Struct QSettings

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

The QSettings class provides persistent platform-independent application settings.

C++ class: QSettings.

C++ documentation:

The QSettings class provides persistent platform-independent application settings.

Users normally expect an application to remember its settings (window sizes and positions, options, etc.) across sessions. This information is often stored in the system registry on Windows, and in property list files on macOS and iOS. On Unix systems, in the absence of a standard, many applications (including the KDE applications) use INI text files.

QSettings is an abstraction around these technologies, enabling you to save and restore application settings in a portable manner. It also supports custom storage formats.

QSettings's API is based on QVariant, allowing you to save most value-based types, such as QString, QRect, and QImage, with the minimum of effort.

If all you need is a non-persistent memory-based structure, consider using QMap<QString, QVariant> instead.

Implementations

impl QSettings

pub unsafe fn all_keys(&self) -> CppBox<QStringList>

Returns a list of all keys, including subkeys, that can be read using the QSettings object.

Calls C++ function: QStringList QSettings::allKeys() const.

C++ documentation:

Returns a list of all keys, including subkeys, that can be read using the QSettings object.

Example:

QSettings settings;
settings.setValue(“fridge/color”, QColor(Qt::white));
settings.setValue(“fridge/size”, QSize(32, 96));
settings.setValue(“sofa”, true);
settings.setValue(“tv”, false);
QStringList keys = settings.allKeys();
// keys: [“fridge/color”, “fridge/size”, “sofa”, “tv”]

If a group is set using beginGroup(), only the keys in the group are returned, without the group prefix:

settings.beginGroup(“fridge”);
keys = settings.allKeys();
// keys: [“color”, “size”]

See also childGroups() and childKeys().

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

Returns the application name used for storing the settings.

Calls C++ function: QString QSettings::applicationName() const.

C++ documentation:

Returns the application name used for storing the settings.

This function was introduced in Qt 4.4.

See also QCoreApplication::applicationName(), format(), scope(), and organizationName().

pub unsafe fn begin_group(&self, prefix: impl CastInto<Ref<QString>>)

Appends prefix to the current group.

Calls C++ function: void QSettings::beginGroup(const QString& prefix).

C++ documentation:

Appends prefix to the current group.

The current group is automatically prepended to all keys specified to QSettings. In addition, query functions such as childGroups(), childKeys(), and allKeys() are based on the group. By default, no group is set.

Groups are useful to avoid typing in the same setting paths over and over. For example:

settings.beginGroup(“mainwindow”);
settings.setValue(“size”, win->size());
settings.setValue(“fullScreen”, win->isFullScreen());
settings.endGroup();
settings.beginGroup(“outputpanel”);
settings.setValue(“visible”, panel->isVisible());
settings.endGroup();

This will set the value of three settings:

• mainwindow/size
• mainwindow/fullScreen
• outputpanel/visible

Call endGroup() to reset the current group to what it was before the corresponding beginGroup() call. Groups can be nested.

See also endGroup() and group().

pub unsafe fn begin_read_array( &self, prefix: impl CastInto<Ref<QString>>, ) -> c_int

Adds prefix to the current group and starts reading from an array. Returns the size of the array.

Calls C++ function: int QSettings::beginReadArray(const QString& prefix).

C++ documentation:

Adds prefix to the current group and starts reading from an array. Returns the size of the array.

Example:

struct Login {
      QString userName;
      QString password;
};
QList<Login> logins;
...
QSettings settings;
int size = settings.beginReadArray(“logins”);
for (int i = 0; i < size; ++i) {
      settings.setArrayIndex(i);
      Login login;
      login.userName = settings.value(“userName”).toString();
      login.password = settings.value(“password”).toString();
      logins.append(login);
}
settings.endArray();

Use beginWriteArray() to write the array in the first place.

See also beginWriteArray(), endArray(), and setArrayIndex().

pub unsafe fn begin_write_array_2a( &self, prefix: impl CastInto<Ref<QString>>, size: c_int, )

Adds prefix to the current group and starts writing an array of size size. If size is -1 (the default), it is automatically determined based on the indexes of the entries written.

Calls C++ function: void QSettings::beginWriteArray(const QString& prefix, int size = …).

C++ documentation:

Adds prefix to the current group and starts writing an array of size size. If size is -1 (the default), it is automatically determined based on the indexes of the entries written.

