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39 | |
40 | #ifndef QQMLNOTIFIER_P_H |
41 | #define QQMLNOTIFIER_P_H |
42 | |
43 | // |
44 | // W A R N I N G |
45 | // ------------- |
46 | // |
47 | // This file is not part of the Qt API. It exists purely as an |
48 | // implementation detail. This header file may change from version to |
49 | // version without notice, or even be removed. |
50 | // |
51 | // We mean it. |
52 | // |
53 | |
54 | #include "qqmldata_p.h" |
55 | #include <QtCore/qmetaobject.h> |
56 | #include <private/qmetaobject_p.h> |
57 | |
58 | QT_BEGIN_NAMESPACE |
59 | |
60 | class QQmlNotifierEndpoint; |
61 | class Q_QML_PRIVATE_EXPORT QQmlNotifier |
62 | { |
63 | public: |
64 | inline QQmlNotifier(); |
65 | inline ~QQmlNotifier(); |
66 | inline void notify(); |
67 | |
68 | static void notify(QQmlData *ddata, int notifierIndex); |
69 | |
70 | private: |
71 | friend class QQmlData; |
72 | friend class QQmlNotifierEndpoint; |
73 | friend class QQmlThreadNotifierProxyObject; |
74 | |
75 | static void emitNotify(QQmlNotifierEndpoint *, void **a); |
76 | QQmlNotifierEndpoint *endpoints = nullptr; |
77 | }; |
78 | |
79 | class QQmlEngine; |
80 | class QQmlNotifierEndpoint |
81 | { |
82 | QQmlNotifierEndpoint *next; |
83 | QQmlNotifierEndpoint **prev; |
84 | public: |
85 | // QQmlNotifierEndpoint can only invoke one of a set of pre-defined callbacks. |
86 | // To add another callback, extend this enum and add the callback to the top |
87 | // of qqmlnotifier.cpp. Four bits are reserved for the callback, so there can |
88 | // be up to 15 of them (0 is reserved). |
89 | enum Callback { |
90 | None = 0, |
91 | QQmlBoundSignal = 1, |
92 | QQmlJavaScriptExpressionGuard = 2, |
93 | QQmlVMEMetaObjectEndpoint = 3 |
94 | }; |
95 | |
96 | inline QQmlNotifierEndpoint(Callback callback); |
97 | inline ~QQmlNotifierEndpoint(); |
98 | |
99 | inline bool isConnected() const; |
100 | inline bool isConnected(QObject *source, int sourceSignal) const; |
101 | inline bool isConnected(QQmlNotifier *) const; |
102 | |
103 | void connect(QObject *source, int sourceSignal, QQmlEngine *engine, bool doNotify = true); |
104 | inline void connect(QQmlNotifier *); |
105 | inline void disconnect(); |
106 | |
107 | inline bool isNotifying() const; |
108 | inline void startNotifying(qintptr *originalSenderPtr); |
109 | inline void stopNotifying(qintptr *originalSenderPtr); |
110 | |
111 | inline void cancelNotify(); |
112 | |
113 | inline int signalIndex() const { return sourceSignal; } |
114 | |
115 | inline qintptr sender() const; |
116 | inline void setSender(qintptr sender); |
117 | |
118 | inline QObject *senderAsObject() const; |
119 | inline QQmlNotifier *senderAsNotifier() const; |
120 | |
121 | private: |
122 | friend class QQmlData; |
123 | friend class QQmlNotifier; |
124 | |
125 | // Contains either the QObject*, or the QQmlNotifier* that this |
126 | // endpoint is connected to. While the endpoint is notifying, the |
127 | // senderPtr points to another qintptr that contains this value. |
128 | qintptr senderPtr; |
129 | |
130 | Callback callback:4; |
131 | int needsConnectNotify:1; |
132 | // The index is in the range returned by QObjectPrivate::signalIndex(). |
133 | // This is different from QMetaMethod::methodIndex(). |
134 | signed int sourceSignal:27; |
135 | }; |
136 | |
137 | QQmlNotifier::QQmlNotifier() |
138 | { |
139 | } |
140 | |
141 | QQmlNotifier::~QQmlNotifier() |
142 | { |
143 | QQmlNotifierEndpoint *endpoint = endpoints; |
144 | while (endpoint) { |
145 | QQmlNotifierEndpoint *n = endpoint; |
146 | endpoint = n->next; |
147 | n->setSender(0x0); |
148 | n->next = nullptr; |
149 | n->prev = nullptr; |
150 | n->sourceSignal = -1; |
151 | } |
152 | endpoints = nullptr; |
153 | } |
154 | |
155 | void QQmlNotifier::notify() |
156 | { |
157 | void *args[] = { nullptr }; |
158 | if (endpoints) emitNotify(endpoints, a: args); |
159 | } |
160 | |
161 | QQmlNotifierEndpoint::QQmlNotifierEndpoint(Callback callback) |
162 | : next(nullptr), prev(nullptr), senderPtr(0), callback(callback), needsConnectNotify(false), sourceSignal(-1) |
163 | { |
164 | } |
165 | |
