clipboard: add clipboard monitoring API

This adds a clipboard monitoring API for backends which use polling
to monitor clipboard updates. --clipboard-monitor option can turn
clipboard monitoring on and off at runtime.

player/clipboard/clipboard.c

@@ -22,12 +22,14 @@
 
 struct clipboard_opts {
     bool enabled;
+    bool monitor;
 };
 
 #define OPT_BASE_STRUCT struct clipboard_opts
 const struct m_sub_options clipboard_conf = {
     .opts = (const struct m_option[]) {
         {"enable", OPT_BOOL(enabled), .flags = UPDATE_CLIPBOARD},
+        {"monitor", OPT_BOOL(monitor), .flags = UPDATE_CLIPBOARD},
         {0}
     },
     .defaults = &(const struct clipboard_opts) {
@@ -54,6 +56,7 @@ struct clipboard_ctx *mp_clipboard_create(struct clipboard_init_params *params,
     *cl = (struct clipboard_ctx) {
         .log = mp_log_new(cl, global->log, "clipboard"),
         .global = global,
+        .monitor = params->flags & CLIPBOARD_INIT_ENABLE_MONITORING,
     };
 
     for (int i = 0; i < MP_ARRAY_SIZE(clipboard_backend_list); i++) {
@@ -79,6 +82,13 @@ void mp_clipboard_destroy(struct clipboard_ctx *cl)
     talloc_free(cl);
 }
 
+bool mp_clipboard_data_changed(struct clipboard_ctx *cl)
+{
+    if (cl && cl->backend->data_changed && cl->monitor)
+        return cl->backend->data_changed(cl);
+    return false;
+}
+
 int mp_clipboard_get_data(struct clipboard_ctx *cl, struct clipboard_access_params *params,
                           struct clipboard_data *out, void *talloc_ctx)
 {
@@ -102,7 +112,10 @@ void reinit_clipboard(struct MPContext *mpctx)
 
     struct clipboard_opts *opts = mp_get_config_group(NULL, mpctx->global, &clipboard_conf);
     if (opts->enabled) {
-        struct clipboard_init_params params = {.mpctx = mpctx};
+        struct clipboard_init_params params = {
+            .mpctx = mpctx,
+            .flags = opts->monitor ? CLIPBOARD_INIT_ENABLE_MONITORING : 0,
+        };
         mpctx->clipboard = mp_clipboard_create(&params, mpctx->global);
     }
     talloc_free(opts);

player/clipboard/clipboard.h

@@ -24,6 +24,8 @@
 struct clipboard_ctx;
 struct MPContext;
 
+#define CLIPBOARD_INIT_ENABLE_MONITORING 1
+
 enum clipboard_data_type {
     CLIPBOARD_DATA_TEXT,
     CLIPBOARD_DATA_IMAGE,
@@ -65,6 +67,7 @@ struct clipboard_backend {
     // Return 0 on success, otherwise -1
     int (*init)(struct clipboard_ctx *cl, struct clipboard_init_params *params);
     void (*uninit)(struct clipboard_ctx *cl);
+    bool (*data_changed)(struct clipboard_ctx *cl);
     int (*get_data)(struct clipboard_ctx *cl, struct clipboard_access_params *params,
                     struct clipboard_data *out, void *talloc_ctx);
     int (*set_data)(struct clipboard_ctx *cl, struct clipboard_access_params *params,
@@ -76,11 +79,13 @@ struct clipboard_ctx {
     struct mp_log *log;
     void *priv;   // backend-specific internal data
     struct mpv_global *global;
+    bool monitor;
 };
 
 struct clipboard_ctx *mp_clipboard_create(struct clipboard_init_params *params,
                                           struct mpv_global *global);
 void mp_clipboard_destroy(struct clipboard_ctx *cl);
+bool mp_clipboard_data_changed(struct clipboard_ctx *cl);
 int mp_clipboard_get_data(struct clipboard_ctx *cl, struct clipboard_access_params *params,
                           struct clipboard_data *out, void *talloc_ctx);
 int mp_clipboard_set_data(struct clipboard_ctx *cl, struct clipboard_access_params *params,

player/playloop.c

@@ -1211,6 +1211,12 @@ static void handle_eof(struct MPContext *mpctx)
     }
 }
 
+static void handle_clipboard_updates(struct MPContext *mpctx)
+{
+    if (mp_clipboard_data_changed(mpctx->clipboard))
+        mp_notify_property(mpctx, "clipboard");
+}
+
 void run_playloop(struct MPContext *mpctx)
 {
     if (encode_lavc_didfail(mpctx->encode_lavc_ctx)) {
@@ -1236,6 +1242,8 @@ void run_playloop(struct MPContext *mpctx)
 
     handle_dummy_ticks(mpctx);
 
+    handle_clipboard_updates(mpctx);
+
     update_osd_msg(mpctx);
 
     handle_update_subtitles(mpctx);
@@ -1276,6 +1284,7 @@ void run_playloop(struct MPContext *mpctx)
 void mp_idle(struct MPContext *mpctx)
 {
     handle_dummy_ticks(mpctx);
+    handle_clipboard_updates(mpctx);
     mp_wait_events(mpctx);
     mp_process_input(mpctx);
     handle_command_updates(mpctx);