Merge pull request #12 from Blakeinstein/master

Implement saving + implement svg files

9 files changed, 115 insertions, 320 deletions

diff --git a/src/main/python/shapes/__init__.py b/src/main/python/shapes/__init__.py
index af92a6a..536caf6 100644
--- a/src/main/python/shapes/__init__.py
+++ b/src/main/python/shapes/__init__.py
@@ -1,4 +1,4 @@
 from .shapes import *
-# from .line import *
+from .line import LineLabel
 from PyQt5.QtWidgets import *
 dir()
\ No newline at end of file
diff --git a/src/main/python/shapes/line.py b/src/main/python/shapes/line.py
index 92c5b1d..466e22b 100644
--- a/src/main/python/shapes/line.py
+++ b/src/main/python/shapes/line.py
@@ -259,6 +259,19 @@ class LineLabel(QGraphicsTextItem):
     def focusOutEvent(self, event):
         super(LineLabel, self).focusOutEvent(event)
         self.setTextInteractionFlags(Qt.NoTextInteraction)
+        
+    def __getstate__(self):
+        return {
+            "text": self.toPlainText(),
+            "index": self.index,
+            "gap": self.gap,
+            "pos": (self.pos().x(), self.pos().y())
+        }
+    
+    def __setstate__(self, dict):
+        self.setPlainText(dict['text'])
+        self.index = dict['index']
+        self.gap = dict['gap']
 
 
 def findIndex(line, pos):
@@ -919,8 +932,13 @@ class Line(QGraphicsPathItem):
             "_classname_": self.__class__.__name__,
             "startPoint": (self.startPoint.x(), self.startPoint.y()),
             "endPoint": (self.endPoint.x(), self.endPoint.y()),
-            "points": [(point.x(), point.y()) for point in self.points]
+            "points": [(point.x(), point.y()) for point in self.points],
+            "startGripItem": hex(id(self.startGripItem)),
+            "endGripItem": hex(id(self.endGripItem)) if self.endGripItem else 0,
+            "refLine": hex(id(self.refLine)) if self.refLine else 0,
+            "refIndex": self.refIndex,
+            "label": [i for i in self.label],
+            "id": hex(id(self))
         }
-    
     def __setstate__(self, dict):
         self.points = [QPointF(x, y) for x, y in dict["points"]]
diff --git a/src/main/python/shapes/shapes.py b/src/main/python/shapes/shapes.py
index 0358898..b825653 100644
--- a/src/main/python/shapes/shapes.py
+++ b/src/main/python/shapes/shapes.py
@@ -12,7 +12,6 @@ from PyQt5.QtWidgets import (QGraphicsColorizeEffect, QGraphicsEllipseItem,
 from .line import Line, findIndex
 from utils.app import fileImporter
 
-from utils.app import fileImporter
 
 class ItemLabel(QGraphicsTextItem):
     def __init__(self, pos, parent=None):
@@ -33,7 +32,16 @@ class ItemLabel(QGraphicsTextItem):
     def focusOutEvent(self, event):
         super(ItemLabel, self).focusOutEvent(event)
         self.setTextInteractionFlags(Qt.NoTextInteraction)
+    
+    def __getstate__(self):
+        return {
+            "text": self.toPlainText(),
+            "pos": (self.pos().x(), self.pos().y())
+        }
 
+    def __setstate__(self, dict):
+        self.setPlainText(dict['text'])
+        self.setPos(*dict['pos'])
 
 class GripItem(QGraphicsPathItem):
     """
@@ -318,16 +326,13 @@ class NodeItem(QGraphicsSvgItem):
         Extends PyQt5's QGraphicsSvgItem to create the basic structure of shapes with given unit operation type
     """
     # set a common renderer for all svg
-    renderer = QSvgRenderer(fileImporter(f'svg/ellipse.svg'))
+    # renderer = QSvgRenderer(fileImporter(f'svg/ellipse.svg'))
 
