[gnome-builder/wip/gtk4-port] plugins/omni-gutter: add margin to omni gutter

[Christian Hergert <chergert src gnome org>]

commit afa4d7d143dc9d00380933bdc6c35e1164dff5fc
Author: Christian Hergert <chergert redhat com>
Date:   Fri Apr 29 20:01:05 2022 -0700

    plugins/omni-gutter: add margin to omni gutter
    
    Since we can't really do this with the text view, we can do it from the
    margin for now. However, we still need to tweak how we draw the background
    for that space, but that can happen later.

 src/plugins/omni-gutter/gbp-omni-gutter-renderer.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c 
b/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c
index 7d2c35413..e1bc59216 100644
--- a/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c
+++ b/src/plugins/omni-gutter/gbp-omni-gutter-renderer.c
@@ -52,6 +52,7 @@
  * Since: 3.32
  */
 
+#define RIGHT_MARGIN 4
 #define CHANGE_WIDTH 2
 #define DELETE_WIDTH 5
 #define DELETE_HEIGHT 2
@@ -805,6 +806,9 @@ gbp_omni_gutter_renderer_measure (GbpOmniGutterRenderer *self)
   if (self->show_line_changes)
     size += CHANGE_WIDTH + 2;
 
+  /* Extra margin */
+  size += RIGHT_MARGIN;
+
   if (size != old_width)
     {
       /* Update the size and ensure we are re-drawn */
@@ -941,7 +945,7 @@ gbp_omni_gutter_renderer_begin (GtkSourceGutterRenderer *renderer,
   /* Create a new layout for rendering lines to */
   self->layout = gtk_widget_create_pango_layout (GTK_WIDGET (self), "");
   pango_layout_set_alignment (self->layout, PANGO_ALIGN_RIGHT);
-  pango_layout_set_width (self->layout, (width - BREAKPOINT_XPAD - 4) * PANGO_SCALE);
+  pango_layout_set_width (self->layout, (width - BREAKPOINT_XPAD - RIGHT_MARGIN - 4) * PANGO_SCALE);
 }
 
 static gboolean
@@ -1251,7 +1255,7 @@ gbp_omni_gutter_renderer_snapshot_line (GtkSourceGutterRenderer *renderer,
        * breakpoint arrows.
        */
       if (self->show_line_changes && IS_LINE_CHANGE (info))
-        draw_line_change (self, snapshot, line_y, width, line_height, active, info);
+        draw_line_change (self, snapshot, line_y, width - RIGHT_MARGIN, line_height, active, info);
 
       /* Draw breakpoint arrows if we have any breakpoints that could
        * potentially match.
@@ -1260,7 +1264,7 @@ gbp_omni_gutter_renderer_snapshot_line (GtkSourceGutterRenderer *renderer,
         {
           has_breakpoint = IS_BREAKPOINT (info);
           if (has_breakpoint || active)
-            draw_breakpoint_bg (self, snapshot, line_y, width, line_height, active, info);
+            draw_breakpoint_bg (self, snapshot, line_y, width - RIGHT_MARGIN, line_height, active, info);
         }
 
       /* Now that we might have an altered background for the line,
@@ -1268,7 +1272,7 @@ gbp_omni_gutter_renderer_snapshot_line (GtkSourceGutterRenderer *renderer,
        * color for symbolic icon).
        */
       if (self->show_line_diagnostics && IS_DIAGNOSTIC (info))
-        draw_diagnostic (self, snapshot, line_y, width, line_height, active, info);
+        draw_diagnostic (self, snapshot, line_y, width - RIGHT_MARGIN, line_height, active, info);
 
       /*
        * Now draw the line numbers if we are showing them. Ensure