Struct qt_core::QLibrary

#[repr(C)]
pub struct QLibrary { /* private fields */ }

The QLibrary class loads shared libraries at runtime.

C++ class: QLibrary.

C++ documentation:

The QLibrary class loads shared libraries at runtime.

An instance of a QLibrary object operates on a single shared object file (which we call a "library", but is also known as a "DLL"). A QLibrary provides access to the functionality in the library in a platform independent way. You can either pass a file name in the constructor, or set it explicitly with setFileName(). When loading the library, QLibrary searches in all the system-specific library locations (e.g. LD_LIBRARY_PATH on Unix), unless the file name has an absolute path.

If the file name is an absolute path then an attempt is made to load this path first. If the file cannot be found, QLibrary tries the name with different platform-specific file prefixes, like "lib" on Unix and Mac, and suffixes, like ".so" on Unix, ".dylib" on the Mac, or ".dll" on Windows.

If the file path is not absolute then QLibrary modifies the search order to try the system-specific prefixes and suffixes first, followed by the file path specified.

This makes it possible to specify shared libraries that are only identified by their basename (i.e. without their suffix), so the same code will work on different operating systems yet still minimise the number of attempts to find the library.

The most important functions are load() to dynamically load the library file, isLoaded() to check whether loading was successful, and resolve() to resolve a symbol in the library. The resolve() function implicitly tries to load the library if it has not been loaded yet. Multiple instances of QLibrary can be used to access the same physical library. Once loaded, libraries remain in memory until the application terminates. You can attempt to unload a library using unload(), but if other instances of QLibrary are using the same library, the call will fail, and unloading will only happen when every instance has called unload().

A typical use of QLibrary is to resolve an exported symbol in a library, and to call the C function that this symbol represents. This is called "explicit linking" in contrast to "implicit linking", which is done by the link step in the build process when linking an executable against a library.

The following code snippet loads a library, resolves the symbol "mysymbol", and calls the function if everything succeeded. If something goes wrong, e.g. the library file does not exist or the symbol is not defined, the function pointer will be 0 and won't be called.

QLibrary myLib(“mylib”);
typedef void (*MyPrototype)();
MyPrototype myFunction = (MyPrototype) myLib.resolve(“mysymbol”);
if (myFunction)
      myFunction();

The symbol must be exported as a C function from the library for resolve() to work. This means that the function must be wrapped in an extern "C" block if the library is compiled with a C++ compiler. On Windows, this also requires the use of a dllexport macro; see resolve() for the details of how this is done. For convenience, there is a static resolve() function which you can use if you just want to call a function in a library without explicitly loading the library first:

typedef void (*MyPrototype)();
MyPrototype myFunction =
          (MyPrototype) QLibrary::resolve(“mylib”, “mysymbol”);
if (myFunction)
      myFunction();

Implementations

impl QLibrary

pub unsafe fn error_string(&self) -> CppBox<QString>

Returns a text string with the description of the last error that occurred. Currently, errorString will only be set if load(), unload() or resolve() for some reason fails.

Calls C++ function: QString QLibrary::errorString() const.

C++ documentation:

Returns a text string with the description of the last error that occurred. Currently, errorString will only be set if load(), unload() or resolve() for some reason fails.

This function was introduced in Qt 4.2.

pub unsafe fn file_name(&self) -> CppBox<QString>

This property holds the file name of the library

Calls C++ function: QString QLibrary::fileName() const.

C++ documentation:

This property holds the file name of the library

We recommend omitting the file's suffix in the file name, since QLibrary will automatically look for the file with the appropriate suffix (see isLibrary()).

When loading the library, QLibrary searches in all system-specific library locations (for example, LD_LIBRARY_PATH on Unix), unless the file name has an absolute path. After loading the library successfully, fileName() returns the fully-qualified file name of the library, including the full path to the library if one was given in the constructor or passed to setFileName().

For example, after successfully loading the "GL" library on Unix platforms, fileName() will return "libGL.so". If the file name was originally passed as "/usr/lib/libGL", fileName() will return "/usr/lib/libGL.so".

Access functions:

QString	fileName() const
void	setFileName(const QString &fileName)

pub unsafe fn is_library(file_name: impl CastInto<Ref<QString>>) -> bool

Returns true if fileName has a valid suffix for a loadable library; otherwise returns false.

Calls C++ function: static bool QLibrary::isLibrary(const QString& fileName).

C++ documentation:

Returns true if fileName has a valid suffix for a loadable library; otherwise returns false.

Platform	Valid suffixes
Windows	.dll, .DLL
Unix/Linux	.so
AIX	.a
HP-UX	.sl, .so (HP-UXi)
macOS and iOS	.dylib, .bundle, .so

Trailing versioning numbers on Unix are ignored.

pub unsafe fn is_loaded(&self) -> bool

Returns true if the library is loaded; otherwise returns false.

Calls C++ function: bool QLibrary::isLoaded() const.

C++ documentation:

Returns true if the library is loaded; otherwise returns false.

See also load().

pub unsafe fn load(&self) -> bool

Loads the library and returns true if the library was loaded successfully; otherwise returns false. Since resolve() always calls this function before resolving any symbols it is not necessary to call it explicitly. In some situations you might want the library loaded in advance, in which case you would use this function.

Calls C++ function: bool QLibrary::load().

C++ documentation:

Loads the library and returns true if the library was loaded successfully; otherwise returns false. Since resolve() always calls this function before resolving any symbols it is not necessary to call it explicitly. In some situations you might want the library loaded in advance, in which case you would use this function.

See also unload().

pub unsafe fn load_hints(&self) -> QFlags<LoadHint>

Give the load() function some hints on how it should behave.

Calls C++ function: QFlags<QLibrary::LoadHint> QLibrary::loadHints() const.

C++ documentation:

Give the load() function some hints on how it should behave.

You can give some hints on how the symbols are resolved. Usually, the symbols are not resolved at load time, but resolved lazily, (that is, when resolve() is called). If you set the loadHints to ResolveAllSymbolsHint, then all symbols will be resolved at load time if the platform supports it.

Setting ExportExternalSymbolsHint will make the external symbols in the library available for resolution in subsequent loaded libraries.

If LoadArchiveMemberHint is set, the file name is composed of two components: A path which is a reference to an archive file followed by the second component which is the reference to the archive member. For instance, the fileName libGL.a(shr_64.o) will refer to the library shr_64.o in the archive file named libGL.a. This is only supported on the AIX platform.

The interpretation of the load hints is platform dependent, and if you use it you are probably making some assumptions on which platform you are compiling for, so use them only if you understand the consequences of them.

By default, none of these flags are set, so libraries will be loaded with lazy symbol resolution, and will not export external symbols for resolution in other dynamically-loaded libraries.

Note: Setting this property after the library has been loaded has no effect and loadHints() will not reflect those changes.

Note: This property is shared among all QLibrary instances that refer to the same library.

Access functions:

LoadHints	loadHints() const
void	setLoadHints(LoadHints hints)

pub unsafe fn meta_object(&self) -> Ptr<QMetaObject>

Calls C++ function: virtual const QMetaObject* QLibrary::metaObject() const.

pub unsafe fn from_q_object( parent: impl CastInto<Ptr<QObject>> ) -> QBox<QLibrary>

Constructs a library with the given parent.

