src/qml/qml/qqmlabstractbinding.cpp

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  41
  42 #include "qqmlabstractbinding_p.h"
  43
  44 #include <QtQml/qqmlinfo.h>
  45 #include <private/qqmlbinding_p.h>
  46 #include <private/qqmlvaluetypeproxybinding_p.h>
  47
  48 QT_BEGIN_NAMESPACE
  49
  50 extern QQmlAbstractBinding::VTable QQmlBinding_vtable;
  51 extern QQmlAbstractBinding::VTable QQmlValueTypeProxyBinding_vtable;
  52 extern QQmlAbstractBinding::VTable QV4Bindings_Binding_vtable;
  53 extern QQmlAbstractBinding::VTable QV8Bindings_Binding_vtable;
  54
  55 QQmlAbstractBinding::VTable *QQmlAbstractBinding::vTables[] = {
  56     &QQmlBinding_vtable,
  57     &QV4Bindings_Binding_vtable,
  58     &QV8Bindings_Binding_vtable,
  59     &QQmlValueTypeProxyBinding_vtable
  60 };
  61
  62 QQmlAbstractBinding::QQmlAbstractBinding(BindingType bt)
  63 : m_nextBindingPtr(bt)
  64 {
  65     Q_ASSERT(bt <= 0x03);
  66 }
  67
  68 QQmlAbstractBinding::~QQmlAbstractBinding()
  69 {
  70     Q_ASSERT(isAddedToObject() == false);
  71     Q_ASSERT(nextBinding() == 0);
  72     Q_ASSERT(*m_mePtr == 0);
  73 }
  74
  75 /*!
  76 Add this binding to \a object.
  77
  78 This transfers ownership of the binding to the object, marks the object's property as
  79 being bound.
  80
  81 However, it does not enable the binding itself or call update() on it.
  82 */
  83 void QQmlAbstractBinding::addToObject()
  84 {
  85     Q_ASSERT(!nextBinding());
  86     Q_ASSERT(isAddedToObject() == false);
  87
  88     QObject *obj = object();
  89     Q_ASSERT(obj);
  90
  91     int index = propertyIndex();
  92
  93     QQmlData *data = QQmlData::get(obj, true);
  94
  95     if (index & 0xFFFF0000) {
  96         // Value type
  97
  98         int coreIndex = index & 0x0000FFFF;
  99
 100         // Find the value type proxy (if there is one)
 101         QQmlValueTypeProxyBinding *proxy = 0;
 102         if (data->hasBindingBit(coreIndex)) {
 103             QQmlAbstractBinding *b = data->bindings;
 104             while (b && b->propertyIndex() != coreIndex)
 105                 b = b->nextBinding();
 106             Q_ASSERT(b && b->bindingType() == QQmlAbstractBinding::ValueTypeProxy);
 107             proxy = static_cast<QQmlValueTypeProxyBinding *>(b);
 108         }
 109
 110         if (!proxy) {
 111             proxy = new QQmlValueTypeProxyBinding(obj, coreIndex);
 112
 113             Q_ASSERT(proxy->propertyIndex() == coreIndex);
 114             Q_ASSERT(proxy->object() == obj);
 115
 116             proxy->addToObject();
 117         }
 118
 119         setNextBinding(proxy->m_bindings);
 120         proxy->m_bindings = this;
 121
 122     } else {
 123         setNextBinding(data->bindings);
 124         data->bindings = this;
 125
 126         data->setBindingBit(obj, index);
 127     }
 128
 129     setAddedToObject(true);
 130 }
 131
 132 /*!
 133 Remove the binding from the object.
 134 */
 135 void QQmlAbstractBinding::removeFromObject()
 136 {
 137     if (isAddedToObject()) {
 138         QObject *obj = object();
 139         int index = propertyIndex();
 140
 141         QQmlData *data = QQmlData::get(obj, false);
 142         Q_ASSERT(data);
 143
 144         if (index & 0xFFFF0000) {
 145
 146             // Find the value type binding
 147             QQmlAbstractBinding *vtbinding = data->bindings;
 148             while (vtbinding->propertyIndex() != (index & 0x0000FFFF)) {
 149                 vtbinding = vtbinding->nextBinding();
 150                 Q_ASSERT(vtbinding);
 151             }
 152             Q_ASSERT(vtbinding->bindingType() == QQmlAbstractBinding::ValueTypeProxy);
 153
 154             QQmlValueTypeProxyBinding *vtproxybinding =
 155                 static_cast<QQmlValueTypeProxyBinding *>(vtbinding);
 156
 157             QQmlAbstractBinding *binding = vtproxybinding->m_bindings;
 158             if (binding == this) {
 159                 vtproxybinding->m_bindings = nextBinding();
 160             } else {
 161                while (binding->nextBinding() != this) {
 162                   binding = binding->nextBinding();
 163                   Q_ASSERT(binding);
 164                }
 165                binding->setNextBinding(nextBinding());
 166             }
 167
 168             // Value type - we don't remove the proxy from the object.  It will sit their happily
 169             // doing nothing until it is removed by a write, a binding change or it is reused
 170             // to hold more sub-bindings.
 171
 172         } else {
 173
 174             if (data->bindings == this) {
 175                 data->bindings = nextBinding();
 176             } else {
 177                 QQmlAbstractBinding *binding = data->bindings;
 178                 while (binding->nextBinding() != this) {
 179                     binding = binding->nextBinding();
 180                     Q_ASSERT(binding);
 181                 }
 182                 binding->setNextBinding(nextBinding());
 183             }
 184
 185             data->clearBindingBit(index);
 186         }
 187
 188         setNextBinding(0);
 189         setAddedToObject(false);
 190     }
 191 }
 192
 193 void QQmlAbstractBinding::printBindingLoopError(QQmlProperty &prop)
 194 {
 195     qmlInfo(prop.object()) << QString(QLatin1String("Binding loop detected for property \"%1\"")).arg(prop.name());
 196 }
 197
 198
 199 static void bindingDummyDeleter(QQmlAbstractBinding *)
 200 {
 201 }
 202
 203 QQmlAbstractBinding::Pointer QQmlAbstractBinding::weakPointer()
 204 {
 205     if (m_mePtr.value().isNull())
 206         m_mePtr.value() = QSharedPointer<QQmlAbstractBinding>(this, bindingDummyDeleter);
 207
 208     return m_mePtr.value().toWeakRef();
 209 }
 210
 211 void QQmlAbstractBinding::clear()
 212 {
 213     if (!m_mePtr.isNull()) {
 214         **m_mePtr = 0;
 215         m_mePtr = 0;
 216     }
 217 }
 218
 219 void QQmlAbstractBinding::default_retargetBinding(QQmlAbstractBinding *, QObject *, int)
 220 {
 221     qFatal("QQmlAbstractBinding::retargetBinding() called on illegal binding.");
 222 }
 223
 224 QString QQmlAbstractBinding::default_expression(const QQmlAbstractBinding *)
 225 {
 226     return QLatin1String("<Unknown>");
 227 }
 228
 229 QT_END_NAMESPACE