Added rough QSettings support

tests/QBind/QBind.pro

@@ -52,6 +52,7 @@ HEADERS += \
     QBind_impl.h \
     QCbor_impl.h \
     QJson_impl.h \
+    QSettings_impl.h \
     QVariant_impl.h \
     QModel_impl.h \
     QData_impl.h \
@@ -62,4 +63,5 @@ DISTFILES += \
     README.md \
     design.md \
     persons.proto \
+    sample.ini \
     samples.txt

tests/QBind/QSettings_impl.h

+/****************************************************************************
+ * **
+ * ** Copyright (C) 2017 MinMaxMedical.
+ * ** All rights reserved.
+ * ** Contact: MinMaxMedical <InCAS@MinMaxMedical.com>
+ * **
+ * ** This file is part of the modmedLog module.
+ * **
+ * ** $QT_BEGIN_LICENSE:BSD$
+ * ** You may use this file under the terms of the BSD license as follows:
+ * **
+ * ** "Redistribution and use in source and binary forms, with or without
+ * ** modification, are permitted provided that the following conditions are
+ * ** met:
+ * **   * Redistributions of source code must retain the above copyright
+ * **     notice, this list of conditions and the following disclaimer.
+ * **   * Redistributions in binary form must reproduce the above copyright
+ * **     notice, this list of conditions and the following disclaimer in
+ * **     the documentation and/or other materials provided with the
+ * **     distribution.
+ * **   * Neither the name of MinMaxMedical S.A.S. and its Subsidiary(-ies) nor
+ * **     the names of its contributors may be used to endorse or promote
+ * **     products derived from this software without specific prior written
+ * **     permission.
+ * **
+ * ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+ * ** $QT_END_LICENSE$
+ * **
+ * ****************************************************************************/
+#pragma once
+
+#include <QtCore/qsettings.h>
+#include <QtCore/qvariant.h>
+#include <QtCore/qstack.h>
+
+#include "QBind_impl.h"
+
+// //////////////////////////////////////////////////////////////////////////
+// QBind<T,QVariant*> support for the fixed set of QSettingsWriter's BindNative types
+
+class QSettingsWriter : public IWriter
+{
+    Q_DISABLE_COPY(QSettingsWriter)
+public:
+    QSettingsWriter(QSettings* s) : settings(s) { Q_ASSERT(s); levels.push(Level("")); }
+
+    // Shortcuts
+    /**/             Val<Cursor> value   (                  ) { return Cursor(this).value(); }
+    /**/             Seq<Cursor> sequence(quint32* s=nullptr) { return Cursor(this).value().sequence            ( s); }
+    template<typename T> Cursor  bind    (             T&& t) { return Cursor(this).value().bind(std::forward<T>(t)); }
+protected:
+    template<typename T>
+    bool _bind    (        T&& t) { settings->setValue(key(), QVariant::fromValue(t) ); return true; }
+    bool _bind    (   quint8&& t) { settings->setValue(key(), QVariant       (int(t))); return true; }
+    bool _bind    (  quint16&& t) { settings->setValue(key(), QVariant       (int(t))); return true; }
+    bool _bind    (  quint32&& t) { settings->setValue(key(), QVariant       (int(t))); return true; }
+    bool _bind    (const char* u) { settings->setValue(key(), QVariant           (u) ); return true; }
+    bool _null    (             ) { settings->setValue(key(), QVariant           ( ) ); return true; }
+
+    bool _sequence(quint32* =nullptr) { settings->beginGroup(key()); levels.push(Level(  )); return true; }
+    bool _record  (quint32* =nullptr) { settings->beginGroup(key()); levels.push(Level("")); return true; }
+
+    bool _item(QName n) { levels.last().key=n; return true; }
+    bool _item(       ) { levels.last().idx++; return true; }
+    bool _out (       ) { levels.pop (); settings->endGroup(); return true; }
+private:
+    QString key() {
+        Q_ASSERT(!levels.isEmpty());
+        return levels.last().key!=nullptr
+            ? QString        (levels.last().key)
+            : QString::number(levels.last().idx);
+    }
+
+    QSettings* settings;
+    struct Level { QName key; quint32 idx=0; Level(QName k=nullptr) : key(k) {} };
