1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QQMLJAVASCRIPTEXPRESSION_P_H
5#define QQMLJAVASCRIPTEXPRESSION_P_H
6
7//
8// W A R N I N G
9// -------------
10//
11// This file is not part of the Qt API. It exists purely as an
12// implementation detail. This header file may change from version to
13// version without notice, or even be removed.
14//
15// We mean it.
16//
17
18#include <QtCore/qglobal.h>
19#include <QtCore/qtaggedpointer.h>
20#include <QtQml/qqmlerror.h>
21#include <private/qqmlengine_p.h>
22#include <QtQml/private/qbipointer_p.h>
23
24QT_BEGIN_NAMESPACE
25
26struct QQmlSourceLocation;
27
28class QQmlDelayedError
29{
30public:
31 inline QQmlDelayedError() : nextError(nullptr), prevError(nullptr) {}
32 inline ~QQmlDelayedError() { (void)removeError(); }
33
34 bool addError(QQmlEnginePrivate *);
35
36 Q_REQUIRED_RESULT inline QQmlError removeError() {
37 if (prevError) {
38 if (nextError) nextError->prevError = prevError;
39 *prevError = nextError;
40 nextError = nullptr;
41 prevError = nullptr;
42 }
43 return m_error;
44 }
45
46 inline bool isValid() const { return m_error.isValid(); }
47 inline const QQmlError &error() const { return m_error; }
48 inline void clearError() { m_error = QQmlError(); }
49
50 void setErrorLocation(const QQmlSourceLocation &sourceLocation);
51 void setErrorDescription(const QString &description);
52 void setErrorObject(QObject *object);
53
54 // Call only from catch(...) -- will re-throw if no JS exception
55 void catchJavaScriptException(QV4::ExecutionEngine *engine);
56
57private:
58
59 mutable QQmlError m_error;
60
61 QQmlDelayedError *nextError;
62 QQmlDelayedError **prevError;
63};
64
65class Q_QML_PRIVATE_EXPORT QQmlJavaScriptExpression
66{
67 Q_DISABLE_COPY_MOVE(QQmlJavaScriptExpression)
68public:
69 QQmlJavaScriptExpression();
70 virtual ~QQmlJavaScriptExpression();
71
72 virtual QString expressionIdentifier() const;
73 virtual void expressionChanged() = 0;
74
75 QV4::ReturnedValue evaluate(bool *isUndefined);
76 QV4::ReturnedValue evaluate(QV4::CallData *callData, bool *isUndefined);
77 bool evaluate(void **a, const QMetaType *types, int argc);
78
79 inline bool notifyOnValueChanged() const;
80
81 void setNotifyOnValueChanged(bool v);
82 void resetNotifyOnValueChanged();
83
84 inline QObject *scopeObject() const;
85 inline void setScopeObject(QObject *v);
86
87 virtual QQmlSourceLocation sourceLocation() const;
88
89 bool hasContext() const { return m_context != nullptr; }
90 bool hasValidContext() const { return m_context && m_context->isValid(); }
91 QQmlContext *publicContext() const { return m_context ? m_context->asQQmlContext() : nullptr; }
92
93 QQmlRefPointer<QQmlContextData> context() const { return m_context; }
94 void setContext(const QQmlRefPointer<QQmlContextData> &context);
95
96 void insertIntoList(QQmlJavaScriptExpression **listHead)
97 {
98 m_nextExpression = *listHead;
99 if (m_nextExpression)
100 m_nextExpression->m_prevExpression = &m_nextExpression;
101 m_prevExpression = listHead;
102 *listHead = this;
103 }
104
105 QV4::Function *function() const { return m_v4Function; }
106
107 virtual void refresh();
108
109 class DeleteWatcher {
110 public:
111 inline DeleteWatcher(QQmlJavaScriptExpression *);
112 inline ~DeleteWatcher();
113 inline bool wasDeleted() const;
114 private:
115 friend class QQmlJavaScriptExpression;
116 QObject *_c;
117 QQmlJavaScriptExpression **_w;
118 QQmlJavaScriptExpression *_s;
119 };
120
121 inline bool hasError() const;
122 inline bool hasDelayedError() const;
123 QQmlError error(QQmlEngine *) const;
124 void clearError();
125 void clearActiveGuards();
126 QQmlDelayedError *delayedError();
127 virtual bool mustCaptureBindableProperty() const {return true;}
128
129 static QV4::ReturnedValue evalFunction(
130 const QQmlRefPointer<QQmlContextData> &ctxt, QObject *scope, const QString &code,
131 const QString &filename, quint16 line);
132
133 QQmlEngine *engine() const { return m_context ? m_context->engine() : nullptr; }
134 bool hasUnresolvedNames() const { return m_context && m_context->hasUnresolvedNames(); }
135
136 bool needsPropertyChangeTrigger(QObject *target, int propertyIndex);
137 QPropertyChangeTrigger *allocatePropertyChangeTrigger(QObject *target, int propertyIndex);
138
139protected:
140 void createQmlBinding(const QQmlRefPointer<QQmlContextData> &ctxt, QObject *scope,
141 const QString &code, const QString &filename, quint16 line);
142
143 void setupFunction(QV4::ExecutionContext *qmlContext, QV4::Function *f);
144 void setCompilationUnit(const QQmlRefPointer<QV4::ExecutableCompilationUnit> &compilationUnit);
145
146 // We store some flag bits in the following flag pointers.
