[gimp] libgimpwidgets: enable ratio expressions for size entries with two fields

[N/A <ell src gnome org>]

commit f2a80a093a9adc8864e43928e137d35d7cbb82b0
Author: Ell <ell_se yahoo com>
Date:   Wed Oct 4 12:37:45 2017 -0400

    libgimpwidgets: enable ratio expressions for size entries with two fields
    
    When a size entry has exactly two fields, enable ratio expressions
    in eevl.  Set the reference value to the value of the field that is
    not currently being evaluated, and invert the ratio when evaluating
    the second field.

 libgimpwidgets/gimpsizeentry.c |   24 ++++++++++++++++++++++++
 1 files changed, 24 insertions(+), 0 deletions(-)
---
diff --git a/libgimpwidgets/gimpsizeentry.c b/libgimpwidgets/gimpsizeentry.c
index 9ac1030..1f82fee 100644
--- a/libgimpwidgets/gimpsizeentry.c
+++ b/libgimpwidgets/gimpsizeentry.c
@@ -1282,6 +1282,30 @@ gimp_size_entry_eevl_input_callback (GtkSpinButton *spinner,
   options.unit_resolver_proc = gimp_size_entry_eevl_unit_resolver;
   options.data               = data;
 
+  /* enable ratio expressions when there are two fields */
+  if (gsef->gse->number_of_fields == 2)
+    {
+      GimpSizeEntryField *other_gsef;
+
+      options.ratio_expressions = TRUE;
+
+      if (gsef == gsef->gse->fields->data)
+        {
+          other_gsef = gsef->gse->fields->next->data;
+
+          options.ratio_invert = FALSE;
+        }
+      else
+        {
+          other_gsef = gsef->gse->fields->data;
+
+          options.ratio_invert = TRUE;
+        }
+
+      options.ratio_quantity.value     = other_gsef->value;
+      options.ratio_quantity.dimension = 0;
+    }
+
   success = gimp_eevl_evaluate (gtk_entry_get_text (GTK_ENTRY (spinner)),
                                 &options,
                                 &result,