[geary/wip/730682-refine-convo-list] Property set up Email field consts on new list model and preview loader.

[Michael Gratton <mjog src gnome org>]

commit 4388209c218abbb73d839e7aa32801a2198ce20e
Author: Michael James Gratton <mike vee net>
Date:   Tue Dec 12 09:58:52 2017 +1100

    Property set up Email field consts on new list model and preview loader.

 src/client/application/geary-controller.vala       |    2 +-
 .../conversation-list/conversation-list-model.vala |    7 +++++++
 src/client/conversation-list/preview-loader.vala   |   15 ++++++++++-----
 3 files changed, 18 insertions(+), 6 deletions(-)
---
diff --git a/src/client/application/geary-controller.vala b/src/client/application/geary-controller.vala
index e3667c5..6d54410 100644
--- a/src/client/application/geary-controller.vala
+++ b/src/client/application/geary-controller.vala
@@ -1330,7 +1330,7 @@ public class GearyController : Geary.BaseObject {
         current_conversations = new Geary.App.ConversationMonitor(
             current_folder,
             Geary.Folder.OpenFlags.NO_DELAY,
-            ConversationListStore.REQUIRED_FIELDS,
+            ConversationListModel.REQUIRED_FIELDS,
             CONVERSATION_PAGE_SIZE * 2 // load double up front when not scrolling
         );
 
diff --git a/src/client/conversation-list/conversation-list-model.vala 
b/src/client/conversation-list/conversation-list-model.vala
index e0171b6..61b28ad 100644
--- a/src/client/conversation-list/conversation-list-model.vala
+++ b/src/client/conversation-list/conversation-list-model.vala
@@ -18,6 +18,13 @@
 public class ConversationListModel : Geary.BaseObject, GLib.ListModel {
 
 
+    /** Email fields required to load the message in this model. */
+    public const Geary.Email.Field REQUIRED_FIELDS =
+        Geary.Email.Field.ENVELOPE |
+        Geary.Email.Field.FLAGS |
+        Geary.Email.Field.PROPERTIES;
+
+
     /** The source of conversations for this model. */
     public Geary.App.ConversationMonitor monitor { get; private set; }
 
diff --git a/src/client/conversation-list/preview-loader.vala 
b/src/client/conversation-list/preview-loader.vala
index 217a529..9b0a698 100644
--- a/src/client/conversation-list/preview-loader.vala
+++ b/src/client/conversation-list/preview-loader.vala
@@ -12,6 +12,16 @@
 public class PreviewLoader : Geary.BaseObject {
 
 
+    /** Email fields required to load message previews. */
+    public const Geary.Email.Field REQUIRED_FIELDS =
+        ConversationListModel.REQUIRED_FIELDS |
+        Geary.Email.Field.PREVIEW |
+        // XXX Remove ALL and NONE below when PREVIEW has been
+        // fixed. See Bug 714317.
+        Geary.Email.Field.ALL | Geary.Email.Field.NONE;
+
+
+    /** Progress monitor for loading previews from the database. */
     public Geary.ProgressMonitor progress {
         get;
         private set;
@@ -20,11 +30,6 @@ public class PreviewLoader : Geary.BaseObject {
         );
     }
 
-    // XXX Remove ALL and NONE when PREVIEW has been fixed. See Bug 714317.
-    private const Geary.Email.Field WITH_PREVIEW_FIELDS =
-        Geary.Email.Field.ENVELOPE | Geary.Email.Field.FLAGS |
-        Geary.Email.Field.PROPERTIES | Geary.Email.Field.PREVIEW |
-        Geary.Email.Field.ALL | Geary.Email.Field.NONE;
 
     private Geary.App.EmailStore email_store;
     private Cancellable cancellable;