     def __init__(self, unitOperationType=None, parent=None):
         QGraphicsSvgItem.__init__(self, parent)
         self.m_type = str(unitOperationType)
         self.id = None
-        # self.m_renderer = QSvgRenderer("svg/" + unitOperationType + ".svg")
-        # self.m_renderer = QSvgRenderer(fileImporter(f'svg/{unitOperationType}.svg'))
-        self.m_renderer = QSvgRenderer(fileImporter(f'svg/ellipse.svg'))
-        # self.m_renderer = QSvgRenderer(resourceManager.get_resource(f'toolbar/{unitOperationType}.svg'))
+        self.m_renderer = QSvgRenderer(fileImporter(f'{unitOperationType}.svg'))
         self.setSharedRenderer(self.m_renderer)
         # set initial size of item
         self.width = 100
@@ -498,7 +503,9 @@ class NodeItem(QGraphicsSvgItem):
             "_classname_": self.__class__.__name__,
             "width": self.width,
             "height": self.height,
-            "pos": (self.pos().x(), self.pos().y())
+            "pos": (self.pos().x(), self.pos().y()),
+            "lineGripItems": [(hex(id(i)), i.m_index) for i in self.lineGripItems],
+            "label": self.label
         }
     
     def __setstate__(self, dict):
@@ -506,287 +513,5 @@ class NodeItem(QGraphicsSvgItem):
         self.width = dict['width']
         self.height = dict['height']
         self.rect = QRectF(-self.width / 2, -self.height / 2, self.width, self.height)
-        transform = QTransform()
-        transform.translate(self.width / 2, self.height / 2)
-        self.setTransform(transform, True)
         self.updateSizeGripItem()
-        
-# classes of pfd-symbols
-class AirBlownCooler(NodeItem):
-    def __init__(self):
-        super(AirBlownCooler, self).__init__("AirBlownCooler", parent=None)
-
-
-class Bag(NodeItem):
-    def __init__(self):
-        super(Bag, self).__init__("Bag", parent=None)
-
-
-class Boiler(NodeItem):
-    def __init__(self):
-        super(Boiler, self).__init__("Boiler", parent=None)
-
-
-class Breaker(NodeItem):
-    def __init__(self):
-        super(Breaker, self).__init__("Breaker", parent=None)
-
-
-class BriquettingMachine(NodeItem):
-    def __init__(self):
-        super(BriquettingMachine, self).__init__("BriquettingMachine", parent=None)
-
-
-class Centrifugal(NodeItem):
-    def __init__(self):
-        super(Centrifugal, self).__init__("Centrifugal", parent=None)
-
-
-class CentrifugalCompressor(NodeItem):
-    def __init__(self):
-        super(CentrifugalCompressor, self).__init__("CentrifugalCompressor", parent=None)
-
-
-class Centrifugalpump(NodeItem):
-    def __init__(self):
-        super(Centrifugalpump, self).__init__("Centrifugalpump", parent=None)
-
-
-class CentrifugalPump2(NodeItem):
-    def __init__(self):
-        super(CentrifugalPump2, self).__init__("CentrifugalPump2", parent=None)
-
-
-class CentrifugalPump3(NodeItem):
-    def __init__(self):
-        super(CentrifugalPump3, self).__init__("CentrifugalPump3", parent=None)
-
-
-class Column(NodeItem):
-    def __init__(self):
-        super(Column, self).__init__("Column", parent=None)
-
-
-class Compressor(NodeItem):
-    def __init__(self):
-        super(Compressor, self).__init__("Compressor", parent=None)
-
-
-class CompressorSilencers(NodeItem):
-    def __init__(self):
-        super(CompressorSilencers, self).__init__("CompressorSilencers", parent=None)
-
-
-class Condenser(NodeItem):
-    def __init__(self):
-        super(Condenser, self).__init__("Condenser", parent=None)
-
-
-class Cooler(NodeItem):
-    def __init__(self):
-        super(Cooler, self).__init__("Cooler", parent=None)
-
-
-class CoolingTower3(NodeItem):
-    def __init__(self):
-        super(CoolingTower3, self).__init__("CoolingTower3", parent=None)
-
-
-class CoolingTwoer2(NodeItem):
-    def __init__(self):
-        super(CoolingTwoer2, self).__init__("CoolingTwoer2", parent=None)
-
-
-class Crusher(NodeItem):
-    def __init__(self):
-        super(Crusher, self).__init__("Crusher", parent=None)
-
-
-class DoublePipeHeat(NodeItem):
-    def __init__(self):
-        super(DoublePipeHeat, self).__init__("DoublePipeHeat", parent=None)
-
-
-class ExtractorHood(NodeItem):
-    def __init__(self):
-        super(ExtractorHood, self).__init__("ExtractorHood", parent=None)
-
-
-class FiredHeater(NodeItem):
-    def __init__(self):
-        super(FiredHeater, self).__init__("FiredHeater", parent=None)
-
-
-class ForcedDraftCooling(NodeItem):
-    def __init__(self):
-        super(ForcedDraftCooling, self).__init__("ForcedDraftCooling", parent=None)
-
-
-class Furnace(NodeItem):
-    def __init__(self):
-        super(Furnace, self).__init__("Furnace", parent=None)
-
-
-class GasBottle(NodeItem):
-    def __init__(self):
-        super(GasBottle, self).__init__("GasBottle", parent=None)
