153,7 @@ struct _GbpOmniGutterRenderer
    */
   int diag_size;
 
-  /*
-   * Line that the cursor is on. Used for relative line number rendering.
-   */
+  /* Line that the cursor is on. Used for relative line number rendering. */
   guint cursor_line;
 
   /* Delayed reload timeout source */
@@ -724,7 +723,6 @@ gbp_omni_gutter_renderer_measure (GbpOmniGutterRenderer *self)
   PangoLayout *layout;
   GtkTextIter end;
   guint line;
-  int height;
   int size = 0;
   int old_width;
 
@@ -763,14 +761,14 @@ gbp_omni_gutter_renderer_measure (GbpOmniGutterRenderer *self)
    * positioning later. We simply size everything the same and then
    * align to the right to reduce the draw overhead.
    */
-  pango_layout_get_pixel_size (layout, &self->number_width, &height);
+  pango_layout_get_pixel_size (layout, &self->number_width, &self->number_height);
   pango_layout_set_attributes (layout, bold_attrs);
 
   /*
    * Calculate the nearest size for diagnostics so they scale somewhat
    * reasonable with the character size.
    */
-  self->diag_size = calculate_diagnostics_size (MAX (16, height));
+  self->diag_size = calculate_diagnostics_size (MAX (16, self->number_height));
   g_assert (self->diag_size > 0);
 
   /* Now calculate the size based on enabled features */
@@ -1191,8 +1189,8 @@ gbp_omni_gutter_renderer_snapshot_line (GtkSourceGutterRenderer *renderer,
         {
           const GdkRGBA *rgba;
           const gchar *linestr = NULL;
-          int len;
           guint shown_line;
+          int len;
 
           if (!self->show_relative_line_numbers || line == self->cursor_line)
             shown_line = line + 1;
@@ -1223,7 +1221,7 @@ gbp_omni_gutter_renderer_snapshot_line (GtkSourceGutterRenderer *renderer,
           pango_layout_set_attributes (self->layout, bold ? bold_attrs : NULL);
 
           gtk_snapshot_save (snapshot);
-          gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (0, line_y));
+          gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (0, line_y + ((line_height - 
self->number_height) / 2)));
           gtk_snapshot_append_layout (snapshot, self->layout, rgba);
           gtk_snapshot_restore (snapshot);
         }