166 | QQmlNotifierEndpoint::~QQmlNotifierEndpoint() |
167 | { |
168 | disconnect(); |
169 | } |
170 | |
171 | bool QQmlNotifierEndpoint::isConnected() const |
172 | { |
173 | return prev != nullptr; |
174 | } |
175 | |
176 | /*! \internal |
177 | \a sourceSignal MUST be in the signal index range (see QObjectPrivate::signalIndex()). |
178 | This is different from QMetaMethod::methodIndex(). |
179 | */ |
180 | bool QQmlNotifierEndpoint::isConnected(QObject *source, int sourceSignal) const |
181 | { |
182 | return this->sourceSignal != -1 && senderAsObject() == source && |
183 | this->sourceSignal == sourceSignal; |
184 | } |
185 | |
186 | bool QQmlNotifierEndpoint::isConnected(QQmlNotifier *notifier) const |
187 | { |
188 | return sourceSignal == -1 && senderAsNotifier() == notifier; |
189 | } |
190 | |
191 | void QQmlNotifierEndpoint::connect(QQmlNotifier *notifier) |
192 | { |
193 | disconnect(); |
194 | |
195 | next = notifier->endpoints; |
196 | if (next) { next->prev = &next; } |
197 | notifier->endpoints = this; |
198 | prev = ¬ifier->endpoints; |
199 | setSender(qintptr(notifier)); |
200 | } |
201 | |
202 | void QQmlNotifierEndpoint::disconnect() |
203 | { |
204 | // Remove from notifier chain before calling disconnectNotify(), so that that |
205 | // QObject::receivers() returns the correct value in there |
206 | if (next) next->prev = prev; |
207 | if (prev) *prev = next; |
208 | |
209 | if (sourceSignal != -1) { |
210 | QObject * const obj = senderAsObject(); |
211 | Q_ASSERT(obj); |
212 | QObjectPrivate * const priv = QObjectPrivate::get(o: obj); |
213 | if (needsConnectNotify) |
214 | priv->disconnectNotify(signal: QMetaObjectPrivate::signal(m: obj->metaObject(), signal_index: sourceSignal)); |
215 | } |
216 | |
217 | setSender(0x0); |
218 | next = nullptr; |
219 | prev = nullptr; |
220 | sourceSignal = -1; |
221 | } |
222 | |
223 | /*! |
224 | Returns true if a notify is in progress. This means that the signal or QQmlNotifier |
225 | that this endpoing is connected to has been triggered, but this endpoint's callback has not |
226 | yet been called. |
227 | |
228 | An in progress notify can be cancelled by calling cancelNotify. |
229 | */ |
230 | bool QQmlNotifierEndpoint::isNotifying() const |
231 | { |
232 | return senderPtr & 0x1; |
233 | } |
234 | |
235 | void QQmlNotifierEndpoint::startNotifying(qintptr *originalSenderPtr) |
236 | { |
237 | Q_ASSERT(*originalSenderPtr == 0); |
238 | // Set the endpoint to notifying: |
239 | // - Save the original senderPtr, |
240 | *originalSenderPtr = senderPtr; |
241 | // - Take a pointer of it, |
242 | // - And assign that to the senderPtr, including a flag to signify "notifying". |
243 | senderPtr = qintptr(originalSenderPtr) | 0x1; |
244 | } |
245 | |
246 | void QQmlNotifierEndpoint::stopNotifying(qintptr *originalSenderPtr) |
247 | { |
248 | // End of notifying, restore values |
249 | Q_ASSERT((senderPtr & ~0x1) == qintptr(originalSenderPtr)); |
250 | senderPtr = *originalSenderPtr; |
251 | *originalSenderPtr = 0; |
252 | } |
253 | |
254 | /*! |
255 | Cancel any notifies that are in progress. |
256 | */ |
257 | void QQmlNotifierEndpoint::cancelNotify() |
258 | { |
259 | if (isNotifying()) { |
260 | auto *ptr = (qintptr *)(senderPtr & ~0x1); |
261 | Q_ASSERT(ptr); |
262 | senderPtr = *ptr; |
263 | *ptr = 0; |
264 | } |
265 | } |
266 | |
267 | qintptr QQmlNotifierEndpoint::sender() const |
268 | { |
269 | return isNotifying() ? *(qintptr *)(senderPtr & ~0x1) : senderPtr; |
270 | } |
271 | |
272 | void QQmlNotifierEndpoint::setSender(qintptr sender) |
273 | { |
274 | // If we're just notifying, we write through to the originalSenderPtr |
275 | if (isNotifying()) |
276 | *(qintptr *)(senderPtr & ~0x1) = sender; |
277 | else |
278 | senderPtr = sender; |
279 | } |
280 | |
281 | QObject *QQmlNotifierEndpoint::senderAsObject() const |
282 | { |
283 | return (QObject *)(sender()); |
284 | } |
285 | |
286 | QQmlNotifier *QQmlNotifierEndpoint::senderAsNotifier() const |
287 | { |
288 | return (QQmlNotifier *)(sender()); |
289 | } |
290 | |
291 | QT_END_NAMESPACE |
292 | |
293 | #endif // QQMLNOTIFIER_P_H |
294 | |
295 | |