GI.Gtk.Declarative.CustomWidget

While you can instantiate Patchable and EventSource for your own data types, it's a bit complicated. The CustomWidget data type takes care of some lower-level detail, so that you can focus on the custom behavior of your widget. You still need to think about and implement a patching function, but in an easier way.

Documentation

data CustomPatch widget internalState

Similar to Patch, describing a possible action to perform on a Widget, decided by customPatch.

Constructors

CustomReplace

CustomModify (widget -> IO internalState)

CustomKeep

data CustomWidget widget params internalState event

A custom widget specification, with all functions needed to instantiate Patchable and EventSource. A custom widget:

• is based on a top widget
• can use internalState as a way of keeping an internal state value threaded through updates, which is often useful for passing references to child widgets used in a custom widget
• emits events of type event

Constructors

CustomWidget

Fields

• customWidget :: ManagedPtr widget -> widget

  The widget constructor

• customCreate :: params -> IO (widget, internalState)

  Action that creates the initial widget

• customPatch :: params -> params -> internalState -> CustomPatch widget internalState

  Patch function, calculating a CustomPatch based on the state, old custom data, and new custom data

• customSubscribe :: params -> internalState -> widget -> (event -> IO ()) -> IO Subscription

  Action that creates an event subscription for the custom widget

• customAttributes :: Vector (Attribute widget event)

  Declarative Attributes for the custom widget (properties and classes are handled automatically in patching)

• customParams :: params

  Parameters passed when constructing the declarative custom widget

Instances

Functor (CustomWidget widget params internalState)

Defined in GI.Gtk.Declarative.CustomWidget

Methods

fmap :: (a -> b) -> CustomWidget widget params internalState a -> CustomWidget widget params internalState b

(<$) :: a -> CustomWidget widget params internalState b -> CustomWidget widget params internalState a

(Typeable widget, Typeable internalState, IsWidget widget) => Patchable (CustomWidget widget params internalState)

Defined in GI.Gtk.Declarative.CustomWidget

Methods

create :: CustomWidget widget params internalState e -> IO SomeState

patch :: SomeState -> CustomWidget widget params internalState e1 -> CustomWidget widget params internalState e2 -> Patch

(Typeable internalState, GObject widget) => EventSource (CustomWidget widget params internalState)

Defined in GI.Gtk.Declarative.CustomWidget

Methods

subscribe :: CustomWidget widget params internalState event -> SomeState -> (event -> IO ()) -> IO Subscription