Forward all clicks by default for UHID and AOA

In relative mouse modes (when the cursor appears on the device), it
makes more sense to forward all clicks (disable HOME/BACK shortcuts on
secondary clicks).

Transform the boolean option --forward-all-clicks into a 3-state option:
 - --forward-all-clicks=true or --forward-all-clicks: enable
 - --forward-all-clicks=false: disable
 - --forward-all-clicks=auto (default): enable only for UHID and AOA

That way, by default, all clicks are forwarded with `scrcpy -M`.

Refs <https://github.com/Genymobile/scrcpy/issues/4727#issuecomment-2069869750>

app/scrcpy.1

@@ -165,7 +165,14 @@ Do not attempt to use "adb reverse" to connect to the device.
 
 .TP
 .B \-\-forward\-all\-clicks
-By default, right-click triggers BACK (or POWER on) and middle-click triggers HOME. This option disables these shortcuts and forward the clicks to the device instead.
+Two behaviors are possible: either right-click triggers BACK (or POWER on) and middle-click triggers HOME, or these shortcuts are disabled and the clicks are forwarded to the device.
+
+Possible values are "auto" (forward all clicks only for UHID and AOA mouse modes), "true" (fordward all clicks) and "false" (enable shortcuts for right-click and middle-click).
+
+Default is "auto".
+
+Passing the option without argument is equivalent to passing "true".
+
 
 .TP
 .B \-h, \-\-help

app/src/cli.c

@@ -354,9 +354,18 @@ static const struct sc_option options[] = {
     {
         .longopt_id = OPT_FORWARD_ALL_CLICKS,
         .longopt = "forward-all-clicks",
-        .text = "By default, right-click triggers BACK (or POWER on) and "
-                "middle-click triggers HOME. This option disables these "
-                "shortcuts and forwards the clicks to the device instead.",
+        .argdesc = "value",
+        .optional_arg = true,
+        .text = "Two behaviors are possible: either right-click triggers BACK "
+                "(or POWER on) and middle-click triggers HOME, or these "
+                "shortcuts are disabled and the clicks are forwarded to the "
+                "device.\n"
+                "Possible values are \"auto\" (forward all clicks only for "
+                "UHID and AOA mouse modes), \"true\" (forward all clicks) and "
+                "\"false\" (enable shortcuts for right and middle clicks).\n"
+                "Default is \"auto\".\n"
+                "Passing the option without argument is equivalent to passing "
+                "\"true\".",
     },
     {
         .shortopt = 'h',
@@ -1531,6 +1540,28 @@ parse_lock_video_orientation(const char *s,
     return false;
 }
 
+static bool
+parse_forward_all_clicks(const char *s, enum sc_forward_all_clicks *value) {
+    if (!s || !strcmp(s, "true")) {
+        *value = SC_FORWARD_ALL_CLICKS_TRUE;
+        return true;
+    }
+
+    if (!strcmp(s, "false")) {
+        *value = SC_FORWARD_ALL_CLICKS_FALSE;
+        return true;
+    }
+
+    if (!strcmp(s, "auto")) {
+        *value = SC_FORWARD_ALL_CLICKS_AUTO;
+        return true;
+    }
+
+    LOGE("Unsupported --forward-all-clicks value: %s (expected auto, true or "
+         "false).", s);
+    return false;
+}
+
 static bool
 parse_rotation(const char *s, uint8_t *rotation) {
     long value;
@@ -2342,7 +2373,10 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
                 }
                 break;
             case OPT_FORWARD_ALL_CLICKS:
-                opts->forward_all_clicks = true;
+                if (!parse_forward_all_clicks(optarg,
+                        &opts->forward_all_clicks)) {
+                    return false;
+                }
                 break;
             case OPT_LEGACY_PASTE:
                 opts->legacy_paste = true;
@@ -2624,6 +2658,15 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             LOGE("SDK mouse mode requires video playback. Try --mouse=uhid.");
             return false;
         }
+
+        if (opts->forward_all_clicks == SC_FORWARD_ALL_CLICKS_AUTO) {
+            // By default, forward all clicks only for UHID and AOA
+            if (opts->mouse_input_mode == SC_MOUSE_INPUT_MODE_SDK) {
+                opts->forward_all_clicks = SC_FORWARD_ALL_CLICKS_FALSE;
+            } else {
+                opts->forward_all_clicks = SC_FORWARD_ALL_CLICKS_TRUE;
+            }
+        }
     }
 
