compositor: add WESTON_COMPOSITOR_OFFSCREEN state

This state is used when the user switches the vt. It turns of rendering
and frame events, but doesn't set the DPMS state to off.

As a part of this change, also turn off the idle timer when entering
the SLEEPING or OFFSCREEN states, which fixes
https://bugs.freedesktop.org/show_bug.cgi?id=61910 (rpi backend
untested).

src/compositor-drm.c

@@ -2020,12 +2020,12 @@ vt_func(struct weston_compositor *compositor, int event)
 
 		compositor->focus = 0;
 		ec->prev_state = compositor->state;
-		compositor->state = WESTON_COMPOSITOR_SLEEPING;
+		weston_compositor_offscreen(compositor);
 
 		/* If we have a repaint scheduled (either from a
 		 * pending pageflip or the idle handler), make sure we
 		 * cancel that so we don't try to pageflip when we're
-		 * vt switched away.  The SLEEPING state will prevent
+		 * vt switched away.  The OFFSCREEN state will prevent
 		 * further attemps at repainting.  When we switch
 		 * back, we schedule a repaint, which will process
 		 * pending frame callbacks. */

src/compositor-fbdev.c

@@ -791,11 +791,11 @@ vt_func(struct weston_compositor *base, int event)
 
 		compositor->base.focus = 0;
 		compositor->prev_state = compositor->base.state;
-		compositor->base.state = WESTON_COMPOSITOR_SLEEPING;
+		weston_compositor_offscreen(&compositor->base);
 
 		/* If we have a repaint scheduled (from the idle handler), make
 		 * sure we cancel that so we don't try to pageflip when we're
-		 * vt switched away.  The SLEEPING state will prevent
+		 * vt switched away.  The OFFSCREEN state will prevent
 		 * further attemps at repainting.  When we switch
 		 * back, we schedule a repaint, which will process
 		 * pending frame callbacks. */

src/compositor-rpi.c

@@ -1381,12 +1381,12 @@ vt_func(struct weston_compositor *base, int event)
 
 		compositor->base.focus = 0;
 		compositor->prev_state = compositor->base.state;
-		compositor->base.state = WESTON_COMPOSITOR_SLEEPING;
+		weston_compositor_offscreen(&compositor->base);
 
 		/* If we have a repaint scheduled (either from a
 		 * pending pageflip or the idle handler), make sure we
 		 * cancel that so we don't try to pageflip when we're
-		 * vt switched away.  The SLEEPING state will prevent
+		 * vt switched away.  The OFFSCREEN state will prevent
 		 * further attemps at repainting.  When we switch
 		 * back, we schedule a repaint, which will process
 		 * pending frame callbacks. */

src/compositor.c

@@ -1325,7 +1325,8 @@ weston_output_schedule_repaint(struct weston_output *output)
 	struct weston_compositor *compositor = output->compositor;
 	struct wl_event_loop *loop;
 
-	if (compositor->state == WESTON_COMPOSITOR_SLEEPING)
+	if (compositor->state == WESTON_COMPOSITOR_SLEEPING ||
+	    compositor->state == WESTON_COMPOSITOR_OFFSCREEN)
 		return;
 
 	loop = wl_display_get_event_loop(compositor->wl_display);
@@ -1670,6 +1671,7 @@ weston_compositor_wake(struct weston_compositor *compositor)
 		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
 		/* fall through */
 	case WESTON_COMPOSITOR_IDLE:
+	case WESTON_COMPOSITOR_OFFSCREEN:
 		wl_signal_emit(&compositor->wake_signal, compositor);
 		/* fall through */
 	default:
@@ -1679,12 +1681,28 @@ weston_compositor_wake(struct weston_compositor *compositor)
 	}
 }
 
+WL_EXPORT void
+weston_compositor_offscreen(struct weston_compositor *compositor)
+{
+	switch (compositor->state) {
+	case WESTON_COMPOSITOR_OFFSCREEN:
+		return;
+	case WESTON_COMPOSITOR_SLEEPING:
+		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
+		/* fall through */
+	default:
+		compositor->state = WESTON_COMPOSITOR_OFFSCREEN;
+		wl_event_source_timer_update(compositor->idle_source, 0);
+	}
+}
+
 WL_EXPORT void
 weston_compositor_sleep(struct weston_compositor *compositor)
 {
 	if (compositor->state == WESTON_COMPOSITOR_SLEEPING)
 		return;
 
+	wl_event_source_timer_update(compositor->idle_source, 0);
 	compositor->state = WESTON_COMPOSITOR_SLEEPING;
 	weston_compositor_dpms(compositor, WESTON_DPMS_OFF);
 }
@@ -3619,7 +3637,7 @@ int main(int argc, char *argv[])
 
  out:
 	/* prevent further rendering while shutting down */
-	ec->state = WESTON_COMPOSITOR_SLEEPING;
+	ec->state = WESTON_COMPOSITOR_OFFSCREEN;
 
 	wl_signal_emit(&ec->destroy_signal, ec);
 

src/compositor.h

@@ -262,7 +262,9 @@ struct weston_seat {
 enum {
 	WESTON_COMPOSITOR_ACTIVE,
 	WESTON_COMPOSITOR_IDLE,		/* shell->unlock called on activity */
-	WESTON_COMPOSITOR_SLEEPING	/* no rendering, no frame events */
+	WESTON_COMPOSITOR_OFFSCREEN,	/* no rendering, no frame events */
+	WESTON_COMPOSITOR_SLEEPING	/* same as offscreen, but also set dmps
+                                         * to off */
 };
 
 struct weston_layer {
@@ -621,6 +623,8 @@ weston_compositor_unlock(struct weston_compositor *compositor);
 void
 weston_compositor_wake(struct weston_compositor *compositor);
 void
+weston_compositor_offscreen(struct weston_compositor *compositor);
+void
 weston_compositor_sleep(struct weston_compositor *compositor);
 void
 weston_compositor_update_drag_surfaces(struct weston_compositor *compositor);