libs/ardour/ardour/configuration_variable.h

   1 /*
   2     Copyright (C) 2000-2007 Paul Davis
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #ifndef __ardour_configuration_variable_h__
  21 #define __ardour_configuration_variable_h__
  22
  23 #include <sstream>
  24 #include <ostream>
  25
  26 #include <pbd/xml++.h>
  27
  28 namespace ARDOUR {
  29
  30 class ConfigVariableBase {
  31   public:
  32         enum Owner {
  33                 Default = 0x1,
  34                 System = 0x2,
  35                 Config = 0x4,
  36                 Session = 0x8,
  37                 Interface = 0x10
  38         };
  39
  40         ConfigVariableBase (std::string str) : _name (str), _owner (Default) {}
  41         virtual ~ConfigVariableBase() {}
  42
  43         std::string name() const { return _name; }
  44         Owner owner() const { return _owner; }
  45
  46         virtual void add_to_node (XMLNode& node) = 0;
  47         virtual bool set_from_node (const XMLNode& node, Owner owner) = 0;
  48
  49         void show_stored_value (const std::string&);
  50         static void set_show_stored_values (bool yn);
  51
  52   protected:
  53         std::string _name;
  54         Owner _owner;
  55         static bool show_stores;
  56
  57         void notify ();
  58         void miss ();
  59 };
  60
  61 template<class T>
  62 class ConfigVariable : public ConfigVariableBase
  63 {
  64   public:
  65         ConfigVariable (std::string str) : ConfigVariableBase (str) {}
  66         ConfigVariable (std::string str, T val) : ConfigVariableBase (str), value (val) {}
  67
  68         virtual bool set (T val, Owner owner) {
  69                 if (val == value) {
  70                         miss ();
  71                         return false;
  72                 }
  73                 value = val;
  74                 _owner = (ConfigVariableBase::Owner)(_owner |owner);
  75                 notify ();
  76                 return true;
  77         }
  78
  79         T get() const {
  80                 return value;
  81         }
  82
  83         void add_to_node (XMLNode& node) {
  84                 std::stringstream ss;
  85                 ss << value;
  86                 show_stored_value (ss.str());
  87                 XMLNode* child = new XMLNode ("Option");
  88                 child->add_property ("name", _name);
  89                 child->add_property ("value", ss.str());
  90                 node.add_child_nocopy (*child);
  91         }
  92
  93         bool set_from_node (const XMLNode& node, Owner owner) {
  94
  95                 if (node.name() == "Config") {
  96
  97                         /* ardour.rc */
  98
  99                         const XMLProperty* prop;
 100                         XMLNodeList nlist;
 101                         XMLNodeConstIterator niter;
 102                         XMLNode* child;
 103
 104                         nlist = node.children();
 105
 106                         for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
 107
 108                                 child = *niter;
 109
 110                                 if (child->name() == "Option") {
 111                                         if ((prop = child->property ("name")) != 0) {
 112                                                 if (prop->value() == _name) {
 113                                                         if ((prop = child->property ("value")) != 0) {
 114                                                                 std::stringstream ss;
 115                                                                 ss << prop->value();
 116                                                                 ss >> value;
 117                                                                 _owner = (ConfigVariableBase::Owner)(_owner |owner);
 118                                                                 return true;
 119                                                         }
 120                                                 }
 121                                         }
 122                                 }
 123                         }
 124
 125                 } else if (node.name() == "Options") {
 126
 127                         /* session file */
 128
 129                         XMLNodeList olist;
 130                         XMLNodeConstIterator oiter;
 131                         XMLNode* option;
 132                         const XMLProperty* opt_prop;
 133
 134                         olist = node.children();
 135
 136                         for (oiter = olist.begin(); oiter != olist.end(); ++oiter) {
 137
 138                                 option = *oiter;
 139
 140                                 if (option->name() == _name) {
 141                                         if ((opt_prop = option->property ("val")) != 0) {
 142                                                 std::stringstream ss;
 143                                                 ss << opt_prop->value();
 144                                                 ss >> value;
 145                                                 _owner = (ConfigVariableBase::Owner)(_owner |owner);
 146                                                 return true;
 147                                         }
 148                                 }
 149                         }
 150                 }
 151
 152                 return false;
 153         }
 154
 155   protected:
 156         virtual T get_for_save() { return value; }
 157         T value;
 158 };
 159
 160 template<class T>
 161 class ConfigVariableWithMutation : public ConfigVariable<T>
 162 {
 163   public:
 164         ConfigVariableWithMutation (std::string name, T val, T (*m)(T))
 165                 : ConfigVariable<T> (name, val), mutator (m) {}
 166
 167         bool set (T val, ConfigVariableBase::Owner owner) {
 168                 if (unmutated_value != val) {
 169                         unmutated_value = val;
 170                         return ConfigVariable<T>::set (mutator (val), owner);
 171                 }
 172                 return false;
 173         }
 174
 175   protected:
 176         virtual T get_for_save() { return unmutated_value; }
 177         T unmutated_value;
 178         T (*mutator)(T);
 179 };
 180
 181 }
 182
 183 #endif /* __ardour_configuration_variable_h__ */