Add --list-device-displays

app/data/bash-completion/scrcpy

@@ -19,6 +19,7 @@ _scrcpy() {
         -K --hid-keyboard
         -h --help
         --legacy-paste
+        --list-displays
         --list-encoders
         --lock-video-orientation
         --lock-video-orientation=

app/data/zsh-completion/_scrcpy

@@ -26,6 +26,7 @@ arguments=(
     {-K,--hid-keyboard}'[Simulate a physical keyboard by using HID over AOAv2]'
     {-h,--help}'[Print the help]'
     '--legacy-paste[Inject computer clipboard text as a sequence of key events on Ctrl+v]'
+    '--list-displays[List displays available on the device]'
     '--list-encoders[List video and audio encoders available on the device]'
     '--lock-video-orientation=[Lock video orientation]:orientation:(unlocked initial 0 1 2 3)'
     '--max-fps=[Limit the frame rate of screen capture]'

app/scrcpy.1

@@ -63,10 +63,9 @@ Disable screensaver while scrcpy is running.
 
 .TP
 .BI "\-\-display " id
-Specify the display id to mirror.
+Specify the device display id to mirror.
 
-The list of possible display ids can be listed by "adb shell dumpsys display"
-(search "mDisplayId=" in the output).
+The available display ids can be listed by \-\-list\-displays.
 
 Default is 0.
 
@@ -124,6 +123,10 @@ This is a workaround for some devices not behaving as expected when setting the
 .B \-\-list\-encoders
 List video and audio encoders available on the device.
 
+.TP
+.B \-\-list\-displays
+List displays available on the device.
+
 .TP
 \fB\-\-lock\-video\-orientation\fR[=\fIvalue\fR]
 Lock video orientation to \fIvalue\fR. Possible values are "unlocked", "initial" (locked to the initial orientation), 0, 1, 2 and 3. Natural device orientation is 0, and each increment adds a 90 degrees rotation counterclockwise.

app/src/cli.c

@@ -68,6 +68,7 @@ enum {
     OPT_AUDIO_CODEC_OPTIONS,
     OPT_AUDIO_ENCODER,
     OPT_LIST_ENCODERS,
+    OPT_LIST_DISPLAYS,
 };
 
 struct sc_option {
@@ -191,10 +192,9 @@ static const struct sc_option options[] = {
         .longopt_id = OPT_DISPLAY_ID,
         .longopt = "display",
         .argdesc = "id",
-        .text = "Specify the display id to mirror.\n"
-                "The list of possible display ids can be listed by:\n"
-                "    adb shell dumpsys display\n"
-                "(search \"mDisplayId=\" in the output)\n"
+        .text = "Specify the device display id to mirror.\n"
+                "The available display ids can be listed by:\n"
+                "    scrcpy --list-displays\n"
                 "Default is 0.",
     },
     {
@@ -265,6 +265,11 @@ static const struct sc_option options[] = {
                 "This is a workaround for some devices not behaving as "
                 "expected when setting the device clipboard programmatically.",
     },
+    {
+        .longopt_id = OPT_LIST_DISPLAYS,
+        .longopt = "list-displays",
+        .text = "List device displays.",
+    },
     {
         .longopt_id = OPT_LIST_ENCODERS,
         .longopt = "list-encoders",
@@ -1793,6 +1798,9 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             case OPT_LIST_ENCODERS:
                 opts->list_encoders = true;
                 break;
+            case OPT_LIST_DISPLAYS:
+                opts->list_displays = true;
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/options.c

@@ -73,4 +73,5 @@ const struct scrcpy_options scrcpy_options_default = {
     .power_on = true,
     .audio = true,
     .list_encoders = false,
+    .list_displays = false,
 };

app/src/options.h

@@ -155,6 +155,7 @@ struct scrcpy_options {
     bool power_on;
     bool audio;
     bool list_encoders;
+    bool list_displays;
 };
 
 extern const struct scrcpy_options scrcpy_options_default;

app/src/scrcpy.c

@@ -353,6 +353,7 @@ scrcpy(struct scrcpy_options *options) {
         .cleanup = options->cleanup,
         .power_on = options->power_on,
         .list_encoders = options->list_encoders,
+        .list_displays = options->list_displays,
     };
 
     static const struct sc_server_callbacks cbs = {
@@ -370,7 +371,7 @@ scrcpy(struct scrcpy_options *options) {
 
     server_started = true;
 
-    if (options->list_encoders) {
+    if (options->list_encoders || options->list_displays) {
         bool ok = await_for_server(NULL);
         ret = ok ? SCRCPY_EXIT_SUCCESS : SCRCPY_EXIT_FAILURE;
         goto end;

app/src/server.c

@@ -303,6 +303,9 @@ execute_server(struct sc_server *server,
     if (params->list_encoders) {
         ADD_PARAM("list_encoders=true");
     }
+    if (params->list_displays) {
+        ADD_PARAM("list_displays=true");
+    }
 
 #undef ADD_PARAM
 
@@ -851,9 +854,9 @@ run_server(void *data) {
         goto error_connection_failed;
     }
 
-    // If --list-encoders is passed, then the server just prints the encoders
+    // If --list-* is passed, then the server just prints the requested data
     // then exits.
-    if (params->list_encoders) {
+    if (params->list_encoders || params->list_displays) {
         sc_pid pid = execute_server(server, params);
         if (pid == SC_PROCESS_NONE) {
             goto error_connection_failed;

app/src/server.h

@@ -56,6 +56,7 @@ struct sc_server_params {
     bool cleanup;
     bool power_on;
     bool list_encoders;
+    bool list_displays;
 };
 
 struct sc_server {