If you have many occurrences of a certain set of keys, you can use arrays to make your life easier. For example, let's suppose that you want to save a variable-length list of user names and passwords. You could then write:

struct Login {
      QString userName;
      QString password;
};
QList<Login> logins;
...
QSettings settings;
settings.beginWriteArray(“logins”);
for (int i = 0; i < logins.size(); ++i) {
      settings.setArrayIndex(i);
      settings.setValue(“userName”, list.at(i).userName);
      settings.setValue(“password”, list.at(i).password);
}
settings.endArray();

The generated keys will have the form

• logins/size
• logins/1/userName
• logins/1/password
• logins/2/userName
• logins/2/password
• logins/3/userName
• logins/3/password
• ...

To read back an array, use beginReadArray().

See also beginReadArray(), endArray(), and setArrayIndex().

pub unsafe fn begin_write_array_1a(&self, prefix: impl CastInto<Ref<QString>>)

Adds prefix to the current group and starts writing an array of size size. If size is -1 (the default), it is automatically determined based on the indexes of the entries written.

Calls C++ function: void QSettings::beginWriteArray(const QString& prefix).

C++ documentation:

Adds prefix to the current group and starts writing an array of size size. If size is -1 (the default), it is automatically determined based on the indexes of the entries written.

If you have many occurrences of a certain set of keys, you can use arrays to make your life easier. For example, let's suppose that you want to save a variable-length list of user names and passwords. You could then write:

struct Login {
      QString userName;
      QString password;
};
QList<Login> logins;
...
QSettings settings;
settings.beginWriteArray(“logins”);
for (int i = 0; i < logins.size(); ++i) {
      settings.setArrayIndex(i);
      settings.setValue(“userName”, list.at(i).userName);
      settings.setValue(“password”, list.at(i).password);
}
settings.endArray();

The generated keys will have the form

• logins/size
• logins/1/userName
• logins/1/password
• logins/2/userName
• logins/2/password
• logins/3/userName
• logins/3/password
• ...

To read back an array, use beginReadArray().

See also beginReadArray(), endArray(), and setArrayIndex().

pub unsafe fn child_groups(&self) -> CppBox<QStringList>

Returns a list of all key top-level groups that contain keys that can be read using the QSettings object.

Calls C++ function: QStringList QSettings::childGroups() const.

C++ documentation:

Returns a list of all key top-level groups that contain keys that can be read using the QSettings object.

Example:

QSettings settings;
settings.setValue(“fridge/color”, QColor(Qt::white));
settings.setValue(“fridge/size”, QSize(32, 96));
settings.setValue(“sofa”, true);
settings.setValue(“tv”, false);
QStringList groups = settings.childGroups();
// groups: [“fridge”]

If a group is set using beginGroup(), the first-level keys in that group are returned, without the group prefix.

settings.beginGroup(“fridge”);
groups = settings.childGroups();
// groups: []

You can navigate through the entire setting hierarchy using childKeys() and childGroups() recursively.

See also childKeys() and allKeys().

pub unsafe fn child_keys(&self) -> CppBox<QStringList>

Returns a list of all top-level keys that can be read using the QSettings object.

Calls C++ function: QStringList QSettings::childKeys() const.

C++ documentation:

Returns a list of all top-level keys that can be read using the QSettings object.

Example:

QSettings settings;
settings.setValue(“fridge/color”, QColor(Qt::white));
settings.setValue(“fridge/size”, QSize(32, 96));
settings.setValue(“sofa”, true);
settings.setValue(“tv”, false);
QStringList keys = settings.childKeys();
// keys: [“sofa”, “tv”]

If a group is set using beginGroup(), the top-level keys in that group are returned, without the group prefix:

settings.beginGroup(“fridge”);
keys = settings.childKeys();
// keys: [“color”, “size”]

You can navigate through the entire setting hierarchy using childKeys() and childGroups() recursively.

See also childGroups() and allKeys().

pub unsafe fn clear(&self)

Removes all entries in the primary location associated to this QSettings object.

Calls C++ function: void QSettings::clear().

C++ documentation:

Removes all entries in the primary location associated to this QSettings object.

Entries in fallback locations are not removed.

If you only want to remove the entries in the current group(), use remove("") instead.

See also remove() and setFallbacksEnabled().

pub unsafe fn contains(&self, key: impl CastInto<Ref<QString>>) -> bool

Returns true if there exists a setting called key; returns false otherwise.

Calls C++ function: bool QSettings::contains(const QString& key) const.

C++ documentation:

Returns true if there exists a setting called key; returns false otherwise.

If a group is set using beginGroup(), key is taken to be relative to that group.

Note that the Windows registry and INI files use case-insensitive keys, whereas the CFPreferences API on macOS and iOS uses case-sensitive keys. To avoid portability problems, see the Section and Key Syntax rules.

