kworship/css/KwCssStyleState.h

   1 /***************************************************************************
   2  *   This file is part of KWorship.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   KWorship 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  *   KWorship 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 KWorship.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 #ifndef _KwCssStyleState_h_
  21 #define _KwCssStyleState_h_
  22
  23 /**
  24  * @file KwCssStyleState.h
  25  * @brief Typed cascading style property state.
  26  * @author James Hogan <james@albanarts.com>
  27  */
  28
  29 #include "KwCssAbstractStyleState.h"
  30 #include "KwCssStyle.h"
  31
  32 #include <QStack>
  33
  34 #include <cassert>
  35
  36 /// Typed cascading style property state.
  37 /**
  38  * @param T The type of the property.
  39  */
  40 template <typename T>
  41 class KwCssStyleState : public KwCssAbstractStyleState
  42 {
  43   public:
  44
  45     /*
  46      * Constructors + destructors
  47      */
  48
  49     /// Default constructor.
  50     KwCssStyleState()
  51     : KwCssAbstractStyleState()
  52     , m_value()
  53     {
  54     }
  55
  56     /// Copy constructor.
  57     KwCssStyleState(const KwCssStyleState& copy)
  58     : KwCssAbstractStyleState(copy)
  59     , m_value(copy.m_value)
  60     {
  61     }
  62
  63     /// Destructor.
  64     virtual ~KwCssStyleState()
  65     {
  66     }
  67
  68     /*
  69      * Main interface
  70      */
  71
  72     /// Create a new style for this state.
  73     virtual KwCssAbstractStyle* createStyle() const
  74     {
  75       return new KwCssStyle<T>;
  76     }
  77
  78     /// Duplicate this style.
  79     virtual KwCssAbstractStyleState* duplicate() const
  80     {
  81       return new KwCssStyleState<T>(*this);
  82     }
  83
  84     T getValue() const
  85     {
  86       if (!m_value.empty())
  87       {
  88         return m_value.back();
  89       }
  90       else
  91       {
  92         return T();
  93       }
  94     }
  95
  96     /*
  97      * Operators
  98      */
  99
 100     /// Apply the style to this state.
 101     virtual KwCssAbstractStyleState& operator << (const KwCssAbstractStyle* style)
 102     {
 103       const KwCssStyle<T>* styleRetyped = dynamic_cast<const KwCssStyle<T>*>(style);
 104       assert(styleRetyped != 0 &&"Bad style type for this style state");
 105
 106       switch (styleRetyped->getOperation())
 107       {
 108         case KwCssStyle<T>::override:
 109         {
 110           m_value.push_back(styleRetyped->getValue());
 111           break;
 112         }
 113         case KwCssStyle<T>::revert:
 114         {
 115           if (m_value.size() != 0)
 116           {
 117             m_value.pop_back();
 118           }
 119           break;
 120         }
 121         case KwCssStyle<T>::clear:
 122         {
 123           m_value.clear();
 124           break;
 125         }
 126         default:
 127         {
 128           // No change
 129           break;
 130         }
 131       }
 132       return *this;
 133     }
 134
 135   private:
 136
 137     /*
 138      * Variables
 139      */
 140
 141     /// Stack of values.
 142     QStack<T> m_value;
 143 };
 144
 145 #endif // _KwCssStyleState_h_
 146