Replaced app getUndoStack by addToUndoStack. Fixes #197.

Allows to check if the stack is created. Thanks @yossidev!

src/app/application.js

@@ -202,11 +202,15 @@ dwv.App = function ()
     this.getToolboxController = function () { return toolboxController; };
 
     /**
-     * Get the undo stack.
-     * @method getUndoStack
-     * @return {Object} The undo stack.
+     * Add a command to the undo stack.
+     * @method addToUndoStack
+     * @param {Object} The command to add.
      */
-    this.getUndoStack = function () { return undoStack; };
+    this.addToUndoStack = function (cmd) { 
+        if ( undoStack !== null ) {
+            undoStack.add(cmd);
+        }
+    };
 
     /**
      * Get the data loaders.

src/app/state.js

@@ -75,7 +75,7 @@ dwv.State = function (app)
                     cmd.onUndo = eventCallback;
                 }
                 cmd.execute();
-                app.getUndoStack().add(cmd);
+                app.addToUndoStack(cmd);
             }
         }
     };

src/tools/draw.js

@@ -489,7 +489,7 @@ dwv.tool.Draw = function (app, shapeFactoryList)
             // execute it
             command.execute();
             // save it in undo stack
-            app.getUndoStack().add(command);
+            app.addToUndoStack(command);
 
             // set shape on
             var shape = group.getChildren( function (node) {
@@ -749,7 +749,7 @@ dwv.tool.Draw = function (app, shapeFactoryList)
                 delcmd.onExecute = fireEvent;
                 delcmd.onUndo = fireEvent;
                 delcmd.execute();
-                app.getUndoStack().add(delcmd);
+                app.addToUndoStack(delcmd);
             }
             else {
                 // save drag move
@@ -759,7 +759,7 @@ dwv.tool.Draw = function (app, shapeFactoryList)
                     var mvcmd = new dwv.tool.MoveGroupCommand(this.getParent(), cmdName, translation, drawLayer);
                     mvcmd.onExecute = fireEvent;
                     mvcmd.onUndo = fireEvent;
-                    app.getUndoStack().add(mvcmd);
+                    app.addToUndoStack(mvcmd);
                     // the move is handled by kinetic, trigger an event manually
                     fireEvent({'type': 'draw-move'});
                 }

src/tools/editor.js

@@ -373,7 +373,7 @@ dwv.tool.ShapeEditor = function (app)
             chgcmd.onExecute = drawEventCallback;
             chgcmd.onUndo = drawEventCallback;
             chgcmd.execute();
-            app.getUndoStack().add(chgcmd);
+            app.addToUndoStack(chgcmd);
             // reset start anchor
             startAnchor = endAnchor;
         });

src/tools/filter.js

@@ -244,7 +244,7 @@ dwv.tool.filter.Threshold = function ( app )
         var command = new dwv.tool.RunFilterCommand(filter, app);
         command.execute();
         // save command in undo stack
-        app.getUndoStack().add(command);
+        app.addToUndoStack(command);
     };
 
 }; // class dwv.tool.filter.Threshold
@@ -305,7 +305,7 @@ dwv.tool.filter.Sharpen = function ( app )
         var command = new dwv.tool.RunFilterCommand(filter, app);
         command.execute();
         // save command in undo stack
-        app.getUndoStack().add(command);
+        app.addToUndoStack(command);
     };
 
 }; // dwv.tool.filter.Sharpen
@@ -365,7 +365,7 @@ dwv.tool.filter.Sobel = function ( app )
         var command = new dwv.tool.RunFilterCommand(filter, app);
         command.execute();
         // save command in undo stack
-        app.getUndoStack().add(command);
+        app.addToUndoStack(command);
     };
 
 }; // class dwv.tool.filter.Sobel

src/tools/livewire.js

@@ -144,7 +144,7 @@ dwv.tool.Livewire = function(app)
                 self.mousemove(event);
                 console.log("Done.");
                 // save command in undo stack
-                app.getUndoStack().add(command);
+                app.addToUndoStack(command);
                 // set flag
                 self.started = false;
             }