geo/tcLandsatMetaData.h

   1 /***************************************************************************
   2  *   This file is part of Tecorrec.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   Tecorrec is free software: you can redistribute it and/or modify      *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation, either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   Tecorrec is distributed in the hope that it will be useful,           *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with Tecorrec.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 #ifndef _tcLandsatMetaData_h_
  21 #define _tcLandsatMetaData_h_
  22
  23 /**
  24  * @file tcLandsatMetaData.h
  25  * @brief Landsat metadata file.
  26  */
  27
  28 #include <QHash>
  29 #include <QString>
  30 #include <QStringList>
  31 #include <QVariant>
  32
  33 class QFile;
  34
  35 /** Landsat metadata file.
  36  * This aims to be generic enough to read both Landsat 5 and Landsat 7 metadata files.
  37  */
  38 class tcLandsatMetaData
  39 {
  40   public:
  41
  42     /*
  43      * Types
  44      */
  45
  46     /// Nice wrapper class.
  47     class Reference;
  48
  49     /*
  50      * Constructors + destructor
  51      */
  52
  53     /// Load metadata from a file.
  54     tcLandsatMetaData(QFile& file);
  55
  56     /// Destructor.
  57     virtual ~tcLandsatMetaData();
  58
  59     /*
  60      * Accessors
  61      */
  62
  63     /// Get the list of group names.
  64     QStringList groupNames() const;
  65
  66     /// Get the list of object names.
  67     QStringList objectNames() const;
  68
  69     /// Get the number of objects with a particular name.
  70     int numObjects(const QString& name) const;
  71
  72     /// Get the list of value names.
  73     QStringList valueNames() const;
  74
  75     /// Find whether a certain group exists.
  76     bool hasGroup(const QString& name) const;
  77
  78     /// Find whether a certain object exists.
  79     bool hasObject(const QString& name) const;
  80
  81     /// Find whether a certain value exists.
  82     bool hasValue(const QString& name) const;
  83
  84     /// Access a group.
  85     tcLandsatMetaData* group(const QString& name) const;
  86
  87     /// Access an object.
  88     tcLandsatMetaData* object(const QString& name, int index) const;
  89
  90     /// Access a value.
  91     QVariant value(const QString& name) const;
  92
  93   private:
  94
  95     /*
  96      * Variables
  97      */
  98
  99     /// Hash of groups.
 100     QHash<QString, tcLandsatMetaData*> m_groups;
 101
 102     /// Hash of objects.
 103     QHash<QString, QList<tcLandsatMetaData*> > m_objects;
 104
 105     /// Hash of values.
 106     QHash<QString, QVariant> m_values;
 107 };
 108
 109 /// Nice wrapper class.
 110 class tcLandsatMetaData::Reference
 111 {
 112   public:
 113
 114     /*
 115      * Constructors + destructor
 116      */
 117
 118     /// Primary constructor.
 119     Reference(tcLandsatMetaData* metaData = 0)
 120     : m_metaData(metaData)
 121     {
 122     }
 123
 124     /*
 125      * Accessors
 126      */
 127
 128     /// Return whether the reference is valid
 129     bool isValid() const
 130     {
 131       return 0 != m_metaData;
 132     }
 133
 134     /// Return whether the reference is valid
 135     operator bool() const
 136     {
 137       return isValid();
 138     }
 139
 140     /// Find if a group exists.
 141     bool hasGroup(const QString& name) const
 142     {
 143       if (isValid())
 144       {
 145         return m_metaData->hasGroup(name);
 146       }
 147       return false;
 148     }
 149
 150     /// Find if an object exists.
 151     int hasObject(const QString& name) const
 152     {
 153       if (isValid())
 154       {
 155         return m_metaData->numObjects(name);
 156       }
 157       return false;
 158     }
 159
 160     /// Find if a value exists.
 161     bool hasValue(const QString& name) const
 162     {
 163       if (isValid())
 164       {
 165         return m_metaData->hasValue(name);
 166       }
 167       return false;
 168     }
 169
 170     /// Get a reference to a group.
 171     Reference operator () (const QString& name) const
 172     {
 173       if (isValid())
 174       {
 175         return m_metaData->group(name);
 176       }
 177       return 0;
 178     }
 179
 180     /// Get a reference to an object.
 181     Reference operator () (const QString& name, int index) const
 182     {
 183       if (isValid())
 184       {
 185         return m_metaData->object(name, index);
 186       }
 187       return 0;
 188     }
 189
 190     /** Get a value.
 191      * We get an error when using string literals without this extra
 192      * definition. oh well.
 193      */
 194     QVariant operator [] (const char* name) const
 195     {
 196       if (isValid())
 197       {
 198         return m_metaData->value(name);
 199       }
 200       return QVariant();
 201     }
 202
 203     /// Get a value.
 204     QVariant operator [] (const QString& name) const
 205     {
 206       if (isValid())
 207       {
 208         return m_metaData->value(name);
 209       }
 210       return QVariant();
 211     }
 212
 213   private:
 214
 215     /*
 216      * Variables
 217      */
 218
 219     /// Meta data object.
 220     tcLandsatMetaData* m_metaData;
 221 };
 222
 223 #endif
 224