src/qml/qml/qqmlbinding.cpp

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  41
  42 #include "qqmlbinding_p.h"
  43
  44 #include "qqml.h"
  45 #include "qqmlcontext.h"
  46 #include "qqmlinfo.h"
  47 #include "qqmlcompiler_p.h"
  48 #include "qqmldata_p.h"
  49 #include <private/qqmlprofilerservice_p.h>
  50 #include <private/qqmltrace_p.h>
  51 #include <private/qqmlexpression_p.h>
  52 #include <private/qqmlrewrite_p.h>
  53
  54 #include <QVariant>
  55 #include <QtCore/qdebug.h>
  56
  57 QT_BEGIN_NAMESPACE
  58
  59 // Used in qqmlabstractbinding.cpp
  60 QQmlAbstractBinding::VTable QQmlBinding_vtable = {
  61     QQmlAbstractBinding::default_destroy<QQmlBinding>,
  62     QQmlBinding::expression,
  63     QQmlBinding::propertyIndex,
  64     QQmlBinding::object,
  65     QQmlBinding::setEnabled,
  66     QQmlBinding::update,
  67     QQmlBinding::retargetBinding
  68 };
  69
  70 QQmlBinding::Identifier QQmlBinding::Invalid = -1;
  71
  72 QQmlBinding *
  73 QQmlBinding::createBinding(Identifier id, QObject *obj, QQmlContext *ctxt,
  74                                    const QString &url, int lineNumber)
  75 {
  76     if (id < 0)
  77         return 0;
  78
  79     QQmlBinding *rv = 0;
  80
  81     QQmlContextData *ctxtdata = QQmlContextData::get(ctxt);
  82     QQmlEnginePrivate *engine = QQmlEnginePrivate::get(ctxt->engine());
  83     if (engine && ctxtdata && !ctxtdata->url.isEmpty()) {
  84         QQmlTypeData *typeData = engine->typeLoader.getType(ctxtdata->url);
  85         Q_ASSERT(typeData);
  86
  87         if (QQmlCompiledData *cdata = typeData->compiledData()) {
  88             rv = new QQmlBinding(cdata->primitives.at(id), true, obj, ctxtdata, url, lineNumber, 0);
  89         }
  90
  91         typeData->release();
  92     }
  93
  94     return rv;
  95 }
  96
  97 static QQmlJavaScriptExpression::VTable QQmlBinding_jsvtable = {
  98     QQmlBinding::expressionIdentifier,
  99     QQmlBinding::expressionChanged
 100 };
 101
 102 QQmlBinding::QQmlBinding(const QString &str, QObject *obj, QQmlContext *ctxt)
 103 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 104   m_lineNumber(-1), m_columnNumber(-1)
 105 {
 106     setNotifyOnValueChanged(true);
 107     QQmlAbstractExpression::setContext(QQmlContextData::get(ctxt));
 108     setScopeObject(obj);
 109
 110     QQmlRewrite::RewriteBinding rewriteBinding;
 111     QString code = rewriteBinding(str);
 112
 113     m_expression = str.toUtf8();
 114     v8function = evalFunction(context(), obj, code, QString(), 0);
 115 }
 116
 117 QQmlBinding::QQmlBinding(const QString &str, QObject *obj, QQmlContextData *ctxt)
 118 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 119   m_lineNumber(-1), m_columnNumber(-1)
 120 {
 121     setNotifyOnValueChanged(true);
 122     QQmlAbstractExpression::setContext(ctxt);
 123     setScopeObject(obj);
 124
 125     QQmlRewrite::RewriteBinding rewriteBinding;
 126     QString code = rewriteBinding(str);
 127
 128     m_expression = str.toUtf8();
 129     v8function = evalFunction(ctxt, obj, code, QString(), 0);
 130 }
 131
 132 QQmlBinding::QQmlBinding(const QString &str, bool isRewritten, QObject *obj,
 133                          QQmlContextData *ctxt,
 134                          const QString &url, int lineNumber, int columnNumber)
 135 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 136   m_lineNumber(-1), m_columnNumber(-1)
 137 {
 138     setNotifyOnValueChanged(true);
 139     QQmlAbstractExpression::setContext(ctxt);
 140     setScopeObject(obj);
 141
 142     QString code;
 143     if (isRewritten) {
 144         code = str;
 145     } else {
 146         QQmlRewrite::RewriteBinding rewriteBinding;
 147         code = rewriteBinding(str);
 148     }
 149
 150     m_url = url;
 151     m_lineNumber = lineNumber;
 152     m_columnNumber = columnNumber;
 153     m_expression = str.toUtf8();
 154
 155     v8function = evalFunction(ctxt, obj, code, url, lineNumber);
 156 }
 157
 158 /*!