+    QStack<Level> levels = QStack<Level>(); //!< minimal dynamic context to implement out() and ensure actual building in case QSettingsWriter is abandoned
+};
+
+// --------------------------------------------------------------------------
+
+class QSettingsReader : public IReader
+{
+    Q_DISABLE_COPY(QSettingsReader)
+public:
+    Q_ENABLE_MOVE(QSettingsReader, std::swap(isChoice, o.isChoice); )
+    QSettingsReader(QSettings* s) : settings(s) { Q_ASSERT(s); levels.push(Level("")); }
+
+    struct Error { const char* error; QUtf8String path; template<class T> T bind(Val<T>&& value) { return value.bind(QUtf8String(error)+' '+path); } };
+    QVector<Error> errors;
+
+    QUtf8String currentPath() {
+        QUtf8String path;
+        Q_FOREACH(Level l, levels) {
+            if (l.key) { path.append('/').append(                    l.key ); }
+            else       { path.append('/').append(QUtf8String::number(l.idx)); }
+        }
+        return path;
+    }
+
+    // Shortcuts
+    template<typename T> Cursor bind(T&& t) { return Cursor(this).value().bind(std::forward<T>(t)); }
+protected:
+    template<typename T>
+    bool _bind(T& t) { return set(t, "Expected declared metatype T"); }
+
+    bool _bind(QUtf8String& t) { return set(t, qBindExpectedText   ); }
+    bool _bind(    QString& t) { return set(t, qBindExpectedText   ); }
+    bool _bind(       bool& t) { return set(t, qBindExpectedBoolean); }
+    bool _bind( QByteArray& t) { return set(t, qBindExpectedBytes  ); }
+    // Convert numerical types to strictly larger ones // TODO convert all compatible values
+    bool _bind(      qint8& t) { return set(t, qBindExpectedInteger       ); }
+    bool _bind(     qint16& t) { return set(t, qBindExpectedInteger       ); }
+    bool _bind(     qint32& t) { return set(t, qBindExpectedInteger       ); }
+    bool _bind(     qint64& t) { return set(t, qBindExpectedInteger       ); }
+    bool _bind(     quint8& t) { return set(t, qBindExpectedPositiveNumber); }
+    bool _bind(    quint16& t) { return set(t, qBindExpectedPositiveNumber); }
+    bool _bind(    quint32& t) { return set(t, qBindExpectedPositiveNumber); }
+    bool _bind(    quint64& t) { return set(t, qBindExpectedPositiveNumber); }
+    bool _bind(      float& t) { return set(t, qBindExpectedDecimal       ); }
+    bool _bind(     double& t) { return set(t, qBindExpectedDecimal       ); }
+
+    bool _sequence(quint32* =nullptr) { if (levels.last().isGroup) { levels.push(Level(  )); return true; } _reportError(qBindExpectedSequence); return false; }
+    bool _record  (quint32* =nullptr) { if (levels.last().isGroup) { levels.push(Level("")); return true; } _reportError(qBindExpectedRecord  ); return false; }
+    bool _null    (                 ) { if (settings->value(key()).isNull())               { return true; } _reportError(qBindExpectedNull    ); return false; }
+
+    bool _item(QUtf8String& k) { levels.last().key=k;                return true; }
+    bool _item(              ) { levels.last().idx++;                return true; }
+    bool _out (              ) { levels.pop(); settings->endGroup(); return true; }
+
+    bool _isOk() { return settings; }
+    void _setChoice(bool v) { isChoice=v; }
+    void _reportError(const char* error) { if (!isChoice) errors.append(Error{ error, currentPath() }); }
+private:
+    template<typename T>
+    bool set(T& t, const char* error) { QVariant v = settings->value(key()); if (v.convert(qMetaTypeId<T>())) { t = v.value<T>(); return true; } _reportError(error); return false; }
+    QString key() {
+        Q_ASSERT(!levels.isEmpty());
+        return levels.last().key!=nullptr
+            ? QString        (levels.last().key)
+            : QString::number(levels.last().idx);
+    }
+
+    QSettings* settings;
+    struct Level { QName key; int idx=-1; bool isGroup=true; Level(QName n=nullptr, bool isGroup=true) : key(n), isGroup(isGroup) {} };
+    QStack<Level> levels;
+    bool isChoice = false;
+};

