Merge pull request #531 from mantidproject/9505_Fitting_with_no_peaks

Fitting with no peaks

Code/Mantid/MantidQt/CustomInterfaces/inc/MantidQtCustomInterfaces/Muon/ALCPeakFittingView.h

@@ -59,6 +59,7 @@ namespace CustomInterfaces
     void setParameter(const QString& funcIndex, const QString& paramName, double value);
     void setPeakPickerEnabled(bool enabled);
     void setPeakPicker(const IPeakFunction_const_sptr& peak);
+    void displayError(const QString& message);
     void help();
 
     // -- End of IALCPeakFitting interface ---------------------------------------------------------

Code/Mantid/MantidQt/CustomInterfaces/inc/MantidQtCustomInterfaces/Muon/IALCPeakFittingView.h

@@ -86,6 +86,12 @@ namespace CustomInterfaces
     /// @param peak :: A new peak to represent
     virtual void setPeakPicker(const IPeakFunction_const_sptr& peak) = 0;
 
+    /**
+     * Pops-up an error box
+     * @param message :: Error message to display
+     */
+    virtual void displayError(const QString& message) = 0;
+
     /// Opens the Mantid Wiki web page
     virtual void help() = 0;
 

Code/Mantid/MantidQt/CustomInterfaces/src/Muon/ALCPeakFittingPresenter.cpp

@@ -31,7 +31,12 @@ namespace CustomInterfaces
 
   void ALCPeakFittingPresenter::fit()
   {
-    m_model->fitPeaks(m_view->function(""));
+    IFunction_const_sptr func = m_view->function("");
+    if ( func ) {
+      m_model->fitPeaks(func);
+    } else {
+       m_view->displayError("Couldn't fit an empty function");
+    }
   }
 
   void ALCPeakFittingPresenter::onCurrentFunctionChanged()

Code/Mantid/MantidQt/CustomInterfaces/src/Muon/ALCPeakFittingView.cpp

@@ -2,6 +2,8 @@
 
 #include "MantidQtAPI/HelpWindow.h"
 
+#include <QMessageBox>
+
 #include <qwt_symbol.h>
 
 namespace MantidQt
@@ -109,6 +111,11 @@ void ALCPeakFittingView::help()
   MantidQt::API::HelpWindow::showCustomInterface(NULL, QString("Muon_ALC"));
 }
 
+void ALCPeakFittingView::displayError(const QString& message)
+{
+  QMessageBox::critical(m_widget, "Error", message);
+}
+
 } // namespace CustomInterfaces
 } // namespace Mantid
 

Code/Mantid/MantidQt/CustomInterfaces/test/ALCPeakFittingPresenterTest.h

@@ -50,6 +50,7 @@ public:
   MOCK_METHOD1(setPeakPicker, void(const IPeakFunction_const_sptr&));
   MOCK_METHOD1(setFunction, void(const IFunction_const_sptr&));
   MOCK_METHOD3(setParameter, void(const QString&, const QString&, double));
+  MOCK_METHOD1(displayError, void(const QString&));
   MOCK_METHOD0(help, void());
 };
 
@@ -127,6 +128,14 @@ public:
     presenter.initialize();
   }
 
+  void test_fitEmptyFunction()
+  {
+    ON_CALL(*m_view, function(QString(""))).WillByDefault(Return(IFunction_const_sptr()));
+    EXPECT_CALL(*m_view, displayError(QString("Couldn't fit an empty function"))).Times(1);
+
+    m_view->requestFit();
+  }
+
   void test_fit()
   {
     IFunction_sptr peaks = createGaussian(1,2,3);