 159     \internal
 160
 161     To avoid exposing v8 in the public API, functionPtr must be a pointer to a v8::Handle<v8::Function>.
 162     For example:
 163         v8::Handle<v8::Function> function;
 164         new QQmlBinding(&function, scope, ctxt);
 165  */
 166 QQmlBinding::QQmlBinding(void *functionPtr, QObject *obj, QQmlContextData *ctxt,
 167                          const QString &url, int lineNumber, int columnNumber)
 168 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 169   m_url(url), m_lineNumber(lineNumber), m_columnNumber(columnNumber)
 170 {
 171     setNotifyOnValueChanged(true);
 172     QQmlAbstractExpression::setContext(ctxt);
 173     setScopeObject(obj);
 174
 175     v8function = qPersistentNew<v8::Function>(*(v8::Handle<v8::Function> *)functionPtr);
 176 }
 177
 178 QQmlBinding::~QQmlBinding()
 179 {
 180     qPersistentDispose(v8function);
 181 }
 182
 183 void QQmlBinding::setEvaluateFlags(EvaluateFlags flags)
 184 {
 185     setRequiresThisObject(flags & RequiresThisObject);
 186 }
 187
 188 QQmlBinding::EvaluateFlags QQmlBinding::evaluateFlags() const
 189 {
 190     return requiresThisObject()?RequiresThisObject:None;
 191 }
 192
 193 void QQmlBinding::setNotifyOnValueChanged(bool v)
 194 {
 195     QQmlJavaScriptExpression::setNotifyOnValueChanged(v);
 196 }
 197
 198 void QQmlBinding::update(QQmlPropertyPrivate::WriteFlags flags)
 199 {
 200     if (!enabledFlag() || !context() || !context()->isValid())
 201         return;
 202
 203     // Check that the target has not been deleted
 204     if (QQmlData::wasDeleted(object()))
 205         return;
 206
 207     QQmlTrace trace("General Binding Update");
 208     trace.addDetail("URL", m_url);
 209     trace.addDetail("Line", m_lineNumber);
 210     trace.addDetail("Column", m_columnNumber);
 211
 212     if (!updatingFlag()) {
 213         QQmlBindingProfiler prof(m_url, m_lineNumber, m_columnNumber, QQmlProfilerService::QmlBinding);
 214         setUpdatingFlag(true);
 215
 216         QQmlAbstractExpression::DeleteWatcher watcher(this);
 217
 218         if (m_core.propType == qMetaTypeId<QQmlBinding *>()) {
 219
 220             int idx = m_core.coreIndex;
 221             Q_ASSERT(idx != -1);
 222
 223             QQmlBinding *t = this;
 224             int status = -1;
 225             void *a[] = { &t, 0, &status, &flags };
 226             QMetaObject::metacall(*m_coreObject, QMetaObject::WriteProperty, idx, a);
 227
 228         } else {
 229             QQmlEnginePrivate *ep = QQmlEnginePrivate::get(context()->engine);
 230             ep->referenceScarceResources();
 231
 232             bool isUndefined = false;
 233
 234             v8::HandleScope handle_scope;
 235             v8::Context::Scope scope(ep->v8engine()->context());
 236             v8::Local<v8::Value> result =
 237                 QQmlJavaScriptExpression::evaluate(context(), v8function, &isUndefined);
 238
 239             trace.event("writing binding result");
 240
 241             bool needsErrorData = false;
 242             if (!watcher.wasDeleted() && !hasError())
 243                 needsErrorData = !QQmlPropertyPrivate::writeBinding(*m_coreObject, m_core, context(),
 244                                                                     this, result, isUndefined, flags);
 245
 246             if (!watcher.wasDeleted()) {
 247
 248                 if (needsErrorData) {
 249                     QUrl url = QUrl(m_url);
 250
 251                     delayedError()->error.setUrl(url);
 252                     delayedError()->error.setLine(m_lineNumber);
 253                     delayedError()->error.setColumn(m_columnNumber);
 254                 }
 255
 256                 if (hasError()) {
 257                     if (!delayedError()->addError(ep)) ep->warning(this->error());
 258                 } else {
 259                     clearError();
