create index of PDF documents

ft/document.c

@@ -298,3 +298,28 @@ zathura_page_render(zathura_page_t* page)
 
   return page->document->functions.page_render(page);
 }
+
+zathura_index_element_t*
+zathura_index_element_new(const char* title)
+{
+  if (!title)
+    return NULL;
+
+  zathura_index_element_t* res = g_malloc0(sizeof(zathura_index_element_t));
+  if (!res)
+    return NULL;
+  res->title = g_strdup(title);
+  return res;
+}
+
+void
+zathura_index_element_free(zathura_index_element_t* index)
+{
+  if (!index)
+    return;
+
+  g_free(index->title);
+  if (index->type == ZATHURA_LINK_EXTERNAL)
+    g_free(index->target.uri);
+  g_free(index);
+}

ft/document.h

@@ -50,6 +50,17 @@ typedef struct zathura_link_s
   } target;
 } zathura_link_t;
 
+typedef struct zathura_index_element_s
+{
+  char* title;
+  zathura_link_type_t type;
+  union
+  {
+    unsigned int page_number;
+    char* uri;
+  } target;
+} zathura_index_element_t;
+
 typedef enum zathura_form_type_e
 {
   ZATHURA_FORM_CHECKBOX,
@@ -113,4 +124,7 @@ zathura_list_t* zathura_page_form_fields_get(zathura_page_t* page);
 bool zathura_page_form_fields_free(zathura_list_t* list);
 cairo_surface_t* zathura_page_render(zathura_page_t* page);
 
+zathura_index_element_t* zathura_index_element_new(const char* title);
+void zathura_index_element_free(zathura_index_element_t* index);
+
 #endif // DOCUMENT_H

ft/pdf/pdf.c

@@ -83,10 +83,76 @@ pdf_document_free(zathura_document_t* document)
   return true;
 }
 
+static void
+build_index(pdf_document_t* pdf, girara_tree_node_t* root, PopplerIndexIter* iter)
+{
+  if (!root || !iter)
+    return;
+
+  do
+  {
+    PopplerAction* action = poppler_index_iter_get_action(iter);
+    if (!action)
+      continue;
+
+    gchar* markup = g_markup_escape_text(action->any.title, -1);
+    zathura_index_element_t* indexelement = zathura_index_element_new(markup);
+    if (action->type == POPPLER_ACTION_URI)
+    {
+      indexelement->type = ZATHURA_LINK_EXTERNAL;
+      indexelement->target.uri = g_strdup(action->uri.uri);
+    }
+    else if (action->type == POPPLER_ACTION_GOTO_DEST)
+    {
+      indexelement->type = ZATHURA_LINK_TO_PAGE;
+      if (action->goto_dest.dest->type == POPPLER_DEST_NAMED)
+      {
+        PopplerDest* dest = poppler_document_find_dest(pdf->document, action->goto_dest.dest->named_dest);
+        if (dest)
+        {
+          indexelement->target.page_number = dest->page_num - 1;
+          poppler_dest_free(dest);
+        }
+      }
+      else
+        indexelement->target.page_number = action->goto_dest.dest->page_num - 1;
+    }
+    else
+    {
+      poppler_action_free(action);
+      zathura_index_element_free(indexelement);
+      continue;
+    }
+    poppler_action_free(action);
+
+    girara_tree_node_t* node = girara_node_append_data(root, indexelement);
+    PopplerIndexIter* child = poppler_index_iter_get_child(iter);
+    if (child)
+      build_index(pdf, node, child);
+    poppler_index_iter_free(child);
+  } while (poppler_index_iter_next(iter));
+}
+
 girara_tree_node_t*
 pdf_document_index_generate(zathura_document_t* document)
 {
-  return NULL;
+  if (!document || !document->data) {
+    return NULL;
+  }
+
+  pdf_document_t* pdf_document = (pdf_document_t*) document->data;
+  PopplerIndexIter* iter = poppler_index_iter_new(pdf_document->document);
+  if (!iter) {
+    // XXX: error message?
+    return NULL;
+  }
+
+  girara_tree_node_t* root = girara_node_new(zathura_index_element_new("ROOT"));
+  girara_node_set_free_function(root, (girara_free_function_t)zathura_index_element_free);
+  build_index(pdf_document, root, iter);
+
+  poppler_index_iter_free(iter);
+  return root;
 }
 
 bool