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 #include <private/qqmlscriptstring_p.h>
  54
  55 #include <QVariant>
  56 #include <QtCore/qdebug.h>
  57
  58 QT_BEGIN_NAMESPACE
  59
  60 // Used in qqmlabstractbinding.cpp
  61 QQmlAbstractBinding::VTable QQmlBinding_vtable = {
  62     QQmlAbstractBinding::default_destroy<QQmlBinding>,
  63     QQmlBinding::expression,
  64     QQmlBinding::propertyIndex,
  65     QQmlBinding::object,
  66     QQmlBinding::setEnabled,
  67     QQmlBinding::update,
  68     QQmlBinding::retargetBinding
  69 };
  70
  71 QQmlBinding::Identifier QQmlBinding::Invalid = -1;
  72
  73 QQmlBinding *
  74 QQmlBinding::createBinding(Identifier id, QObject *obj, QQmlContext *ctxt,
  75                                    const QString &url, quint16 lineNumber)
  76 {
  77     if (id < 0)
  78         return 0;
  79
  80     QQmlBinding *rv = 0;
  81
  82     QQmlContextData *ctxtdata = QQmlContextData::get(ctxt);
  83     QQmlEnginePrivate *engine = QQmlEnginePrivate::get(ctxt->engine());
  84     if (engine && ctxtdata && !ctxtdata->url.isEmpty()) {
  85         QQmlTypeData *typeData = engine->typeLoader.getType(ctxtdata->url);
  86         Q_ASSERT(typeData);
  87
  88         if (QQmlCompiledData *cdata = typeData->compiledData()) {
  89             rv = new QQmlBinding(cdata->primitives.at(id), true, obj, ctxtdata, url, lineNumber, 0);
  90         }
  91
  92         typeData->release();
  93     }
  94
  95     return rv;
  96 }
  97
  98 static QQmlJavaScriptExpression::VTable QQmlBinding_jsvtable = {
  99     QQmlBinding::expressionIdentifier,
 100     QQmlBinding::expressionChanged
 101 };
 102
 103 QQmlBinding::QQmlBinding(const QString &str, QObject *obj, QQmlContext *ctxt)
 104 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 105   m_lineNumber(0), m_columnNumber(0)
 106 {
 107     setNotifyOnValueChanged(true);
 108     QQmlAbstractExpression::setContext(QQmlContextData::get(ctxt));
 109     setScopeObject(obj);
 110
 111     QQmlRewrite::RewriteBinding rewriteBinding;
 112     QString code = rewriteBinding(str);
 113
 114     m_expression = str.toUtf8();
 115     v8function = evalFunction(context(), obj, code, QString(), 0);
 116 }
 117
 118 QQmlBinding::QQmlBinding(const QQmlScriptString &script, QObject *obj, QQmlContext *ctxt)
 119 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding)
 120 {
 121     if (ctxt && !ctxt->isValid())
 122         return;
 123
 124     const QQmlScriptStringPrivate *scriptPrivate = script.d.data();
 125     if (!ctxt && (!scriptPrivate->context || !scriptPrivate->context->isValid()))
 126         return;
 127
 128     bool needRewrite = true;
 129     QString code;
 130
 131     int id = scriptPrivate->bindingId;
 132     if (id >= 0) {
 133         QQmlContextData *ctxtdata = QQmlContextData::get(scriptPrivate->context);
 134         QQmlEnginePrivate *engine = QQmlEnginePrivate::get(scriptPrivate->context->engine());
 135         if (engine && ctxtdata && !ctxtdata->url.isEmpty()) {
 136             QQmlTypeData *typeData = engine->typeLoader.getType(ctxtdata->url);
 137             Q_ASSERT(typeData);
 138
 139             if (QQmlCompiledData *cdata = typeData->compiledData()) {
 140                 needRewrite = false;
 141                 code = cdata->primitives.at(id);
 142                 m_url = cdata->name;
 143             }
 144
 145             typeData->release();
 146         }
 147     }
 148
 149     if (needRewrite) {
 150         QQmlRewrite::RewriteBinding rewriteBinding;
 151         code = rewriteBinding(scriptPrivate->script);
 152     }
 153
 154     setNotifyOnValueChanged(true);
 155     QQmlAbstractExpression::setContext(QQmlContextData::get(ctxt ? ctxt : scriptPrivate->context));
 156     setScopeObject(obj ? obj : scriptPrivate->scope);
 157
 158     m_expression = scriptPrivate->script.toUtf8();
 159     m_lineNumber = scriptPrivate->lineNumber;
 160     m_columnNumber = scriptPrivate->columnNumber;
 161
 162     v8function = evalFunction(context(), scopeObject(), code, QString(), m_lineNumber);
 163 }
 164
 165 QQmlBinding::QQmlBinding(const QString &str, QObject *obj, QQmlContextData *ctxt)
 166 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 167   m_lineNumber(0), m_columnNumber(0)
 168 {
 169     setNotifyOnValueChanged(true);
 170     QQmlAbstractExpression::setContext(ctxt);
 171     setScopeObject(obj);
 172
 173     QQmlRewrite::RewriteBinding rewriteBinding;
 174     QString code = rewriteBinding(str);
 175
 176     m_expression = str.toUtf8();
 177     v8function = evalFunction(ctxt, obj, code, QString(), 0);
 178 }
 179
 180 QQmlBinding::QQmlBinding(const QString &str, bool isRewritten, QObject *obj,
 181                          QQmlContextData *ctxt,
 182                          const QString &url, quint16 lineNumber, quint16 columnNumber)
 183 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 184   m_url(url), m_lineNumber(lineNumber), m_columnNumber(columnNumber)
 185 {
 186     setNotifyOnValueChanged(true);
 187     QQmlAbstractExpression::setContext(ctxt);
 188     setScopeObject(obj);
 189
 190     QString code;
 191     if (isRewritten) {
 192         code = str;
 193     } else {
 194         QQmlRewrite::RewriteBinding rewriteBinding;
 195         code = rewriteBinding(str);
 196     }
 197
 198     m_expression = str.toUtf8();
 199
 200     v8function = evalFunction(ctxt, obj, code, url, m_lineNumber);
 201 }
 202
 203 /*!