147 // activeGuards:flag1 - notifyOnValueChanged
148 // activeGuards:flag2 - useSharedContext
149 QBiPointer<QObject, DeleteWatcher> m_scopeObject;
150
151 enum GuardTag {
152 NoGuardTag,
153 NotifyOnValueChanged
154 };
155
156 QForwardFieldList<QQmlJavaScriptExpressionGuard, &QQmlJavaScriptExpressionGuard::next, GuardTag> activeGuards;
157
158 enum Tag {
159 NoTag,
160 InEvaluationLoop
161 };
162
163 QTaggedPointer<QQmlDelayedError, Tag> m_error;
164
165private:
166 friend class QQmlContextData;
167 friend class QQmlPropertyCapture;
168 friend void QQmlJavaScriptExpressionGuard_callback(QQmlNotifierEndpoint *, void **);
169 friend class QQmlTranslationBindingFromBinding;
170 friend class QQmlTranslationBindingFromTranslationInfo;
171 friend class QQmlJavaScriptExpressionCapture;
172
173 // Not refcounted as the context will clear the expressions when destructed.
174 QQmlContextData *m_context;
175
176 QQmlJavaScriptExpression **m_prevExpression;
177 QQmlJavaScriptExpression *m_nextExpression;
178
179 QV4::PersistentValue m_qmlScope;
180 QQmlRefPointer<QV4::ExecutableCompilationUnit> m_compilationUnit;
181
182 QV4::Function *m_v4Function;
183
184protected:
185 TriggerList *qpropertyChangeTriggers = nullptr;
186};
187
188class Q_QML_PRIVATE_EXPORT QQmlPropertyCapture
189{
190public:
191 QQmlPropertyCapture(QQmlEngine *engine, QQmlJavaScriptExpression *e, QQmlJavaScriptExpression::DeleteWatcher *w)
192 : engine(engine), expression(e), watcher(w), errorString(nullptr) { }
193
194 ~QQmlPropertyCapture() {
195 Q_ASSERT(guards.isEmpty());
196 Q_ASSERT(errorString == nullptr);
197 }
198
199 void captureProperty(QQmlNotifier *);
200 void captureProperty(QObject *, int, int, bool doNotify = true);
201 void captureProperty(QObject *, const QQmlPropertyCache *, const QQmlPropertyData *, bool doNotify = true);
202 void captureTranslation();
203
204 QQmlEngine *engine;
205 QQmlJavaScriptExpression *expression;
206 QQmlJavaScriptExpression::DeleteWatcher *watcher;
207 QForwardFieldList<QQmlJavaScriptExpressionGuard, &QQmlJavaScriptExpressionGuard::next> guards;
208 QStringList *errorString;
209
210private:
211 void captureBindableProperty(QObject *o, const QMetaObject *metaObjectForBindable, int c);
212 void captureNonBindableProperty(QObject *o, int n, int c, bool doNotify);
213};
214
215QQmlJavaScriptExpression::DeleteWatcher::DeleteWatcher(QQmlJavaScriptExpression *e)
216: _c(nullptr), _w(nullptr), _s(e)
217{
218 if (e->m_scopeObject.isT1()) {
219 _w = &_s;
220 _c = e->m_scopeObject.asT1();
221 e->m_scopeObject = this;
222 } else {
223 // Another watcher is already registered
224 _w = &e->m_scopeObject.asT2()->_s;
225 }
226}
227
228QQmlJavaScriptExpression::DeleteWatcher::~DeleteWatcher()
229{
230 Q_ASSERT(*_w == nullptr || (*_w == _s && _s->m_scopeObject.isT2()));
231 if (*_w && _s->m_scopeObject.asT2() == this)
232 _s->m_scopeObject = _c;
233}
234
235bool QQmlJavaScriptExpression::DeleteWatcher::wasDeleted() const
236{
237 return *_w == nullptr;
238}
239
240bool QQmlJavaScriptExpression::notifyOnValueChanged() const
241{
242 return activeGuards.tag() == NotifyOnValueChanged;
243}
244
245QObject *QQmlJavaScriptExpression::scopeObject() const
246{
247 if (m_scopeObject.isT1()) return m_scopeObject.asT1();
248 else return m_scopeObject.asT2()->_c;
249}
250
251void QQmlJavaScriptExpression::setScopeObject(QObject *v)
252{
253 if (m_scopeObject.isT1()) m_scopeObject = v;
254 else m_scopeObject.asT2()->_c = v;
255}
256
257bool QQmlJavaScriptExpression::hasError() const
258{
259 return !m_error.isNull() && m_error->isValid();
260}
261
262bool QQmlJavaScriptExpression::hasDelayedError() const
263{
264 return !m_error.isNull();
265}
266
267inline void QQmlJavaScriptExpression::clearError()
268{
269 delete m_error.data();
270 m_error = nullptr;
271}
272
273QQmlJavaScriptExpressionGuard::QQmlJavaScriptExpressionGuard(QQmlJavaScriptExpression *e)
274 : QQmlNotifierEndpoint(QQmlNotifierEndpoint::QQmlJavaScriptExpressionGuard),
275 expression(e), next(nullptr)
276{
277}
278
279QQmlJavaScriptExpressionGuard *
280QQmlJavaScriptExpressionGuard::New(QQmlJavaScriptExpression *e,
281 QQmlEngine *engine)
282{
283 Q_ASSERT(e);
284 return QQmlEnginePrivate::get(e: engine)->jsExpressionGuardPool.New(a&: e);
285}
286
287void QQmlJavaScriptExpressionGuard::Delete()
288{
289 QRecyclePool<QQmlJavaScriptExpressionGuard>::Delete(t: this);
290}
291
292
293QT_END_NAMESPACE
294
295#endif // QQMLJAVASCRIPTEXPRESSION_P_H
296

source code of qtdeclarative/src/qml/qml/qqmljavascriptexpression_p.h