Adding helper class to launch qtassistan from ApplicationWindow.

Re #6630. The helper class is rhobust, but only tested on linux so
far. Still needs help with other operating systems and working on
installed versions.

Code/Mantid/MantidPlot/CMakeLists.txt

@@ -47,6 +47,7 @@ set ( QTIPLOT_SRCS src/ApplicationWindow.cpp
                    src/Graph3D.cpp
                    src/Graph.cpp
                    src/Grid.cpp
+		   src/HelpWindow.cpp
                    src/ImageDialog.cpp
                    src/ImageExportDialog.cpp
                    src/ImageMarker.cpp
@@ -277,6 +278,7 @@ set ( QTIPLOT_HDRS src/ApplicationWindow.h
                    src/Graph3D.h
                    src/Graph.h
                    src/Grid.h
+		   src/HelpWindow.h
                    src/ImageDialog.h
                    src/ImageExportDialog.h
                    src/ImageMarker.h

Code/Mantid/MantidPlot/src/ApplicationWindow.cpp

@@ -14606,7 +14606,9 @@ void ApplicationWindow::showMantidConcepts()
 }
 void ApplicationWindow::showalgorithmDescriptions()
 {
-  QDesktopServices::openUrl(QUrl("http://www.mantidproject.org/Category:Algorithms"));
+  if (!m_helpWindow)
+      m_helpWindow = boost::make_shared<HelpWindow>();
+  m_helpWindow->showURL("qthelp://org.mantidproject/doc/algorithms_index.html");
 }
 
 void ApplicationWindow::showSetupParaview()
@@ -14630,7 +14632,9 @@ void ApplicationWindow::showFirstTimeSetup()
  */
 void ApplicationWindow::showmantidplotHelp()
 {
-  QDesktopServices::openUrl(QUrl("http://www.mantidproject.org/MantidPlot:_Help"));
+  if (!m_helpWindow)
+    m_helpWindow = boost::make_shared<HelpWindow>();
+  m_helpWindow->showURL("qthelp://org.mantidproject/doc/index.html");
 }
 
 //

Code/Mantid/MantidPlot/src/ApplicationWindow.h

@@ -42,6 +42,7 @@ Description          : QtiPlot's main window
 #include <QSet>
 #include <QSettings>
 
+#include "HelpWindow.h"
 #include "Table.h"
 #include "ScriptingEnv.h"
 #include "Scripted.h"
@@ -1367,6 +1368,8 @@ public slots:
   // Flag telling if table values should be automatically recalculated when values in a column are modified.
   bool d_auto_update_table_values;
   int d_matrix_undo_stack_size;
+  /// Smart pointer to the help window
+  boost::shared_ptr<HelpWindow> m_helpWindow;
 
   /// A method to populate the CurveLayout struct on loading a project
   CurveLayout fillCurveSettings(const QStringList & curve, unsigned int offset = 0);