tests/QBind/README.md

@@ -3,7 +3,7 @@
 QBind was developed to demonstrate the feasibility and advantages of a novel (de)serialization mechanism on top of
 existing [Qt](http://qt.io) data formats (Settings, QDataStream, Json, Cbor, Xml) and generic data types (containers, QVariant, QMetaObject, etc.).
 
-> **DISLAIMER** It is not currently unit-tested but only provided with a [sample and benchmark](main.cpp). Also, the 
+> **DISLAIMER** It is not currently unit-tested but provided with a [sample and benchmark](main.cpp). Also, the
 > implementation is written in a concise style that supported the multiple refactorings but does not help explaining it.
 > The README and [design](design.md) documentation should be read before trying to understand the implementation.
 
@@ -45,7 +45,7 @@ See below:
 * **W4. Format can be changed at runtime**
   (a compiled tracepoint in a library must be able to generate Json or Cbor as desired by library user)
 * **W5. Good support of Qt data**:
-  1. almost all features of simple data (QJson..., QDataStream, *QSettings (TBD)*)
+  1. almost all features of simple data (QJson..., QDataStream, QSettings)
   2. most features of complex data (QCbor..., QXml..., QMetaObject, QModel...)
 * **W6. No restriction on output data size**
   (some restrictions may apply with specific implementations that may, e.g. store context for each data structure levels)
@@ -75,7 +75,7 @@ for data formats supporting it like [CBOR value sharing tags](http://cbor.schmor
 
 ## The key idea
 
-QBind is more general than (de)serialization and should be understood as a generic way to traverse[^1] a C++ dataset along with 
+QBind is more general than (de)serialization and should be understood as a generic way to traverse[^1] a C++ dataset and
 another generic dataset, binding the related parts together. In effect:
 * the traversal may be partial, leaving out unrelated dataset parts (satisfying R2)
 * the same traversal may be used to:

tests/QBind/main.cpp

@@ -52,6 +52,7 @@
 #include "QVariant_impl.h"  // QVariantBuilder, QVariantVisitor and QBind<QVariant,_> support
 #include "QModel_impl.h"    // Q*ModelWriter support
 #include "QXml_impl.h"      // QXmlWriter support
+#include "QSettings_impl.h" // QSettings* support
 
 #ifdef PROTOBUF
 #include "persons.pb.h"
@@ -944,6 +945,31 @@ int main(int argc, char *argv[])
         STOP("Cbor>Json",QString(b.buffer()+" | "+Text(readerErrors)))
     }
     GROUP_STOP
+    GROUP("Person<>Settings")//====================================================
+    {
+        QFileInfo iniFile(QDir::currentPath()+"/../QBind");
+        QSettings::setPath(QSettings::IniFormat,QSettings::UserScope,iniFile.path());
+        QSettings   ini(QSettings::IniFormat,QSettings::UserScope,"QBind","sample");
+        QSettings   nat(                     QSettings::UserScope,"QBind","sample");
+        QVector<QSettingsReader::Error> errors;
+        //---------------------------------------------------------------------
+        START {
+            QSettingsWriter(&nat).bind(person);
+        }
+        STOP("P>Settings",QString(Text(person)))
+        START {
+            QSettingsReader r(&nat);
+            r.bind(person);
+            errors = r.errors;
+        }
+        STOP("Settings>P",QString(Text(person)+" | "+Text(errors)))
+        START {
+            QSettingsWriter(&ini).bind(person);
+        }
+        STOP("P>Settings",iniFile.fileName())
+        //---------------------------------------------------------------------
+    }
+    GROUP_STOP
 
     if (argc<=1 || strcmp(argv[1],"gui")==0) {
         doGuiExample();

tests/QBind/sample.ini

+[names]
+1=John
+2=Doe
+
+[General]
+height=1.75
+age=18
+comments=unicode is likely U+01 \x1 + U+1F \x1f + U+A4 \xa4 U+B0 \xb0 U+D8 \xd8 U+FF \xff

tests/QBind/samples.txt

@@ -73,3 +73,7 @@ CborValue>P   |(Person)[ names:[ John Doe] height:1.75 age:-1 phones:[] comments
 Cbor>CborValue|{"names": ["John", "Doe"], "height": 1.75, "age": -1, "phones": [], "comments": "", "children": []} | []
 CborValue>Cbor|a6656e616d657382644a6f686e63446f6566686569676874fb3ffc00000000000063616765206670686f6e65738068636f6d6d656e747360686368696c6472656e80
 Cbor>Json     |{"names":["John","Doe"],"height":1.75,"age":} | []
+Person<>Settings |================================================================================
+P>Settings    |(Person)[ names:[ John Doe] height:1.75 age:18 phones:[] comments:unicode is likely U+01 
 + U+1F  + U+A4 ¤ U+B0 ° U+D8 Ø U+FF ÿ children:[]]
+Settings>P    |(Person)[ names:[ John Doe] height:1.75 age:18 phones:[] comments:unicode is likely U+01 
 + U+1F  + U+A4 ¤ U+B0 ° U+D8 Ø U+FF ÿ children:[]] | []
+P>Settings    |QBind