command: add read-only focused property

Add a property that returns whether the window is focused, currently
only for X11 and Wayland.

My use cause for this is having an equivalent of pause-when-minimize.lua
for tiling window managers: make mpv play only while it's in the current
workspace or is focused (I'm fine with either one but prefer focus).
On X I do this by observing display-names, which is empty when the
rectangles of the display and mpv don't intersect, but on Wayland its
value doesn't change when mpv leaves the current workspace (and the same
check doesn't work since the geometries still intersect).

This could later be made writable as requested in #6252.

Note that on Wayland se shouldn't consider an unactivated window with
keyboard input focused.

The wlroots compositors I tested set activated after changing the
keyboard focus, so if you set wl->focused only in
keyboard_handle_enter() and keyboard_handle_leave() to avoid adding the
"has_keyboard_input" member, focused isn't set to true when first
opening mpv until you focus another window and focus mpv again.

Conversely, if that order can't be assumed for all compositors, we
should toggle wl->focused when necessary in keyboard_handle_enter() and
keyboard_handle_leave() as well as in handle_toplevel_config().

3 files changed, 20 insertions, 0 deletions

diff --git a/player/command.c b/player/command.c
index 5b9e8bcbb4..723996d9be 100644
--- a/player/command.c
+++ b/player/command.c
@@ -2410,6 +2410,21 @@ static int mp_property_hidpi_scale(void *ctx, struct m_property *prop,
     return m_property_double_ro(action, arg, cmd->cached_window_scale);
 }
 
+static int mp_property_focused(void *ctx, struct m_property *prop,
+                                     int action, void *arg)
+{
+    MPContext *mpctx = ctx;
+    struct vo *vo = mpctx->video_out;
+    if (!vo)
+        return M_PROPERTY_UNAVAILABLE;
+
+    bool focused;
+    if (vo_control(vo, VOCTRL_GET_FOCUSED, &focused) < 1)
+        return M_PROPERTY_UNAVAILABLE;
+
+    return m_property_flag_ro(action, arg, focused);
+}
+
 static int mp_property_display_names(void *ctx, struct m_property *prop,
                                      int action, void *arg)
 {
@@ -3593,6 +3608,7 @@ static const struct m_property mp_properties_base[] = {
     PROPERTY_BITRATE("audio-bitrate", false, STREAM_AUDIO),
     PROPERTY_BITRATE("sub-bitrate", false, STREAM_SUB),
 
+    {"focused", mp_property_focused},
     {"display-names", mp_property_display_names},
     {"display-fps", mp_property_display_fps},
     {"estimated-display-fps", mp_property_estimated_display_fps},
@@ -3676,6 +3692,7 @@ static const char *const *const mp_event_property_change[] = {
       "osd-par", "osd-dimensions"),
     E(MP_EVENT_WIN_STATE, "display-names", "display-fps"),
     E(MP_EVENT_WIN_STATE2, "display-hidpi-scale"),
+    E(MP_EVENT_FOCUS, "focused"),
     E(MP_EVENT_CHANGE_PLAYLIST, "playlist", "playlist-pos", "playlist-pos-1",
       "playlist-count", "playlist/count", "playlist-current-pos",
       "playlist-playing-pos"),
diff --git a/player/command.h b/player/command.h
index 17e0726b0b..c47ed40f1d 100644
--- a/player/command.h
+++ b/player/command.h
@@ -98,6 +98,7 @@ enum {
     MP_EVENT_WIN_RESIZE,
     MP_EVENT_WIN_STATE,
     MP_EVENT_WIN_STATE2,
+    MP_EVENT_FOCUS,
     MP_EVENT_CHANGE_PLAYLIST,
     MP_EVENT_CORE_IDLE,
     MP_EVENT_DURATION_UPDATE,
diff --git a/player/playloop.c b/player/playloop.c
index ddd3f6dbdb..44ccb4819b 100644
--- a/player/playloop.c
+++ b/player/playloop.c
@@ -844,6 +844,8 @@ static void handle_vo_events(struct MPContext *mpctx)
         mp_notify(mpctx, MP_EVENT_WIN_STATE, NULL);
     if (events & VO_EVENT_DPI)
         mp_notify(mpctx, MP_EVENT_WIN_STATE2, NULL);
+    if (events & VO_EVENT_FOCUS)
+        mp_notify(mpctx, MP_EVENT_FOCUS, NULL);
 }
 
 static void handle_sstep(struct MPContext *mpctx)