 260                 }
 261
 262             }
 263
 264             ep->dereferenceScarceResources();
 265         }
 266
 267         if (!watcher.wasDeleted())
 268             setUpdatingFlag(false);
 269     } else {
 270         QQmlProperty p = property();
 271         QQmlAbstractBinding::printBindingLoopError(p);
 272     }
 273 }
 274
 275 QVariant QQmlBinding::evaluate()
 276 {
 277     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(context()->engine);
 278     ep->referenceScarceResources();
 279
 280     bool isUndefined = false;
 281
 282     v8::HandleScope handle_scope;
 283     v8::Context::Scope scope(ep->v8engine()->context());
 284     v8::Local<v8::Value> result =
 285         QQmlJavaScriptExpression::evaluate(context(), v8function, &isUndefined);
 286
 287     ep->dereferenceScarceResources();
 288
 289     return ep->v8engine()->toVariant(result, qMetaTypeId<QList<QObject*> >());
 290 }
 291
 292 QString QQmlBinding::expressionIdentifier(QQmlJavaScriptExpression *e)
 293 {
 294     QQmlBinding *This = static_cast<QQmlBinding *>(e);
 295
 296     return QLatin1Char('"') + QString::fromUtf8(This->m_expression) + QLatin1Char('"');
 297 }
 298
 299 void QQmlBinding::expressionChanged(QQmlJavaScriptExpression *e)
 300 {
 301     QQmlBinding *This = static_cast<QQmlBinding *>(e);
 302     This->update();
 303 }
 304
 305 void QQmlBinding::refresh()
 306 {
 307     update();
 308 }
 309
 310 QString QQmlBinding::expression(const QQmlAbstractBinding *This)
 311 {
 312     return static_cast<const QQmlBinding *>(This)->expression();
 313 }
 314
 315 int QQmlBinding::propertyIndex(const QQmlAbstractBinding *This)
 316 {
 317     return static_cast<const QQmlBinding *>(This)->propertyIndex();
 318 }
 319
 320 QObject *QQmlBinding::object(const QQmlAbstractBinding *This)
 321 {
 322     return static_cast<const QQmlBinding *>(This)->object();
 323 }
 324
 325 void QQmlBinding::setEnabled(QQmlAbstractBinding *This, bool e, QQmlPropertyPrivate::WriteFlags f)
 326 {
 327     static_cast<QQmlBinding *>(This)->setEnabled(e, f);
 328 }
 329
 330 void QQmlBinding::update(QQmlAbstractBinding *This , QQmlPropertyPrivate::WriteFlags f)
 331 {
 332     static_cast<QQmlBinding *>(This)->update(f);
 333 }
 334
 335 void QQmlBinding::retargetBinding(QQmlAbstractBinding *This, QObject *o, int i)
 336 {
 337     static_cast<QQmlBinding *>(This)->retargetBinding(o, i);
 338 }
 339
 340 void QQmlBinding::setEnabled(bool e, QQmlPropertyPrivate::WriteFlags flags)
 341 {
 342     setEnabledFlag(e);
 343     setNotifyOnValueChanged(e);
 344
 345     if (e)
 346         update(flags);
 347 }
 348
 349 QString QQmlBinding::expression() const
 350 {
 351     return QString::fromUtf8(m_expression);
 352 }
 353
 354 QObject *QQmlBinding::object() const
 355 {
 356     if (m_coreObject.hasValue()) return m_coreObject.constValue()->target;
 357     else return *m_coreObject;
 358 }
 359
 360 int QQmlBinding::propertyIndex() const
 361 {
 362     if (m_coreObject.hasValue()) return m_coreObject.constValue()->targetProperty;
 363     else return m_core.encodedIndex();
 364 }
 365
 366 void QQmlBinding::retargetBinding(QObject *t, int i)
 367 {
 368     m_coreObject.value().target = t;
 369     m_coreObject.value().targetProperty = i;
 370 }
 371
 372 void QQmlBinding::setTarget(const QQmlProperty &prop)
 373 {
 374     setTarget(prop.object(), QQmlPropertyPrivate::get(prop)->core,
 375               QQmlPropertyPrivate::get(prop)->context);
 376 }
 377
 378 void QQmlBinding::setTarget(QObject *object, const QQmlPropertyData &core, QQmlContextData *ctxt)
 379 {
 380     m_coreObject = object;
 381     m_core = core;
 382     m_ctxt = ctxt;
 383 }
 384
 385 QQmlProperty QQmlBinding::property() const
 386 {
 387     return QQmlPropertyPrivate::restore(object(), m_core, *m_ctxt);
 388 }
 389
 390 QT_END_NAMESPACE