Packages allows thumbnails per variant.

Change API for thumbnail access, so each variant can have a unique thumbnail alongside other data. Map existing catalog XML format to
this system.

simgear/package/CatalogTest.cxx

@@ -167,14 +167,10 @@ int parseTest()
     SG_CHECK_EQUAL(index->url, "http://foo.bar.com/thumb-panel.png");
     SG_VERIFY(index->type == pkg::Package::Preview::Type::PANEL);
 
-// old-style thumbnails
-    string_list oldThumbUrls = p2->thumbnailUrls();
-    SG_CHECK_EQUAL(oldThumbUrls.size(), 1);
-    SG_CHECK_EQUAL(oldThumbUrls.at(0), "http://foo.bar.com/thumb-exterior.png");
-
-    string_list oldThumbPaths = p2->thumbnails();
-    SG_CHECK_EQUAL(oldThumbPaths.size(), 1);
-    SG_CHECK_EQUAL(oldThumbPaths.at(0), "exterior.png");
+// thumbnails
+    const pkg::Package::Thumbnail& thumb = p2->thumbnailForVariant(0);
+    SG_CHECK_EQUAL(thumb.url, "http://foo.bar.com/thumb-exterior.png");
+    SG_CHECK_EQUAL(thumb.path, "exterior.png");
 
 // test variants
     try {
@@ -215,6 +211,9 @@ int parseTest()
     SG_CHECK_EQUAL(index->url, "http://foo.bar.com/thumb-exterior-skis.png");
     SG_VERIFY(index->type == pkg::Package::Preview::Type::EXTERIOR);
 
+    const pkg::Package::Thumbnail& thumb2 = p2->thumbnailForVariant(floatsVariant);
+    SG_CHECK_EQUAL(thumb2.url, "http://foo.bar.com/thumb-floats.png");
+    SG_CHECK_EQUAL(thumb2.path, "thumb-floats.png");
 
 // test filtering / searching too
     string_set tags(p2->tags());

simgear/package/Install.cxx

@@ -455,33 +455,6 @@ void Install::cancelDownload()
     m_package->catalog()->root()->cancelDownload(this);
 }
 
-struct PathAppender
-{
-    PathAppender(const SGPath& p) : m_path(p) {}
-
-    SGPath operator()(const std::string& s) const
-    {
-        SGPath p(m_path);
-        p.append(s);
-        return p;
-    }
-
-    SGPath m_path;
-};
-
-PathList Install::thumbnailPaths() const
-{
-    const string_list& thumbs(m_package->thumbnails());
-    PathList result;
-    if (thumbs.empty())
-        return result;
-
-    std::transform(thumbs.begin(), thumbs.end(),
-                   std::back_inserter(result),
-                   PathAppender(m_path));
-    return result;
-}
-
 SGPath Install::primarySetPath() const
 {
     SGPath setPath(m_path);

simgear/package/Install.hxx

@@ -98,13 +98,6 @@ public:
      */
     void cancelDownload();
     
-    /**
-     * return the thumbnails associated with this install, but as locations
-     * on the file system, not URLs. It is assumed the order of thumbnails
-     * is consistent with the URLs returned from Package::thumbnailUrls()
-     */
-    PathList thumbnailPaths() const;
-    
     /**
      * Set the handler to be called when the installation successfully
      * completes.

simgear/package/Package.cxx

@@ -274,28 +274,12 @@ SGPropertyNode* Package::properties() const
 
 string_list Package::thumbnailUrls() const
 {
-    string_list r;
-    if (!m_props) {
-        return r;
+    string_list urls;
+    const Thumbnail& thumb(thumbnailForVariant(0));
+    if (!thumb.url.empty()) {
+        urls.push_back(thumb.url);
     }
-
-    BOOST_FOREACH(SGPropertyNode* dl, m_props->getChildren("thumbnail")) {
-        r.push_back(dl->getStringValue());
-    }
-    return r;
-}
-
-string_list Package::thumbnails() const
-{
-    string_list r;
-    if (!m_props) {
-        return r;
-    }
-
-    BOOST_FOREACH(SGPropertyNode* dl, m_props->getChildren("thumbnail-path")) {
-        r.push_back(dl->getStringValue());
-    }
-    return r;
+    return urls;
 }
 
 string_list Package::downloadUrls() const
@@ -429,6 +413,17 @@ SGPropertyNode_ptr Package::propsForVariant(const unsigned int vIndex, const cha
     throw sg_exception("Unknow variant in package " + id());
 }
 
+Package::Thumbnail Package::thumbnailForVariant(unsigned int vIndex) const
+{
+    SGPropertyNode_ptr var = propsForVariant(vIndex);
+    // allow for variants without distinct thumbnails
+    if (!var->hasChild("thumbnail") || !var->hasChild("thumbnail-path")) {
+        var = m_props;
+    }
+
+    return {var->getStringValue("thumbnail"), var->getStringValue("thumbnail-path")};
+}
+
 Package::PreviewVec Package::previewsForVariant(unsigned int vIndex) const
 {
     SGPropertyNode_ptr var = propsForVariant(vIndex);

simgear/package/Package.hxx

@@ -131,13 +131,15 @@ public:
      * download URLs for the package
      */
     string_list downloadUrls() const;
-    
     string_list thumbnailUrls() const;
 
-    /**
-     * thumbnail file paths within the package on disk
-     */
-    string_list thumbnails() const;
+    struct Thumbnail
+    {
+        std::string url;
+        std::string path;
+    };
+
+    Thumbnail thumbnailForVariant(unsigned int vIndex) const;
 
     /**
      * information about a preview image

simgear/package/catalogTest1/catalog.xml

@@ -89,6 +89,9 @@
               <path>thumb-panel.png</path>
               <url>http://foo.bar.com/thumb-panel.png</url>
             </preview>
+
+            <thumbnail>http://foo.bar.com/thumb-floats.png</thumbnail>
+            <thumbnail-path>thumb-floats.png</thumbnail-path>
         </variant>
 
         <variant>
@@ -112,7 +115,6 @@
         <md5>ec0e2ffdf98d6a5c05c77445e5447ff5</md5>
         <url>http://localhost:2000/catalogTest1/c172p.zip</url>
 
-        <!-- legacy thumbnails also supported -->
         <thumbnail>http://foo.bar.com/thumb-exterior.png</thumbnail>
         <thumbnail-path>exterior.png</thumbnail-path>
     </package>