Update icon visibility on dialog after error when hitting run.

The updateIconVisibility method now accepts an error string so that
it doesn't have to recheck the property if it already has the error
string from it.
Refs #9756

Code/Mantid/MantidQt/API/inc/MantidQtAPI/PropertyWidget.h

@@ -113,7 +113,7 @@ namespace API
 
   public slots:
     /// Update which icons should be shown.
-    void updateIconVisibility();
+    void updateIconVisibility(const QString & error = "");
     /// Deal with the "replace workspace" button being clicked.
     void replaceWSButtonClicked();
     /// Emits a signal that the value of the property was changed.

Code/Mantid/MantidQt/API/src/GenericDialog.cpp

@@ -167,18 +167,13 @@ void GenericDialog::accept()
   else
   {
     // Highlight the validators that are in error (combined from them + whole algorithm)
-    auto itr = m_algoPropertiesWidget->m_propWidgets.begin();
-    for(; itr != m_algoPropertiesWidget->m_propWidgets.end(); itr++ )
-    {
-      if (m_errors.contains(itr.key()))
-        itr.value()->setError( m_errors[itr.key()] );
-    }
+    // If got there, there were errors
+    for(auto it = m_errors.begin(); it != m_errors.end(); it++)
+      m_algoPropertiesWidget->m_propWidgets[it.key()]->updateIconVisibility(it.value());
 
     QMessageBox::critical(this, "",
               "One or more properties are invalid. The invalid properties are\n"
         "marked with a *, hold your mouse over the * for more information." );
   }
 }
 
-
-

Code/Mantid/MantidQt/API/src/PropertyWidget.cpp

@@ -298,29 +298,33 @@ namespace API
 
   /**
    * Update which icons should be shown.
+   * @param error An optional error string. If empty the property is revalidated by calling prop->setValue and
+   * the error is pulled from here
    */
-  void PropertyWidget::updateIconVisibility()
+  void PropertyWidget::updateIconVisibility(const QString &error)
   {
-    // Show "*" icon if the value is invalid for this property.
-    QString value = this->getValue().trimmed();
-    // Use the default if empty
-    if( value.isEmpty() )
-      value = QString::fromStdString(m_prop->getDefault());
-
-    std::string error("");
-    try
+    QString userError(error);
+    if(userError.isEmpty())
     {
-      error = m_prop->setValue(value.toStdString());
+      // Show "*" icon if the value is invalid for this property.
+      QString value = this->getValue().trimmed();
+      // Use the default if empty
+      if( value.isEmpty() )
+        value = QString::fromStdString(m_prop->getDefault());
+
+      try
+      {
+        userError = QString::fromStdString(m_prop->setValue(value.toStdString()));
+      }
+      catch(std::exception & err_details)
+      {
+        userError = QString::fromAscii(err_details.what());
+      }
     }
-    catch(std::exception & err_details)
-    {
-      error = err_details.what();
-    }
-    this->setError(QString::fromStdString(error).trimmed());
+    this->setError(userError.trimmed());
 
     m_icons[INVALID]->setVisible(!m_error.isEmpty());
     m_icons[INVALID]->setToolTip(m_error);
-
     // Show "!" icon if a workspace would be overwritten.
     if( m_isOutputWsProp )
     {

Code/Mantid/MantidQt/CustomDialogs/src/SmoothNeighboursDialog.cpp

@@ -103,5 +103,5 @@ void SmoothNeighboursDialog::accept()
 
   // If got there, there were errors
   for(auto it = m_errors.begin(); it != m_errors.end(); it++)
-    m_propertiesWidget->m_propWidgets[it.key()]->setError(it.value());
+    m_propertiesWidget->m_propWidgets[it.key()]->updateIconVisibility(it.value());
 }