Refs #9213. Extend FunctionBrowser functionality

This allows for finer-grain function retrieval and updating, plus a few
signals to indicate basic changes.

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

@@ -8,6 +8,8 @@
 #include <QWidget>
 #include <QMap>
 
+#include <boost/optional.hpp>
+
     /* Forward declarations */
 
 class QtTreePropertyBrowser;
@@ -92,6 +94,24 @@ class EXPORT_OPT_MANTIDQT_MANTIDWIDGETS FunctionBrowser: public QWidget
   /// Return the function
   Mantid::API::IFunction_sptr getFunction(QtProperty* prop = NULL, bool attributesOnly = false);
 
+  /// Return a function with specified index
+  Mantid::API::IFunction_sptr getFunctionByIndex(const QString& index);
+
+  /// Return index of the current function, if one is selected
+  boost::optional<QString> currentFunctionIndex() { return m_currentFunctionIndex; }
+
+  /// Update the function parameter value
+  void setParameter(const QString& funcIndex, const QString& paramName, double value);
+
+signals:
+  /// User selects a different function (or one of it's sub-properties)
+  void currentFunctionChanged();
+
+  /// Function parameter gets changed
+  /// @param funcIndex :: Index of the changed function
+  /// @param paramName :: Name of the changed parameter
+  void parameterChanged(const QString& funcIndex, const QString& paramName);
+
 protected:
   /// Create the Qt property browser
   void createBrowser();
@@ -141,6 +161,8 @@ class EXPORT_OPT_MANTIDQT_MANTIDWIDGETS FunctionBrowser: public QWidget
   bool isIndex(QtProperty* prop) const;
   /// Get the function index for a property
   QString getIndex(QtProperty* prop) const;
+  /// Get function property for the index
+  QtProperty* getFunctionProperty(const QString& index);
 
   /// Add a tie property
   AProperty addTieProperty(QtProperty* prop, QString tie);
@@ -189,13 +211,17 @@ protected slots:
   void addConstraints50();
   /// Remove one of the constraints
   void removeConstraint();
+  /// Update current function index depending on currently selected item
+  void updateCurrentFunctionIndex();
 
   //   Property change slots
 
   /// Called when a function attribute property is changed
   void attributeChanged(QtProperty*);
   /// Called when a member of a vector attribute is changed
   void attributeVectorDoubleChanged(QtProperty*);
+  /// Called when a function parameter property is changed
+  void parameterChanged(QtProperty*);
 
 protected:
   /// Manager for function group properties
@@ -266,6 +292,9 @@ protected slots:
   /// Remove one constraints from current parameter
   QAction *m_actionRemoveConstraint;
 
+  /// Index of currently selected function. Gets updated in updateCurrentFunctionIndex()
+  boost::optional<QString> m_currentFunctionIndex;
+
   friend class CreateAttributePropertyForFunctionBrowser;
   friend class SetAttributeFromProperty;
 };

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

@@ -145,7 +145,6 @@ void FunctionBrowser::createBrowser()
 
   m_browser->setContextMenuPolicy(Qt::CustomContextMenu);
   connect(m_browser, SIGNAL(customContextMenuRequested(const QPoint &)), this, SLOT(popupMenu(const QPoint &)));
-  //connect(m_browser, SIGNAL(currentItemChanged(QtBrowserItem*)), this, SLOT(currentItemChanged(QtBrowserItem*)));
 