See also value() and setValue().

pub unsafe fn default_format() -> Format

Returns default file format used for storing settings for the QSettings(QObject *) constructor. If no default format is set, QSettings::NativeFormat is used.

Calls C++ function: static QSettings::Format QSettings::defaultFormat().

C++ documentation:

Returns default file format used for storing settings for the QSettings(QObject *) constructor. If no default format is set, QSettings::NativeFormat is used.

This function was introduced in Qt 4.4.

See also setDefaultFormat() and format().

pub unsafe fn end_array(&self)

Closes the array that was started using beginReadArray() or beginWriteArray().

Calls C++ function: void QSettings::endArray().

C++ documentation:

Closes the array that was started using beginReadArray() or beginWriteArray().

See also beginReadArray() and beginWriteArray().

pub unsafe fn end_group(&self)

Resets the group to what it was before the corresponding beginGroup() call.

Calls C++ function: void QSettings::endGroup().

C++ documentation:

Resets the group to what it was before the corresponding beginGroup() call.

Example:

settings.beginGroup(“alpha”);
// settings.group() == “alpha”
settings.beginGroup(“beta”);
// settings.group() == “alpha/beta”
settings.endGroup();
// settings.group() == “alpha”
settings.endGroup();
// settings.group() == “”

See also beginGroup() and group().

pub unsafe fn fallbacks_enabled(&self) -> bool

Returns true if fallbacks are enabled; returns false otherwise.

Calls C++ function: bool QSettings::fallbacksEnabled() const.

C++ documentation:

Returns true if fallbacks are enabled; returns false otherwise.

By default, fallbacks are enabled.

See also setFallbacksEnabled().

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

Returns the path where settings written using this QSettings object are stored.

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

C++ documentation:

Returns the path where settings written using this QSettings object are stored.

On Windows, if the format is QSettings::NativeFormat, the return value is a system registry path, not a file path.

See also isWritable() and format().

pub unsafe fn format(&self) -> Format

Returns the format used for storing the settings.

Calls C++ function: QSettings::Format QSettings::format() const.

C++ documentation:

Returns the format used for storing the settings.

This function was introduced in Qt 4.4.

See also defaultFormat(), fileName(), scope(), organizationName(), and applicationName().

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

Returns the current group.

Calls C++ function: QString QSettings::group() const.

C++ documentation:

Returns the current group.

See also beginGroup() and endGroup().

pub unsafe fn ini_codec(&self) -> Ptr<QTextCodec>

Returns the codec that is used for accessing INI files. By default, no codec is used, so a null pointer is returned.

Calls C++ function: QTextCodec* QSettings::iniCodec() const.

C++ documentation:

Returns the codec that is used for accessing INI files. By default, no codec is used, so a null pointer is returned.

This function was introduced in Qt 4.5.

See also setIniCodec().

pub unsafe fn is_atomic_sync_required(&self) -> bool

Available on cpp_lib_version="5.11.3" or cpp_lib_version="5.12.2" or cpp_lib_version="5.13.0" or cpp_lib_version="5.14.0" only.

Returns true if QSettings is only allowed to perform atomic saving and reloading (synchronization) of the settings. Returns false if it is allowed to save the settings contents directly to the configuration file.

Calls C++ function: bool QSettings::isAtomicSyncRequired() const.

C++ documentation:

Returns true if QSettings is only allowed to perform atomic saving and reloading (synchronization) of the settings. Returns false if it is allowed to save the settings contents directly to the configuration file.

The default is true.

This function was introduced in Qt 5.10.

See also setAtomicSyncRequired() and QSaveFile.

pub unsafe fn is_writable(&self) -> bool

Returns true if settings can be written using this QSettings object; returns false otherwise.

Calls C++ function: bool QSettings::isWritable() const.

C++ documentation:

Returns true if settings can be written using this QSettings object; returns false otherwise.

One reason why isWritable() might return false is if QSettings operates on a read-only file.

Warning: This function is not perfectly reliable, because the file permissions can change at any time.

See also fileName(), status(), and sync().

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

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

pub unsafe fn from_2_q_string_q_object( organization: impl CastInto<Ref<QString>>, application: impl CastInto<Ref<QString>>, parent: impl CastInto<Ptr<QObject>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

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

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Example:

QSettings settings(“Moose Tech”, “Facturo-Pro”);

The scope is set to QSettings::UserScope, and the format is set to QSettings::NativeFormat (i.e. calling setDefaultFormat() before calling this constructor has no effect).

