glib-0.12.4: Binding to the GLIB library for Gtk2Hs.

Safe Haskell | None

System.Glib.Signals

Synopsis

- newtype Signal object handler = Signal (Bool -> object -> handler -> IO (ConnectId object))
- on :: object -> Signal object callback -> callback -> IO (ConnectId object)
- after :: object -> Signal object callback -> callback -> IO (ConnectId object)
- type SignalName = String
- type ConnectAfter = Bool
- data GObjectClass o => ConnectId o = ConnectId CULong o
- signalDisconnect :: GObjectClass obj => ConnectId obj -> IO ()
- signalBlock :: GObjectClass obj => ConnectId obj -> IO ()
- signalUnblock :: GObjectClass obj => ConnectId obj -> IO ()
- signalStopEmission :: GObjectClass obj => obj -> SignalName -> IO ()
- disconnect :: GObjectClass obj => ConnectId obj -> IO ()
- data GClosure
- connectGeneric :: GObjectClass obj => SignalName -> ConnectAfter -> obj -> handler -> IO (ConnectId obj)

# Documentation

newtype Signal object handler Source

Constructors

Signal (Bool -> object -> handler -> IO (ConnectId object)) |

on :: object -> Signal object callback -> callback -> IO (ConnectId object)Source

Perform an action in response to a signal.

Use it like this:

     on obj sig $ do
     ...

or if the signal handler takes any arguments:

     on obj sig $ \args -> do
     ...

after :: object -> Signal object callback -> callback -> IO (ConnectId object)Source

Perform an action in response to a signal.

- Like `on` but the signal is executed after Gtk's default handler has run.

type SignalName = String Source

type ConnectAfter = Bool Source

data GObjectClass o => ConnectId o Source

The type of signal handler ids. If you ever need to `disconnect` a signal handler then you will need to retain the `ConnectId` you got when you registered it.

Constructors

ConnectId CULong o |

signalDisconnect :: GObjectClass obj => ConnectId obj -> IO ()Source

Disconnect a signal handler. After disconnecting the handler will no longer be invoked when the event occurs.

signalBlock :: GObjectClass obj => ConnectId obj -> IO ()Source

Block a specific signal handler.

- Blocks a handler of an instance so it will not be called during any signal emissions unless it is unblocked again. Thus "blocking" a signal handler means to temporarily deactive it, a signal handler has to be unblocked exactly the same amount of times it has been blocked before to become active again.

signalUnblock :: GObjectClass obj => ConnectId obj -> IO ()Source

Unblock a specific signal handler.

- Undoes the effect of a previous `signalBlock` call. A blocked handler is skipped during signal emissions and will not be invoked, unblocking it (for exactly the amount of times it has been blocked before) reverts its "blocked" state, so the handler will be recognized by the signal system and is called upon future or currently ongoing signal emissions (since the order in which handlers are called during signal emissions is deterministic, whether the unblocked handler in question is called as part of a currently ongoing emission depends on how far that emission has proceeded yet).

signalStopEmission :: GObjectClass obj => obj -> SignalName -> IO ()Source

Stops a signal's current emission.

- This will prevent the default method from running. The sequence in which handlers are run is "first", "on", "last" then "after" where Gtk-internal signals are connected either at "first" or at "last". Hence this function can only stop the signal processing if it is called from within a handler that is connected with an "on" signal and if the Gtk-internal handler is connected as "last". Gtk prints a warning if this function is used on a signal which isn't being emitted.

disconnect :: GObjectClass obj => ConnectId obj -> IO ()Source

Deprecated: use signalDisconnect instead

data GClosure Source

connectGeneric :: GObjectClass obj => SignalName -> ConnectAfter -> obj -> handler -> IO (ConnectId obj)Source