Code/Mantid/MantidPlot/src/HelpWindow.cpp

@@ -0,0 +1,214 @@
+#include "HelpWindow.h"
+#include "MantidKernel/ConfigService.h"
+#include <boost/make_shared.hpp>
+#include <iostream>
+#include <Poco/File.h>
+#include <Poco/Path.h>
+#include <QByteArray>
+#include <QDesktopServices>
+#include <stdexcept>
+#include <strstream>
+
+using std::string;
+
+/// Base url for all of the files in the project
+const string BASEURL("qthelp://org.mantidproject/doc/");
+
+/**
+ * Default constructor.
+ */
+HelpWindow::HelpWindow() :
+    m_collectionFile(""),
+    m_cacheFile(""),
+  m_log(Mantid::Kernel::Logger::get("HelpWindow"))
+{
+    this->determineFileLocs();
+    this->start();
+}
+
+/// Destructor does nothing.
+HelpWindow::~HelpWindow()
+{
+    // do nothing
+}
+
+/**
+ * Have the help window show a specific url. If the url doesn't exist
+ * this just pops up the default view for the help.
+ *
+ * \param url The url to open. This should start with \link BASEURL.
+ */
+void HelpWindow::showURL(const string &url)
+{
+    // make sure the process is going
+    this->start();
+
+    m_log.debug() << "open help url \"" << url << "\"\n";
+    string temp("setSource " + url + "\n");
+    QByteArray ba;
+    ba.append(QLatin1String(temp.c_str()));
+    m_process->write(ba);
+}
+
+/**
+ * Show the help page for a particular algorithm. The page is picked
+ * using matching naming conventions.
+ *
+ * @param name The name of the algorithm to show.
+ * @param version The version of the algorithm to jump do. The default
+ * value (-1) will show the top of the page.
+ */
+void HelpWindow::showAlgorithm(const string &name, const int version)
+{
+    // TODO jump to the version within the page
+    (void)version;
+
+    string url(BASEURL + "Algo_" + name + ".html");
+    this->showURL(url);
+}
+
+/**
+ * Show the help page for a particular fit function. The page is
+ * picked using matching naming conventions.
+ *
+ * @param name The name of the fit function to show.
+ */
+void HelpWindow::showFitFunction(const std::string &name)
+{
+    string url(BASEURL + "FitFunc_" + name + ".html");
+}
+
+/**
+ * Start up the help browser in a separate process.
+ *
+ * This will only do something if the browser is not already
+ * running. Due to a bug in qt 4.8.1 this will delete the
+ * cache file every time the browser is started.
+ */
+void HelpWindow::start()
+{
+    // check if it is already started
+    if (this->isRunning())
+    {
+        m_log.debug() << "helpwindow process already running\n";
+        return;
+    }
+
+    // see if chache file exists and remove it
+    if ((!m_cacheFile.empty()) && (Poco::File(m_cacheFile).exists()))
+    {
+        m_log.debug() << "Removing help cache file \"" << m_cacheFile << "\"\n";
+        Poco::File(m_cacheFile).remove();
+    }
+
+    // start the process
+    m_process = boost::make_shared<QProcess>();
+    QStringList args;
+    args << QLatin1String("-collectionFile")
+         << QLatin1String(m_collectionFile.c_str())
+         << QLatin1String("-enableRemoteControl");
+    m_process->start(QLatin1String("/usr/bin/assistant"), args);
+    if (!m_process->waitForStarted())
+        return;
+    m_log.debug() << QString("/usr/bin/assistant").toStdString()
+                        << " " << args.join(QString(" ")).toStdString()
+                        << " (state = " << m_process->state() << ")\n";
+}
+
+/**
+ * @return True if the browser is running.
+ */
+bool HelpWindow::isRunning()
+{
+    // NULL pointer definitely isn't running
+    if (!m_process)
+        return false;
+
+    // ask the process for its state
+    if (m_process->state() == QProcess::NotRunning)
+        return false;
+    else
+        return true;
+}
+
+/**
+ * Determine the location of the collection file, "mantid.qhc". This
+ * checks in multiple locations and can throw an exception.
+ *
+ * @param binDir The location of the mantid executable.
+ */
+void HelpWindow::findCollectionFile(std::string &binDir)
+{
+    const std::string COLLECTION("mantid.qhc");
+
+    // try next to the executable
+    Poco::Path path(binDir, COLLECTION);
+    if (Poco::File(path).exists())
+    {
+        m_collectionFile =path.absolute().toString();
+        return;
+    }
+
+    // try one level up
+    path = Poco::Path(binDir, "../"+COLLECTION);
+    if (Poco::File(path).exists())
+    {
+        m_collectionFile = path.absolute().toString();
+        return;
+    }
+
+    // try where the builds will put it
+    path = Poco::Path(binDir, "../qtassistant/"+COLLECTION);
+    if (Poco::File(path).exists())
+    {
+        m_collectionFile = path.absolute().toString();
+        return;
+    }
+
+    // try in a good linux install location
+    path = Poco::Path(binDir, "../share/doc/" + COLLECTION);
+    if (Poco::File(path).exists())
+    {
+        m_collectionFile = path.absolute().toString();
+        return;
+    }
+
+    // all tries have failed
+    std::strstream msg;
+    msg << "Failed to find help system collection file \"" << COLLECTION << "\"";
+    throw std::runtime_error(msg.str());
+}
+
+/**
+ * Determine the location of the collection and cache files.
+ */
+void HelpWindow::determineFileLocs()
+{
+    // determine collection file location
+    string binDir = Mantid::Kernel::ConfigService::Instance().getDirectoryOfExecutable();
+    this->findCollectionFile(binDir);
+    m_log.debug() << "using collection file \"" << m_collectionFile << "\"\n";
+
+    // determine cache file location
+    m_cacheFile = "mantid.qhc";
+    QString dataLoc = QDesktopServices::storageLocation(QDesktopServices::DataLocation);
+    if (dataLoc.endsWith("mantidproject"))
+    {
+        Poco::Path path (dataLoc.toStdString(), m_cacheFile);
+        m_cacheFile = path.absolute().toString();
+    }
+    else if (dataLoc.endsWith("MantidPlot")) // understood to end in "ISIS/MantidPlot"
+    {
+        Poco::Path path(dataLoc.toStdString());
+        path = path.parent(); // drop off "MantidPlot"
+        path = path.parent(); // drop off "ISIS"
+        path = Poco::Path(path, "mantidproject");
+        path = Poco::Path(path, m_cacheFile);
+        m_cacheFile = path.absolute().toString();
+    }
+    else
+    {
+        m_log.debug() << "Failed to determine help cache file location\n"; // REMOVE
+        m_cacheFile = "";
+    }
+}

Code/Mantid/MantidPlot/src/HelpWindow.h

@@ -0,0 +1,33 @@
+#ifndef HELPWINDOW_H
+#define HELPWINDOW_H
+#include <boost/shared_ptr.hpp>
+#include <QProcess>
+#include <string>
+#include "MantidKernel/Logger.h"
+
+class HelpWindow
+{
+public:
+    HelpWindow();
+    virtual ~HelpWindow();
+    void showURL(const std::string & url);
+    void showAlgorithm(const std::string &name, const int version=-1);
+    void showFitFunction(const std::string &name);
+
+private:
+    /// Shared pointer to the process running qt assistant.
+    boost::shared_ptr<QProcess> m_process;
+    /// The full path of the collection file.
+    std::string m_collectionFile;
+    /** The full path of the cache file. If it is not
+        determined this is an empty string. */
+    std::string m_cacheFile;
+    /// The logger for the class.
+    Mantid::Kernel::Logger& m_log;
+
+    void start();
+    bool isRunning();
+    void findCollectionFile(std::string & binDir);
+    void determineFileLocs();
+};
+#endif // HELPWINDOW_H