[libgee] Add read_only_view to Gee.MultiMap, fixes bug #687158

[Maciej Marcin Piechotka <mpiechotka src gnome org>]

commit ff36eae259f93fc9ef00615da7f072824e5efaed
Author: Maciej Piechotka <uzytkownik2 gmail com>
Date:   Sat Feb 16 12:59:56 2013 +0000

    Add read_only_view to Gee.MultiMap, fixes bug #687158

 gee/Makefile.am           |    1 +
 gee/abstractmultimap.vala |   15 ++++++++++++++-
 gee/multimap.vala         |    6 ++++++
 gee/readonlymap.vala      |    2 +-
 4 files changed, 22 insertions(+), 2 deletions(-)
---
diff --git a/gee/Makefile.am b/gee/Makefile.am
index a129b1f..f67d58a 100644
--- a/gee/Makefile.am
+++ b/gee/Makefile.am
@@ -56,6 +56,7 @@ libgee_0_8_la_SOURCES = \
        readonlycollection.vala \
        readonlylist.vala \
        readonlymap.vala \
+       readonlymultimap.vala \
        readonlymultiset.vala \
        readonlyset.vala \
        readonlysortedmap.vala \
diff --git a/gee/abstractmultimap.vala b/gee/abstractmultimap.vala
index 81bd97c..12e84dd 100644
--- a/gee/abstractmultimap.vala
+++ b/gee/abstractmultimap.vala
@@ -309,6 +309,19 @@ public abstract class Gee.AbstractMultiMap<K,V> : Object, MultiMap<K,V> {
                public bool mutable { get { return false; } }
        }
 
+       private weak MultiMap<K, V> _read_only_view;
+       public virtual new MultiMap<K, V> read_only_view {
+               owned get {
+                       MultiMap<K, V> instance = _read_only_view;
+                       if (_read_only_view == null) {
+                               instance = new ReadOnlyMultiMap<K, V> (this);
+                               _read_only_view = instance;
+                               instance.add_weak_pointer ((void**) (&_read_only_view));
+                       }
+                       return instance;
+               }
+       }
+
        // Future-proofing
        internal new virtual void reserved0() {}
        internal new virtual void reserved1() {}
@@ -319,5 +332,5 @@ public abstract class Gee.AbstractMultiMap<K,V> : Object, MultiMap<K,V> {
        internal new virtual void reserved6() {}
        internal new virtual void reserved7() {}
        internal new virtual void reserved8() {}
-       internal new virtual void reserved9() {}
 }
+
diff --git a/gee/multimap.vala b/gee/multimap.vala
index 89efe17..01c158f 100644
--- a/gee/multimap.vala
+++ b/gee/multimap.vala
@@ -124,4 +124,10 @@ public interface Gee.MultiMap<K,V> : Object {
         * The type of the values in this multimap.
         */
        public Type value_type { get { return typeof (V); } }
+
+       public virtual MultiMap<K, V> read_only_view {
+               owned get {
+                       return new ReadOnlyMultiMap<K, V> (this);
+               }
+       }
 }
diff --git a/gee/readonlymap.vala b/gee/readonlymap.vala
index 7d2e7bf..f916d85 100644
--- a/gee/readonlymap.vala
+++ b/gee/readonlymap.vala
@@ -244,7 +244,7 @@ internal class Gee.ReadOnlyMap<K,V> : Object, Traversable<Map.Entry<K,V>>, Itera
                return _map.chop (offset, length);
        }
 
-       protected class MapIterator<K,V> : Object, Gee.MapIterator<K,V> {
+       internal class MapIterator<K,V> : Object, Gee.MapIterator<K,V> {
                protected Gee.MapIterator<K,V> _iter;
 
                public MapIterator (Gee.MapIterator<K,V> iterator) {