We can't Undo if only opening pattern.

--HG--
branch : develop

src/app/dialogs/app/dialogundo.cpp

@@ -39,7 +39,15 @@ DialogUndo::DialogUndo(QWidget *parent)
 {
     ui->setupUi(this);
 
-    connect(ui->pushButtonUndo, &QPushButton::clicked, this, &DialogUndo::Undo);
+    bool opening = qApp->getOpeningPattern();
+    if (opening)
+    {
+        ui->pushButtonUndo->setDisabled(opening);
+    }
+    else
+    {
+        connect(ui->pushButtonUndo, &QPushButton::clicked, this, &DialogUndo::Undo);
+    }
     connect(ui->pushButtonFix, &QPushButton::clicked, this, &DialogUndo::Fix);
     connect(ui->pushButtonCancel, &QPushButton::clicked, this, &DialogUndo::Cancel);
 }

src/app/mainwindow.cpp

@@ -2194,6 +2194,7 @@ MainWindow::~MainWindow()
  */
 void MainWindow::LoadPattern(const QString &fileName)
 {
+    qApp->setOpeningPattern();//Begin opening file
     try
     {
         VDomDocument::ValidateXML("://schema/pattern.xsd", fileName);
@@ -2257,6 +2258,8 @@ void MainWindow::LoadPattern(const QString &fileName)
         PatternWasModified(patternModified);
     }
     helpLabel->setText(tr("File loaded"));
+
+    qApp->setOpeningPattern();// End opening file
 }
 
 //---------------------------------------------------------------------------------------------------------------------

src/app/widgets/vapplication.cpp

@@ -59,7 +59,7 @@ VApplication::VApplication(int &argc, char **argv)
       guiTexts(QMap<QString, VTranslation>()), descriptions(QMap<QString, VTranslation>()),
       variables(QMap<QString, VTranslation>()), functions(QMap<QString, VTranslation>()),
       postfixOperators(QMap<QString, VTranslation>()), undoStack(nullptr), sceneView(nullptr), autoSaveTimer(nullptr),
-      mainWindow(nullptr)
+      mainWindow(nullptr), openingPattern(false)
 {
     undoStack = new QUndoStack(this);
 
@@ -1967,3 +1967,16 @@ void VApplication::setMainWindow(QWidget *value)
     mainWindow = value;
 }
 
+//---------------------------------------------------------------------------------------------------------------------
+bool VApplication::getOpeningPattern() const
+{
+    return openingPattern;
+}
+
+//---------------------------------------------------------------------------------------------------------------------
+void VApplication::setOpeningPattern()
+{
+    openingPattern = !openingPattern;
+}
+
+

src/app/widgets/vapplication.h

@@ -78,6 +78,8 @@ public:
     void               setAutoSaveTimer(QTimer *value);
     QWidget            *getMainWindow() const;
     void               setMainWindow(QWidget *value);
+    bool               getOpeningPattern() const;
+    void               setOpeningPattern();
 private:
     Q_DISABLE_COPY(VApplication)
     Unit               _patternUnit;
@@ -98,6 +100,11 @@ private:
      * modality doesn't work.
      */
     QWidget            *mainWindow;
+    /**
+     * @brief openingPattern true when we opening pattern. If something will be wrong in formula this help understand if
+     * we can allow user use Undo option.
+     */
+    bool               openingPattern;
     void               InitLineWidth();
     void               InitMeasurements();
     void               InitVariables();