Calls C++ function: [constructor] void QLibrary::QLibrary(QObject* parent = …).

C++ documentation:

Constructs a library with the given parent.

pub unsafe fn from_q_string_q_object( file_name: impl CastInto<Ref<QString>>, parent: impl CastInto<Ptr<QObject>> ) -> QBox<QLibrary>

Constructs a library object with the given parent that will load the library specified by fileName.

Calls C++ function: [constructor] void QLibrary::QLibrary(const QString& fileName, QObject* parent = …).

C++ documentation:

Constructs a library object with the given parent that will load the library specified by fileName.

We recommend omitting the file's suffix in fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on macOS and iOS, and ".dll" on Windows. (See fileName.)

pub unsafe fn from_q_string_int_q_object( file_name: impl CastInto<Ref<QString>>, ver_num: c_int, parent: impl CastInto<Ptr<QObject>> ) -> QBox<QLibrary>

Constructs a library object with the given parent that will load the library specified by fileName and major version number verNum. Currently, the version number is ignored on Windows.

Calls C++ function: [constructor] void QLibrary::QLibrary(const QString& fileName, int verNum, QObject* parent = …).

C++ documentation:

Constructs a library object with the given parent that will load the library specified by fileName and major version number verNum. Currently, the version number is ignored on Windows.

We recommend omitting the file's suffix in fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on macOS and iOS, and ".dll" on Windows. (See fileName.)

pub unsafe fn from_2_q_string_q_object( file_name: impl CastInto<Ref<QString>>, version: impl CastInto<Ref<QString>>, parent: impl CastInto<Ptr<QObject>> ) -> QBox<QLibrary>

Constructs a library object with the given parent that will load the library specified by fileName and full version number version. Currently, the version number is ignored on Windows.

Calls C++ function: [constructor] void QLibrary::QLibrary(const QString& fileName, const QString& version, QObject* parent = …).

C++ documentation:

Constructs a library object with the given parent that will load the library specified by fileName and full version number version. Currently, the version number is ignored on Windows.

We recommend omitting the file's suffix in fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on macOS and iOS, and ".dll" on Windows. (See fileName.)

pub unsafe fn new() -> QBox<QLibrary>

The QLibrary class loads shared libraries at runtime.

Calls C++ function: [constructor] void QLibrary::QLibrary().

C++ documentation:

The QLibrary class loads shared libraries at runtime.

An instance of a QLibrary object operates on a single shared object file (which we call a "library", but is also known as a "DLL"). A QLibrary provides access to the functionality in the library in a platform independent way. You can either pass a file name in the constructor, or set it explicitly with setFileName(). When loading the library, QLibrary searches in all the system-specific library locations (e.g. LD_LIBRARY_PATH on Unix), unless the file name has an absolute path.

If the file name is an absolute path then an attempt is made to load this path first. If the file cannot be found, QLibrary tries the name with different platform-specific file prefixes, like "lib" on Unix and Mac, and suffixes, like ".so" on Unix, ".dylib" on the Mac, or ".dll" on Windows.

If the file path is not absolute then QLibrary modifies the search order to try the system-specific prefixes and suffixes first, followed by the file path specified.

This makes it possible to specify shared libraries that are only identified by their basename (i.e. without their suffix), so the same code will work on different operating systems yet still minimise the number of attempts to find the library.

The most important functions are load() to dynamically load the library file, isLoaded() to check whether loading was successful, and resolve() to resolve a symbol in the library. The resolve() function implicitly tries to load the library if it has not been loaded yet. Multiple instances of QLibrary can be used to access the same physical library. Once loaded, libraries remain in memory until the application terminates. You can attempt to unload a library using unload(), but if other instances of QLibrary are using the same library, the call will fail, and unloading will only happen when every instance has called unload().

A typical use of QLibrary is to resolve an exported symbol in a library, and to call the C function that this symbol represents. This is called "explicit linking" in contrast to "implicit linking", which is done by the link step in the build process when linking an executable against a library.

The following code snippet loads a library, resolves the symbol "mysymbol", and calls the function if everything succeeded. If something goes wrong, e.g. the library file does not exist or the symbol is not defined, the function pointer will be 0 and won't be called.

QLibrary myLib(“mylib”);
typedef void (*MyPrototype)();
MyPrototype myFunction = (MyPrototype) myLib.resolve(“mysymbol”);
if (myFunction)
      myFunction();

The symbol must be exported as a C function from the library for resolve() to work. This means that the function must be wrapped in an extern "C" block if the library is compiled with a C++ compiler. On Windows, this also requires the use of a dllexport macro; see resolve() for the details of how this is done. For convenience, there is a static resolve() function which you can use if you just want to call a function in a library without explicitly loading the library first:

typedef void (*MyPrototype)();
MyPrototype myFunction =
          (MyPrototype) QLibrary::resolve(“mylib”, “mysymbol”);
if (myFunction)
      myFunction();

pub unsafe fn from_q_string( file_name: impl CastInto<Ref<QString>> ) -> QBox<QLibrary>

Constructs a library object with the given parent that will load the library specified by fileName.

Calls C++ function: [constructor] void QLibrary::QLibrary(const QString& fileName).

C++ documentation:

Constructs a library object with the given parent that will load the library specified by fileName.

We recommend omitting the file's suffix in fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on macOS and iOS, and ".dll" on Windows. (See fileName.)

pub unsafe fn from_q_string_int( file_name: impl CastInto<Ref<QString>>, ver_num: c_int ) -> QBox<QLibrary>

Constructs a library object with the given parent that will load the library specified by fileName and major version number verNum. Currently, the version number is ignored on Windows.

Calls C++ function: [constructor] void QLibrary::QLibrary(const QString& fileName, int verNum).

C++ documentation:

Constructs a library object with the given parent that will load the library specified by fileName and major version number verNum. Currently, the version number is ignored on Windows.

We recommend omitting the file's suffix in fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on macOS and iOS, and ".dll" on Windows. (See fileName.)

pub unsafe fn from_2_q_string( file_name: impl CastInto<Ref<QString>>, version: impl CastInto<Ref<QString>> ) -> QBox<QLibrary>

Constructs a library object with the given parent that will load the library specified by fileName and full version number version. Currently, the version number is ignored on Windows.

Calls C++ function: [constructor] void QLibrary::QLibrary(const QString& fileName, const QString& version).

C++ documentation:

Constructs a library object with the given parent that will load the library specified by fileName and full version number version. Currently, the version number is ignored on Windows.

We recommend omitting the file's suffix in fileName, since QLibrary will automatically look for the file with the appropriate suffix in accordance with the platform, e.g. ".so" on Unix, ".dylib" on macOS and iOS, and ".dll" on Windows. (See fileName.)

pub unsafe fn qt_metacall( &self, arg1: Call, arg2: c_int, arg3: *mut *mut c_void ) -> c_int

Calls C++ function: virtual int QLibrary::qt_metacall(QMetaObject::Call arg1, int arg2, void** arg3).

pub unsafe fn qt_metacast(&self, arg1: *const c_char) -> *mut c_void

Calls C++ function: virtual void* QLibrary::qt_metacast(const char* arg1).

pub unsafe fn resolve_char( &self, symbol: *const c_char ) -> Option<extern "C" fn()>

Returns the address of the exported symbol symbol. The library is loaded if necessary. The function returns 0 if the symbol could not be resolved or if the library could not be loaded.