See also setDefaultFormat() and Fallback Mechanism.

pub unsafe fn from_scope2_q_string_q_object( scope: Scope, organization: impl CastInto<Ref<QString>>, application: impl CastInto<Ref<QString>>, parent: impl CastInto<Ptr<QObject>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Scope scope, const QString& organization, const QString& application = …, QObject* parent = …).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

If scope is QSettings::UserScope, the QSettings object searches user-specific settings first, before it searches system-wide settings as a fallback. If scope is QSettings::SystemScope, the QSettings object ignores user-specific settings and provides access to system-wide settings.

The storage format is set to QSettings::NativeFormat (i.e. calling setDefaultFormat() before calling this constructor has no effect).

If no application name is given, the QSettings object will only access the organization-wide locations.

See also setDefaultFormat().

pub unsafe fn from_format_scope2_q_string_q_object( format: Format, scope: Scope, organization: impl CastInto<Ref<QString>>, application: impl CastInto<Ref<QString>>, parent: impl CastInto<Ptr<QObject>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Format format, QSettings::Scope scope, const QString& organization, const QString& application = …, QObject* parent = …).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

If scope is QSettings::UserScope, the QSettings object searches user-specific settings first, before it searches system-wide settings as a fallback. If scope is QSettings::SystemScope, the QSettings object ignores user-specific settings and provides access to system-wide settings.

If format is QSettings::NativeFormat, the native API is used for storing settings. If format is QSettings::IniFormat, the INI format is used.

If no application name is given, the QSettings object will only access the organization-wide locations.

pub unsafe fn from_q_string_format_q_object( file_name: impl CastInto<Ref<QString>>, format: Format, parent: impl CastInto<Ptr<QObject>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing the settings stored in the file called fileName, with parent parent. If the file doesn't already exist, it is created.

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

C++ documentation:

Constructs a QSettings object for accessing the settings stored in the file called fileName, with parent parent. If the file doesn’t already exist, it is created.

If format is QSettings::NativeFormat, the meaning of fileName depends on the platform. On Unix, fileName is the name of an INI file. On macOS and iOS, fileName is the name of a .plist file. On Windows, fileName is a path in the system registry.

If format is QSettings::IniFormat, fileName is the name of an INI file.

Warning: This function is provided for convenience. It works well for accessing INI or .plist files generated by Qt, but might fail on some syntaxes found in such files originated by other programs. In particular, be aware of the following limitations:

• QSettings provides no way of reading INI "path" entries, i.e., entries with unescaped slash characters. (This is because these entries are ambiguous and cannot be resolved automatically.)
• In INI files, QSettings uses the @ character as a metacharacter in some contexts, to encode Qt-specific data types (e.g., @Rect), and might therefore misinterpret it when it occurs in pure INI files.

See also fileName().

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

Constructs a QSettings object for accessing settings of the application and organization set previously with a call to QCoreApplication::setOrganizationName(), QCoreApplication::setOrganizationDomain(), and QCoreApplication::setApplicationName().

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

C++ documentation:

Constructs a QSettings object for accessing settings of the application and organization set previously with a call to QCoreApplication::setOrganizationName(), QCoreApplication::setOrganizationDomain(), and QCoreApplication::setApplicationName().

The scope is QSettings::UserScope and the format is defaultFormat() (QSettings::NativeFormat by default). Use setDefaultFormat() before calling this constructor to change the default format used by this constructor.

The code

QSettings settings(“Moose Soft”, “Facturo-Pro”);

is equivalent to

QCoreApplication::setOrganizationName(“Moose Soft”);
QCoreApplication::setApplicationName(“Facturo-Pro”);
QSettings settings;

If QCoreApplication::setOrganizationName() and QCoreApplication::setApplicationName() has not been previously called, the QSettings object will not be able to read or write any settings, and status() will return AccessError.

On macOS and iOS, if both a name and an Internet domain are specified for the organization, the domain is preferred over the name. On other platforms, the name is preferred over the domain.

See also QCoreApplication::setOrganizationName(), QCoreApplication::setOrganizationDomain(), QCoreApplication::setApplicationName(), and setDefaultFormat().

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

The QSettings class provides persistent platform-independent application settings.

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

C++ documentation:

The QSettings class provides persistent platform-independent application settings.

Users normally expect an application to remember its settings (window sizes and positions, options, etc.) across sessions. This information is often stored in the system registry on Windows, and in property list files on macOS and iOS. On Unix systems, in the absence of a standard, many applications (including the KDE applications) use INI text files.

QSettings is an abstraction around these technologies, enabling you to save and restore application settings in a portable manner. It also supports custom storage formats.

QSettings's API is based on QVariant, allowing you to save most value-based types, such as QString, QRect, and QImage, with the minimum of effort.

