From 5af5ada4d2eaeb5ab0c1598ad7d3d8dfaa620d45 Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Fri, 3 Mar 2017 04:56:50 +0100
Subject: [PATCH] refs #894, commands can be registered for help

---
 src/blackmisc/simplecommandparser.cpp | 50 +++++++++++++++++++++++++++
 src/blackmisc/simplecommandparser.h   | 30 ++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/src/blackmisc/simplecommandparser.cpp b/src/blackmisc/simplecommandparser.cpp
index 71fef6878..511dcd913 100644
--- a/src/blackmisc/simplecommandparser.cpp
+++ b/src/blackmisc/simplecommandparser.cpp
@@ -19,6 +19,9 @@ using namespace BlackMisc::PhysicalQuantities;
 
 namespace BlackMisc
 {
+    QList<CSimpleCommandParser::CommandHtmlHelp> CSimpleCommandParser::s_commands = QList<CSimpleCommandParser::CommandHtmlHelp>();
+    QSet<QString> CSimpleCommandParser::s_registered = QSet<QString>();
+
     CSimpleCommandParser::CSimpleCommandParser(const QStringList &knownCommands)
     {
         this->setCheckedCommandList(knownCommands);
@@ -130,6 +133,53 @@ namespace BlackMisc
         return (p.length() == toMatch.length() && p.startsWith(toMatch, cs));
     }
 
+    void CSimpleCommandParser::registerCommand(const CSimpleCommandParser::CommandHtmlHelp &command)
+    {
+        for (const CommandHtmlHelp &help : as_const(CSimpleCommandParser::s_commands))
+        {
+            // avoid duplicates
+            if (help.command == command.command) { return; }
+        }
+        CSimpleCommandParser::s_commands.append(command);
+    }
+
+    bool CSimpleCommandParser::registered(const QString &helpContext)
+    {
+        if (CSimpleCommandParser::s_registered.contains(helpContext)) { return true; };
+        CSimpleCommandParser::s_registered.insert(helpContext);
+        return false;
+    }
+
+    QString CSimpleCommandParser::commandsHtmlHelp()
+    {
+        if (CSimpleCommandParser::s_commands.isEmpty()) { return ""; }
+
+        static const QString html("<table style=\"font-size: 8pt; white-space: nowrap;\">\n%1\n</table>");
+        static const QString row("<td>%1</td><td>%2</td>");
+
+        QString rows;
+        QList<CommandHtmlHelp> cmds(CSimpleCommandParser::s_commands);
+        qSort(cmds.begin(), cmds.end(), CommandHtmlHelp::less);
+        for (int i = 0; i < cmds.size(); i++)
+        {
+            CommandHtmlHelp help = cmds[i];
+            rows += "<tr>";
+            rows += row.arg(help.command, help.help);
+            i++;
+            if (i < cmds.size())
+            {
+                help = cmds[i];
+                rows += row.arg(help.command, help.help);
+            }
+            else
+            {
+                rows += row.arg("", "");
+            }
+            rows += "</tr>\n";
+        }
+        return html.arg(rows);
+    }
+
     QString CSimpleCommandParser::removeLeadingDot(const QString &candidate)
     {
         if (!candidate.startsWith('.')) { return candidate; }
diff --git a/src/blackmisc/simplecommandparser.h b/src/blackmisc/simplecommandparser.h
index 03a95cfc6..e402e275b 100644
--- a/src/blackmisc/simplecommandparser.h
+++ b/src/blackmisc/simplecommandparser.h
@@ -76,6 +76,33 @@ namespace BlackMisc
         //! Matches given part
         bool matchesPart(int index, const QString &toMatch, Qt::CaseSensitivity cs = Qt::CaseInsensitive) const;
 
+        //! Help info
+        struct CommandHtmlHelp
+        {
+            QString command; //!< command
+            QString help;    //!< help text
+
+            //! Constructor
+            CommandHtmlHelp(const QString &command, const QString &help) : command(command), help(help)
+            { }
+
+            //! Compare by command
+            static bool less(const CommandHtmlHelp &a, const CommandHtmlHelp &b)
+            {
+                // may want to check that the pointers aren't zero...
+                return a.command < b.command;
+            }
+        };
+
+        //! Register a command
+        static void registerCommand(const CommandHtmlHelp &command);
+
+        //! Help already registered
+        static bool registered(const QString &helpContext);
+
+        //! HTML commans HELP
+        static QString commandsHtmlHelp();
+
     private:
         QString m_originalLine;      //!< line as entered by user
         QString m_cleanedLine;       //!< trimmed, no double spaces etc.
@@ -84,6 +111,9 @@ namespace BlackMisc
         QStringList m_knownCommands; //!< known / handled commands
         bool m_knownCommand = false; //!< known command
 
+        static QList<CommandHtmlHelp> s_commands; //!< all registered commands
+        static QSet<QString> s_registered; //!< registered commands
+
         //! Avoid wrong usage
         void setCheckedCommandList(const QStringList &commands);