fuchsia.ui.policy

PROTOCOLS

DeviceListenerRegistry

Defined in fuchsia.ui.policy/device_listener.fidl

Service for exposing state and events of devices, such as media buttons.

RegisterListener

Registers a listener to receive media button related events, such as changes from volume buttons and mute switches. On registration, the listener receives the last media button event that occurred, if one exists, and all media button events going forward.

Request

Name	Type
listener	MediaButtonsListener

Response

<EMPTY>

RegisterMediaButtonsListener

Registers a listener to receive media button related events, such as changes from volume buttons and mute switches.

DEPRECATED - Use RegisterListener()

Request

Name	Type
listener	MediaButtonsListener

DisplayBacklight

Defined in fuchsia.ui.policy/display_backlight.fidl

Manipulates global policy for display backlight. Serves as the main "front end" interface for usage by UX components; other protocols (such as fuchsia.ui.scenic.Session and fuchsia.hardware.display.Controller) act as implementation.

Global Scope. All displays, in all display controllers, are affected uniformly.

Effect Timing. This protocol does not guarantee a deadline by which the minimum value is applied to a display; it is best effort.

Multiple clients. This protocol does not guarantee unique access to manipulate display backlight functionality.

Reference. Related to fuchsia.hardware.display.Controller.

SetMinimumRgb

Submits a new minimum color channel value for display backlight.

The valid range for a minimum value is [0, 255] (inclusive). For a new minimum value M, each color channel's range will be limited to [M, 255].

Flow control: The caller is allowed at most one in-flight |SetMinimumRgb| at at time. Subsequent calls must wait until the acknowledgment returns. Non-compliance results in channel closure.

Request

Name	Type
minimum_rgb	uint8

Response

<EMPTY>

MediaButtonsListener

Defined in fuchsia.ui.policy/device_listener.fidl

A listener for media buttons events. DeviceListenerRegistry.RegisterMediaButtonsListener will consume this listener interface and call OnMediaButtonsEvent when the registered media buttons event occurs.

OnEvent

Request

Name	Type
event	fuchsia.ui.input/MediaButtonsEvent

Response

<EMPTY>

OnMediaButtonsEvent

DEPRECATED - Use OnEvent()

Request

Name	Type
event	fuchsia.ui.input/MediaButtonsEvent

PointerCaptureListenerHACK

Defined in fuchsia.ui.policy/presentation.fidl

OnPointerEvent

Request

Name	Type
event	fuchsia.ui.input/PointerEvent

Presentation

Defined in fuchsia.ui.policy/presentation.fidl

CapturePointerEventsHACK

Request

Name	Type
listener	PointerCaptureListenerHACK

Presenter

Defined in fuchsia.ui.policy/presenter.fidl

The Presenter service provides a way for applications to ask that a view be added to a view tree, leaving any window management concerns up to the discretion of the presenter implementation.

PresentOrReplaceView

Request that the View's contents be displayed on the screen as a Presentation. Destroys any existing presentations and replaces them with the new one. This is true whether the existing view was created by a call to PresentView, PresentOrReplaceView or PresentOrReplaceView2.

Request

Name	Type
view_holder_token	fuchsia.ui.views/ViewHolderToken
presentation_request	server_end<Presentation>?

PresentOrReplaceView2

Request

Name	Type
view_holder_token	fuchsia.ui.views/ViewHolderToken
view_ref	fuchsia.ui.views/ViewRef
presentation_request	server_end<Presentation>?

PresentView

Request that the View's contents be displayed on the screen as a Presentation. Each call to PresentView creates a new Presentation. Having more than one simultaneous Presentation (i.e. calling PresentView more than once) is not allowed and will result

Request

Name	Type
view_holder_token	fuchsia.ui.views/ViewHolderToken
presentation_request	server_end<Presentation>?

ENUMS

DisplayUsage strict

Type: uint32

Defined in fuchsia.ui.policy/display_usage.fidl

Describes the intended usage ofthe display.

Name	Value	Description
kUnknown	0
kHandheld	1	Display is held in one or both hands.
kClose	2	Display is used well within arm's reach.
kNear	3	Display is used at arm's reach.
kMidrange	4	Display is used beyond arm's reach.
kFar	5	Display is used well beyond arm's reach.