Calls C++ function: void (*FN_PTR)() QLibrary::resolve(const char* symbol).

C++ documentation:

Returns the address of the exported symbol symbol. The library is loaded if necessary. The function returns 0 if the symbol could not be resolved or if the library could not be loaded.

Example:

typedef int (*AvgFunction)(int, int);
AvgFunction avg = (AvgFunction) library->resolve(“avg”);
if (avg)
      return avg(5, 8);
else
      return -1;

The symbol must be exported as a C function from the library. This means that the function must be wrapped in an extern "C" if the library is compiled with a C++ compiler. On Windows you must also explicitly export the function from the DLL using the __declspec(dllexport) compiler directive, for example:

extern “C” MY_EXPORT int avg(int a, int b)
{
      return (a + b) / 2;
}

with MY_EXPORT defined as

#ifdef Q_OS_WIN
#define MY_EXPORT __declspec(dllexport)
#else
#define MY_EXPORT
#endif

pub unsafe fn resolve_q_string_char( file_name: impl CastInto<Ref<QString>>, symbol: *const c_char ) -> Option<extern "C" fn()>

This is an overloaded function.

Calls C++ function: static void (*FN_PTR)() QLibrary::resolve(const QString& fileName, const char* symbol).

C++ documentation:

This is an overloaded function.

Loads the library fileName and returns the address of the exported symbol symbol. Note that fileName should not include the platform-specific file suffix; (see fileName). The library remains loaded until the application exits.

The function returns 0 if the symbol could not be resolved or if the library could not be loaded.

See also resolve().

pub unsafe fn resolve_q_string_int_char( file_name: impl CastInto<Ref<QString>>, ver_num: c_int, symbol: *const c_char ) -> Option<extern "C" fn()>

This is an overloaded function.

Calls C++ function: static void (*FN_PTR)() QLibrary::resolve(const QString& fileName, int verNum, const char* symbol).

C++ documentation:

This is an overloaded function.

Loads the library fileName with major version number verNum and returns the address of the exported symbol symbol. Note that fileName should not include the platform-specific file suffix; (see fileName). The library remains loaded until the application exits. verNum is ignored on Windows.

The function returns 0 if the symbol could not be resolved or if the library could not be loaded.

See also resolve().

pub unsafe fn resolve_2_q_string_char( file_name: impl CastInto<Ref<QString>>, version: impl CastInto<Ref<QString>>, symbol: *const c_char ) -> Option<extern "C" fn()>

This is an overloaded function.

Calls C++ function: static void (*FN_PTR)() QLibrary::resolve(const QString& fileName, const QString& version, const char* symbol).

C++ documentation:

This is an overloaded function.

Loads the library fileName with full version number version and returns the address of the exported symbol symbol. Note that fileName should not include the platform-specific file suffix; (see fileName). The library remains loaded until the application exits. version is ignored on Windows.

The function returns 0 if the symbol could not be resolved or if the library could not be loaded.

This function was introduced in Qt 4.4.

See also resolve().

pub unsafe fn set_file_name(&self, file_name: impl CastInto<Ref<QString>>)

This property holds the file name of the library

Calls C++ function: void QLibrary::setFileName(const QString& fileName).

C++ documentation:

This property holds the file name of the library

We recommend omitting the file's suffix in the file name, since QLibrary will automatically look for the file with the appropriate suffix (see isLibrary()).

When loading the library, QLibrary searches in all system-specific library locations (for example, LD_LIBRARY_PATH on Unix), unless the file name has an absolute path. After loading the library successfully, fileName() returns the fully-qualified file name of the library, including the full path to the library if one was given in the constructor or passed to setFileName().

For example, after successfully loading the "GL" library on Unix platforms, fileName() will return "libGL.so". If the file name was originally passed as "/usr/lib/libGL", fileName() will return "/usr/lib/libGL.so".

Access functions:

QString	fileName() const
void	setFileName(const QString &fileName)

pub unsafe fn set_file_name_and_version_q_string_int( &self, file_name: impl CastInto<Ref<QString>>, ver_num: c_int )

Sets the fileName property and major version number to fileName and versionNumber respectively. The versionNumber is ignored on Windows.

Calls C++ function: void QLibrary::setFileNameAndVersion(const QString& fileName, int verNum).

C++ documentation:

Sets the fileName property and major version number to fileName and versionNumber respectively. The versionNumber is ignored on Windows.

See also setFileName().

pub unsafe fn set_file_name_and_version_2_q_string( &self, file_name: impl CastInto<Ref<QString>>, version: impl CastInto<Ref<QString>> )

Sets the fileName property and full version number to fileName and version respectively. The version parameter is ignored on Windows.

Calls C++ function: void QLibrary::setFileNameAndVersion(const QString& fileName, const QString& version).

C++ documentation:

Sets the fileName property and full version number to fileName and version respectively. The version parameter is ignored on Windows.

This function was introduced in Qt 4.4.

See also setFileName().

pub unsafe fn set_load_hints(&self, hints: QFlags<LoadHint>)

Give the load() function some hints on how it should behave.

Calls C++ function: void QLibrary::setLoadHints(QFlags<QLibrary::LoadHint> hints).

C++ documentation:

Give the load() function some hints on how it should behave.

You can give some hints on how the symbols are resolved. Usually, the symbols are not resolved at load time, but resolved lazily, (that is, when resolve() is called). If you set the loadHints to ResolveAllSymbolsHint, then all symbols will be resolved at load time if the platform supports it.

Setting ExportExternalSymbolsHint will make the external symbols in the library available for resolution in subsequent loaded libraries.

If LoadArchiveMemberHint is set, the file name is composed of two components: A path which is a reference to an archive file followed by the second component which is the reference to the archive member. For instance, the fileName libGL.a(shr_64.o) will refer to the library shr_64.o in the archive file named libGL.a. This is only supported on the AIX platform.

The interpretation of the load hints is platform dependent, and if you use it you are probably making some assumptions on which platform you are compiling for, so use them only if you understand the consequences of them.

By default, none of these flags are set, so libraries will be loaded with lazy symbol resolution, and will not export external symbols for resolution in other dynamically-loaded libraries.

Note: Setting this property after the library has been loaded has no effect and loadHints() will not reflect those changes.

Note: This property is shared among all QLibrary instances that refer to the same library.

Access functions:

LoadHints	loadHints() const
void	setLoadHints(LoadHints hints)

pub unsafe fn static_meta_object() -> Ref<QMetaObject>

Returns a reference to the staticMetaObject field.

pub unsafe fn tr( s: *const c_char, c: *const c_char, n: c_int ) -> CppBox<QString>

Calls C++ function: static QString QLibrary::tr(const char* s, const char* c, int n).

pub unsafe fn tr_utf8( s: *const c_char, c: *const c_char, n: c_int ) -> CppBox<QString>

Calls C++ function: static QString QLibrary::trUtf8(const char* s, const char* c, int n).

pub unsafe fn unload(&self) -> bool

Unloads the library and returns true if the library could be unloaded; otherwise returns false.