If all you need is a non-persistent memory-based structure, consider using QMap<QString, QVariant> instead.

pub unsafe fn from_2_q_string( organization: impl CastInto<Ref<QString>>, application: impl CastInto<Ref<QString>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(const QString& organization, const QString& application = …).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Example:

QSettings settings(“Moose Tech”, “Facturo-Pro”);

The scope is set to QSettings::UserScope, and the format is set to QSettings::NativeFormat (i.e. calling setDefaultFormat() before calling this constructor has no effect).

See also setDefaultFormat() and Fallback Mechanism.

pub unsafe fn from_q_string( organization: impl CastInto<Ref<QString>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(const QString& organization).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Example:

QSettings settings(“Moose Tech”, “Facturo-Pro”);

The scope is set to QSettings::UserScope, and the format is set to QSettings::NativeFormat (i.e. calling setDefaultFormat() before calling this constructor has no effect).

See also setDefaultFormat() and Fallback Mechanism.

pub unsafe fn from_scope2_q_string( scope: Scope, organization: impl CastInto<Ref<QString>>, application: impl CastInto<Ref<QString>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Scope scope, const QString& organization, const QString& application = …).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

If scope is QSettings::UserScope, the QSettings object searches user-specific settings first, before it searches system-wide settings as a fallback. If scope is QSettings::SystemScope, the QSettings object ignores user-specific settings and provides access to system-wide settings.

The storage format is set to QSettings::NativeFormat (i.e. calling setDefaultFormat() before calling this constructor has no effect).

If no application name is given, the QSettings object will only access the organization-wide locations.

See also setDefaultFormat().

pub unsafe fn from_scope_q_string( scope: Scope, organization: impl CastInto<Ref<QString>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Scope scope, const QString& organization).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

If scope is QSettings::UserScope, the QSettings object searches user-specific settings first, before it searches system-wide settings as a fallback. If scope is QSettings::SystemScope, the QSettings object ignores user-specific settings and provides access to system-wide settings.

The storage format is set to QSettings::NativeFormat (i.e. calling setDefaultFormat() before calling this constructor has no effect).

If no application name is given, the QSettings object will only access the organization-wide locations.

See also setDefaultFormat().

pub unsafe fn from_format_scope2_q_string( format: Format, scope: Scope, organization: impl CastInto<Ref<QString>>, application: impl CastInto<Ref<QString>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Format format, QSettings::Scope scope, const QString& organization, const QString& application = …).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

If scope is QSettings::UserScope, the QSettings object searches user-specific settings first, before it searches system-wide settings as a fallback. If scope is QSettings::SystemScope, the QSettings object ignores user-specific settings and provides access to system-wide settings.

If format is QSettings::NativeFormat, the native API is used for storing settings. If format is QSettings::IniFormat, the INI format is used.

If no application name is given, the QSettings object will only access the organization-wide locations.

pub unsafe fn from_format_scope_q_string( format: Format, scope: Scope, organization: impl CastInto<Ref<QString>>, ) -> QBox<QSettings>

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Format format, QSettings::Scope scope, const QString& organization).

C++ documentation:

Constructs a QSettings object for accessing settings of the application called application from the organization called organization, and with parent parent.

If scope is QSettings::UserScope, the QSettings object searches user-specific settings first, before it searches system-wide settings as a fallback. If scope is QSettings::SystemScope, the QSettings object ignores user-specific settings and provides access to system-wide settings.

If format is QSettings::NativeFormat, the native API is used for storing settings. If format is QSettings::IniFormat, the INI format is used.

If no application name is given, the QSettings object will only access the organization-wide locations.

pub unsafe fn from_q_string_format( file_name: impl CastInto<Ref<QString>>, format: Format, ) -> QBox<QSettings>

Constructs a QSettings object for accessing the settings stored in the file called fileName, with parent parent. If the file doesn't already exist, it is created.

Calls C++ function: [constructor] void QSettings::QSettings(const QString& fileName, QSettings::Format format).

C++ documentation:

Constructs a QSettings object for accessing the settings stored in the file called fileName, with parent parent. If the file doesn’t already exist, it is created.

If format is QSettings::NativeFormat, the meaning of fileName depends on the platform. On Unix, fileName is the name of an INI file. On macOS and iOS, fileName is the name of a .plist file. On Windows, fileName is a path in the system registry.

If format is QSettings::IniFormat, fileName is the name of an INI file.

Warning: This function is provided for convenience. It works well for accessing INI or .plist files generated by Qt, but might fail on some syntaxes found in such files originated by other programs. In particular, be aware of the following limitations:

• QSettings provides no way of reading INI "path" entries, i.e., entries with unescaped slash characters. (This is because these entries are ambiguous and cannot be resolved automatically.)
• In INI files, QSettings uses the @ character as a metacharacter in some contexts, to encode Qt-specific data types (e.g., @Rect), and might therefore misinterpret it when it occurs in pure INI files.

