Do a manual file search when run is clicked on LoadDialog

If the text field got updated but didn't emit the filesFound signal then
the dialog would load the old file. When run is clicked a search is forced
but it only performs a new search if something has actually changed in
the box.
Refs #7055

Code/Mantid/MantidQt/CustomDialogs/inc/MantidQtCustomDialogs/LoadDialog.h

@@ -102,6 +102,8 @@ namespace MantidQt
       QString m_currentFiles;
       /// The initial height
       int m_initialHeight;
+      /// Flag to indicating if we are populating the dialog
+      bool m_populating;
     };
 
   }

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

@@ -24,6 +24,22 @@ namespace MantidQt
 {
   namespace CustomDialogs
   {
+    namespace
+    {
+      /// Holds a flag at a given value
+      /// and flips it back to its starting value on destruction
+      struct HoldFlag
+      {
+        HoldFlag(bool& current, const bool holdValue) : initial(current), heldflag(current)
+        {
+          heldflag = holdValue;
+        }
+        ~HoldFlag() { heldflag = initial; }
+        bool initial;
+        bool & heldflag;
+      };
+    }
+
     // Declare the dialog. Name must match the class name
     DECLARE_DIALOG(LoadDialog);
 
@@ -33,7 +49,8 @@ namespace MantidQt
 
     /// Default constructor
     LoadDialog:: LoadDialog(QWidget *parent) 
-      : API::AlgorithmDialog(parent), m_form(), m_currentFiles(), m_initialHeight(0)
+      : API::AlgorithmDialog(parent), m_form(), m_currentFiles(), m_initialHeight(0),
+        m_populating(false)
     {
       // We will handle parsing the input ourselves on startup
       m_autoParseOnInit = false;
@@ -48,6 +65,8 @@ namespace MantidQt
     */
     void LoadDialog::createDynamicWidgets()
     {
+      HoldFlag hold(m_populating, true);
+
       m_form.fileWidget->blockSignals(true);
       createDynamicLayout();
       m_form.fileWidget->blockSignals(false);
@@ -95,10 +114,20 @@ namespace MantidQt
     }
 
     /**
-     * Protection against removing the file while the dialog is up.
+     * Called when the run button is clicked
      */
     void LoadDialog::accept()
     {
+      // The file widget may have been edited but not lost focus so that the search wasn't
+      // attempted for the new contents. Force one here.
+      // The widget does nothing if the contents have not changed so it will be quick for this case
+      m_form.fileWidget->findFiles();
+      while(m_form.fileWidget->isSearching() || m_populating)
+      {
+        QApplication::instance()->processEvents();
+      }
+
+      // Check that the file still exists just incase it somehow got removed
       std::string errMess = getAlgorithm()->getPointerToProperty("Filename")->isValid();
       if ( !errMess.empty() )
       {

Code/Mantid/MantidQt/MantidWidgets/inc/MantidQtMantidWidgets/MWRunFiles.h

@@ -166,6 +166,7 @@ namespace MantidQt
       QString getText() const;
 
       bool isValid() const;
+      bool isSearching() const;
       QStringList getFilenames() const;
       QString getFirstFilename() const;
       int getEntryNum() const;

Code/Mantid/MantidQt/MantidWidgets/src/MWRunFiles.cpp

@@ -73,6 +73,8 @@ void FindFilesThread::run()
   // Reset result member vars.
   m_error.clear();
   m_filenames.clear();
+  m_valueForProperty.clear();
+
   if( m_text.empty() )
   {
     if( m_isOptional )
@@ -87,7 +89,6 @@ void FindFilesThread::run()
 
   try
   {
-    m_valueForProperty = "";
     // Use the property of the algorithm to find files, if one has been specified.
     if( m_algorithm.length() != 0 && m_property.length() != 0 )
     {
@@ -494,6 +495,16 @@ bool MWRunFiles::isValid() const
   }
 }
 
+/**
+ * Is the widget currently searching
+ * @return True if a search is inprogress
+ */
+bool MWRunFiles::isSearching() const
+{
+  return (m_thread ? m_thread->isRunning() : false);
+}
+
+
 /** 
 * Returns the names of the files found
 * @return an array of filenames entered in the box