ladybird/Userland/Libraries/LibCore/EventLoop.h
Jelle Raaijmakers 558fd5b166 LibCore: Make EventLoop::pump() return event count
Sometimes, pumping the event loop will cause new events to be
generated. For example, an IPC message could be delivered which then
dispatches a new event to be handled by the GUI. To the invoker of
`EventLoop::pump()`, it is not obvious if any events were processed at
all.

Libraries like SDL2 might not have the opportunity to run the event
loop often enough that events can be processed swiftly, since it might
spend time doing other things. This can result in stuttering GUI
interactions.

This changes `EventLoop::pump()` to return the number of processed
events. This functionality will be used by our SDL2 port in another PR.
2022-01-06 11:30:04 +01:00

125 lines
3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Forward.h>
#include <AK/Function.h>
#include <AK/HashMap.h>
#include <AK/Noncopyable.h>
#include <AK/NonnullOwnPtr.h>
#include <AK/NonnullRefPtr.h>
#include <AK/Time.h>
#include <AK/Vector.h>
#include <AK/WeakPtr.h>
#include <LibCore/DeferredInvocationContext.h>
#include <LibCore/Event.h>
#include <LibCore/Forward.h>
#include <sys/time.h>
#include <sys/types.h>
namespace Core {
class EventLoop {
public:
enum class MakeInspectable {
No,
Yes,
};
explicit EventLoop(MakeInspectable = MakeInspectable::No);
~EventLoop();
int exec();
enum class WaitMode {
WaitForEvents,
PollForEvents,
};
// processe events, generally called by exec() in a loop.
// this should really only be used for integrating with other event loops
size_t pump(WaitMode = WaitMode::WaitForEvents);
void spin_until(Function<bool()>);
void post_event(Object& receiver, NonnullOwnPtr<Event>&&);
static EventLoop& main();
static EventLoop& current();
bool was_exit_requested() const { return m_exit_requested; }
static int register_timer(Object&, int milliseconds, bool should_reload, TimerShouldFireWhenNotVisible);
static bool unregister_timer(int timer_id);
static void register_notifier(Badge<Notifier>, Notifier&);
static void unregister_notifier(Badge<Notifier>, Notifier&);
void quit(int);
void unquit();
void take_pending_events_from(EventLoop& other)
{
m_queued_events.extend(move(other.m_queued_events));
}
static void wake();
static int register_signal(int signo, Function<void(int)> handler);
static void unregister_signal(int handler_id);
// Note: Boost uses Parent/Child/Prepare, but we don't really have anything
// interesting to do in the parent or before forking.
enum class ForkEvent {
Child,
};
static void notify_forked(ForkEvent);
static bool has_been_instantiated();
void deferred_invoke(Function<void()> invokee)
{
auto context = DeferredInvocationContext::construct();
post_event(context, make<Core::DeferredInvocationEvent>(context, move(invokee)));
}
private:
void wait_for_event(WaitMode);
Optional<Time> get_next_timer_expiration();
static void dispatch_signal(int);
static void handle_signal(int);
struct QueuedEvent {
AK_MAKE_NONCOPYABLE(QueuedEvent);
public:
QueuedEvent(Object& receiver, NonnullOwnPtr<Event>);
QueuedEvent(QueuedEvent&&);
~QueuedEvent();
WeakPtr<Object> receiver;
NonnullOwnPtr<Event> event;
};
Vector<QueuedEvent, 64> m_queued_events;
static pid_t s_pid;
bool m_exit_requested { false };
int m_exit_code { 0 };
static int s_wake_pipe_fds[2];
struct Private;
NonnullOwnPtr<Private> m_private;
};
inline void deferred_invoke(Function<void()> invokee)
{
EventLoop::current().deferred_invoke(move(invokee));
}
}