See also fileName().

pub unsafe fn from_scope_q_object( scope: Scope, parent: impl CastInto<Ptr<QObject>>, ) -> QBox<QSettings>

Available on cpp_lib_version="5.13.0" or cpp_lib_version="5.14.0" only.

Constructs a QSettings object in the same way as QSettings(QObject *parent) but with the given scope.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Scope scope, QObject* parent = …).

C++ documentation:

Constructs a QSettings object in the same way as QSettings(QObject *parent) but with the given scope.

This function was introduced in Qt 5.13.

See also QSettings(QObject *parent).

pub unsafe fn from_scope(scope: Scope) -> QBox<QSettings>

Available on cpp_lib_version="5.13.0" or cpp_lib_version="5.14.0" only.

Constructs a QSettings object in the same way as QSettings(QObject *parent) but with the given scope.

Calls C++ function: [constructor] void QSettings::QSettings(QSettings::Scope scope).

C++ documentation:

Constructs a QSettings object in the same way as QSettings(QObject *parent) but with the given scope.

This function was introduced in Qt 5.13.

See also QSettings(QObject *parent).

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

Returns the organization name used for storing the settings.

Calls C++ function: QString QSettings::organizationName() const.

C++ documentation:

Returns the organization name used for storing the settings.

This function was introduced in Qt 4.4.

See also QCoreApplication::organizationName(), format(), scope(), and applicationName().

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

Calls C++ function: virtual int QSettings::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* QSettings::qt_metacast(const char* arg1).

pub unsafe fn remove(&self, key: impl CastInto<Ref<QString>>)

Removes the setting key and any sub-settings of key.

Calls C++ function: void QSettings::remove(const QString& key).

C++ documentation:

Removes the setting key and any sub-settings of key.

Example:

QSettings settings;
settings.setValue(“ape”);
settings.setValue(“monkey”, 1);
settings.setValue(“monkey/sea”, 2);
settings.setValue(“monkey/doe”, 4);
settings.remove(“monkey”);
QStringList keys = settings.allKeys();
// keys: [“ape”]

Be aware that if one of the fallback locations contains a setting with the same key, that setting will be visible after calling remove().

If key is an empty string, all keys in the current group() are removed. For example:

QSettings settings;
settings.setValue(“ape”);
settings.setValue(“monkey”, 1);
settings.setValue(“monkey/sea”, 2);
settings.setValue(“monkey/doe”, 4);
settings.beginGroup(“monkey”);
settings.remove(“”);
settings.endGroup();
QStringList keys = settings.allKeys();
// keys: [“ape”]

Note that the Windows registry and INI files use case-insensitive keys, whereas the CFPreferences API on macOS and iOS uses case-sensitive keys. To avoid portability problems, see the Section and Key Syntax rules.

See also setValue(), value(), and contains().

pub unsafe fn scope(&self) -> Scope

Returns the scope used for storing the settings.

Calls C++ function: QSettings::Scope QSettings::scope() const.

C++ documentation:

Returns the scope used for storing the settings.

This function was introduced in Qt 4.4.

See also format(), organizationName(), and applicationName().

pub unsafe fn set_array_index(&self, i: c_int)

Sets the current array index to i. Calls to functions such as setValue(), value(), remove(), and contains() will operate on the array entry at that index.

Calls C++ function: void QSettings::setArrayIndex(int i).

C++ documentation:

Sets the current array index to i. Calls to functions such as setValue(), value(), remove(), and contains() will operate on the array entry at that index.

You must call beginReadArray() or beginWriteArray() before you can call this function.

pub unsafe fn set_atomic_sync_required(&self, enable: bool)

Available on cpp_lib_version="5.11.3" or cpp_lib_version="5.12.2" or cpp_lib_version="5.13.0" or cpp_lib_version="5.14.0" only.

Configures whether QSettings is required to perform atomic saving and reloading (synchronization) of the settings. If the enable argument is true (the default), sync() will only perform synchronization operations that are atomic. If this is not possible, sync() will fail and status() will be an error condition.

Calls C++ function: void QSettings::setAtomicSyncRequired(bool enable).

C++ documentation:

Configures whether QSettings is required to perform atomic saving and reloading (synchronization) of the settings. If the enable argument is true (the default), sync() will only perform synchronization operations that are atomic. If this is not possible, sync() will fail and status() will be an error condition.