Calls C++ function: bool QLibrary::unload().

C++ documentation:

Unloads the library and returns true if the library could be unloaded; otherwise returns false.

This happens automatically on application termination, so you shouldn't normally need to call this function.

If other instances of QLibrary are using the same library, the call will fail, and unloading will only happen when every instance has called unload().

Note that on Mac OS X 10.3 (Panther), dynamic libraries cannot be unloaded.

See also resolve() and load().

Methods from Deref<Target = QObject>

pub unsafe fn find_child<T>( &self, name: &str ) -> Result<QPtr<T>, FindChildError>

where QObject: DynamicCast<T>, T: StaticUpcast<QObject>,

Finds a child of self with the specified object name and casts it to type T.

The search is performed recursively. If there is more than one child matching the search, the most direct ancestor is returned. If there are several direct ancestors, it is undefined which one will be returned.

Returns an error if there is no child object with object name name or the found object cannot be cast to T.

pub fn destroyed(&self) -> Signal<(*mut QObject,)>

This signal is emitted immediately before the object obj is destroyed, and can not be blocked.

Returns a built-in Qt signal QObject::destroyed that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted immediately before the object obj is destroyed, and can not be blocked.

All the objects's children are destroyed immediately after this signal is emitted.

See also deleteLater() and QPointer.

pub fn object_name_changed(&self) -> Signal<(*const QString,)>

This signal is emitted after the object's name has been changed. The new object name is passed as objectName.

Returns a built-in Qt signal QObject::objectNameChanged that can be passed to qt_core::Signal::connect.

C++ documentation:

This signal is emitted after the object’s name has been changed. The new object name is passed as objectName.

Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.

Note: Notifier signal for property objectName.

See also QObject::objectName.

pub fn slot_delete_later(&self) -> Receiver<()>

Schedules this object for deletion.

Returns a built-in Qt slot QObject::deleteLater that can be passed to qt_core::Signal::connect.

C++ documentation:

Schedules this object for deletion.

The object will be deleted when control returns to the event loop. If the event loop is not running when this function is called (e.g. deleteLater() is called on an object before QCoreApplication::exec()), the object will be deleted once the event loop is started. If deleteLater() is called after the main event loop has stopped, the object will not be deleted. Since Qt 4.8, if deleteLater() is called on an object that lives in a thread with no running event loop, the object will be destroyed when the thread finishes.

Note that entering and leaving a new event loop (e.g., by opening a modal dialog) will not perform the deferred deletion; for the object to be deleted, the control must return to the event loop from which deleteLater() was called.

Note: It is safe to call this function more than once; when the first deferred deletion event is delivered, any pending events for the object are removed from the event queue.

See also destroyed() and QPointer.

pub unsafe fn block_signals(&self, b: bool) -> bool

If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). If block is false, no such blocking will occur.

Calls C++ function: bool QObject::blockSignals(bool b).

C++ documentation:

If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). If block is false, no such blocking will occur.

The return value is the previous value of signalsBlocked().

Note that the destroyed() signal will be emitted even if the signals for this object have been blocked.

Signals emitted while being blocked are not buffered.

See also signalsBlocked() and QSignalBlocker.

pub unsafe fn children(&self) -> Ref<QListOfQObject>

Returns a list of child objects. The QObjectList class is defined in the <QObject> header file as the following:

Calls C++ function: const QList<QObject*>& QObject::children() const.

C++ documentation:

Returns a list of child objects. The QObjectList class is defined in the <QObject> header file as the following:

  typedef QList<QObject*> QObjectList;

The first child added is the first object in the list and the last child added is the last object in the list, i.e. new children are appended at the end.

Note that the list order changes when QWidget children are raised or lowered. A widget that is raised becomes the last object in the list, and a widget that is lowered becomes the first object in the list.

See also findChild(), findChildren(), parent(), and setParent().

pub unsafe fn delete_later(&self)

Schedules this object for deletion.

Calls C++ function: [slot] void QObject::deleteLater().

C++ documentation:

Schedules this object for deletion.

The object will be deleted when control returns to the event loop. If the event loop is not running when this function is called (e.g. deleteLater() is called on an object before QCoreApplication::exec()), the object will be deleted once the event loop is started. If deleteLater() is called after the main event loop has stopped, the object will not be deleted. Since Qt 4.8, if deleteLater() is called on an object that lives in a thread with no running event loop, the object will be destroyed when the thread finishes.

Note that entering and leaving a new event loop (e.g., by opening a modal dialog) will not perform the deferred deletion; for the object to be deleted, the control must return to the event loop from which deleteLater() was called.

Note: It is safe to call this function more than once; when the first deferred deletion event is delivered, any pending events for the object are removed from the event queue.

See also destroyed() and QPointer.

pub unsafe fn disconnect_char_q_object_char( &self, signal: *const c_char, receiver: impl CastInto<Ptr<QObject>>, member: *const c_char ) -> bool

This function overloads disconnect().

Calls C++ function: bool QObject::disconnect(const char* signal = …, const QObject* receiver = …, const char* member = …) const.

C++ documentation:

This function overloads disconnect().

Disconnects signal from method of receiver.

A signal-slot connection is removed when either of the objects involved are destroyed.

Note: This function is thread-safe.

pub unsafe fn disconnect_q_object_char( &self, receiver: impl CastInto<Ptr<QObject>>, member: *const c_char ) -> bool

This function overloads disconnect().

Calls C++ function: bool QObject::disconnect(const QObject* receiver, const char* member = …) const.

C++ documentation:

This function overloads disconnect().

Disconnects all signals in this object from receiver's method.

A signal-slot connection is removed when either of the objects involved are destroyed.

pub unsafe fn disconnect_char_q_object( &self, signal: *const c_char, receiver: impl CastInto<Ptr<QObject>> ) -> bool

This function overloads disconnect().

Calls C++ function: bool QObject::disconnect(const char* signal = …, const QObject* receiver = …) const.

C++ documentation:

This function overloads disconnect().

Disconnects signal from method of receiver.

A signal-slot connection is removed when either of the objects involved are destroyed.

Note: This function is thread-safe.

pub unsafe fn disconnect_char(&self, signal: *const c_char) -> bool

This function overloads disconnect().

Calls C++ function: bool QObject::disconnect(const char* signal = …) const.

C++ documentation:

This function overloads disconnect().

Disconnects signal from method of receiver.

A signal-slot connection is removed when either of the objects involved are destroyed.

Note: This function is thread-safe.

pub unsafe fn disconnect(&self) -> bool

This function overloads disconnect().

Calls C++ function: bool QObject::disconnect() const.

C++ documentation:

This function overloads disconnect().

Disconnects signal from method of receiver.

A signal-slot connection is removed when either of the objects involved are destroyed.

Note: This function is thread-safe.

pub unsafe fn disconnect_q_object( &self, receiver: impl CastInto<Ptr<QObject>> ) -> bool

This function overloads disconnect().

Calls C++ function: bool QObject::disconnect(const QObject* receiver) const.

