[libcalamares] Add some debugging Jobs

- FailJob always fails, and GoodJob always succeeds, both without doing
   anything. These aren't particularly useful, except for debugging.

src/libcalamares/CMakeLists.txt

@@ -16,6 +16,7 @@ set( libSources
     CppJob.cpp
     GlobalStorage.cpp
     Job.cpp
+    JobExample.cpp
     JobQueue.cpp
     ProcessJob.cpp
     Settings.cpp

src/libcalamares/JobExample.cpp

@@ -0,0 +1,42 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot.org>
+ *
+ *   Calamares 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.
+ *
+ *   Calamares 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 Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "JobExample.h"
+
+namespace Calamares
+{
+
+QString
+NamedJob::prettyName() const
+{
+    return tr( "Example job (%1)" ).arg( m_name );
+}
+
+JobResult
+GoodJob::exec()
+{
+    return JobResult::ok();
+}
+
+JobResult
+FailJob::exec()
+{
+    return JobResult::error( tr( "Job failed (%1)" ).arg( m_name ), tr( "Programmed job failure was explicitly requested." ) );
+}
+
+}  // namespace

src/libcalamares/JobExample.h

@@ -0,0 +1,73 @@
+/* === This file is part of Calamares - <https://github.com/calamares> ===
+ *
+ *   Copyright 2019, Adriaan de Groot <groot.org>
+ *
+ *   Calamares 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.
+ *
+ *   Calamares 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 Calamares. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef CALAMARES_JOB_EXAMPLE_H
+#define CALAMARES_JOB_EXAMPLE_H
+
+#include "Job.h"
+
+namespace Calamares {
+
+/** @brief A Job with a name
+ *
+ * This includes a default implementation of prettyName(),
+ * but is only used as a base for FailJob and GoodJob,
+ * which are support / bogus classes.
+ */
+class DLLEXPORT NamedJob : public Job
+{
+public:
+    explicit NamedJob( const QString& name, QObject* parent = nullptr )
+        : Job( parent )
+        , m_name( name )
+    {
+    }
+
+    virtual QString prettyName() const override;
+protected:
+    const QString m_name;
+} ;
+
+/// @brief Job does nothing, always succeeds
+class DLLEXPORT GoodJob : public NamedJob
+{
+public:
+    explicit GoodJob( const QString& name, QObject* parent = nullptr )
+        : NamedJob( name, parent )
+    {
+    }
+
+    virtual JobResult exec() override;
+} ;
+
+
+/// @brief Job does nothing, always fails
+class DLLEXPORT FailJob : public NamedJob
+{
+public:
+    explicit FailJob( const QString& name, QObject* parent = nullptr )
+        : NamedJob( name, parent )
+    {
+    }
+
+    virtual JobResult exec() override;
+} ;
+
+} // namespace Calamares
+
+#endif // CALAMARES_JOB_EXAMPLE_H