Setting this property to false will allow QSettings to write directly to the configuration file and ignore any errors trying to lock it against other processes trying to write at the same time. Because of the potential for corruption, this option should be used with care, but is required in certain conditions, like a QSettings::IniFormat configuration file that exists in an otherwise non-writeable directory or NTFS Alternate Data Streams.

See QSaveFile for more information on the feature.

This function was introduced in Qt 5.10.

See also isAtomicSyncRequired() and QSaveFile.

pub unsafe fn set_default_format(format: Format)

Sets the default file format to the given format, which is used for storing settings for the QSettings(QObject *) constructor.

Calls C++ function: static void QSettings::setDefaultFormat(QSettings::Format format).

C++ documentation:

Sets the default file format to the given format, which is used for storing settings for the QSettings(QObject *) constructor.

If no default format is set, QSettings::NativeFormat is used. See the documentation for the QSettings constructor you are using to see if that constructor will ignore this function.

This function was introduced in Qt 4.4.

See also defaultFormat() and format().

pub unsafe fn set_fallbacks_enabled(&self, b: bool)

Sets whether fallbacks are enabled to b.

Calls C++ function: void QSettings::setFallbacksEnabled(bool b).

C++ documentation:

Sets whether fallbacks are enabled to b.

By default, fallbacks are enabled.

See also fallbacksEnabled().

pub unsafe fn set_ini_codec_q_text_codec( &self, codec: impl CastInto<Ptr<QTextCodec>>, )

Sets the codec for accessing INI files (including .conf files on Unix) to codec. The codec is used for decoding any data that is read from the INI file, and for encoding any data that is written to the file. By default, no codec is used, and non-ASCII characters are encoded using standard INI escape sequences.

Calls C++ function: void QSettings::setIniCodec(QTextCodec* codec).

C++ documentation:

Sets the codec for accessing INI files (including .conf files on Unix) to codec. The codec is used for decoding any data that is read from the INI file, and for encoding any data that is written to the file. By default, no codec is used, and non-ASCII characters are encoded using standard INI escape sequences.

Warning: The codec must be set immediately after creating the QSettings object, before accessing any data.

This function was introduced in Qt 4.5.

See also iniCodec().

pub unsafe fn set_ini_codec_char(&self, codec_name: *const c_char)

This is an overloaded function.

Calls C++ function: void QSettings::setIniCodec(const char* codecName).

C++ documentation:

This is an overloaded function.

Sets the codec for accessing INI files (including .conf files on Unix) to the QTextCodec for the encoding specified by codecName. Common values for codecName include "ISO 8859-1", "UTF-8", and "UTF-16". If the encoding isn't recognized, nothing happens.

This function was introduced in Qt 4.5.

See also QTextCodec::codecForName().

pub unsafe fn set_path( format: Format, scope: Scope, path: impl CastInto<Ref<QString>>, )

Sets the path used for storing settings for the given format and scope, to path. The format can be a custom format.

Calls C++ function: static void QSettings::setPath(QSettings::Format format, QSettings::Scope scope, const QString& path).

C++ documentation:

Sets the path used for storing settings for the given format and scope, to path. The format can be a custom format.

The table below summarizes the default values:

Platform	Format	Scope	Path
Windows	IniFormat	UserScope	FOLDERID_RoamingAppData
		SystemScope	FOLDERID_ProgramData
Unix	NativeFormat, IniFormat	UserScope	$HOME/.config
		SystemScope	/etc/xdg
Qt for Embedded Linux	NativeFormat, IniFormat	UserScope	$HOME/Settings
		SystemScope	/etc/xdg
macOS and iOS	IniFormat	UserScope	$HOME/.config
		SystemScope	/etc/xdg

The default UserScope paths on Unix, macOS, and iOS ($HOME/.config or $HOME/Settings) can be overridden by the user by setting the XDG_CONFIG_HOME environment variable. The default SystemScope paths on Unix, macOS, and iOS (/etc/xdg) can be overridden when building the Qt library using the configure script's -sysconfdir flag (see QLibraryInfo for details).

Setting the NativeFormat paths on Windows, macOS, and iOS has no effect.

Warning: This function doesn't affect existing QSettings objects.

This function was introduced in Qt 4.1.

See also registerFormat().

pub unsafe fn set_system_ini_path(dir: impl CastInto<Ref<QString>>)

Use setPath() instead.

Calls C++ function: static void QSettings::setSystemIniPath(const QString& dir).

C++ documentation:

Use setPath() instead.