-
-
-class HalfPipeMixingVessel(NodeItem):
-    def __init__(self):
-        super(HalfPipeMixingVessel, self).__init__("HalfPipeMixingVessel", parent=None)
-
-
-class Heater(NodeItem):
-    def __init__(self):
-        super(Heater, self).__init__("Heater", parent=None)
-
-
-class HeatExchanger(NodeItem):
-    def __init__(self):
-        super(HeatExchanger, self).__init__("HeatExchanger", parent=None)
-
-
-class HeatExchanger2(NodeItem):
-    def __init__(self):
-        super(HeatExchanger2, self).__init__("HeatExchanger2", parent=None)
-
-
-class HorizontalVessel(NodeItem):
-    def __init__(self):
-        super(HorizontalVessel, self).__init__("HorizontalVessel", parent=None)
-
-
-class InducedDraftCooling(NodeItem):
-    def __init__(self):
-        super(InducedDraftCooling, self).__init__("InducedDraftCooling", parent=None)
-
-
-class JacketedMixingVessel(NodeItem):
-    def __init__(self):
-        super(JacketedMixingVessel, self).__init__("JacketedMixingVessel", parent=None)
-
-
-class LiquidRingCompressor(NodeItem):
-    def __init__(self):
-        super(LiquidRingCompressor, self).__init__("LiquidRingCompressor", parent=None)
-
-
-class Mixing(NodeItem):
-    def __init__(self):
-        super(Mixing, self).__init__("Mixing", parent=None)
-
-
-class MixingReactor(NodeItem):
-    def __init__(self):
-        super(MixingReactor, self).__init__("MixingReactor", parent=None)
-
-
-class OilBurner(NodeItem):
-    def __init__(self):
-        super(OilBurner, self).__init__("OilBurner", parent=None)
-
-
-class OpenTank(NodeItem):
-    def __init__(self):
-        super(OpenTank, self).__init__("OpenTank", parent=None)
-
-
-class ProportionalPump(NodeItem):
-    def __init__(self):
-        super(ProportionalPump, self).__init__("ProportionalPump", parent=None)
-
-
-class Pump(NodeItem):
-    def __init__(self):
-        super(Pump, self).__init__("Pump", parent=None)
-
-
-class Pump2(NodeItem):
-    def __init__(self):
-        super(Pump2, self).__init__("Pump2", parent=None)
-
-
-class ReboilerHeatExchange(NodeItem):
-    def __init__(self):
-        super(ReboilerHeatExchange, self).__init__("ReboilerHeatExchange", parent=None)
-
-
-class ReciprocatingCompressor(NodeItem):
-    def __init__(self):
-        super(ReciprocatingCompressor, self).__init__("ReciprocatingCompressor", parent=None)
-
-
-class RotaryCompresor(NodeItem):
-    def __init__(self):
-        super(RotaryCompresor, self).__init__("RotaryCompresor", parent=None)
-
-
-class RotaryGearPump(NodeItem):
-    def __init__(self):
-        super(RotaryGearPump, self).__init__("RotaryGearPump", parent=None)
-
-
-class ScrewPump(NodeItem):
-    def __init__(self):
-        super(ScrewPump, self).__init__("ScrewPump", parent=None)
-
-
-class SelectableCompressor(NodeItem):
-    def __init__(self):
-        super(SelectableCompressor, self).__init__("SelectableCompressor", parent=None)
-
-
-class SelectableFan(NodeItem):
-    def __init__(self):
-        super(SelectableFan, self).__init__("SelectableFan", parent=None)
-
-
-class SinglePassHeat(NodeItem):
-    def __init__(self):
-        super(SinglePassHeat, self).__init__("SinglePassHeat", parent=None)
-
-
-class SpiralHeatExchanger(NodeItem):
-    def __init__(self):
-        super(SpiralHeatExchanger, self).__init__("SpiralHeatExchanger", parent=None)
-
-
-class StraightTubersHeat(NodeItem):
-    def __init__(self):
-        super(StraightTubersHeat, self).__init__("StraightTubersHeat", parent=None)
-
-
-class Tank(NodeItem):
-    def __init__(self):
-        super(Tank, self).__init__("Tank", parent=None)
-
-
-class TurbinePump(NodeItem):
-    def __init__(self):
-        super(TurbinePump, self).__init__("TurbinePump", parent=None)
-
-
-class UTubeHeatExchanger(NodeItem):
-    def __init__(self):
-        super(UTubeHeatExchanger, self).__init__("UTubeHeatExchanger", parent=None)
-
-
-class VaccumPump(NodeItem):
-    def __init__(self):
-        super(VaccumPump, self).__init__("VaccumPump", parent=None)
-
-
-class VerticalPump(NodeItem):
-    def __init__(self):
-        super(VerticalPump, self).__init__("VerticalPump", parent=None)
-
-
-class VerticalVessel(NodeItem):
-    def __init__(self):
-        super(VerticalVessel, self).__init__("VerticalVessel", parent=None)
-
-
-class WastewaterTreatment(NodeItem):
-    def __init__(self):
-        super(WastewaterTreatment, self).__init__("WastewaterTreatment", parent=None)
+        
\ No newline at end of file
diff --git a/src/main/python/utils/app.py b/src/main/python/utils/app.py
index 5d85cb7..9812fda 100644
--- a/src/main/python/utils/app.py
+++ b/src/main/python/utils/app.py
@@ -8,6 +8,7 @@ from json import JSONEncoder, dumps, loads, dump, load
 
