QSocketNotifiermakes it possible to integrate Qt’s event loop with other event loops based on file descriptors. File descriptor action is detected in Qt’s main event loop (
Once you have opened a device using a low-level (usually platform-specific) API, you can create a socket notifier to monitor the file descriptor. The socket notifier is enabled by default, i.e. it emits the
activated()signal whenever a socket event corresponding to its type occurs. Connect the
activated()signal to the slot you want to be called when an event corresponding to your socket notifier’s type occurs.
There are three types of socket notifiers: read, write, and exception. The type is described by the
Typeenum, and must be specified when constructing the socket notifier. After construction it can be determined using the
type()function. Note that if you need to monitor both reads and writes for the same file descriptor, you must create two socket notifiers. Note also that it is not possible to install two socket notifiers of the same type (
Exception) on the same socket.
setEnabled()function allows you to disable as well as enable the socket notifier. It is generally advisable to explicitly enable or disable the socket notifier, especially for write notifiers. A disabled notifier ignores socket events (the same effect as not creating the socket notifier). Use the
isEnabled()function to determine the notifier’s current status.
Finally, you can use the
socket()function to retrieve the socket identifier. Although the class is called
QSocketNotifier, it is normally used for other types of devices than sockets.
QUdpSocketprovide notification through signals, so there is normally no need to use a
QSocketNotifier(arg__1, arg__2[, parent=None])¶
Constructs a socket notifier with the given
parent. It enables the
socket, and watches for events of the given
It is generally advisable to explicitly enable or disable the socket notifier, especially for write notifiers.
Note for Windows users: The socket passed to
QSocketNotifierwill become non-blocking, even if it was created as a blocking socket.
This enum describes the various types of events that a socket notifier can recognize. The type must be specified when constructing the socket notifier.
Note that if you need to monitor both reads and writes for the same file descriptor, you must create two socket notifiers. Note also that it is not possible to install two socket notifiers of the same type (Read, Write, Exception) on the same socket.
There is data to be read.
Data can be written.
An exception has occurred. We recommend against using this.
- Return type
trueif the notifier is enabled; otherwise returns
arg__1 – bool
enableis true, the notifier is enabled; otherwise the notifier is disabled.
The notifier is enabled by default, i.e. it emits the
activated()signal whenever a socket event corresponding to its
typeoccurs. If it is disabled, it ignores socket events (the same effect as not creating the socket notifier).
Write notifiers should normally be disabled immediately after the
activated()signal has been emitted
- Return type
Returns the socket identifier specified to the constructor.
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