[libcalamares] Add support for formatted, table-like output

- Use DebugRow for one-row-at-a-time output with continuations.
 - Use DebugList for one-item-per-line with continuations.
 - Use DebugMap for one-row-at-a-time output of a QVariantMap.

src/libcalamares/utils/Logger.cpp

@@ -177,4 +177,22 @@ CDebug::~CDebug()
 {
 }
 
+const char* continuation = "\n    ";
+
+QString toString( const QVariant& v )
+{
+    auto t = v.type();
+
+    if ( t == QVariant::List )
+    {
+        QStringList s;
+        auto l = v.toList();
+        for ( auto lit = l.constBegin(); lit != l.constEnd(); ++lit )
+            s << lit->toString();
+        return s.join(", ");
+    }
+    else
+        return v.toString();
+}
+
 }  // namespace

src/libcalamares/utils/Logger.h

@@ -2,7 +2,7 @@
  *
  *   Copyright 2010-2011, Christian Muehlhaeuser <muesli@tomahawk-player.org>
  *   Copyright 2014,      Teo Mrnjavac <teo@kde.org>
- *   Copyright 2017, Adriaan de Groot <groot@kde.org>
+ *   Copyright 2017-2018, Adriaan de Groot <groot@kde.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
@@ -27,6 +27,8 @@
 
 namespace Logger
 {
+    extern const char* continuation;
+
     enum
     {
         LOG_DISABLE = 0,
@@ -77,6 +79,97 @@ namespace Logger
      * Practical values are 0, 1, 2, and 6.
      */
     DLLEXPORT void setupLogLevel( unsigned int level );
+
+    /**
+     * @brief Row-oriented formatted logging.
+     *
+     * Use DebugRow to produce multiple rows of 2-column output
+     * in a debugging statement. For instance,
+     *      cDebug() << DebugRow<int,int>(1,12)
+     *               << DebugRow<int,int>(2,24)
+     * will produce a single timestamped debug line with continuations.
+     * Each DebugRow produces one line of output, with the two values.
+     */
+    template<typename T, typename U>
+    struct DebugRow
+    {
+    public:
+        explicit DebugRow(const T& t, const U& u)
+            : first(t)
+            , second(u)
+        {}
+
+        const T& first;
+        const U& second;
+    } ;
+
+    /**
+     * @brief List-oriented formatted logging.
+     *
+     * Use DebugList to produce multiple rows of output in a debugging
+     * statement. For instance,
+     *      cDebug() << DebugList( QStringList() << "foo" << "bar" )
+     * will produce a single timestamped debug line with continuations.
+     * Each element of the list of strings will be logged on a separate line.
+     */
+    struct DebugList
+    {
+        explicit DebugList( const QStringList& l )
+            : list(l)
+        {}
+
+        const QStringList& list;
+    } ;
+
+    /**
+     * @brief Map-oriented formatted logging.
+     *
+     * Use DebugMap to produce multiple rows of output in a debugging
+     * statement from a map. The output is intentionally a bit-yaml-ish.
+     *      cDebug() << DebugMap( map )
+     * will produce a single timestamped debug line with continuations.
+     * The continued lines will have a key (from the map) and a value
+     * on each line.
+     */
+    struct DebugMap
+    {
+    public:
+        explicit DebugMap(const QVariantMap& m)
+            : map( m )
+        {}
+
+        const QVariantMap& map;
+    } ;
+
+    /** @brief output operator for DebugRow */
+    template<typename T, typename U>
+    inline QDebug&
+    operator <<( QDebug& s, const DebugRow<T, U>& t )
+    {
+        s << continuation << t.first << ':' << ' ' << t.second;
+        return s;
+    }
+
+    /** @brief output operator for DebugList */
+    inline QDebug&
+    operator <<( QDebug& s, const DebugList& c )
+    {
+        for( const auto& i : c.list )
+            s << continuation << i;
+        return s;
+    }
+
+    /** @brief supporting method for outputting a DebugMap */
+    QString toString( const QVariant& v );
+
+    /** @brief output operator for DebugMap */
+    inline QDebug&
+    operator <<( QDebug& s, const DebugMap& t )
+    {
+        for ( auto it = t.map.constBegin(); it != t.map.constEnd(); ++it )
+            s << continuation << it.key().toUtf8().constData() << ':' << ' ' << toString( it.value() ).toUtf8().constData();
+        return s;
+    }
 }
 
 #define cDebug Logger::CDebug

src/libcalamaresui/ExecutionViewStep.cpp

@@ -2,6 +2,7 @@
  *
  *   Copyright 2014, Aurélien Gâteau <agateau@kde.org>
  *   Copyright 2014-2015, Teo Mrnjavac <teo@kde.org>
+ *   Copyright 2018, Adriaan de Groot <groot@kde.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
@@ -64,7 +65,7 @@ ExecutionViewStep::ExecutionViewStep( QObject* parent )
     innerLayout->addWidget( m_progressBar );
     innerLayout->addWidget( m_label );
 
-    cDebug() << "QML import paths:" << m_slideShow->engine()->importPathList();
+    cDebug() << "QML import paths:" << Logger::DebugList( m_slideShow->engine()->importPathList() );
 
     connect( JobQueue::instance(), &JobQueue::progress,
              this, &ExecutionViewStep::updateFromJobQueue );

src/modules/welcome/checker/RequirementsChecker.cpp

@@ -1,7 +1,7 @@
 /* === This file is part of Calamares - <https://github.com/calamares> ===
  *
  *   Copyright 2014-2017, Teo Mrnjavac <teo@kde.org>
- *   Copyright 2017, Adriaan de Groot <groot@kde.org>
+ *   Copyright 2017-2018, Adriaan de Groot <groot@kde.org>
  *   Copyright 2017, Gabriel Craciunescu <crazy@frugalware.org>
  *
  *   Calamares is free software: you can redistribute it and/or modify
@@ -100,12 +100,14 @@ RequirementsChecker::RequirementsChecker( QObject* parent )
         if ( m_entriesToCheck.contains( "root" ) )
             isRoot = checkIsRoot();
 
+        using TR = Logger::DebugRow<const char *, bool>;
+
         cDebug() << "RequirementsChecker output:"
-                 << " enoughStorage:" << enoughStorage
+                 << TR("enoughStorage", enoughStorage)
-                 << " enoughRam:" << enoughRam
+                 << TR("enoughRam", enoughRam)
-                 << " hasPower:" << hasPower
+                 << TR("hasPower", hasPower)
-                 << " hasInternet:" << hasInternet
+                 << TR("hasInternet", hasInternet)
-                 << " isRoot:" << isRoot;
+                 << TR("isRoot", isRoot);
 
         QList< PrepareEntry > checkEntries;
         foreach ( const QString& entry, m_entriesToCheck )
@@ -305,7 +307,9 @@ RequirementsChecker::setConfigurationMap( const QVariantMap& configurationMap )
     }
 
     if ( incompleteConfiguration )
-        cWarning() << "RequirementsChecker configuration map:\n" << configurationMap;
+    {
+        cWarning() << "RequirementsChecker configuration map:" << Logger::DebugMap( configurationMap );
+    }
 }