 app = ApplicationContext()
 settings = QSettings(QSettings.IniFormat, QSettings.UserScope ,"FOSSEE", "Chemical-PFD")
+version = app.build_settings['version']
 
 def fileImporter(file):
     # Helper function to fetch files from src/main/resources
@@ -49,4 +50,7 @@ class JSON_Typer(JSONEncoder):
         return JSON_Encoder._encode(obj)
 
     def encode(self, obj):
-        return super(JSON_Typer, self).encode(self._encode(obj))
\ No newline at end of file
+        return super(JSON_Typer, self).encode(self._encode(obj))
+    
+shapeGrips = {}
+lines = {}
\ No newline at end of file
diff --git a/src/main/python/utils/canvas.py b/src/main/python/utils/canvas.py
index a83aeb2..3f9cee5 100644
--- a/src/main/python/utils/canvas.py
+++ b/src/main/python/utils/canvas.py
@@ -6,7 +6,7 @@ from PyQt5.QtWidgets import (QFileDialog, QApplication, QHBoxLayout, QMenu,
 from . import dialogs
 from .graphics import customView, customScene
 from .data import paperSizes, ppiList, sheetDimensionList
-from .app import dumps, loads, JSON_Typer
+from .app import shapeGrips, lines
 
 import shapes
 
@@ -129,9 +129,7 @@ class canvas(QWidget):
             "canvasSize": self._canvasSize,
             "ObjectName": self.objectName(),
             "symbols": [i for i in self.painter.items() if isinstance(i, shapes.NodeItem)],
-            "lines": [i for i in self.painter.items() if isinstance(i, shapes.Line)],
-            # "lineLabels": [i.__getstate__() for i in self.painter.items() if isinstance(i, shapes.LineLabel)],
-            # "itemLabels": [i.__getstate__() for i in self.painter.items() if isinstance(i, shapes.itemLabel)]
+            "lines": sorted([i for i in self.painter.items() if isinstance(i, shapes.Line)], key = lambda x: 1 if x.refLine else 0)
         }
     
     def __setstate__(self, dict):
@@ -144,17 +142,43 @@ class canvas(QWidget):
             graphic.__setstate__(dict = item)
             self.painter.addItem(graphic)
             graphic.setPos(*item['pos'])
+            graphic.updateLineGripItem()
+            graphic.updateSizeGripItem()
+            for gripitem in item['lineGripItems']:
+                shapeGrips[gripitem[0]] = (graphic, gripitem[1])
+            if item['label']:
+                graphicLabel = shapes.ItemLabel(pos = QPointF(*item['label']['pos']), parent = graphic)
+                graphicLabel.__setstate__(item['label'])
+                self.painter.addItem(graphicLabel)
         
