DBusNames.watchName

Starts watching name on the bus specified by bus_type and calls name_appeared_handler and name_vanished_handler when the name is known to have a owner respectively known to lose its owner. Callbacks will be invoked in the thread-default main loop of the thread you are calling this function from. You are guaranteed that one of the handlers will be invoked after calling this function. When you are done watching the name, just call g_bus_unwatch_name() with the watcher id this function returns. If the name vanishes or appears (for example the application owning the name could restart), the handlers are also invoked. If the GDBusConnection that is used for watching the name disconnects, then name_vanished_handler is invoked since it is no longer possible to access the name. Another guarantee is that invocations of name_appeared_handler and name_vanished_handler are guaranteed to alternate; that is, if name_appeared_handler is invoked then you are guaranteed that the next time one of the handlers is invoked, it will be name_vanished_handler. The reverse is also true. This behavior makes it very simple to write applications that wants to take action when a certain name exists, see Example 13, “Simple application watching a name”. Basically, the application should create object proxies in name_appeared_handler and destroy them again (if any) in name_vanished_handler. Since 2.26

Parameters

busType GBusType

The type of bus to watch a name on.

name string

The name (well-known or unique) to watch.

flags GBusNameWatcherFlags

Flags from the GBusNameWatcherFlags enumeration.

nameAppearedHandler GBusNameAppearedCallback

Handler to invoke when name is known to exist or NULL. [allow-none]

nameVanishedHandler GBusNameVanishedCallback

Handler to invoke when name is known to not exist or NULL. [allow-none]

userData void*

User data to pass to handlers.

userDataFreeFunc GDestroyNotify

Function for freeing user_data or NULL. [allow-none]

Return Value

Type: uint

An identifier (never 0) that an be used with g_bus_unwatch_name() to stop watching the name.

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