Add area to list of arguments

qt/python/mantidqt/_common.sip

@@ -328,7 +328,7 @@ public:
   void showAlgorithmHelp(const QString &name, const int version=-1);
   void showConceptHelp(const QString &name);
   void showFitFunctionHelp(const QString &name=QString());
-  void showCustomInterfaceHelp(const QString &name);
+  void showCustomInterfaceHelp(const QString &name, const QString &area=QString(), const QString &section=QString());
   void showWebPage(const QString &url);
   void closeHelpWindow();
 };

qt/scientific_interfaces/Muon/MuonAnalysis.cpp

@@ -394,7 +394,8 @@ void MuonAnalysis::muonAnalysisHelpClicked() {
  */
 void MuonAnalysis::muonAnalysisHelpGroupingClicked() {
   MantidQt::API::HelpWindow::showCustomInterface(
-      nullptr, QString("Muon Analysis"), QString("grouping-options"));
+      nullptr, QString("Muon Analysis"), QString(""),
+      QString("grouping-options"));
 }
 
 /**

qt/scientific_interfaces/Muon/MuonAnalysisOptionTab.cpp

@@ -151,7 +151,7 @@ void MuonAnalysisOptionTab::initLayout() {
  */
 void MuonAnalysisOptionTab::muonAnalysisHelpSettingsClicked() {
   MantidQt::API::HelpWindow::showCustomInterface(
-      nullptr, QString("Muon Analysis"), QString("settings"));
+      nullptr, QString("Muon Analysis"), QString(""), QString("settings"));
 }
 
 /*
@@ -159,7 +159,7 @@ void MuonAnalysisOptionTab::muonAnalysisHelpSettingsClicked() {
  */
 void MuonAnalysisOptionTab::rebinHelpClicked() {
   MantidQt::API::HelpWindow::showCustomInterface(
-      nullptr, QString("Muon Analysis"), QString("data-binning"));
+      nullptr, QString("Muon Analysis"), QString(""), QString("data-binning"));
 }
 
 /**

qt/scientific_interfaces/Muon/MuonAnalysisResultTableTab.cpp

@@ -102,7 +102,7 @@ MuonAnalysisResultTableTab::MuonAnalysisResultTableTab(Ui::MuonAnalysis &uiForm)
  */
 void MuonAnalysisResultTableTab::helpResultsClicked() {
   MantidQt::API::HelpWindow::showCustomInterface(
-      nullptr, QString("Muon Analysis"), QString("results-table"));
+      nullptr, QString("Muon Analysis"), QString(""), QString("results-table"));
 }
 
 /**

qt/widgets/common/inc/MantidQtWidgets/Common/HelpWindow.h

@@ -33,10 +33,12 @@ public:
   static void showFitFunction(QWidget *parent,
                               const std::string &name = std::string());
   static void showCustomInterface(QWidget *parent, const QString &name,
+                                  const QString &area = QString(),
                                   const QString &section = QString());
   static void showCustomInterface(QWidget *parent,
                                   const std::string &name = std::string(),
+                                  const std::string &area = std::string(),
                                   const std::string &section = std::string());
 };
 } // namespace API
-} // namespace MantidQt
\ No newline at end of file
+} // namespace MantidQt

qt/widgets/common/inc/MantidQtWidgets/Common/InterfaceManager.h

@@ -101,7 +101,9 @@ public:
   void showFitFunctionHelp(const QString &name = QString());
 
   /// @param name of interface to show help for
-  void showCustomInterfaceHelp(const QString &name);
+  void showCustomInterfaceHelp(const QString &name,
+                               const QString &area = QString(),
+                               const QString &section = QString());
 
   /// @param url of web page to open in browser
   void showWebPage(const QString &url);

qt/widgets/common/inc/MantidQtWidgets/Common/MantidHelpInterface.h

@@ -40,8 +40,10 @@ public:
   virtual void showFitFunction(const std::string &name = std::string());
   virtual void showFitFunction(const QString &name);
   virtual void showCustomInterface(const std::string &name,
+                                   const std::string &area = std::string(),
                                    const std::string &section = std::string());
   virtual void showCustomInterface(const QString &name,
+                                   const QString &area = QString(),
                                    const QString &section = QString());
 
 public slots:

qt/widgets/common/inc/MantidQtWidgets/Common/MantidHelpWindow.h

@@ -44,8 +44,9 @@ public:
   void showFitFunction(const std::string &name = std::string()) override;
   void showFitFunction(const QString &name) override;
   void showCustomInterface(const std::string &name = std::string(),
+                           const std::string &area = std::string(),
                            const std::string &section = std::string()) override;
-  void showCustomInterface(const QString &name,
+  void showCustomInterface(const QString &name, const QString &area = QString(),
                            const QString &section = QString()) override;
 
 private:
@@ -73,4 +74,4 @@ public slots:
 };
 
