Improve use tag logic by recording the loaded documents in a list.

(bzr r12969)

3 files changed, 35 insertions, 10 deletions

diff --git a/src/document.cpp b/src/document.cpp
index e56adee68..32a025e87 100644
--- a/src/document.cpp
+++ b/src/document.cpp
@@ -106,6 +106,7 @@ SPDocument::SPDocument() :
     profileManager(0), // deferred until after other initialization
     router(new Avoid::Router(Avoid::PolyLineRouting|Avoid::OrthogonalRouting)),
     _collection_queue(0),
+    parent_document(NULL),
     oldSignalsConnected(false),
     current_persp3d(NULL),
     current_persp3d_impl(NULL)
diff --git a/src/document.h b/src/document.h
index cc565e3aa..e804a4980 100644
--- a/src/document.h
+++ b/src/document.h
@@ -25,6 +25,7 @@
 #include "gc-finalized.h"
 #include "gc-anchored.h"
 #include <glibmm/ustring.h>
+#include <boost/ptr_container/ptr_list.hpp>
 #include <vector>
 
 namespace Avoid {
@@ -120,6 +121,10 @@ public:
 
     GSList *_collection_queue;
 
+    // A list of svg documents being used or shown within this document
+    boost::ptr_list<SPDocument> child_documents;
+    SPDocument *parent_document;
+
     bool oldSignalsConnected;
 
     /** Returns our SPRoot */
diff --git a/src/uri-references.cpp b/src/uri-references.cpp
index 718b2d451..adf948c7b 100644
--- a/src/uri-references.cpp
+++ b/src/uri-references.cpp
@@ -58,17 +58,36 @@ void URIReference::attach(const URI &uri) throw(BadURIException)
 
     // The path contains references to seperate document files to load.
     const char *path = uri.getPath();
-    if(path) {
-        if(document != NULL) {
-            // Calculate the absolute path from an available document
-            std::string basePath = std::string( document->getBase() );
-            std::string absPath = Glib::build_filename(basePath, std::string( path ) );
-            path = absPath.c_str();
+    if(path && document != NULL) {
+        // Calculate the absolute path from an available document
+        std::string basePath = std::string( document->getBase() );
+        std::string absPath = Glib::build_filename(basePath, std::string( path ) );
+        path = absPath.c_str();
+
+        // We look at existing children and parents
+        SPDocument *parent = document;
+        SPDocument *original = document;
+        document = NULL;
+
+        while(parent != NULL) {
+            boost::ptr_list<SPDocument>::iterator iter;
+            for (iter = parent->child_documents.begin();
+                iter != parent->child_documents.end(); ++iter) {
+                if(strcmp(iter->getURI(), path)==0)
+                    document = &*iter;
+            }
+            parent = parent->parent_document;
+        }
+        // Load a fresh document from the svg source.
+        if(!document) {
+            document = SPDocument::createNewDoc(path, FALSE);
+            if(document) {
+                document->parent_document = original;
+                original->child_documents.push_back(document);
+            } else {
+                g_warning("Could not load svg file: %s", path);
+            }
         }
-        // TODO: This is inefficient because it will load the same svg file
-        // many times if it's used many times. A global list of documents would
-        // be useful for tracking linked items.
-        document = SPDocument::createNewDoc(path, FALSE);
     }
     g_return_if_fail(document != NULL);