Safe Haskell	None
Language	Haskell2010

Vgrep.App

Synopsis

data App e s = App {
- initialize :: forall m. MonadIO m => m s
- liftEvent :: Event -> e
- handleEvent :: forall m. MonadIO m => e -> Environment -> s -> Next (VgrepT s m Redraw)
- render :: forall m. Monad m => VgrepT s m Picture
}
runApp :: App e s -> Config -> Producer e IO () -> IO s
runApp_ :: App e s -> Config -> Producer e IO () -> IO ()

Documentation

data App e s Source #

The App type is parameterized over the type e of events it handles and the type s of its state.

Constructors

App

Fields

initialize :: forall m. MonadIO m => m s
Creates the initial state for the app.
liftEvent :: Event -> e
How to convert an external Event to the App's event

handleEvent :: forall m. MonadIO m => e -> Environment -> s -> Next (VgrepT s m Redraw)

Handles an event, possibly modifying the App's state.

handleEvent e s = case e of
    EvKey KEnter [] -> Continue (pure Unchanged)
    -- Handles the Enter key, but does nothing.

    EvKey KUp [] -> Continue (pure Redraw)
    -- Handles the Up key and triggers a redraw.

    _otherwise          -> Skip
    -- Does not handle the event, so other handlers may be invoked.

render :: forall m. Monad m => VgrepT s m Picture
Creates a Picture to be displayed. May modify the App's state (e. g. for resizing).

runApp :: App e s -> Config -> Producer e IO () -> IO s Source #

Runs runs the event loop until an Interrupt Halt is encountered. Events handled with Interrupt (Suspend action) will shut down Vty, run the action (e. g. invoking an external editor), and start Vty again.

runApp_ :: App e s -> Config -> Producer e IO () -> IO () Source #

Like runApp, but does not return the final state.