[gimp/gimp-2-10] Issue #3025 - "File/New" doesn't honor "precision" choice ...

[Ell <ell src gnome org>]

commit 8c7e2a9e03ffb3ebbf385350231a81eee59b26cd
Author: Ell <ell_se yahoo com>
Date:   Sun Mar 31 14:54:30 2019 -0400

    Issue #3025 - "File/New" doesn't honor "precision" choice ...
    
    ... for "Edit/Preferences/Default Image"
    
    In GimpTemplateEditor, don't use gimp_prop_enum_combo_box_new() for
    the "Precision" combo-box, and rather synchronize the combo-box and
    the template manually, since we only want to update the "Gamma"
    combo-box according to the precision when it changes through the
    UI, and not when the template's precision otherwise changes.
    
    This fixes an issue where we'd always set the default gamma value
    when resetting the editor's template, overwriting the template's
    original gamma value.
    
    (cherry picked from commit 033082dd9a0850a86c1b0b76187afd4725df4e9f)

 app/widgets/gimptemplateeditor.c | 47 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 41 insertions(+), 6 deletions(-)
---
diff --git a/app/widgets/gimptemplateeditor.c b/app/widgets/gimptemplateeditor.c
index 82311f5cc5..118700f0e2 100644
--- a/app/widgets/gimptemplateeditor.c
+++ b/app/widgets/gimptemplateeditor.c
@@ -31,6 +31,8 @@
 
 #include "config/gimpcoreconfig.h"
 
+#include "gegl/gimp-babl.h"
+
 #include "core/gimp.h"
 #include "core/gimptemplate.h"
 
@@ -71,6 +73,7 @@ struct _GimpTemplateEditorPrivate
   GtkWidget     *more_label;
   GtkWidget     *resolution_se;
   GtkWidget     *chain_button;
+  GtkWidget     *precision_combo;
   GtkWidget     *profile_combo;
 };
 
@@ -158,6 +161,7 @@ gimp_template_editor_constructed (GObject *object)
   GtkWidget                 *scrolled_window;
   GtkWidget                 *text_view;
   GtkTextBuffer             *text_buffer;
+  GtkListStore              *store;
   GList                     *focus_chain = NULL;
   gchar                     *text;
   gint                       row;
@@ -404,15 +408,28 @@ gimp_template_editor_constructed (GObject *object)
                              _("Color _space:"), 0.0, 0.5,
                              combo, 1, FALSE);
 
-  combo = gimp_prop_enum_combo_box_new (G_OBJECT (template),
-                                        "component-type",
-                                        GIMP_COMPONENT_TYPE_U8,
-                                        GIMP_COMPONENT_TYPE_FLOAT);
+  /* construct the precision combo manually, instead of using
+   * gimp_prop_enum_combo_box_new(), so that we only reset the gamma combo when
+   * the precision is changed through the ui.  see issue #3025.
+   */
+  store = gimp_enum_store_new_with_range (GIMP_TYPE_COMPONENT_TYPE,
+                                          GIMP_COMPONENT_TYPE_U8,
+                                          GIMP_COMPONENT_TYPE_FLOAT);
+
+  private->precision_combo = g_object_new (GIMP_TYPE_ENUM_COMBO_BOX,
+                                           "model", store,
+                                           NULL);
+  g_object_unref (store);
+
   gimp_table_attach_aligned (GTK_TABLE (table), 0, row++,
                              _("_Precision:"), 0.0, 0.5,
-                             combo, 1, FALSE);
+                             private->precision_combo, 1, FALSE);
 
-  g_signal_connect (combo, "changed",
+  gimp_int_combo_box_set_active (GIMP_INT_COMBO_BOX (private->precision_combo),
+                                 gimp_babl_component_type (
+                                   gimp_template_get_precision (template)));
+
+  g_signal_connect (private->precision_combo, "changed",
                     G_CALLBACK (gimp_template_editor_precision_changed),
                     editor);
 
@@ -642,6 +659,10 @@ gimp_template_editor_precision_changed (GtkWidget          *widget,
   gimp_int_combo_box_get_active (GIMP_INT_COMBO_BOX (widget),
                                  (gint *) &component_type);
 
+  g_object_set (private->template,
+                "component-type", component_type,
+                NULL);
+
   /* when changing this logic, also change the same switch()
    * in convert-precision-dialog.c
    */
@@ -763,6 +784,20 @@ gimp_template_editor_template_notify (GimpTemplate       *template,
                                           gimp_template_get_resolution_y (template),
                                           FALSE);
         }
+      else if (! strcmp (param_spec->name, "component-type"))
+        {
+          g_signal_handlers_block_by_func (private->precision_combo,
+                                           gimp_template_editor_precision_changed,
+                                           editor);
+
+          gimp_int_combo_box_set_active (
+            GIMP_INT_COMBO_BOX (private->precision_combo),
+            gimp_babl_component_type (gimp_template_get_precision (template)));
+
+          g_signal_handlers_unblock_by_func (private->precision_combo,
+                                             gimp_template_editor_precision_changed,
+                                             editor);
+        }
     }
 
 #ifdef ENABLE_MEMSIZE_LABEL