Fact.h

/*=====================================================================
 
 QGroundControl Open Source Ground Control Station
 
 (c) 2009 - 2014 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 
 This file is part of the QGROUNDCONTROL project
 
 QGROUNDCONTROL 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.
 
 QGROUNDCONTROL 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 QGROUNDCONTROL. If not, see <http://www.gnu.org/licenses/>.
 
 ======================================================================*/

/// @file
///     @author Don Gagne <don@thegagnes.com>

#ifndef Fact_H
#define Fact_H

#include "FactMetaData.h"

#include <QObject>
#include <QString>
#include <QVariant>
#include <QDebug>

/// @brief A Fact is used to hold a single value within the system.
class Fact : public QObject
{
    Q_OBJECT
    
public:
    Fact(QObject* parent = NULL);
    Fact(int componentId, QString name, FactMetaData::ValueType_t type, QObject* parent = NULL);
    Fact(const Fact& other, QObject* parent = NULL);

    const Fact& operator=(const Fact& other);

    Q_PROPERTY(int      componentId             READ componentId                            CONSTANT)
    Q_PROPERTY(QString  group                   READ group                                  CONSTANT)
    Q_PROPERTY(QString  name                    READ name                                   CONSTANT)
    Q_PROPERTY(QVariant value                   READ value                  WRITE setValue  NOTIFY valueChanged USER true)
    Q_PROPERTY(QVariant valueString             READ valueString                            NOTIFY valueChanged)
    Q_PROPERTY(QString  units                   READ units                                  CONSTANT)
    Q_PROPERTY(QVariant defaultValue            READ defaultValue                           CONSTANT)
    Q_PROPERTY(QString  defaultValueString      READ defaultValueString                     CONSTANT)
    Q_PROPERTY(bool     defaultValueAvailable   READ defaultValueAvailable                  CONSTANT)
    Q_PROPERTY(bool     valueEqualsDefault      READ valueEqualsDefault                     NOTIFY valueChanged)
    Q_PROPERTY(FactMetaData::ValueType_t type   READ type                                   CONSTANT)
    Q_PROPERTY(QString  shortDescription        READ shortDescription                       CONSTANT)
    Q_PROPERTY(QString  longDescription         READ longDescription                        CONSTANT)
    Q_PROPERTY(QVariant min                     READ min                                    CONSTANT)
    Q_PROPERTY(QString  minString               READ minString                              CONSTANT)
    Q_PROPERTY(bool     minIsDefaultForType     READ minIsDefaultForType                    CONSTANT)
    Q_PROPERTY(QVariant max                     READ max                                    CONSTANT)
    Q_PROPERTY(QString  maxString               READ maxString                              CONSTANT)
    Q_PROPERTY(bool     maxIsDefaultForType     READ maxIsDefaultForType                    CONSTANT)
    Q_PROPERTY(int      decimalPlaces           READ decimalPlaces                          CONSTANT)
    
    /// Convert and validate value
    ///     @param convertOnly true: validate type conversion only, false: validate against meta data as well
    Q_INVOKABLE QString validate(const QString& value, bool convertOnly);
    
    // Property system methods
    
    QString     name(void) const;
    int         componentId(void) const;
    QVariant    value(void) const;
    QString     valueString(void) const;
    QVariant    defaultValue(void) const;
    QString     defaultValueString(void) const;
    bool        defaultValueAvailable(void) const;
    bool        valueEqualsDefault(void) const;
    QString     shortDescription(void) const;
    QString     longDescription(void) const;
    QString     units(void) const;
    QVariant    min(void) const;
    QString     minString(void) const;
    bool        minIsDefaultForType(void) const;
    QVariant    max(void) const;
    QString     maxString(void) const;
    bool        maxIsDefaultForType(void) const;
    QString     group(void) const;
    int         decimalPlaces(void) const;

    FactMetaData::ValueType_t type(void) const;

    void setValue(const QVariant& value);

    /// Sets and sends new value to vehicle even if value is the same
    void forceSetValue(const QVariant& value);
    
    /// Sets the meta data associated with the Fact.
    void setMetaData(FactMetaData* metaData);
    
    void _containerSetValue(const QVariant& value);
    
    /// Generally you should not change the name of a fact. But if you know what you are doing, you can.
    void _setName(const QString& name) { _name = name; }
    
signals:
    /// QObject Property System signal for value property changes
    ///
    /// This signal is only meant for use by the QT property system. It should not be connected to by client code.
    void valueChanged(QVariant value);
    
    /// Signalled when the param write ack comes back from the vehicle
    void vehicleUpdated(QVariant value);
    
    /// Signalled when property has been changed by a call to the property write accessor
    ///
    /// This signal is meant for use by Fact container implementations.
    void _containerValueChanged(const QVariant& value);
    
private:
    QString _variantToString(const QVariant& variant) const;

    QString                     _name;
    int                         _componentId;
    QVariant                    _value;
    FactMetaData::ValueType_t   _type;
    FactMetaData*               _metaData;
};

#endif