Safe Haskell	None
Language	Haskell2010

GI.Gtk.Declarative.CustomWidget

Description

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.

Synopsis

data CustomPatch widget internalState
- = CustomReplace
- | CustomModify (widget -> IO internalState)
- | CustomKeep
data CustomWidget widget params internalState event = CustomWidget {
- customWidget :: ManagedPtr widget -> widget
- customCreate :: params -> IO (widget, internalState)
- customPatch :: params -> params -> internalState -> CustomPatch widget internalState
- customSubscribe :: params -> internalState -> widget -> (event -> IO ()) -> IO Subscription
- customAttributes :: Vector (Attribute widget event)
- customParams :: params
}

Documentation

data CustomPatch widget internalState Source #

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 Source #

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) Source #
Instance details 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) Source #
Instance details Defined in GI.Gtk.Declarative.CustomWidget Methods create :: CustomWidget widget params internalState e -> IO SomeState Source # patch :: SomeState -> CustomWidget widget params internalState e1 -> CustomWidget widget params internalState e2 -> Patch Source #
(Typeable internalState, GObject widget) => EventSource (CustomWidget widget params internalState) Source #
Instance details Defined in GI.Gtk.Declarative.CustomWidget Methods subscribe :: CustomWidget widget params internalState event -> SomeState -> (event -> IO ()) -> IO Subscription Source #