For example, if you have code like

setSystemIniPath(path);

you can rewrite it as

setPath(QSettings::NativeFormat, QSettings::SystemScope, path);
setPath(QSettings::IniFormat, QSettings::SystemScope, path);

pub unsafe fn set_user_ini_path(dir: impl CastInto<Ref<QString>>)

Use setPath() instead.

Calls C++ function: static void QSettings::setUserIniPath(const QString& dir).

C++ documentation:

Use setPath() instead.

pub unsafe fn set_value( &self, key: impl CastInto<Ref<QString>>, value: impl CastInto<Ref<QVariant>>, )

Sets the value of setting key to value. If the key already exists, the previous value is overwritten.

Calls C++ function: void QSettings::setValue(const QString& key, const QVariant& value).

C++ documentation:

Sets the value of setting key to value. If the key already exists, the previous value is overwritten.

Note that the Windows registry and INI files use case-insensitive keys, whereas the CFPreferences API on macOS and iOS uses case-sensitive keys. To avoid portability problems, see the Section and Key Syntax rules.

Example:

QSettings settings;
settings.setValue(“interval”, 30);
settings.value(“interval”).toInt();     // returns 30
settings.setValue(“interval”, 6.55);
settings.value(“interval”).toDouble();  // returns 6.55

See also value(), remove(), and contains().

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

Returns a reference to the staticMetaObject field.

pub unsafe fn status(&self) -> Status

Returns a status code indicating the first error that was met by QSettings, or QSettings::NoError if no error occurred.

Calls C++ function: QSettings::Status QSettings::status() const.

C++ documentation:

Returns a status code indicating the first error that was met by QSettings, or QSettings::NoError if no error occurred.

Be aware that QSettings delays performing some operations. For this reason, you might want to call sync() to ensure that the data stored in QSettings is written to disk before calling status().

See also sync().

pub unsafe fn sync(&self)

Writes any unsaved changes to permanent storage, and reloads any settings that have been changed in the meantime by another application.

Calls C++ function: void QSettings::sync().

C++ documentation:

Writes any unsaved changes to permanent storage, and reloads any settings that have been changed in the meantime by another application.

This function is called automatically from QSettings's destructor and by the event loop at regular intervals, so you normally don't need to call it yourself.

See also status().

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

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

pub unsafe fn value_2a( &self, key: impl CastInto<Ref<QString>>, default_value: impl CastInto<Ref<QVariant>>, ) -> CppBox<QVariant>

Returns the value for setting key. If the setting doesn't exist, returns defaultValue.

Calls C++ function: QVariant QSettings::value(const QString& key, const QVariant& defaultValue = …) const.

C++ documentation:

Returns the value for setting key. If the setting doesn’t exist, returns defaultValue.

If no default value is specified, a default QVariant is returned.

Note that the Windows registry and INI files use case-insensitive keys, whereas the CFPreferences API on macOS and iOS uses case-sensitive keys. To avoid portability problems, see the Section and Key Syntax rules.

Example:

QSettings settings;
settings.setValue(“animal/snake”, 58);
settings.value(“animal/snake”, 1024).toInt();   // returns 58
settings.value(“animal/zebra”, 1024).toInt();   // returns 1024
settings.value(“animal/zebra”).toInt();         // returns 0

See also setValue(), contains(), and remove().

pub unsafe fn value_1a( &self, key: impl CastInto<Ref<QString>>, ) -> CppBox<QVariant>

Returns the value for setting key. If the setting doesn't exist, returns defaultValue.

Calls C++ function: QVariant QSettings::value(const QString& key) const.

C++ documentation:

Returns the value for setting key. If the setting doesn’t exist, returns defaultValue.

If no default value is specified, a default QVariant is returned.

Note that the Windows registry and INI files use case-insensitive keys, whereas the CFPreferences API on macOS and iOS uses case-sensitive keys. To avoid portability problems, see the Section and Key Syntax rules.

Example:

QSettings settings;
settings.setValue(“animal/snake”, 58);
settings.value(“animal/snake”, 1024).toInt();   // returns 58
settings.value(“animal/zebra”, 1024).toInt();   // returns 1024
settings.value(“animal/zebra”).toInt();         // returns 0

See also setValue(), contains(), and remove().

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 QSettings

unsafe fn delete(&self)

Destroys the QSettings object.

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

C++ documentation:

Destroys the QSettings object.

Any unsaved changes will eventually be written to permanent storage.

See also sync().

impl Deref for QSettings

fn deref(&self) -> &QObject

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

type Target = QObject

The resulting type after dereferencing.

impl DynamicCast<QSettings> for QObject

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

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

impl StaticDowncast<QSettings> for QObject

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

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

impl StaticUpcast<QObject> for QSettings

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

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