C++ documentation:

This function overloads disconnect().

Disconnects all signals in this object from receiver's method.

A signal-slot connection is removed when either of the objects involved are destroyed.

pub unsafe fn dump_object_info_mut(&self)

Dumps information about signal connections, etc. for this object to the debug output.

Calls C++ function: void QObject::dumpObjectInfo().

C++ documentation:

Dumps information about signal connections, etc. for this object to the debug output.

Note: before Qt 5.9, this function was not const.

See also dumpObjectTree().

pub unsafe fn dump_object_info(&self)

Dumps information about signal connections, etc. for this object to the debug output.

Calls C++ function: void QObject::dumpObjectInfo() const.

C++ documentation:

Dumps information about signal connections, etc. for this object to the debug output.

Note: before Qt 5.9, this function was not const.

See also dumpObjectTree().

pub unsafe fn dump_object_tree_mut(&self)

Dumps a tree of children to the debug output.

Calls C++ function: void QObject::dumpObjectTree().

C++ documentation:

Dumps a tree of children to the debug output.

Note: before Qt 5.9, this function was not const.

See also dumpObjectInfo().

pub unsafe fn dump_object_tree(&self)

Dumps a tree of children to the debug output.

Calls C++ function: void QObject::dumpObjectTree() const.

C++ documentation:

Dumps a tree of children to the debug output.

Note: before Qt 5.9, this function was not const.

See also dumpObjectInfo().

pub unsafe fn dynamic_property_names(&self) -> CppBox<QListOfQByteArray>

Returns the names of all properties that were dynamically added to the object using setProperty().

Calls C++ function: QList<QByteArray> QObject::dynamicPropertyNames() const.

C++ documentation:

Returns the names of all properties that were dynamically added to the object using setProperty().

This function was introduced in Qt 4.2.

pub unsafe fn eq(&self, p: impl CastInto<Ref<QPointerOfQObject>>) -> bool

Returns true if c1 and c2 are the same Unicode character; otherwise returns false.

Calls C++ function: bool operator==(QObject* o, const QPointer<QObject>& p).

Warning: no exact match found in C++ documentation. Below is the C++ documentation for bool operator==(QChar c1, QChar c2):

Returns true if c1 and c2 are the same Unicode character; otherwise returns false.

pub unsafe fn event(&self, event: impl CastInto<Ptr<QEvent>>) -> bool

This virtual function receives events to an object and should return true if the event e was recognized and processed.

Calls C++ function: virtual bool QObject::event(QEvent* event).

C++ documentation:

This virtual function receives events to an object and should return true if the event e was recognized and processed.

The event() function can be reimplemented to customize the behavior of an object.

Make sure you call the parent event class implementation for all the events you did not handle.

Example:

class MyClass : public QWidget
{
      Q_OBJECT
public:
      MyClass(QWidget *parent = 0);
      ~MyClass();
      bool event(QEvent* ev)
      {
          if (ev->type() == QEvent::PolishRequest) {
              // overwrite handling of PolishRequest if any
              doThings();
              return true;
          } else  if (ev->type() == QEvent::Show) {
              // complement handling of Show if any
              doThings2();
              QWidget::event(ev);
              return true;
          }
          // Make sure the rest of events are handled
          return QWidget::event(ev);
      }
};

See also installEventFilter(), timerEvent(), QCoreApplication::sendEvent(), and QCoreApplication::postEvent().

pub unsafe fn event_filter( &self, watched: impl CastInto<Ptr<QObject>>, event: impl CastInto<Ptr<QEvent>> ) -> bool

Filters events if this object has been installed as an event filter for the watched object.

Calls C++ function: virtual bool QObject::eventFilter(QObject* watched, QEvent* event).

C++ documentation:

Filters events if this object has been installed as an event filter for the watched object.

In your reimplementation of this function, if you want to filter the event out, i.e. stop it being handled further, return true; otherwise return false.

Example:

class MainWindow : public QMainWindow
{
public:
      MainWindow();
protected:
      bool eventFilter(QObject obj, QEvent ev);
private:
      QTextEdit *textEdit;
};
MainWindow::MainWindow()
{
      textEdit = new QTextEdit;
      setCentralWidget(textEdit);
      textEdit->installEventFilter(this);
}
bool MainWindow::eventFilter(QObject obj, QEvent event)
{
      if (obj == textEdit) {
          if (event->type() == QEvent::KeyPress) {
              QKeyEvent keyEvent = static_cast<QKeyEvent>(event);
              qDebug() << “Ate key press” << keyEvent->key();
              return true;
          } else {
              return false;
          }
      } else {
          // pass the event on to the parent class
          return QMainWindow::eventFilter(obj, event);
      }
}

Notice in the example above that unhandled events are passed to the base class's eventFilter() function, since the base class might have reimplemented eventFilter() for its own internal purposes.

Warning: If you delete the receiver object in this function, be sure to return true. Otherwise, Qt will forward the event to the deleted object and the program might crash.

See also installEventFilter().

pub unsafe fn find_child_q_object_2a( &self, a_name: impl CastInto<Ref<QString>>, options: QFlags<FindChildOption> ) -> QPtr<QObject>

Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

Calls C++ function: QObject* QObject::findChild<QObject*>(const QString& aName = …, QFlags<Qt::FindChildOption> options = …) const.

C++ documentation:

Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

If there is more than one child matching the search, the most direct ancestor is returned. If there are several direct ancestors, it is undefined which one will be returned. In that case, findChildren() should be used.

This example returns a child QPushButton of parentWidget named "button1", even if the button isn't a direct child of the parent:

QPushButton button = parentWidget->findChild<QPushButton >(“button1”);

This example returns a QListWidget child of parentWidget:

QListWidget list = parentWidget->findChild<QListWidget >();

This example returns a child QPushButton of parentWidget (its direct parent) named "button1":

QPushButton button = parentWidget->findChild<QPushButton >(“button1”, Qt::FindDirectChildrenOnly);

This example returns a QListWidget child of parentWidget, its direct parent:

QListWidget list = parentWidget->findChild<QListWidget >(QString(), Qt::FindDirectChildrenOnly);

See also findChildren().

pub unsafe fn find_child_q_object_1a( &self, a_name: impl CastInto<Ref<QString>> ) -> QPtr<QObject>

Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

Calls C++ function: QObject* QObject::findChild<QObject*>(const QString& aName = …) const.

C++ documentation:

Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

If there is more than one child matching the search, the most direct ancestor is returned. If there are several direct ancestors, it is undefined which one will be returned. In that case, findChildren() should be used.

This example returns a child QPushButton of parentWidget named "button1", even if the button isn't a direct child of the parent:

QPushButton button = parentWidget->findChild<QPushButton >(“button1”);

This example returns a QListWidget child of parentWidget:

QListWidget list = parentWidget->findChild<QListWidget >();

This example returns a child QPushButton of parentWidget (its direct parent) named "button1":

QPushButton button = parentWidget->findChild<QPushButton >(“button1”, Qt::FindDirectChildrenOnly);

This example returns a QListWidget child of parentWidget, its direct parent:

QListWidget list = parentWidget->findChild<QListWidget >(QString(), Qt::FindDirectChildrenOnly);

See also findChildren().

pub unsafe fn find_child_q_object_0a(&self) -> QPtr<QObject>

Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

Calls C++ function: QObject* QObject::findChild<QObject*>() const.

