[gnome-boxes/wip/rishi/rhel: 1/17] os-database, wizard-source: Use named constants

[Debarshi Ray <debarshir src gnome org>]

commit 729590ffdb644a9e814c3f5c6b0a160d22419a13
Author: Debarshi Ray <debarshir gnome org>
Date:   Wed Sep 13 19:33:25 2017 +0200

    os-database, wizard-source: Use named constants
    
    ... instead of magic numbers.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=787678

 src/os-database.vala   |   11 +++++++++--
 src/wizard-source.vala |    8 +++++---
 2 files changed, 14 insertions(+), 5 deletions(-)
---
diff --git a/src/os-database.vala b/src/os-database.vala
index e5af73d..e595a37 100644
--- a/src/os-database.vala
+++ b/src/os-database.vala
@@ -10,6 +10,13 @@ public errordomain Boxes.OSDatabaseError {
 }
 
 private class Boxes.OSDatabase : GLib.Object {
+    public enum MediaURLsColumns {
+        URL = 0,  // string
+        OS = 1,   // Osinfo.Os
+
+        LAST
+    }
+
     private const int DEFAULT_VCPUS = 1;
     private const int64 DEFAULT_RAM = 2 * (int64) GIBIBYTES;
 
@@ -135,7 +142,7 @@ private class Boxes.OSDatabase : GLib.Object {
         if (!yield ensure_db_loaded ())
             throw new OSDatabaseError.DB_LOADING_FAILED ("Failed to load OS database");
 
-        var store = new Gtk.ListStore (2, typeof (string), typeof (Osinfo.Os));
+        var store = new Gtk.ListStore (MediaURLsColumns.LAST, typeof (string), typeof (Osinfo.Os));
         foreach (var entity in db.get_os_list ().get_elements ()) {
             var os = entity as Os;
 
@@ -146,7 +153,7 @@ private class Boxes.OSDatabase : GLib.Object {
                     Gtk.TreeIter iter;
 
                     store.append (out iter);
-                    store.set (iter, 0, media.url, 1, os);
+                    store.set (iter, MediaURLsColumns.URL, media.url, MediaURLsColumns.OS, os);
                 }
             }
         }
diff --git a/src/wizard-source.vala b/src/wizard-source.vala
index 8545363..7beef6c 100644
--- a/src/wizard-source.vala
+++ b/src/wizard-source.vala
@@ -146,7 +146,9 @@ private class Boxes.WizardSource: Gtk.Stack {
 
         media_urls_store.foreach ((store, path, iter) => {
             string? os_uri;
-            media_urls_store.get (iter, 0, out os_uri, 1, out os);
+            media_urls_store.get (iter,
+                                  OSDatabase.MediaURLsColumns.URL, out os_uri,
+                                  OSDatabase.MediaURLsColumns.OS, out os);
             return os_uri == uri;
         });
 
@@ -201,14 +203,14 @@ private class Boxes.WizardSource: Gtk.Stack {
             try {
                 media_urls_store = os_db.get_all_media_urls_as_store.end (result);
                 var completion = new Gtk.EntryCompletion ();
-                completion.text_column = 0;
+                completion.text_column = OSDatabase.MediaURLsColumns.URL;
                 completion.model = media_urls_store;
                 weak Gtk.CellRendererText cell = completion.get_cells ().nth_data (0) as 
Gtk.CellRendererText;
                 cell.ellipsize = Pango.EllipsizeMode.MIDDLE;
                 completion.set_match_func ((store, key, iter) => {
                     string url;
 
-                    media_urls_store.get (iter, 0, out url);
+                    media_urls_store.get (iter, OSDatabase.MediaURLsColumns.URL, out url);
 
                     return url.contains (key);
                 });