         for item in dict['lines']:
             line = shapes.Line(QPointF(*item['startPoint']), QPointF(*item['endPoint']))
+            lines[item['id']] = line
             line.__setstate__(dict = item)
             self.painter.addItem(line)
-        
+            graphic, index = shapeGrips[item['startGripItem']]
+            line.startGripItem = graphic.lineGripItems[index]
+            graphic.lineGripItems[index].line = line
+            if item['endGripItem']:                
+                graphic, index = shapeGrips[item['endGripItem']]
+                line.endGripItem = graphic.lineGripItems[index]
+                graphic.lineGripItems[index].line = line
+            else:
+                line.refLine = lines[item['refLine']]
+                lines[item['refLine']].midLines.append(line)
+                line.refIndex = item['refIndex']
+            for label in item['label']:
+                labelItem = shapes.LineLabel(QPointF(*label['pos']), line)
+                line.label.append(labelItem)
+                labelItem.__setstate__(label)
+                self.painter.addItem(labelItem)
+            line.updateLine()
+            line.addGrabber()
+            
+        shapeGrips.clear()
+        lines.clear()
         self.painter.advance()
         
-        # for item in dict['lineLabels']:
-        #     pass
-        # for item in dict['itemLabels']:
-        #     pass
+        
 
  
\ No newline at end of file
diff --git a/src/main/python/utils/fileWindow.py b/src/main/python/utils/fileWindow.py
index 04ed81a..663a7f3 100644
--- a/src/main/python/utils/fileWindow.py
+++ b/src/main/python/utils/fileWindow.py
@@ -3,13 +3,13 @@ from PyQt5.QtGui import QIcon
 from PyQt5.QtWidgets import (QFileDialog, QHBoxLayout,
                              QMdiSubWindow, QMenu, QPushButton, QSizePolicy,
                              QSplitter, QWidget, QStyle)
-
+from os import path
 from . import dialogs
 from .graphics import customView
 from .canvas import canvas
 from .tabs import customTabWidget
 from .undo import resizeCommand
-from .app import dump, loads, JSON_Typer
+from .app import dump, loads, JSON_Typer, version
 
 
 class fileWindow(QMdiSubWindow):
@@ -221,6 +221,8 @@ class fileWindow(QMdiSubWindow):
         # called by dialog.saveEvent, saves the current file
         name = QFileDialog.getSaveFileName(self, 'Save File', f'New Diagram', 'Process Flow Diagram (*.pfd)') if not name else name
         if name[0]:
+            self.setObjectName(path.basename(name[0]).split(".")[0])
+            self.setWindowTitle(self.objectName())
             with open(name[0],'w') as file: 
                 dump(self, file, indent=4, cls=JSON_Typer)
             return True
@@ -241,13 +243,14 @@ class fileWindow(QMdiSubWindow):
     def __getstate__(self) -> dict:
         return {
             "_classname_": self.__class__.__name__,
+            "version": version,
             "ObjectName": self.objectName(),
             "tabs": [i.__getstate__() for i in self.tabList]
         }
     
     def __setstate__(self, dict):
-        self.setObjectName = dict['ObjectName']
-        self.setWindowTitle = dict['ObjectName']
+        self.setObjectName(dict['ObjectName'])
+        self.setWindowTitle(dict['ObjectName'])
         for i in dict['tabs']:
             diagram = self.newDiagram(i['ObjectName'])
             diagram.__setstate__(i)
diff --git a/src/main/python/utils/tabs.py b/src/main/python/utils/tabs.py
index eab056a..5196557 100644
--- a/src/main/python/utils/tabs.py
+++ b/src/main/python/utils/tabs.py
@@ -1,11 +1,12 @@
-from PyQt5.QtWidgets import QTabBar, QPushButton, QTabWidget
-from PyQt5.QtCore import pyqtSignal, QSize
+from PyQt5.QtWidgets import QTabBar, QPushButton, QTabWidget, QInputDialog
+from PyQt5.QtCore import pyqtSignal, QSize, Qt
 
 class tabBarPlus(QTabBar):
     """
     Just implemented to overload resize and layout change to emit a signal
     """
     layoutChanged = pyqtSignal()
+    nameChanged = pyqtSignal(int, str)
     def resizeEvent(self, event):
         super().resizeEvent(event)
         self.layoutChanged.emit()
@@ -14,7 +15,17 @@ class tabBarPlus(QTabBar):
         super().tabLayoutChange()
         self.layoutChanged.emit()
 
