[balsa/gtk4] mime-widget-text: Cite bar dimension calculation

[Peter Bloomfield <peterb src gnome org>]

commit d6a113cd76aea102c1a4161317bdbe0ed0cfcdfb
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Fri Nov 20 17:18:33 2020 -0500

    mime-widget-text: Cite bar dimension calculation
    
    Getting the character width from a pango font description is mysterious.

 src/balsa-mime-widget-text.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/src/balsa-mime-widget-text.c b/src/balsa-mime-widget-text.c
index 3642208c8..3d739aabb 100644
--- a/src/balsa-mime-widget-text.c
+++ b/src/balsa-mime-widget-text.c
@@ -1021,7 +1021,7 @@ draw_cite_bar_real(gpointer data, gpointer user_data)
     BalsaMimeWidgetText *mwt = user_data;
     GtkTextView * view;
     GtkTextBuffer * buffer;
-    gint dimension;
+    int dimension;
     GdkRectangle location;
     int y_pos;
     int height;
@@ -1477,13 +1477,14 @@ fill_text_buf_cited(BalsaMimeWidgetText *mwt,
     }
 
     /* width of monospace characters is 3/5 of the size */
-    char_width = 0.6 * pango_font_description_get_size(desc);
-    if (!pango_font_description_get_size_is_absolute(desc))
-        char_width = char_width / PANGO_SCALE;
+    char_width = 0.6 * (double) pango_font_description_get_size(desc) / (double) PANGO_SCALE;
 
-    /* convert char_width from points to pixels */
-    /* Assume a logical DPI of 96, which is alleged to be common */
-    mwt->cite_bar_dimension = (char_width / 72.0) * 96;
+    if (!pango_font_description_get_size_is_absolute(desc)) {
+        /* convert char_width from points to pixels */
+        /* Assume a logical DPI of 96, which is alleged to be common */
+        char_width = (char_width / 72.0) * 96.0;
+    }
+    mwt->cite_bar_dimension = (int) (char_width + 0.5); /* rounding */
 
     buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(widget));
     rgba = &balsa_app.url_color;