libs/pbd/stateful.cc

   1 /*
   2     Copyright (C) 2000-2001 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18     $Id: stateful.cc 629 2006-06-21 23:01:03Z paul $
  19 */
  20
  21 #include <unistd.h>
  22
  23 #include <pbd/stateful.h>
  24 #include <pbd/xml++.h>
  25 #include <pbd/error.h>
  26
  27 #include "i18n.h"
  28
  29 using namespace PBD;
  30
  31 Stateful::Stateful ()
  32 {
  33         _extra_xml = 0;
  34         _instant_xml = 0;
  35 }
  36
  37 Stateful::~Stateful ()
  38 {
  39         // Do not delete _extra_xml.  The use of add_child_nocopy()
  40         // means it needs to live on indefinately.
  41
  42         if (_instant_xml) {
  43                 delete _instant_xml;
  44         }
  45 }
  46
  47 void
  48 Stateful::add_extra_xml (XMLNode& node)
  49 {
  50         if (_extra_xml == 0) {
  51                 _extra_xml = new XMLNode ("extra");
  52         }
  53
  54         _extra_xml->remove_nodes (node.name());
  55         _extra_xml->add_child_nocopy (node);
  56 }
  57
  58 XMLNode *
  59 Stateful::extra_xml (const string& str)
  60 {
  61         if (_extra_xml == 0) {
  62                 return 0;
  63         }
  64
  65         const XMLNodeList& nlist = _extra_xml->children();
  66         XMLNodeConstIterator i;
  67
  68         for (i = nlist.begin(); i != nlist.end(); ++i) {
  69                 if ((*i)->name() == str) {
  70                         return (*i);
  71                 }
  72         }
  73
  74         return 0;
  75 }
  76
  77 void
  78 Stateful::add_instant_xml (XMLNode& node, const string& dir)
  79 {
  80         if (_instant_xml == 0) {
  81                 _instant_xml = new XMLNode ("instant");
  82         }
  83
  84         _instant_xml->remove_nodes_and_delete (node.name());
  85         _instant_xml->add_child_copy (node);
  86
  87         XMLTree tree;
  88         tree.set_filename(dir+"/instant.xml");
  89
  90         /* Important: the destructor for an XMLTree deletes
  91            all of its nodes, starting at _root. We therefore
  92            cannot simply hand it our persistent _instant_xml
  93            node as its _root, because we will lose it whenever
  94            the Tree goes out of scope.
  95
  96            So instead, copy the _instant_xml node (which does
  97            a deep copy), and hand that to the tree.
  98         */
  99
 100         XMLNode* copy = new XMLNode (*_instant_xml);
 101         tree.set_root (copy);
 102
 103         if (!tree.write()) {
 104                 error << string_compose(_("Error: could not write %1"), dir+"/instant.xml") << endmsg;
 105         }
 106 }
 107
 108 XMLNode *
 109 Stateful::instant_xml (const string& str, const string& dir)
 110 {
 111         if (_instant_xml == 0) {
 112                 string instant_file = dir + "/instant.xml";
 113                 if (access(instant_file.c_str(), F_OK) == 0) {
 114                         XMLTree tree;
 115                         if (tree.read(dir+"/instant.xml")) {
 116                                 _instant_xml = new XMLNode(*(tree.root()));
 117                         } else {
 118                                 warning << string_compose(_("Could not understand XML file %1"), instant_file) << endmsg;
 119                                 return 0;
 120                         }
 121                 } else {
 122                         return 0;
 123                 }
 124         }
 125
 126         const XMLNodeList& nlist = _instant_xml->children();
 127         XMLNodeConstIterator i;
 128
 129         for (i = nlist.begin(); i != nlist.end(); ++i) {
 130                 if ((*i)->name() == str) {
 131                         return (*i);
 132                 }
 133         }
 134
 135         return 0;
 136 }