PhosphorLayer::TopologyCoordinator Class Reference

Reacts to screen hot-plug / virtual-screen reconfiguration / compositor restart; drives surface recreations via the registries. More...

#include <phosphor-layer/include/PhosphorLayer/TopologyCoordinator.h>

Inheritance diagram for PhosphorLayer::TopologyCoordinator:

Public Types
using	Config = TopologyConfig
	Convenience alias — existing call sites that spell out the full name still compile, but TopologyCoordinator::Config reads fine too.
using	SyncCallback = std::function< void()>
	Register a callback invoked whenever the coordinator decides the screen set has materially changed.
using	CallbackId = quint64

Signals
void	screensChanging ()
	Debounce fired; the consumer should snapshot any state that depends on the current screen set before sync callbacks start rebuilding it.
void	screensChanged ()
	All sync callbacks have run; the screen set is stable again.
void	compositorRestarted ()
	Transport signalled compositor loss (wlr-layer-shell global removed).

Public Member Functions
	TopologyCoordinator (IScreenProvider *screens, ILayerShellTransport *transport, TopologyConfig cfg={}, QObject *parent=nullptr)
	~TopologyCoordinator () override
CallbackId	attachSyncCallback (SyncCallback cb)
void	detachSyncCallback (CallbackId id)

Detailed Description

Reacts to screen hot-plug / virtual-screen reconfiguration / compositor restart; drives surface recreations via the registries.

Qt's QGuiApplication emits screensChanged repeatedly during hot-plug (one per wl_output event, plus scaling updates). The coordinator debounces these into a single recreation cycle.

Multiple registries may be attached — e.g. a notification daemon that keeps both a per-screen OSD registry and a singleton modal, where only the former should respond to topology changes.

Note

Status (v0.1): not yet used by the reference consumer (PlasmaZones OverlayService, which wires screen signals directly to QGuiApplication because it also responds to a custom virtualScreensChanged signal not yet modelled here). The coordinator's public API and debounce contract are tested, but real-world behaviour under hot-plug bursts has only been exercised through MockScreenProvider.

Member Typedef Documentation

CallbackId

using PhosphorLayer::TopologyCoordinator::CallbackId = quint64

Config

using PhosphorLayer::TopologyCoordinator::Config = TopologyConfig

Convenience alias — existing call sites that spell out the full name still compile, but TopologyCoordinator::Config reads fine too.

SyncCallback

using PhosphorLayer::TopologyCoordinator::SyncCallback = std::function<void()>

Register a callback invoked whenever the coordinator decides the screen set has materially changed.

The callback receives no arguments; the consumer queries the IScreenProvider to diff the old/new sets. Runs on the GUI thread.

Returns a cookie that can be passed to detachSyncCallback() to unregister. Unregistering during a callback invocation is safe.

Note: v1 exposes callbacks (not typed ScreenSurfaceRegistry handles) so the coordinator can fan out to any consumer-defined state container without knowing the registry's surface type parameter.

Constructor & Destructor Documentation

TopologyCoordinator()

PhosphorLayer::TopologyCoordinator::TopologyCoordinator	(	IScreenProvider *	screens,
		ILayerShellTransport *	transport,
		TopologyConfig	cfg = {},
		QObject *	parent = nullptr
	)

~TopologyCoordinator()

PhosphorLayer::TopologyCoordinator::~TopologyCoordinator ( )

override

Member Function Documentation

attachSyncCallback()

CallbackId PhosphorLayer::TopologyCoordinator::attachSyncCallback

(

SyncCallback

cb

)

compositorRestarted

void PhosphorLayer::TopologyCoordinator::compositorRestarted ( )

signal

Transport signalled compositor loss (wlr-layer-shell global removed).

Consumers must assume every surface has been torn down and will be respawned once the transport is re-bound.

detachSyncCallback()

void PhosphorLayer::TopologyCoordinator::detachSyncCallback

(

CallbackId

id

)

screensChanged

void PhosphorLayer::TopologyCoordinator::screensChanged ( )

signal

All sync callbacks have run; the screen set is stable again.

screensChanging

void PhosphorLayer::TopologyCoordinator::screensChanging ( )

signal

Debounce fired; the consumer should snapshot any state that depends on the current screen set before sync callbacks start rebuilding it.

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The documentation for this class was generated from the following file:

• phosphor-layer/include/PhosphorLayer/TopologyCoordinator.h