Handle "show touches" on the device-side

Now that the server can access the Android settings and clean up
properly, handle the "show touches" option from the server.

The initial state is now correctly restored, even on device
disconnection.

app/scrcpy.1

@@ -136,7 +136,7 @@ Turn the device screen off immediately.
 
 .TP
 .B \-t, \-\-show\-touches
-Enable "show touches" on start, disable on quit.
+Enable "show touches" on start, restore the initial value on exit..
 
 It only shows physical touches (not clicks from scrcpy).
 

app/src/cli.c

@@ -130,7 +130,8 @@ scrcpy_print_usage(const char *arg0) {
         "        Turn the device screen off immediately.\n"
         "\n"
         "    -t, --show-touches\n"
-        "        Enable \"show touches\" on start, disable on quit.\n"
+        "        Enable \"show touches\" on start, restore the initial value\n"
+        "        on exit.\n"
         "        It only shows physical touches (not clicks from scrcpy).\n"
         "\n"
         "    -v, --version\n"

app/src/scrcpy.c

@@ -229,21 +229,6 @@ event_loop(bool display, bool control) {
     return false;
 }
 
-static process_t
-set_show_touches_enabled(const char *serial, bool enabled) {
-    const char *value = enabled ? "1" : "0";
-    const char *const adb_cmd[] = {
-        "shell", "settings", "put", "system", "show_touches", value
-    };
-    return adb_execute(serial, adb_cmd, ARRAY_LEN(adb_cmd));
-}
-
-static void
-wait_show_touches(process_t process) {
-    // reap the process, ignore the result
-    process_check_success(process, "show_touches");
-}
-
 static SDL_LogPriority
 sdl_priority_from_av_level(int level) {
     switch (level) {
@@ -292,19 +277,12 @@ scrcpy(const struct scrcpy_options *options) {
         .lock_video_orientation = options->lock_video_orientation,
         .control = options->control,
         .display_id = options->display_id,
+        .show_touches = options->show_touches,
     };
     if (!server_start(&server, options->serial, &params)) {
         return false;
     }
 
-    process_t proc_show_touches = PROCESS_NONE;
-    bool show_touches_waited;
-    if (options->show_touches) {
-        LOGI("Enable show_touches");
-        proc_show_touches = set_show_touches_enabled(options->serial, true);
-        show_touches_waited = false;
-    }
-
     bool ret = false;
 
     bool fps_counter_initialized = false;
@@ -421,11 +399,6 @@ scrcpy(const struct scrcpy_options *options) {
         }
     }
 
-    if (options->show_touches) {
-        wait_show_touches(proc_show_touches);
-        show_touches_waited = true;
-    }
-
     input_manager.prefer_text = options->prefer_text;
 
     ret = event_loop(options->display, options->control);
@@ -482,16 +455,6 @@ end:
         fps_counter_destroy(&fps_counter);
     }
 
-    if (options->show_touches) {
-        if (!show_touches_waited) {
-            // wait the process which enabled "show touches"
-            wait_show_touches(proc_show_touches);
-        }
-        LOGI("Disable show_touches");
-        proc_show_touches = set_show_touches_enabled(options->serial, false);
-        wait_show_touches(proc_show_touches);
-    }
-
     server_destroy(&server);
 
     return ret;

app/src/server.c

@@ -268,6 +268,7 @@ execute_server(struct server *server, const struct server_params *params) {
         "true", // always send frame meta (packet boundaries + timestamp)
         params->control ? "true" : "false",
         display_id_string,
+        params->show_touches ? "true" : "false",
     };
 #ifdef SERVER_DEBUGGER
     LOGI("Server debugger waiting for a client on device port "

app/src/server.h

@@ -51,6 +51,7 @@ struct server_params {
     int8_t lock_video_orientation;
     bool control;
     uint16_t display_id;
+    bool show_touches;
 };
 
 // init default values