Add option to force legacy method for pasting

Some devices do not behave as expected when setting the device clipboard
programmatically.

Add an option --legacy-paste to change the behavior of Ctrl+v and MOD+v
so that they inject the computer clipboard text as a sequence of key
events (the same way as MOD+Shift+v).

Fixes #1750 <https://github.com/Genymobile/scrcpy/issues/1750>
Fixes #1771 <https://github.com/Genymobile/scrcpy/issues/1771>

app/src/cli.c

@@ -68,6 +68,12 @@ scrcpy_print_usage(const char *arg0) {
         "    -h, --help\n"
         "        Print this help.\n"
         "\n"
+        "    --legacy-paste\n"
+        "        Inject computer clipboard text as a sequence of key events\n"
+        "        on Ctrl+v (like MOD+Shift+v).\n"
+        "        This is a workaround for some devices not behaving as\n"
+        "        expected when setting the device clipboard programmatically.\n"
+        "\n"
         "    --lock-video-orientation value\n"
         "        Lock video orientation to value.\n"
         "        Possible values are -1 (unlocked), 0, 1, 2 and 3.\n"
@@ -657,6 +663,7 @@ guess_record_format(const char *filename) {
 #define OPT_SHORTCUT_MOD           1021
 #define OPT_NO_KEY_REPEAT          1022
 #define OPT_FORWARD_ALL_CLICKS     1023
+#define OPT_LEGACY_PASTE           1024
 
 bool
 scrcpy_parse_args(struct scrcpy_cli_args *args, int argc, char *argv[]) {
@@ -674,6 +681,7 @@ scrcpy_parse_args(struct scrcpy_cli_args *args, int argc, char *argv[]) {
                                                   OPT_FORWARD_ALL_CLICKS},
         {"fullscreen",             no_argument,       NULL, 'f'},
         {"help",                   no_argument,       NULL, 'h'},
+        {"legacy-paste",           no_argument,       NULL, OPT_LEGACY_PASTE},
         {"lock-video-orientation", required_argument, NULL,
                                                   OPT_LOCK_VIDEO_ORIENTATION},
         {"max-fps",                required_argument, NULL, OPT_MAX_FPS},
@@ -867,6 +875,9 @@ scrcpy_parse_args(struct scrcpy_cli_args *args, int argc, char *argv[]) {
             case OPT_FORWARD_ALL_CLICKS:
                 opts->forward_all_clicks = true;
                 break;
+            case OPT_LEGACY_PASTE:
+                opts->legacy_paste = true;
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/input_manager.c

@@ -61,6 +61,7 @@ input_manager_init(struct input_manager *im,
     im->forward_key_repeat = options->forward_key_repeat;
     im->prefer_text = options->prefer_text;
     im->forward_all_clicks = options->forward_all_clicks;
+    im->legacy_paste = options->legacy_paste;
 
     const struct sc_shortcut_mods *shortcut_mods = &options->shortcut_mods;
     assert(shortcut_mods->count);
@@ -441,7 +442,7 @@ input_manager_process_key(struct input_manager *im,
                 return;
             case SDLK_v:
                 if (control && !repeat && down) {
-                    if (shift) {
+                    if (shift || im->legacy_paste) {
                         // inject the text as input events
                         clipboard_paste(controller);
                     } else {
@@ -505,6 +506,11 @@ input_manager_process_key(struct input_manager *im,
     }
 
     if (ctrl && !shift && keycode == SDLK_v && down && !repeat) {
+        if (im->legacy_paste) {
+            // inject the text as input events
+            clipboard_paste(controller);
+            return;
+        }
         // Synchronize the computer clipboard to the device clipboard before
         // sending Ctrl+v, to allow seamless copy-paste.
         set_device_clipboard(controller, false);

app/src/input_manager.h

@@ -26,6 +26,7 @@ struct input_manager {
     bool forward_key_repeat;
     bool prefer_text;
     bool forward_all_clicks;
+    bool legacy_paste;
 
     struct {
         unsigned data[SC_MAX_SHORTCUT_MODS];

app/src/scrcpy.h

@@ -80,6 +80,7 @@ struct scrcpy_options {
     bool disable_screensaver;
     bool forward_key_repeat;
     bool forward_all_clicks;
+    bool legacy_paste;
 };
 
 #define SCRCPY_OPTIONS_DEFAULT { \
@@ -125,6 +126,7 @@ struct scrcpy_options {
     .disable_screensaver = false, \
     .forward_key_repeat = true, \
     .forward_all_clicks = false, \
+    .legacy_paste = false, \
 }
 
 bool