C++ documentation:

Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

If there is more than one child matching the search, the most direct ancestor is returned. If there are several direct ancestors, it is undefined which one will be returned. In that case, findChildren() should be used.

This example returns a child QPushButton of parentWidget named "button1", even if the button isn't a direct child of the parent:

QPushButton button = parentWidget->findChild<QPushButton >(“button1”);

This example returns a QListWidget child of parentWidget:

QListWidget list = parentWidget->findChild<QListWidget >();

This example returns a child QPushButton of parentWidget (its direct parent) named "button1":

QPushButton button = parentWidget->findChild<QPushButton >(“button1”, Qt::FindDirectChildrenOnly);

This example returns a QListWidget child of parentWidget, its direct parent:

QListWidget list = parentWidget->findChild<QListWidget >(QString(), Qt::FindDirectChildrenOnly);

See also findChildren().

pub unsafe fn find_children_q_object_q_string_q_flags_find_child_option( &self, a_name: impl CastInto<Ref<QString>>, options: QFlags<FindChildOption> ) -> CppBox<QListOfQObject>

Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>(const QString& aName = …, QFlags<Qt::FindChildOption> options = …) const.

C++ documentation:

Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

The following example shows how to find a list of child QWidgets of the specified parentWidget named widgetname:

QList<QWidget > widgets = parentWidget.findChildren<QWidget >(“widgetname”);

This example returns all QPushButtons that are children of parentWidget:

QList<QPushButton > allPButtons = parentWidget.findChildren<QPushButton >();

This example returns all QPushButtons that are immediate children of parentWidget:

QList<QPushButton > childButtons = parentWidget.findChildren<QPushButton >(QString(), Qt::FindDirectChildrenOnly);

See also findChild().

pub unsafe fn find_children_q_object_q_reg_exp_q_flags_find_child_option( &self, re: impl CastInto<Ref<QRegExp>>, options: QFlags<FindChildOption> ) -> CppBox<QListOfQObject>

This function overloads findChildren().

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>(const QRegExp& re, QFlags<Qt::FindChildOption> options = …) const.

C++ documentation:

This function overloads findChildren().

Returns the children of this object that can be cast to type T and that have names matching the regular expression regExp, or an empty list if there are no such objects. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

pub unsafe fn find_children_q_object_q_regular_expression_q_flags_find_child_option( &self, re: impl CastInto<Ref<QRegularExpression>>, options: QFlags<FindChildOption> ) -> CppBox<QListOfQObject>

This function overloads findChildren().

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>(const QRegularExpression& re, QFlags<Qt::FindChildOption> options = …) const.

C++ documentation:

This function overloads findChildren().

Returns the children of this object that can be cast to type T and that have names matching the regular expression re, or an empty list if there are no such objects. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

This function was introduced in Qt 5.0.

pub unsafe fn find_children_q_object_q_string( &self, a_name: impl CastInto<Ref<QString>> ) -> CppBox<QListOfQObject>

Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>(const QString& aName = …) const.

C++ documentation:

Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

The following example shows how to find a list of child QWidgets of the specified parentWidget named widgetname:

QList<QWidget > widgets = parentWidget.findChildren<QWidget >(“widgetname”);

This example returns all QPushButtons that are children of parentWidget:

QList<QPushButton > allPButtons = parentWidget.findChildren<QPushButton >();

This example returns all QPushButtons that are immediate children of parentWidget:

QList<QPushButton > childButtons = parentWidget.findChildren<QPushButton >(QString(), Qt::FindDirectChildrenOnly);

See also findChild().

pub unsafe fn find_children_q_object(&self) -> CppBox<QListOfQObject>

Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>() const.

C++ documentation:

Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. Omitting the name argument causes all object names to be matched. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

The following example shows how to find a list of child QWidgets of the specified parentWidget named widgetname:

QList<QWidget > widgets = parentWidget.findChildren<QWidget >(“widgetname”);

This example returns all QPushButtons that are children of parentWidget:

QList<QPushButton > allPButtons = parentWidget.findChildren<QPushButton >();

This example returns all QPushButtons that are immediate children of parentWidget:

QList<QPushButton > childButtons = parentWidget.findChildren<QPushButton >(QString(), Qt::FindDirectChildrenOnly);

See also findChild().

pub unsafe fn find_children_q_object_q_reg_exp( &self, re: impl CastInto<Ref<QRegExp>> ) -> CppBox<QListOfQObject>

This function overloads findChildren().

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>(const QRegExp& re) const.

C++ documentation:

This function overloads findChildren().

Returns the children of this object that can be cast to type T and that have names matching the regular expression regExp, or an empty list if there are no such objects. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

pub unsafe fn find_children_q_object_q_regular_expression( &self, re: impl CastInto<Ref<QRegularExpression>> ) -> CppBox<QListOfQObject>

This function overloads findChildren().

Calls C++ function: QList<QObject*> QObject::findChildren<QObject*>(const QRegularExpression& re) const.

C++ documentation:

This function overloads findChildren().

Returns the children of this object that can be cast to type T and that have names matching the regular expression re, or an empty list if there are no such objects. The search is performed recursively, unless options specifies the option FindDirectChildrenOnly.

This function was introduced in Qt 5.0.

pub unsafe fn inherits(&self, classname: *const c_char) -> bool

Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false.

Calls C++ function: bool QObject::inherits(const char* classname) const.

C++ documentation:

Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false.

A class is considered to inherit itself.

Example:

QTimer *timer = new QTimer;         // QTimer inherits QObject
timer->inherits(“QTimer”);          // returns true
timer->inherits(“QObject”);         // returns true
timer->inherits(“QAbstractButton”); // returns false
// QVBoxLayout inherits QObject and QLayoutItem
QVBoxLayout *layout = new QVBoxLayout;
layout->inherits(“QObject”);        // returns true
layout->inherits(“QLayoutItem”);    // returns true (even though QLayoutItem is not a QObject)

If you need to determine whether an object is an instance of a particular class for the purpose of casting it, consider using qobject_cast<Type *>(object) instead.

See also metaObject() and qobject_cast().

pub unsafe fn install_event_filter( &self, filter_obj: impl CastInto<Ptr<QObject>> )

Installs an event filter filterObj on this object. For example:

Calls C++ function: void QObject::installEventFilter(QObject* filterObj).

C++ documentation:

Installs an event filter filterObj on this object. For example:

  monitoredObj->installEventFilter(filterObj);

An event filter is an object that receives all events that are sent to this object. The filter can either stop the event or forward it to this object. The event filter filterObj receives events via its eventFilter() function. The eventFilter() function must return true if the event should be filtered, (i.e. stopped); otherwise it must return false.

If multiple event filters are installed on a single object, the filter that was installed last is activated first.