 } // namespace MantidWidgets
-} // namespace MantidQt
\ No newline at end of file
+} // namespace MantidQt

qt/widgets/common/src/HelpWindow.cpp

@@ -117,12 +117,15 @@ void HelpWindow::showFitFunction(QWidget *parent, const std::string &name) {
 }
 
 void HelpWindow::showCustomInterface(QWidget *parent, const std::string &name,
+                                     const std::string &area,
                                      const std::string &section) {
   showCustomInterface(parent, QString::fromStdString(name),
+                      QString::fromStdString(area),
                       QString::fromStdString(section));
 }
 
 void HelpWindow::showCustomInterface(QWidget *parent, const QString &name,
+                                     const QString &area,
                                      const QString &section) {
   InterfaceManager interfaceManager;
   MantidHelpInterface *gui = interfaceManager.createHelpWindow();
@@ -132,6 +135,9 @@ void HelpWindow::showCustomInterface(QWidget *parent, const QString &name,
   } else {
     // Open online help
     QString baseUrl = "https://docs.mantidproject.org/interfaces/";
+    if (!area.toStdString().empty()) {
+      baseUrl += area + "/";
+    }
     QString url = baseUrl + name + ".html";
     MantidDesktopServices::openUrl(QUrl(url));
     g_log.debug("Opening online help page:\n" + url.toStdString());

qt/widgets/common/src/InterfaceManager.cpp

@@ -283,9 +283,11 @@ void InterfaceManager::showFitFunctionHelp(const QString &name) {
   window->showFitFunction(name);
 }
 
-void InterfaceManager::showCustomInterfaceHelp(const QString &name) {
+void InterfaceManager::showCustomInterfaceHelp(const QString &name,
+                                               const QString &area,
+                                               const QString &section) {
   auto window = createHelpWindow();
-  window->showCustomInterface(name);
+  window->showCustomInterface(name, area, section);
 }
 
 void InterfaceManager::showWebPage(const QString &url) {

qt/widgets/common/src/MantidHelpInterface.cpp

@@ -56,14 +56,18 @@ void MantidHelpInterface::showFitFunction(const QString &name) {
 }
 
 void MantidHelpInterface::showCustomInterface(const std::string &name,
+                                              const std::string &area,
                                               const std::string &section) {
   UNUSED_ARG(name);
+  UNUSED_ARG(area);
   UNUSED_ARG(section);
 }
 
 void MantidHelpInterface::showCustomInterface(const QString &name,
+                                              const QString &area,
                                               const QString &section) {
   UNUSED_ARG(name);
+  UNUSED_ARG(area);
   UNUSED_ARG(section);
 }
 

qt/widgets/common/src/MantidHelpWindow.cpp

@@ -325,8 +325,10 @@ void MantidHelpWindow::showFitFunction(const QString &name) {
  * @param section :: the section of the interface to show
  */
 void MantidHelpWindow::showCustomInterface(const QString &name,
+                                           const QString &area,
                                            const QString &section) {
-  this->showCustomInterface(name.toStdString(), section.toStdString());
+  this->showCustomInterface(name.toStdString(), area.toStdString(),
+                            section.toStdString());
 }
 
 /**
@@ -336,10 +338,14 @@ void MantidHelpWindow::showCustomInterface(const QString &name,
  * @param section :: the section of the interface to show
  */
 void MantidHelpWindow::showCustomInterface(const std::string &name,
+                                           const std::string &area,
                                            const std::string &section) {
   if (bool(g_helpWindow)) {
     QString url(BASE_URL);
     url += "interfaces/";
+    if (!area.empty()) {
+      url += QString::fromStdString(area) + "/";
+    }
     if (name.empty()) {
       url += "index.html";
     } else {