-
+    def mouseDoubleClickEvent(self, event):
+        if event.button() != Qt.LeftButton:
+            return super().mouseDoubleClickEvent()
+        index = self.currentIndex()
+        newName, bool = QInputDialog.getText(self, "Change Diagram Name", "Enter new name",
+                                       text = self.tabText(index))
+        if bool:
+            self.setTabText(index, newName)
+            self.nameChanged.emit(index, newName)
+            
+        
 class customTabWidget(QTabWidget):
     """
     QTabWidget with a new tab button, also catches layoutChange signal by
@@ -50,6 +61,7 @@ class customTabWidget(QTabWidget):
 
         self.tab.layoutChanged.connect(self.movePlusButton) #connect layout change
         # to dynamically move the button.
+        self.tab.nameChanged.connect(self.changeWidgetName)
         
         #set custom stylesheet for the widget area
         self.setStyleSheet("""QTabWidget::pane { 
@@ -68,4 +80,7 @@ class customTabWidget(QTabWidget):
         if size > w: #if all the tabs do not overflow the tab bar, add at the end
             self.plusButton.move(w-self.plusButton.width(), h)
         else:
-            self.plusButton.move(size-3, h)
\ No newline at end of file
+            self.plusButton.move(size-3, h)
+            
+    def changeWidgetName(self, index, newName):
+        self.widget(index).setObjectName(newName)
\ No newline at end of file
diff --git a/src/main/python/utils/toolbar.py b/src/main/python/utils/toolbar.py
index af6feae..7883136 100644
--- a/src/main/python/utils/toolbar.py
+++ b/src/main/python/utils/toolbar.py
@@ -20,6 +20,7 @@ class toolbar(QDockWidget):
     def __init__(self, parent = None):
         super(toolbar, self).__init__(parent)
         self.toolbarButtonDict = dict() #initializes empty dict to store toolbar buttons
+        self.toolbarButtonClassList = []
         self.toolbarItems(toolbarItems.keys()) #creates all necessary buttons
         
         self.setFeatures(QDockWidget.DockWidgetFloatable | QDockWidget.DockWidgetMovable)
@@ -59,8 +60,9 @@ class toolbar(QDockWidget):
     def populateToolbar(self, list):
         #called everytime the button box needs to be updated(incase of a filter)
         self.clearLayout() #clears layout
-        for item in list:
-            self.diagAreaLayout.addWidget(self.toolbarButtonDict[item])
+        for itemClass in list:
+            for item in self.toolbarButtonDict[itemClass].keys():
+                self.diagAreaLayout.addWidget(self.toolbarButtonDict[itemClass][item])
         self.resize()
             
     def searchQuery(self):
@@ -86,13 +88,16 @@ class toolbar(QDockWidget):
         self.diagAreaWidget.setLayout(self.diagAreaLayout)
         self.diagArea.setWidget(self.diagAreaWidget)
 
-    def toolbarItems(self, items):
+    def toolbarItems(self, itemClasses):
         #helper functions to create required buttons
-        for item in items:
-            obj = toolbarItems[item]
-            button = toolbarButton(self, obj)
-            button.clicked.connect(lambda : self.toolbuttonClicked.emit(obj))
-            self.toolbarButtonDict[item] = button
+        for itemClass in itemClasses:
+            self.toolbarButtonDict[itemClass] = {}
+            self.toolbarButtonClassList.append(itemClass)
+            for item in toolbarItems[itemClass].keys():
+                obj = toolbarItems[itemClass][item]
+                button = toolbarButton(self, obj)
+                button.clicked.connect(lambda : self.toolbuttonClicked.emit(obj))
+                self.toolbarButtonDict[itemClass][item] = button
             
     @property
     def toolbarItemList(self):
diff --git a/src/main/python/utils/undo.py b/src/main/python/utils/undo.py
index 7979bf3..b060550 100644
--- a/src/main/python/utils/undo.py
+++ b/src/main/python/utils/undo.py
@@ -31,12 +31,13 @@ class addCommand(QUndoCommand):
     def undo(self):
         self.scene.removeItem(self.diagramItem)
         self.scene.update()
+        self.scene.advance()
         
     def redo(self):
         self.scene.addItem(self.diagramItem)
         self.diagramItem.setPos(self.itemPos)
         self.scene.clearSelection()
-        self.scene.update()
+        self.scene.advance()
         
 class deleteCommand(QUndoCommand):
     """