   connect(m_attributeStringManager,SIGNAL(propertyChanged(QtProperty*)),this,SLOT(attributeChanged(QtProperty*)));
   connect(m_attributeDoubleManager,SIGNAL(propertyChanged(QtProperty*)),this,SLOT(attributeChanged(QtProperty*)));
@@ -154,6 +153,11 @@ void FunctionBrowser::createBrowser()
   connect(m_formulaManager,SIGNAL(propertyChanged(QtProperty*)),this,SLOT(attributeChanged(QtProperty*)));
   connect(m_filenameManager,SIGNAL(propertyChanged(QtProperty*)),this,SLOT(attributeChanged(QtProperty*)));
   connect(m_attributeVectorDoubleManager,SIGNAL(propertyChanged(QtProperty*)),this,SLOT(attributeVectorDoubleChanged(QtProperty*)));
+
+  connect(m_parameterManager, SIGNAL(valueChanged(QtProperty*,double)),
+          SLOT(parameterChanged(QtProperty*)));
+
+  connect(m_browser, SIGNAL(currentItemChanged(QtBrowserItem*)), SLOT(updateCurrentFunctionIndex()));
 }
 
 /**
@@ -840,7 +844,28 @@ QString FunctionBrowser::getIndex(QtProperty* prop) const
   }
 
   auto ap = m_properties[prop];
-  return getIndex(ap.parent); 
+  return getIndex(ap.parent);
+}
+
+/**
+ * Return function property for a function with given index.
+ * @param index :: Function index to search, or empty string for top-level function
+ * @return Function property, or NULL if not found
+ */
+QtProperty* FunctionBrowser::getFunctionProperty(const QString& index)
+{
+  // Might not be the most efficient way to do it. m_functionManager might be searched instead,
+  // but it is not being kept up-to-date at the moment (is not cleared).
+  foreach (auto property, m_properties.keys())
+  {
+    if(isFunction(property) && getIndex(property) == index)
+    {
+      return property;
+    }
+  }
+
+  // No function with such index
+  return NULL;
 }
 
 
@@ -1380,6 +1405,45 @@ Mantid::API::IFunction_sptr FunctionBrowser::getFunction(QtProperty* prop, bool
   return fun;
 }
 
+/**
+ * Return function at specified function index (e.g. f0.)
+ * @param index :: Index of the function, or empty string for top-level function
+ * @return Function at index, or null pointer if not found
+ */
+Mantid::API::IFunction_sptr FunctionBrowser::getFunctionByIndex(const QString& index)
+{
+  if(auto prop = getFunctionProperty(index))
+  {
+    return getFunction(prop);
+  }
+  else
+  {
+    return Mantid::API::IFunction_sptr();
+  }
+}
+
+/**
+ * Updates the function parameter value
+ * @param funcIndex :: Index of the function
+ * @param paramName :: Parameter name
+ * @param value :: New value
+ */
+void FunctionBrowser::setParameter(const QString& funcIndex, const QString& paramName, double value)
+{
+  if (auto prop = getFunctionProperty(funcIndex))
+  {
+    auto children = prop->subProperties();
+    foreach(QtProperty* child, children)
+    {
+      if (isParameter(child) && child->propertyName() == paramName)
+      {
+        m_parameterManager->setValue(child, value);
+        break;
+      }
+    }
+  }
+}
+
 /**
  * Return FunctionFactory function string
  */
@@ -1560,6 +1624,23 @@ void FunctionBrowser::removeConstraint()
   removeProperty( prop );
 }
 
+void FunctionBrowser::updateCurrentFunctionIndex()
+{
+  boost::optional<QString> newIndex;
+
+  if (auto item = m_browser->currentItem())
+  {
+    auto prop = item->property();
+    newIndex = getIndex(prop);
+  }
+
+  if (m_currentFunctionIndex != newIndex)
+  {
+    m_currentFunctionIndex = newIndex;
+    emit currentFunctionChanged();
+  }
+}
+
 /**
  * Slot connected to all function attribute managers. Update the corresponding function.
  * @param prop :: An attribute property that was changed
@@ -1587,6 +1668,11 @@ void FunctionBrowser::attributeVectorDoubleChanged(QtProperty *prop)
     attributeChanged( vectorProp );
 }
 
+void FunctionBrowser::parameterChanged(QtProperty* prop)
+{
+  emit parameterChanged(getIndex(prop), prop->propertyName());
+}
+
 
 } // MantidWidgets
 } // MantidQt