New command line parser

A new, more flexible and restrictive parser to improve the
usage and experience of Flameshot in the command line.
This parser is based on a parent-child node model and is very easy
to define relationships between arguments and options with
informative error checking. You can define lambdas to check the
received values for every option and custom error messages

src/cli/commandlineparser.h

@@ -0,0 +1,94 @@
+// Copyright 2017 Alejandro Sirgo Rica
+//
+// This file is part of Flameshot.
+//
+//     Flameshot is free software: you can redistribute it and/or modify
+//     it under the terms of the GNU General Public License as published by
+//     the Free Software Foundation, either version 3 of the License, or
+//     (at your option) any later version.
+//
+//     Flameshot is distributed in the hope that it will be useful,
+//     but WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//     GNU General Public License for more details.
+//
+//     You should have received a copy of the GNU General Public License
+//     along with Flameshot.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef COMMANDLINEPARSER_H
+#define COMMANDLINEPARSER_H
+
+#include "src/cli/commandargument.h"
+#include "src/cli/commandoption.h"
+#include <QMap>
+
+class CommandLineParser
+{
+public:
+    CommandLineParser();
+
+    bool parse(const QStringList &args);
+
+    CommandArgument rootArgument() const { return CommandArgument(); }
+
+    CommandOption addVersionOption();
+    CommandOption addHelpOption();
+
+    bool AddArgument(const CommandArgument &arg,
+                     const CommandArgument &parent = CommandArgument());
+
+    bool AddOption(const CommandOption &option,
+                     const CommandArgument &parent = CommandArgument());
+
+    bool AddOptions(const QList<CommandOption> &options,
+                     const CommandArgument &parent = CommandArgument());
+
+    void setGeneralErrorMessage(const QString &msg);
+    void setDescription(const QString &description);
+
+    bool isSet(const CommandArgument &arg) const;
+    bool isSet(const CommandOption &option) const;
+    QString value(const CommandOption &option) const;
+
+private:
+    bool m_withHelp = false;
+    bool m_withVersion = false;
+    QString m_description;
+    QString  m_generalErrorMessage;
+
+    struct Node {
+        Node(const CommandArgument &arg) : argument(arg) {}
+        Node() {}
+        bool operator==(const Node &n) const {
+            return argument == n.argument &&
+                    options == n.options &&
+                    subNodes == n.subNodes;
+        }
+        CommandArgument argument;
+        QMap<QStringList, CommandOption> options;
+        QMap<QString, Node> subNodes;
+    };
+
+    Node m_parseTree;
+    QList<CommandOption> m_foundOptions;
+    QList<CommandArgument> m_foundArgs;
+
+    // helper functions
+    inline void printVersion();
+    void printHelp(QStringList args, const Node *node);
+    Node* findParent(const CommandArgument &parent);
+    Node* recursiveParentSearch(const CommandArgument &parent,
+                                Node &node) const;
+    inline bool processIfOptionIsHelp(const QStringList &args,
+                                QStringList::const_iterator &actualIt,
+                                Node * &actualNode);
+    inline bool processArgs(const QStringList &args,
+                            QStringList::const_iterator &actualIt,
+                            Node * &actualNode);
+    bool processOptions(const QStringList &args,
+                        QStringList::const_iterator &actualIt,
+                        Node *const actualNode);
+
+};
+
+#endif // COMMANDLINEPARSER_H