From 666e92f15e6b90159df6a65e2a6d36777a4b0efc Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Thu, 28 Jan 2021 16:04:17 +0100
Subject: [PATCH] output: introduce request_state event

This allows backends to request the compositor to change the state
of an output.

References: https://github.com/swaywm/wlroots/issues/2300#issuecomment-761819673
---
 include/wlr/interfaces/wlr_output.h |  5 +++++
 include/wlr/types/wlr_output.h      |  6 ++++++
 types/wlr_output.c                  | 10 ++++++++++
 3 files changed, 21 insertions(+)

diff --git a/include/wlr/interfaces/wlr_output.h b/include/wlr/interfaces/wlr_output.h
index 6d8da2a5f..0f7acebfa 100644
--- a/include/wlr/interfaces/wlr_output.h
+++ b/include/wlr/interfaces/wlr_output.h
@@ -138,5 +138,10 @@ void wlr_output_send_frame(struct wlr_output *output);
  */
 void wlr_output_send_present(struct wlr_output *output,
 	struct wlr_output_event_present *event);
+/**
+ * Request the compositor to apply new state.
+ */
+void wlr_output_send_request_state(struct wlr_output *output,
+	const struct wlr_output_state *state);
 
 #endif
diff --git a/include/wlr/types/wlr_output.h b/include/wlr/types/wlr_output.h
index eefddb024..f1b4ff189 100644
--- a/include/wlr/types/wlr_output.h
+++ b/include/wlr/types/wlr_output.h
@@ -171,6 +171,7 @@ struct wlr_output {
 		struct wl_signal enable;
 		struct wl_signal mode;
 		struct wl_signal description;
+		struct wl_signal request_state;
 		struct wl_signal destroy;
 	} events;
 
@@ -238,6 +239,11 @@ struct wlr_output_event_bind {
 	struct wl_resource *resource;
 };
 
+struct wlr_output_event_request_state {
+	struct wlr_output *output;
+	struct wlr_output_state state;
+};
+
 struct wlr_surface;
 
 /**
diff --git a/types/wlr_output.c b/types/wlr_output.c
index bfa1379eb..de4b940c1 100644
--- a/types/wlr_output.c
+++ b/types/wlr_output.c
@@ -344,6 +344,7 @@ void wlr_output_init(struct wlr_output *output, struct wlr_backend *backend,
 	wl_signal_init(&output->events.enable);
 	wl_signal_init(&output->events.mode);
 	wl_signal_init(&output->events.description);
+	wl_signal_init(&output->events.request_state);
 	wl_signal_init(&output->events.destroy);
 	pixman_region32_init(&output->pending.damage);
 
@@ -728,6 +729,15 @@ void wlr_output_send_present(struct wlr_output *output,
 	wlr_signal_emit_safe(&output->events.present, event);
 }
 
+void wlr_output_send_request_state(struct wlr_output *output,
+		const struct wlr_output_state *state) {
+	struct wlr_output_event_request_state event = {
+		.output = output,
+		.state = *state,
+	};
+	wlr_signal_emit_safe(&output->events.request_state, &event);
+}
+
 void wlr_output_queue_state(struct wlr_output *output,
 		const struct wlr_output_state *state) {
 	assert(state != &output->pending);