     if (otg) {

app/src/options.c

@@ -71,7 +71,7 @@ const struct scrcpy_options scrcpy_options_default = {
     .force_adb_forward = false,
     .disable_screensaver = false,
     .forward_key_repeat = true,
-    .forward_all_clicks = false,
+    .forward_all_clicks = SC_FORWARD_ALL_CLICKS_AUTO,
     .legacy_paste = false,
     .power_off_on_close = false,
     .clipboard_autosync = true,

app/src/options.h

@@ -83,6 +83,12 @@ enum sc_orientation {         // v v v
     SC_ORIENTATION_FLIP_270,  // 1 1 1
 };
 
+enum sc_forward_all_clicks {
+    SC_FORWARD_ALL_CLICKS_AUTO,
+    SC_FORWARD_ALL_CLICKS_TRUE,
+    SC_FORWARD_ALL_CLICKS_FALSE,
+};
+
 static inline bool
 sc_orientation_is_mirror(enum sc_orientation orientation) {
     assert(!(orientation & ~7));
@@ -257,7 +263,7 @@ struct scrcpy_options {
     bool force_adb_forward;
     bool disable_screensaver;
     bool forward_key_repeat;
-    bool forward_all_clicks;
+    enum sc_forward_all_clicks forward_all_clicks;
     bool legacy_paste;
     bool power_off_on_close;
     bool clipboard_autosync;

app/src/scrcpy.c

@@ -688,13 +688,18 @@ scrcpy(struct scrcpy_options *options) {
         const char *window_title =
             options->window_title ? options->window_title : info->device_name;
 
+        // The option forward_all_clicks must have been resolved at this point
+        assert(options->forward_all_clicks != SC_FORWARD_ALL_CLICKS_AUTO);
+        bool forward_all_clicks =
+            options->forward_all_clicks == SC_FORWARD_ALL_CLICKS_TRUE;
+
         struct sc_screen_params screen_params = {
             .video = options->video_playback,
             .controller = controller,
             .fp = fp,
             .kp = kp,
             .mp = mp,
-            .forward_all_clicks = options->forward_all_clicks,
+            .forward_all_clicks = forward_all_clicks,
             .legacy_paste = options->legacy_paste,
             .clipboard_autosync = options->clipboard_autosync,
             .shortcut_mods = &options->shortcut_mods,

doc/control.md

@@ -93,11 +93,20 @@ This only works for the default mouse mode (`--mouse=sdk`).
 
 ## Right-click and middle-click
 
-By default, right-click triggers BACK (or POWER on) and middle-click triggers
-HOME. To disable these shortcuts and forward the clicks to the device instead:
+Two behaviors are possible:
+
+ - either right-click triggers BACK (or POWER on) and middle-click triggers
+   HOME, or
+ - these shortcuts are disabled and the clicks are forwarded to the device.
+
+By default, the clicks are forwarded only for UHID and AOA [mouse
+modes](mouse.md).
 
 ```bash
-scrcpy --forward-all-clicks
+scrcpy --forward-all-clicks        # enable
+scrcpy --forward-all-clicks=auto   # enable only for UHID and AOA (default)
+scrcpy --forward-all-clicks=true   # enable (equivalent to no argument)
+scrcpy --forward-all-clicks=false  # disable
 ```
 
 ## File drop