 204     \internal
 205
 206     To avoid exposing v8 in the public API, functionPtr must be a pointer to a v8::Handle<v8::Function>.
 207     For example:
 208         v8::Handle<v8::Function> function;
 209         new QQmlBinding(&function, scope, ctxt);
 210  */
 211 QQmlBinding::QQmlBinding(void *functionPtr, QObject *obj, QQmlContextData *ctxt,
 212                          const QString &url, quint16 lineNumber, quint16 columnNumber)
 213 : QQmlJavaScriptExpression(&QQmlBinding_jsvtable), QQmlAbstractBinding(Binding),
 214   m_url(url), m_lineNumber(lineNumber), m_columnNumber(columnNumber)
 215 {
 216     setNotifyOnValueChanged(true);
 217     QQmlAbstractExpression::setContext(ctxt);
 218     setScopeObject(obj);
 219
 220     v8function = qPersistentNew<v8::Function>(*(v8::Handle<v8::Function> *)functionPtr);
 221 }
 222
 223 QQmlBinding::~QQmlBinding()
 224 {
 225     qPersistentDispose(v8function);
 226 }
 227
 228 void QQmlBinding::setEvaluateFlags(EvaluateFlags flags)
 229 {
 230     setRequiresThisObject(flags & RequiresThisObject);
 231 }
 232
 233 QQmlBinding::EvaluateFlags QQmlBinding::evaluateFlags() const
 234 {
 235     return requiresThisObject()?RequiresThisObject:None;
 236 }
 237
 238 void QQmlBinding::setNotifyOnValueChanged(bool v)
 239 {
 240     QQmlJavaScriptExpression::setNotifyOnValueChanged(v);
 241 }
 242
 243 void QQmlBinding::update(QQmlPropertyPrivate::WriteFlags flags)
 244 {
 245     if (!enabledFlag() || !context() || !context()->isValid())
 246         return;
 247
 248     // Check that the target has not been deleted
 249     if (QQmlData::wasDeleted(object()))
 250         return;
 251
 252     int lineNo = qmlSourceCoordinate(m_lineNumber);
 253     int columnNo = qmlSourceCoordinate(m_columnNumber);
 254
 255     QQmlTrace trace("General Binding Update");
 256     trace.addDetail("URL", m_url);
 257     trace.addDetail("Line", lineNo);
 258     trace.addDetail("Column", columnNo);
 259
 260     if (!updatingFlag()) {
 261         QQmlBindingProfiler prof(m_url, lineNo, columnNo, QQmlProfilerService::QmlBinding);
 262         setUpdatingFlag(true);
 263
 264         QQmlAbstractExpression::DeleteWatcher watcher(this);
 265
 266         if (m_core.propType == qMetaTypeId<QQmlBinding *>()) {
 267
 268             int idx = m_core.coreIndex;
 269             Q_ASSERT(idx != -1);
 270
 271             QQmlBinding *t = this;
 272             int status = -1;
 273             void *a[] = { &t, 0, &status, &flags };
 274             QMetaObject::metacall(*m_coreObject, QMetaObject::WriteProperty, idx, a);
 275
 276         } else {
 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             trace.event("writing binding result");
 288
 289             bool needsErrorLocationData = false;
 290             if (!watcher.wasDeleted() && !hasError())
 291                 needsErrorLocationData = !QQmlPropertyPrivate::writeBinding(*m_coreObject, m_core, context(),
 292                                                                     this, result, isUndefined, flags);
 293
 294             if (!watcher.wasDeleted()) {
 295
 296                 if (needsErrorLocationData)
 297                     delayedError()->setErrorLocation(QUrl(m_url), m_lineNumber, m_columnNumber);
 298
 299                 if (hasError()) {
 300                     if (!delayedError()->addError(ep)) ep->warning(this->error(context()->engine));
 301                 } else {
 302                     clearError();
 303                 }
 304
 305             }
 306
 307             ep->dereferenceScarceResources();
 308         }
 309
 310         if (!watcher.wasDeleted())
 311             setUpdatingFlag(false);
