text: /**
   * Copyright 2013 IBM Corp.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   **/
  RED.history = (function() {
      var undo_history = [];
      
      return {
          //TODO: this function is a placeholder until there is a 'save' event that can be listened to
          markAllDirty: function() {
              for (var i=0;i<undo_history.length;i++) {
                  undo_history[i].dirty = true;
              }
          },
          depth: function() {
              return undo_history.length;
          },
          push: function(ev) {
              undo_history.push(ev);
          },
          pop: function() {
              var ev = undo_history.pop();
              var i;
              if (ev) {
                  if (ev.t == 'add') {
                      if (ev.nodes) {
                          for (i=0;i<ev.nodes.length;i++) {
                              RED.nodes.remove(ev.nodes[i]);
                          }
                      }
                      if (ev.links) {
                          for (i=0;i<ev.links.length;i++) {
                              RED.nodes.removeLink(ev.links[i]);
                          }
                      }
                      if (ev.workspaces) {
                          for (i=0;i<ev.workspaces.length;i++) {
                              RED.nodes.removeWorkspace(ev.workspaces[i].id);
                              RED.view.removeWorkspace(ev.workspaces[i]);
                          }
                      }
                  } else if (ev.t == "delete") {
                      if (ev.workspaces) {
                          for (i=0;i<ev.workspaces.length;i++) {
                              RED.nodes.addWorkspace(ev.workspaces[i]);
                              RED.view.addWorkspace(ev.workspaces[i]);
                          }
                      }
                      if (ev.nodes) {
                          for (i=0;i<ev.nodes.length;i++) {
                              RED.nodes.add(ev.nodes[i]);
                          }
                      }
                      if (ev.links) {
                          for (i=0;i<ev.links.length;i++) {
                              RED.nodes.addLink(ev.links[i]);
                          }
                      }
                  } else if (ev.t == "move") {
                      for (i=0;i<ev.nodes.length;i++) {
                          var n = ev.nodes[i];
                          n.n.x = n.ox;
                          n.n.y = n.oy;
                          n.n.dirty = true;
                      }
                  } else if (ev.t == "edit") {
                      for (i in ev.changes) {
                          if (ev.changes.hasOwnProperty(i)) {
                              ev.node[i] = ev.changes[i];
                          }
                      }
                      RED.editor.updateNodeProperties(ev.node);
                      if (ev.links) {
                          for (i=0;i<ev.links.length;i++) {
                              RED.nodes.addLink(ev.links[i]);
                          }
                      }
                      RED.editor.validateNode(ev.node);
                      ev.node.dirty = true;
                      ev.node.changed = ev.changed;
                  }
                  RED.view.dirty(ev.dirty);
                  RED.view.redraw();
              }
          }
      }
  
  })();
  