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/commandoption.cpp

@@ -0,0 +1,100 @@
+// 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/>.
+
+#include "commandoption.h"
+
+CommandOption::CommandOption(const QString &name, const QString &description,
+                             const QString &valueName,
+                             const QString &defaultValue) :
+    m_names(name), m_description(description), m_valueName(valueName),
+    m_value(defaultValue)
+{
+    m_checker = [](QString const&){ return true; };
+}
+
+CommandOption::CommandOption(const QStringList &names,
+                             const QString &description,
+                             const QString &valueName,
+                             const QString &defaultValue) :
+    m_names(names), m_description(description), m_valueName(valueName),
+    m_value(defaultValue)
+{
+    m_checker = [](QString const&) -> bool { return true; };
+}
+
+void CommandOption::setName(const QString &name) {
+    m_names = QStringList() << name;
+}
+
+void CommandOption::setNames(const QStringList &names) {
+    m_names = names;
+}
+
+QStringList CommandOption::names() const {
+    return m_names;
+}
+
+void CommandOption::setValueName(const QString &name) {
+    m_valueName = name;
+}
+
+QString CommandOption::valueName() const {
+    return m_valueName;
+}
+
+void CommandOption::setValue(const QString &value) {
+    if (m_valueName.isEmpty()) {
+        m_valueName = "value";
+    }
+    m_value = value;
+}
+
+QString CommandOption::value() const {
+    return m_value;
+}
+
+void CommandOption::addChecker(const function<bool (const QString &)> checker,
+                               const QString &errMsg)
+{
+    m_checker = checker;
+    m_errorMsg = errMsg;
+}
+
+bool CommandOption::checkValue(const QString &value) const {
+    return m_checker(value);
+}
+
+QString CommandOption::description() const
+{
+    return m_description;
+}
+
+void CommandOption::setDescription(const QString &description)
+{
+    m_description = description;
+}
+
+QString CommandOption::errorMsg() const {
+    return m_errorMsg;
+}
+
+bool CommandOption::operator ==(const CommandOption &option) const
+{
+    return m_description == option.m_description
+            && m_names == option.m_names
+            && m_valueName == option.m_valueName;
+}