 312     } else {
 313         QQmlProperty p = property();
 314         QQmlAbstractBinding::printBindingLoopError(p);
 315     }
 316 }
 317
 318 QVariant QQmlBinding::evaluate()
 319 {
 320     QQmlEnginePrivate *ep = QQmlEnginePrivate::get(context()->engine);
 321     ep->referenceScarceResources();
 322
 323     bool isUndefined = false;
 324
 325     v8::HandleScope handle_scope;
 326     v8::Context::Scope scope(ep->v8engine()->context());
 327     v8::Local<v8::Value> result =
 328         QQmlJavaScriptExpression::evaluate(context(), v8function, &isUndefined);
 329
 330     ep->dereferenceScarceResources();
 331
 332     return ep->v8engine()->toVariant(result, qMetaTypeId<QList<QObject*> >());
 333 }
 334
 335 QString QQmlBinding::expressionIdentifier(QQmlJavaScriptExpression *e)
 336 {
 337     QQmlBinding *This = static_cast<QQmlBinding *>(e);
 338
 339     return QLatin1Char('"') + QString::fromUtf8(This->m_expression) + QLatin1Char('"');
 340 }
 341
 342 void QQmlBinding::expressionChanged(QQmlJavaScriptExpression *e)
 343 {
 344     QQmlBinding *This = static_cast<QQmlBinding *>(e);
 345     This->update();
 346 }
 347
 348 void QQmlBinding::refresh()
 349 {
 350     update();
 351 }
 352
 353 QString QQmlBinding::expression(const QQmlAbstractBinding *This)
 354 {
 355     return static_cast<const QQmlBinding *>(This)->expression();
 356 }
 357
 358 int QQmlBinding::propertyIndex(const QQmlAbstractBinding *This)
 359 {
 360     return static_cast<const QQmlBinding *>(This)->propertyIndex();
 361 }
 362
 363 QObject *QQmlBinding::object(const QQmlAbstractBinding *This)
 364 {
 365     return static_cast<const QQmlBinding *>(This)->object();
 366 }
 367
 368 void QQmlBinding::setEnabled(QQmlAbstractBinding *This, bool e, QQmlPropertyPrivate::WriteFlags f)
 369 {
 370     static_cast<QQmlBinding *>(This)->setEnabled(e, f);
 371 }
 372
 373 void QQmlBinding::update(QQmlAbstractBinding *This , QQmlPropertyPrivate::WriteFlags f)
 374 {
 375     static_cast<QQmlBinding *>(This)->update(f);
 376 }
 377
 378 void QQmlBinding::retargetBinding(QQmlAbstractBinding *This, QObject *o, int i)
 379 {
 380     static_cast<QQmlBinding *>(This)->retargetBinding(o, i);
 381 }
 382
 383 void QQmlBinding::setEnabled(bool e, QQmlPropertyPrivate::WriteFlags flags)
 384 {
 385     setEnabledFlag(e);
 386     setNotifyOnValueChanged(e);
 387
 388     if (e)
 389         update(flags);
 390 }
 391
 392 QString QQmlBinding::expression() const
 393 {
 394     return QString::fromUtf8(m_expression);
 395 }
 396
 397 QObject *QQmlBinding::object() const
 398 {
 399     if (m_coreObject.hasValue()) return m_coreObject.constValue()->target;
 400     else return *m_coreObject;
 401 }
 402
 403 int QQmlBinding::propertyIndex() const
 404 {
 405     if (m_coreObject.hasValue()) return m_coreObject.constValue()->targetProperty;
 406     else return m_core.encodedIndex();
 407 }
 408
 409 void QQmlBinding::retargetBinding(QObject *t, int i)
 410 {
 411     m_coreObject.value().target = t;
 412     m_coreObject.value().targetProperty = i;
 413 }
 414
 415 void QQmlBinding::setTarget(const QQmlProperty &prop)
 416 {
 417     setTarget(prop.object(), QQmlPropertyPrivate::get(prop)->core,
 418               QQmlPropertyPrivate::get(prop)->context);
 419 }
 420
 421 void QQmlBinding::setTarget(QObject *object, const QQmlPropertyData &core, QQmlContextData *ctxt)
 422 {
 423     m_coreObject = object;
 424     m_core = core;
 425     m_ctxt = ctxt;
 426 }
 427
 428 QQmlProperty QQmlBinding::property() const
 429 {
 430     return QQmlPropertyPrivate::restore(object(), m_core, *m_ctxt);
 431 }
 432
 433 QT_END_NAMESPACE