Here's a KeyPressEater class that eats the key presses of its monitored objects:

class KeyPressEater : public QObject
{
      Q_OBJECT
      ...
protected:
      bool eventFilter(QObject obj, QEvent event);
};
bool KeyPressEater::eventFilter(QObject obj, QEvent event)
{
      if (event->type() == QEvent::KeyPress) {
          QKeyEvent keyEvent = static_cast<QKeyEvent >(event);
          qDebug(“Ate key press %d”, keyEvent->key());
          return true;
      } else {
          // standard event processing
          return QObject::eventFilter(obj, event);
      }
}

And here's how to install it on two widgets:

KeyPressEater keyPressEater = new KeyPressEater(this);
QPushButton pushButton = new QPushButton(this);
QListView *listView = new QListView(this);
pushButton->installEventFilter(keyPressEater);
listView->installEventFilter(keyPressEater);

The QShortcut class, for example, uses this technique to intercept shortcut key presses.

Warning: If you delete the receiver object in your eventFilter() function, be sure to return true. If you return false, Qt sends the event to the deleted object and the program will crash.

Note that the filtering object must be in the same thread as this object. If filterObj is in a different thread, this function does nothing. If either filterObj or this object are moved to a different thread after calling this function, the event filter will not be called until both objects have the same thread affinity again (it is not removed).

See also removeEventFilter(), eventFilter(), and event().

pub unsafe fn is_widget_type(&self) -> bool

Returns true if the object is a widget; otherwise returns false.

Calls C++ function: bool QObject::isWidgetType() const.

C++ documentation:

Returns true if the object is a widget; otherwise returns false.

Calling this function is equivalent to calling inherits("QWidget"), except that it is much faster.

pub unsafe fn is_window_type(&self) -> bool

Returns true if the object is a window; otherwise returns false.

Calls C++ function: bool QObject::isWindowType() const.

C++ documentation:

Returns true if the object is a window; otherwise returns false.

Calling this function is equivalent to calling inherits("QWindow"), except that it is much faster.

pub unsafe fn kill_timer(&self, id: c_int)

Kills the timer with timer identifier, id.

Calls C++ function: void QObject::killTimer(int id).

C++ documentation:

Kills the timer with timer identifier, id.

The timer identifier is returned by startTimer() when a timer event is started.

See also timerEvent() and startTimer().

pub unsafe fn meta_object(&self) -> Ptr<QMetaObject>

Returns a pointer to the meta-object of this object.

Calls C++ function: virtual const QMetaObject* QObject::metaObject() const.

C++ documentation:

Returns a pointer to the meta-object of this object.

A meta-object contains information about a class that inherits QObject, e.g. class name, superclass name, properties, signals and slots. Every QObject subclass that contains the Q_OBJECT macro will have a meta-object.

The meta-object information is required by the signal/slot connection mechanism and the property system. The inherits() function also makes use of the meta-object.

If you have no pointer to an actual object instance but still want to access the meta-object of a class, you can use staticMetaObject.

Example:

QObject *obj = new QPushButton;
obj->metaObject()->className();             // returns “QPushButton”
QPushButton::staticMetaObject.className();  // returns “QPushButton”

See also staticMetaObject.

pub unsafe fn move_to_thread(&self, thread: impl CastInto<Ptr<QThread>>)

Changes the thread affinity for this object and its children. The object cannot be moved if it has a parent. Event processing will continue in the targetThread.

Calls C++ function: void QObject::moveToThread(QThread* thread).

C++ documentation:

Changes the thread affinity for this object and its children. The object cannot be moved if it has a parent. Event processing will continue in the targetThread.

To move an object to the main thread, use QApplication::instance() to retrieve a pointer to the current application, and then use QApplication::thread() to retrieve the thread in which the application lives. For example:

myObject->moveToThread(QApplication::instance()->thread());

If targetThread is zero, all event processing for this object and its children stops.

Note that all active timers for the object will be reset. The timers are first stopped in the current thread and restarted (with the same interval) in the targetThread. As a result, constantly moving an object between threads can postpone timer events indefinitely.

A QEvent::ThreadChange event is sent to this object just before the thread affinity is changed. You can handle this event to perform any special processing. Note that any new events that are posted to this object will be handled in the targetThread.

Warning: This function is not thread-safe; the current thread must be same as the current thread affinity. In other words, this function can only "push" an object from the current thread to another thread, it cannot "pull" an object from any arbitrary thread to the current thread.

See also thread().

pub unsafe fn object_name(&self) -> CppBox<QString>

This property holds the name of this object

Calls C++ function: QString QObject::objectName() const.

C++ documentation:

This property holds the name of this object

You can find an object by name (and type) using findChild(). You can find a set of objects with findChildren().

qDebug(“MyClass::setPrecision(): (%s) invalid precision %f”,
         qPrintable(objectName()), newPrecision);

By default, this property contains an empty string.

Access functions:

QString	objectName() const
void	setObjectName(const QString &name)

Notifier signal:

void

objectNameChanged(const QString &objectName)

[see note below]

Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.

See also metaObject() and QMetaObject::className().

pub unsafe fn parent(&self) -> QPtr<QObject>

Returns a pointer to the parent object.

Calls C++ function: QObject* QObject::parent() const.

C++ documentation:

Returns a pointer to the parent object.

See also setParent() and children().

pub unsafe fn property(&self, name: *const c_char) -> CppBox<QVariant>

Returns the value of the object's name property.

Calls C++ function: QVariant QObject::property(const char* name) const.

C++ documentation:

Returns the value of the object’s name property.

If no such property exists, the returned variant is invalid.

Information about all available properties is provided through the metaObject() and dynamicPropertyNames().

See also setProperty(), QVariant::isValid(), metaObject(), and dynamicPropertyNames().

pub unsafe fn qt_metacall( &self, arg1: Call, arg2: c_int, arg3: *mut *mut c_void ) -> c_int

Calls C++ function: virtual int QObject::qt_metacall(QMetaObject::Call arg1, int arg2, void** arg3).

pub unsafe fn qt_metacast(&self, arg1: *const c_char) -> *mut c_void

Calls C++ function: virtual void* QObject::qt_metacast(const char* arg1).

pub unsafe fn remove_event_filter(&self, obj: impl CastInto<Ptr<QObject>>)

Removes an event filter object obj from this object. The request is ignored if such an event filter has not been installed.

Calls C++ function: void QObject::removeEventFilter(QObject* obj).

C++ documentation:

Removes an event filter object obj from this object. The request is ignored if such an event filter has not been installed.

All event filters for this object are automatically removed when this object is destroyed.

It is always safe to remove an event filter, even during event filter activation (i.e. from the eventFilter() function).

See also installEventFilter(), eventFilter(), and event().

pub unsafe fn set_object_name(&self, name: impl CastInto<Ref<QString>>)

This property holds the name of this object

Calls C++ function: void QObject::setObjectName(const QString& name).

C++ documentation:

This property holds the name of this object

You can find an object by name (and type) using findChild(). You can find a set of objects with findChildren().

qDebug(“MyClass::setPrecision(): (%s) invalid precision %f”,
         qPrintable(objectName()), newPrecision);

By default, this property contains an empty string.

Access functions:

QString	objectName() const
void	setObjectName(const QString &name)

Notifier signal:

void

objectNameChanged(const QString &objectName)

[see note below]

Note: This is a private signal. It can be used in signal connections but cannot be emitted by the user.

