[folks] individual: Prefer data from personas with writeable properties

[Philip Withnall <pwithnall src gnome org>]

commit d0ab83aaccf91b32016649e4c512f37cc5285a08
Author: Philip Withnall <philip tecnocode co uk>
Date:   Wed Sep 14 22:26:04 2011 +0100

    individual: Prefer data from personas with writeable properties
    
    As an addition to the fix for bgo#657783, if two personas come from stores
    which have equal is-primary-store values, we now prefer the persona which
    lists the given property as writeable. If both personas list (or don't list)
    the property as writeable, we fall back to the given ordering function as
    before.
    
    Closes: bgo#657783

 folks/individual.vala |   74 ++++++++++++++++++++++++++----------------------
 1 files changed, 40 insertions(+), 34 deletions(-)
---
diff --git a/folks/individual.vala b/folks/individual.vala
index 6733446..5fb0d16 100644
--- a/folks/individual.vala
+++ b/folks/individual.vala
@@ -1045,10 +1045,11 @@ public class Folks.Individual : Object,
    * { link Individual.groups}.
    *
    * This function uses the given comparison function to order the personas in
-   * this individual, with the highest-positioned persona finally being passed
-   * to the setter function to use in updating the individual's value for the
-   * given property. i.e. If `compare_func(a, b)` is called and returns > 0,
-   * persona `a` will be passed to the setter.
+   * this individual, with the highest-positioned persona (the âgreatestâ
+   * persona in the total order) finally being passed to the setter function to
+   * use in updating the individual's value for the given property. i.e. If
+   * `compare_func(a, b)` is called and returns > 0, persona `a` will be passed
+   * to the setter.
    *
    * At a level above `compare_func`, the function always prefers personas from
    * the primary store (see { link IndividualAggregator.primary_store}) over
@@ -1062,11 +1063,14 @@ public class Folks.Individual : Object,
    * @param interface_type the type of interface which all personas under
    * consideration must implement ({ link Persona} to select all personas)
    * @param compare_func comparison function to order personas for selection
+   * @param prop_name name of the property being set, as used in
+   * { link Persona.writeable_properties}
    * @param setter function to update the individual with the chosen value
    * @since 0.6.2
    */
   private void _update_single_valued_property (Type interface_type,
-      CompareFunc<Persona> compare_func, SingleValuedPropertySetter setter)
+      CompareFunc<Persona> compare_func, string prop_name,
+      SingleValuedPropertySetter setter)
     {
       CompareDataFunc<Persona> primary_compare_func = (a, b) =>
         {
@@ -1076,33 +1080,35 @@ public class Folks.Individual : Object,
           var a_is_primary = a.store.is_primary_store;
           var b_is_primary = b.store.is_primary_store;
 
-          if (a_is_primary == b_is_primary)
+          if (a_is_primary != b_is_primary)
             {
-              /* Use the comparison function to get an ordering over a and b
-               * given that they're both from stores with the same is-primary
-               * value. If the comparison function gives them an equal order,
-               * we use the personas' UIDs to ensure that we end up with a total
-               * order over all personas in the individual (otherwise we might
-               * end up with unstable property values). */
-              var order = compare_func (a, b);
-
-              if (order == 0)
-                {
-                  order = strcmp (a.uid, b.uid);
-                }
-
-              return order;
+              return (a_is_primary ? 1 : 0) - (b_is_primary ? 1 : 0);
             }
-          else if (a_is_primary == true)
+
+          /* If both personas have the same is-primary value, prefer personas
+           * which have the given property as writeable over those which
+           * don't. */
+          var a_is_writeable = (prop_name in a.writeable_properties);
+          var b_is_writeable = (prop_name in b.writeable_properties);
+
+          if (a_is_writeable != b_is_writeable)
             {
-              return -1;
+              return (a_is_writeable ? 1 : 0) - (b_is_writeable ? 1 : 0);
             }
-          else if (b_is_primary == true)
+
+          /* If both personas have the same writeability for this property, fall
+           * back to the given comparison function. If the comparison function
+           * gives them an equal order, we use the personas' UIDs to ensure that
+           * we end up with a total order over all personas in the individual
+           * (otherwise we might end up with unstable property values). */
+          var order = compare_func (a, b);
+
+          if (order == 0)
             {
-              return 1;
+              order = strcmp (a.uid, b.uid);
             }
 
-          assert_not_reached ();
+          return order;
         };
 
       Persona? candidate_p = null;
@@ -1193,7 +1199,7 @@ public class Folks.Individual : Object,
           var b_presence = (b as PresenceDetails).presence_type;
 
           return PresenceDetails.typecmp (a_presence, b_presence);
-        }, (p) =>
+        }, "presence", (p) =>
         {
           var presence_message = ""; /* must not be null */
           var presence_status = ""; /* must not be null */
@@ -1229,7 +1235,7 @@ public class Folks.Individual : Object,
 
           return ((a_is_favourite == true) ? 1 : 0) -
                  ((b_is_favourite == true) ? 1 : 0);
-        }, (p) =>
+        }, "is-favourite", (p) =>
         {
           var favourite = false;
 
@@ -1271,7 +1277,7 @@ public class Folks.Individual : Object,
 
           return (b_is_empty + b_is_display_id) -
                  (a_is_empty + a_is_display_id);
-        }, (p) =>
+        }, "alias", (p) =>
         {
           string alias = ""; /* must not be null */
 
@@ -1300,7 +1306,7 @@ public class Folks.Individual : Object,
           var b_avatar = (b as AvatarDetails).avatar;
 
           return ((a_avatar != null) ? 1 : 0) - ((b_avatar != null) ? 1 : 0);
-        }, (p) =>
+        }, "avatar", (p) =>
         {
           LoadableIcon? avatar = null;
 
@@ -1434,7 +1440,7 @@ public class Folks.Individual : Object,
           var b_is_set = (b_name != null && !b_name.is_empty ()) ? 1 : 0;
 
           return (a_is_set - b_is_set);
-        }, (p) =>
+        }, "structured-name", (p) =>
         {
           StructuredName? name = null;
 
@@ -1472,7 +1478,7 @@ public class Folks.Individual : Object,
           var b_is_set = (b_name.strip () != "") ? 1 : 0;
 
           return (a_is_set - b_is_set);
-        }, (p) =>
+        }, "full-name", (p) =>
         {
           string new_full_name = ""; /* must not be null */
 
@@ -1503,7 +1509,7 @@ public class Folks.Individual : Object,
           var b_is_set = (b_name.strip () != "") ? 1 : 0;
 
           return (a_is_set - b_is_set);
-        }, (p) =>
+        }, "nickname", (p) =>
         {
           string new_nickname = ""; /* must not be null */
 
@@ -1595,7 +1601,7 @@ public class Folks.Individual : Object,
           var b_is_specified = (b_gender != Gender.UNSPECIFIED) ? 1 : 0;
 
           return (a_is_specified - b_is_specified);
-        }, (p) =>
+        }, "gender", (p) =>
         {
           var new_gender = Gender.UNSPECIFIED;
 
@@ -1798,7 +1804,7 @@ public class Folks.Individual : Object,
            * different personas don't match, because that's just scary. */
           return (a_birthday_is_set + a_event_id_is_set) -
                  (b_birthday_is_set + b_event_id_is_set);
-        }, (p) =>
+        }, "birthday", (p) =>
         {
           unowned DateTime? bday = null;
           unowned string? calendar_event_id = null;