[pango/pango-view-spacing-2] pango-viewer: Optionally show line rects

[Matthias Clasen <matthiasc src gnome org>]

commit 4a82a4890757576300abe5000a24ba36ec149d46
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Jul 4 19:33:49 2019 +0000

    pango-viewer: Optionally show line rects
    
    With --annotate 3, show the logical rects
    for each line. This makes the spacing between
    lines easily visible.

 utils/viewer-pangocairo.c | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)
---
diff --git a/utils/viewer-pangocairo.c b/utils/viewer-pangocairo.c
index 3e893207..9054b9fe 100644
--- a/utils/viewer-pangocairo.c
+++ b/utils/viewer-pangocairo.c
@@ -138,7 +138,7 @@ render_callback (PangoLayout *layout,
                 gpointer     state)
 {
   cairo_t *cr = (cairo_t *) context;
-  int annotate = (GPOINTER_TO_INT (state) + opt_annotate) % 3;
+  int annotate = (GPOINTER_TO_INT (state) + opt_annotate) % 4;
 
   cairo_save (cr);
   cairo_translate (cr, x, y);
@@ -252,6 +252,7 @@ render_callback (PangoLayout *layout,
       /* draw the logical rect in red */
       cairo_save (cr);
       cairo_set_source_rgba (cr, 1.0, 0.0, 0.0, 0.5);
+
       cairo_rectangle (cr,
                       (double)logical.x / PANGO_SCALE - lw / 2,
                       (double)logical.y / PANGO_SCALE - lw / 2,
@@ -270,6 +271,30 @@ render_callback (PangoLayout *layout,
                       (double)ink.height / PANGO_SCALE + lw);
       cairo_stroke (cr);
       cairo_restore (cr);
+
+      if (opt_annotate >= 3)
+        {
+          /* draw the logical rects for lines in red */
+          cairo_save (cr);
+          cairo_set_source_rgba (cr, 1.0, 0.0, 0.0, 0.5);
+
+          iter = pango_layout_get_iter (layout);
+          do
+           {
+              PangoRectangle rect;
+
+              pango_layout_iter_get_line_extents (iter, NULL, &rect);
+              cairo_rectangle (cr,
+                               (double)rect.x / PANGO_SCALE - lw / 2,
+                               (double)rect.y / PANGO_SCALE - lw / 2,
+                               (double)rect.width / PANGO_SCALE + lw,
+                               (double)rect.height / PANGO_SCALE + lw);
+              cairo_stroke (cr);
+            }
+          while (pango_layout_iter_next_line (iter));
+          pango_layout_iter_free (iter);
+          cairo_restore (cr);
+        }
     }
 
   cairo_move_to (cr, 0, 0);
@@ -416,7 +441,7 @@ pangocairo_view_get_option_group (const PangoViewer *klass G_GNUC_UNUSED)
   GOptionEntry entries[] =
   {
     {"annotate",       0, 0, G_OPTION_ARG_INT, &opt_annotate,
-     "Annotate the output",                            "1 or 2"},
+     "Annotate the output",                            "1, 2 or 3"},
     {NULL}
   };
   GOptionGroup *group;