Fixed wallpaper prescaling issues

Image::SDLgetScaledImage was changed so that it tries to find an existing
scaled version of the image first, and generates it when none exists.
When it needs to generate one, this resource is added to the resource
manager, partly to avoid duplicating the work later but mainly to keep
memory management straightforward.

This function also used to leak the scaled SDL_Surface since it wrongly
assumed that Image::load would free it.

To avoid filling up the memory with scaled wallpapers that are waiting
30 seconds until they will be deleted, the Resource::decRef function was
extended with a parameter that allows telling it what to do with orphans.
Calling decRef with Resource::DeleteImmediately will delete the resource
immediately in case the resource is orphaned.

Reviewed-by: Yohann Ferreira

1 files changed, 14 insertions, 9 deletions

diff --git a/src/resources/resource.h b/src/resources/resource.h
index 53b05ee8..af688eb0 100644
--- a/src/resources/resource.h
+++ b/src/resources/resource.h
@@ -33,21 +33,26 @@ class Resource
     friend class ResourceManager;
 
     public:
-        Resource(): mRefCount(0) {}
+        enum OrphanPolicy {
+            DeleteLater,
+            DeleteImmediately
+        };
+
+        Resource():
+            mRefCount(0)
+        {}
 
         /**
          * Increments the internal reference count.
          */
-        void incRef();
+        void incRef() { ++mRefCount; }
 
         /**
-         * Decrements the reference count and deletes the object
-         * if no references are left.
-         *
-         * @return <code>true</code> if the object was deleted
-         *         <code>false</code> otherwise.
+         * Decrements the reference count. When no references are left, either
+         * schedules the object for deletion or deletes it immediately,
+         * depending on the \a orphanPolicy.
          */
-        void decRef();
+        void decRef(OrphanPolicy orphanPolicy = DeleteLater);
 
         /**
          * Return the path identifying this resource.
@@ -56,7 +61,7 @@ class Resource
         { return mIdPath; }
 
     protected:
-        virtual ~Resource();
+        virtual ~Resource() {}
 
     private:
         std::string mIdPath; /**< Path identifying this resource. */