See also metaObject() and QMetaObject::className().

pub unsafe fn set_parent(&self, parent: impl CastInto<Ptr<QObject>>)

Makes the object a child of parent.

Calls C++ function: void QObject::setParent(QObject* parent).

C++ documentation:

Makes the object a child of parent.

See also parent() and children().

pub unsafe fn set_property( &self, name: *const c_char, value: impl CastInto<Ref<QVariant>> ) -> bool

Sets the value of the object's name property to value.

Calls C++ function: bool QObject::setProperty(const char* name, const QVariant& value).

C++ documentation:

Sets the value of the object’s name property to value.

If the property is defined in the class using Q_PROPERTY then true is returned on success and false otherwise. If the property is not defined using Q_PROPERTY, and therefore not listed in the meta-object, it is added as a dynamic property and false is returned.

Information about all available properties is provided through the metaObject() and dynamicPropertyNames().

Dynamic properties can be queried again using property() and can be removed by setting the property value to an invalid QVariant. Changing the value of a dynamic property causes a QDynamicPropertyChangeEvent to be sent to the object.

Note: Dynamic properties starting with "_q_" are reserved for internal purposes.

See also property(), metaObject(), dynamicPropertyNames(), and QMetaProperty::write().

pub unsafe fn signals_blocked(&self) -> bool

Returns true if signals are blocked; otherwise returns false.

Calls C++ function: bool QObject::signalsBlocked() const.

C++ documentation:

Returns true if signals are blocked; otherwise returns false.

Signals are not blocked by default.

See also blockSignals() and QSignalBlocker.

pub unsafe fn start_timer_2a( &self, interval: c_int, timer_type: TimerType ) -> c_int

Starts a timer and returns a timer identifier, or returns zero if it could not start a timer.

Calls C++ function: int QObject::startTimer(int interval, Qt::TimerType timerType = …).

C++ documentation:

Starts a timer and returns a timer identifier, or returns zero if it could not start a timer.

A timer event will occur every interval milliseconds until killTimer() is called. If interval is 0, then the timer event occurs once every time there are no more window system events to process.

The virtual timerEvent() function is called with the QTimerEvent event parameter class when a timer event occurs. Reimplement this function to get timer events.

If multiple timers are running, the QTimerEvent::timerId() can be used to find out which timer was activated.

Example:

class MyObject : public QObject
{
      Q_OBJECT
public:
      MyObject(QObject *parent = 0);
protected:
      void timerEvent(QTimerEvent *event);
};
MyObject::MyObject(QObject *parent)
      : QObject(parent)
{
      startTimer(50);     // 50-millisecond timer
      startTimer(1000);   // 1-second timer
      startTimer(60000);  // 1-minute timer
      using namespace std::chrono;
      startTimer(milliseconds(50));
      startTimer(seconds(1));
      startTimer(minutes(1));
      // since C++14 we can use std::chrono::duration literals, e.g.:
      startTimer(100ms);
      startTimer(5s);
      startTimer(2min);
      startTimer(1h);
}
void MyObject::timerEvent(QTimerEvent *event)
{
      qDebug() << “Timer ID:” << event->timerId();
}

Note that QTimer's accuracy depends on the underlying operating system and hardware. The timerType argument allows you to customize the accuracy of the timer. See Qt::TimerType for information on the different timer types. Most platforms support an accuracy of 20 milliseconds; some provide more. If Qt is unable to deliver the requested number of timer events, it will silently discard some.

The QTimer class provides a high-level programming interface with single-shot timers and timer signals instead of events. There is also a QBasicTimer class that is more lightweight than QTimer and less clumsy than using timer IDs directly.

See also timerEvent(), killTimer(), and QTimer::singleShot().

pub unsafe fn start_timer_1a(&self, interval: c_int) -> c_int

Starts a timer and returns a timer identifier, or returns zero if it could not start a timer.

Calls C++ function: int QObject::startTimer(int interval).

C++ documentation:

Starts a timer and returns a timer identifier, or returns zero if it could not start a timer.

A timer event will occur every interval milliseconds until killTimer() is called. If interval is 0, then the timer event occurs once every time there are no more window system events to process.

The virtual timerEvent() function is called with the QTimerEvent event parameter class when a timer event occurs. Reimplement this function to get timer events.

If multiple timers are running, the QTimerEvent::timerId() can be used to find out which timer was activated.

Example:

class MyObject : public QObject
{
      Q_OBJECT
public:
      MyObject(QObject *parent = 0);
protected:
      void timerEvent(QTimerEvent *event);
};
MyObject::MyObject(QObject *parent)
      : QObject(parent)
{
      startTimer(50);     // 50-millisecond timer
      startTimer(1000);   // 1-second timer
      startTimer(60000);  // 1-minute timer
      using namespace std::chrono;
      startTimer(milliseconds(50));
      startTimer(seconds(1));
      startTimer(minutes(1));
      // since C++14 we can use std::chrono::duration literals, e.g.:
      startTimer(100ms);
      startTimer(5s);
      startTimer(2min);
      startTimer(1h);
}
void MyObject::timerEvent(QTimerEvent *event)
{
      qDebug() << “Timer ID:” << event->timerId();
}

Note that QTimer's accuracy depends on the underlying operating system and hardware. The timerType argument allows you to customize the accuracy of the timer. See Qt::TimerType for information on the different timer types. Most platforms support an accuracy of 20 milliseconds; some provide more. If Qt is unable to deliver the requested number of timer events, it will silently discard some.

The QTimer class provides a high-level programming interface with single-shot timers and timer signals instead of events. There is also a QBasicTimer class that is more lightweight than QTimer and less clumsy than using timer IDs directly.

See also timerEvent(), killTimer(), and QTimer::singleShot().

pub unsafe fn thread(&self) -> QPtr<QThread>

Returns the thread in which the object lives.

Calls C++ function: QThread* QObject::thread() const.

C++ documentation:

Returns the thread in which the object lives.

See also moveToThread().

Trait Implementations

impl CppDeletable for QLibrary

unsafe fn delete(&self)

Destroys the QLibrary object.

Calls C++ function: virtual [destructor] void QLibrary::~QLibrary().

C++ documentation:

Destroys the QLibrary object.

Unless unload() was called explicitly, the library stays in memory until the application terminates.

See also isLoaded() and unload().

impl Deref for QLibrary

fn deref(&self) -> &QObject

Calls C++ function: QObject* static_cast<QObject*>(QLibrary* ptr).

type Target = QObject

The resulting type after dereferencing.

impl DynamicCast<QLibrary> for QObject

unsafe fn dynamic_cast(ptr: Ptr<QObject>) -> Ptr<QLibrary>

Calls C++ function: QLibrary* dynamic_cast<QLibrary*>(QObject* ptr).

impl StaticDowncast<QLibrary> for QObject

unsafe fn static_downcast(ptr: Ptr<QObject>) -> Ptr<QLibrary>

Calls C++ function: QLibrary* static_cast<QLibrary*>(QObject* ptr).

impl StaticUpcast<QObject> for QLibrary

unsafe fn static_upcast(ptr: Ptr<QLibrary>) -> Ptr<QObject>

Calls C++ function: QObject* static_cast<QObject*>(QLibrary* ptr).