juce/source/src/containers/juce_Value.cpp

   1 /*
   2   ==============================================================================
   3
   4    This file is part of the JUCE library - "Jules' Utility Class Extensions"
   5    Copyright 2004-11 by Raw Material Software Ltd.
   6
   7   ------------------------------------------------------------------------------
   8
   9    JUCE can be redistributed and/or modified under the terms of the GNU General
  10    Public License (Version 2), as published by the Free Software Foundation.
  11    A copy of the license is included in the JUCE distribution, or can be found
  12    online at www.gnu.org/licenses.
  13
  14    JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
  15    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  16    A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  17
  18   ------------------------------------------------------------------------------
  19
  20    To release a closed-source product which uses JUCE, commercial licenses are
  21    available: visit www.rawmaterialsoftware.com/juce for more information.
  22
  23   ==============================================================================
  24 */
  25
  26 #include "../core/juce_StandardHeader.h"
  27
  28 BEGIN_JUCE_NAMESPACE
  29
  30 #include "juce_Value.h"
  31
  32 //==============================================================================
  33 Value::ValueSource::ValueSource()
  34 {
  35 }
  36
  37 Value::ValueSource::~ValueSource()
  38 {
  39 }
  40
  41 void Value::ValueSource::sendChangeMessage (const bool synchronous)
  42 {
  43     if (synchronous)
  44     {
  45         // (hold a local reference to this object in case it's freed during the callbacks)
  46         const ReferenceCountedObjectPtr<ValueSource> localRef (this);
  47
  48         for (int i = valuesWithListeners.size(); --i >= 0;)
  49         {
  50             Value* const v = valuesWithListeners[i];
  51
  52             if (v != nullptr)
  53                 v->callListeners();
  54         }
  55     }
  56     else
  57     {
  58         triggerAsyncUpdate();
  59     }
  60 }
  61
  62 void Value::ValueSource::handleAsyncUpdate()
  63 {
  64     sendChangeMessage (true);
  65 }
  66
  67 //==============================================================================
  68 class SimpleValueSource  : public Value::ValueSource
  69 {
  70 public:
  71     SimpleValueSource()
  72     {
  73     }
  74
  75     SimpleValueSource (const var& initialValue)
  76         : value (initialValue)
  77     {
  78     }
  79
  80     var getValue() const
  81     {
  82         return value;
  83     }
  84
  85     void setValue (const var& newValue)
  86     {
  87         if (! newValue.equalsWithSameType (value))
  88         {
  89             value = newValue;
  90             sendChangeMessage (false);
  91         }
  92     }
  93
  94 private:
  95     var value;
  96
  97     JUCE_DECLARE_NON_COPYABLE (SimpleValueSource);
  98 };
  99
 100
 101 //==============================================================================
 102 Value::Value()
 103     : value (new SimpleValueSource())
 104 {
 105 }
 106
 107 Value::Value (ValueSource* const value_)
 108     : value (value_)
 109 {
 110     jassert (value_ != nullptr);
 111 }
 112
 113 Value::Value (const var& initialValue)
 114     : value (new SimpleValueSource (initialValue))
 115 {
 116 }
 117
 118 Value::Value (const Value& other)
 119     : value (other.value)
 120 {
 121 }
 122
 123 Value& Value::operator= (const Value& other)
 124 {
 125     value = other.value;
 126     return *this;
 127 }
 128
 129 Value::~Value()
 130 {
 131     if (listeners.size() > 0)
 132         value->valuesWithListeners.removeValue (this);
 133 }
 134
 135 //==============================================================================
 136 var Value::getValue() const
 137 {
 138     return value->getValue();
 139 }
 140
 141 Value::operator var() const
 142 {
 143     return getValue();
 144 }
 145
 146 void Value::setValue (const var& newValue)
 147 {
 148     value->setValue (newValue);
 149 }
 150
 151 String Value::toString() const
 152 {
 153     return value->getValue().toString();
 154 }
 155
 156 Value& Value::operator= (const var& newValue)
 157 {
 158     value->setValue (newValue);
 159     return *this;
 160 }
 161
 162 void Value::referTo (const Value& valueToReferTo)
 163 {
 164     if (valueToReferTo.value != value)
 165     {
 166         if (listeners.size() > 0)
 167         {
 168             value->valuesWithListeners.removeValue (this);
 169             valueToReferTo.value->valuesWithListeners.add (this);
 170         }
 171
 172         value = valueToReferTo.value;
 173         callListeners();
 174     }
 175 }
 176
 177 bool Value::refersToSameSourceAs (const Value& other) const
 178 {
 179     return value == other.value;
 180 }
 181
 182 bool Value::operator== (const Value& other) const
 183 {
 184     return value == other.value || value->getValue() == other.getValue();
 185 }
 186
 187 bool Value::operator!= (const Value& other) const
 188 {
 189     return value != other.value && value->getValue() != other.getValue();
 190 }
 191
 192 //==============================================================================
 193 void Value::addListener (ValueListener* const listener)
 194 {
 195     if (listener != nullptr)
 196     {
 197         if (listeners.size() == 0)
 198             value->valuesWithListeners.add (this);
 199
 200         listeners.add (listener);
 201     }
 202 }
 203
 204 void Value::removeListener (ValueListener* const listener)
 205 {
 206     listeners.remove (listener);
 207
 208     if (listeners.size() == 0)
 209         value->valuesWithListeners.removeValue (this);
 210 }
 211
 212 void Value::callListeners()
 213 {
 214     Value v (*this); // (create a copy in case this gets deleted by a callback)
 215     listeners.call (&ValueListener::valueChanged, v);
 216 }
 217
 218 OutputStream& JUCE_CALLTYPE operator<< (OutputStream& stream, const Value& value)
 219 {
 220     return stream << value.toString();
 221 }
 222
 223 END_JUCE_NAMESPACE