Always prefer text events by default

This improves text input, but it breaks the expected behavior in games
again: <https://github.com/Genymobile/scrcpy/issues/87>.

To get the previous behavior back, pass an explicit option:

    scrcpy --prefer-text-events=non-alpha

app/scrcpy.1

@@ -61,6 +61,16 @@ Set the TCP port the client listens on.
 
 Default is 27183.
 
+.TP
+.BI \-\-prefer\-text\-events " mode
+Configure how key/text events are forwarded to the Android device.
+
+Possible \fImode\fRs are "always" (every text is sent as text), "non-alpha"
+(only letters are sent as a sequence of key events, other characters are sent
+as text) and "never" (every text is sent as a sequence of key events).
+
+Default is "always".
+
 .TP
 .BI "\-\-push\-target " path
 Set the target directory for pushing files to the device by drag & drop. It is passed as\-is to "adb push".

app/src/event_converter.c

@@ -75,7 +75,8 @@ convert_meta_state(SDL_Keymod mod) {
 }
 
 bool
-convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod) {
+convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod,
+                enum text_events_pref pref) {
     switch (from) {
         MAP(SDLK_RETURN,       AKEYCODE_ENTER);
         MAP(SDLK_KP_ENTER,     AKEYCODE_NUMPAD_ENTER);
@@ -92,6 +93,16 @@ convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod) {
         MAP(SDLK_DOWN,         AKEYCODE_DPAD_DOWN);
         MAP(SDLK_UP,           AKEYCODE_DPAD_UP);
     }
+
+    if (pref == PREFER_TEXT_EVENTS_ALWAYS) {
+        // never forward key events
+        return false;
+    }
+
+    // forward all supported key events
+    SDL_assert(pref == PREFER_TEXT_EVENTS_NEVER ||
+               pref == PREFER_TEXT_EVENTS_NON_ALPHA);
+
     if (mod & (KMOD_LALT | KMOD_RALT | KMOD_LGUI | KMOD_RGUI)) {
         return false;
     }

app/src/event_converter.h

@@ -2,10 +2,12 @@
 #define CONVERT_H
 
 #include <stdbool.h>
+#include <SDL2/SDL_assert.h>
 #include <SDL2/SDL_events.h>
 
 #include "config.h"
 #include "control_msg.h"
+#include "input_manager.h"
 
 bool
 convert_keycode_action(SDL_EventType from, enum android_keyevent_action *to);
@@ -14,7 +16,8 @@ enum android_metastate
 convert_meta_state(SDL_Keymod mod);
 
 bool
-convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod);
+convert_keycode(SDL_Keycode from, enum android_keycode *to, uint16_t mod,
+                enum text_events_pref pref);
 
 enum android_motionevent_buttons
 convert_mouse_buttons(uint32_t state);

app/src/input_manager.c

@@ -214,12 +214,20 @@ clipboard_paste(struct controller *controller) {
 void
 input_manager_process_text_input(struct input_manager *im,
                                  const SDL_TextInputEvent *event) {
+    if (im->text_events_pref == PREFER_TEXT_EVENTS_NEVER) {
+        // ignore all text events (key events will be injected instead)
+        return;
+    }
+
+    if (im->text_events_pref == PREFER_TEXT_EVENTS_NON_ALPHA) {
         char c = event->text[0];
         if (isalpha(c) || c == ' ') {
             SDL_assert(event->text[1] == '\0');
             // letters and space are handled as raw key event
             return;
         }
+    }
+
     struct control_msg msg;
     msg.type = CONTROL_MSG_TYPE_INJECT_TEXT;
     msg.inject_text.text = SDL_strdup(event->text);
@@ -234,7 +242,8 @@ input_manager_process_text_input(struct input_manager *im,
 }
 
 static bool
-convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to) {
+convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to,
+                  enum text_events_pref pref) {
     to->type = CONTROL_MSG_TYPE_INJECT_KEYCODE;
 
     if (!convert_keycode_action(from->type, &to->inject_keycode.action)) {
@@ -242,7 +251,8 @@ convert_input_key(const SDL_KeyboardEvent *from, struct control_msg *to) {
     }
 
     uint16_t mod = from->keysym.mod;
-    if (!convert_keycode(from->keysym.sym, &to->inject_keycode.keycode, mod)) {
+    if (!convert_keycode(from->keysym.sym, &to->inject_keycode.keycode, mod,
+                         pref)) {
         return false;
     }
 
@@ -393,7 +403,7 @@ input_manager_process_key(struct input_manager *im,
     }
 
     struct control_msg msg;
-    if (convert_input_key(event, &msg)) {
+    if (convert_input_key(event, &msg, im->text_events_pref)) {
         if (!controller_push_msg(controller, &msg)) {
             LOGW("Could not request 'inject keycode'");
         }

app/src/input_manager.h

@@ -10,10 +10,17 @@
 #include "video_buffer.h"
 #include "screen.h"
 
+enum text_events_pref {
+    PREFER_TEXT_EVENTS_ALWAYS,
+    PREFER_TEXT_EVENTS_NON_ALPHA,
+    PREFER_TEXT_EVENTS_NEVER,
+};
+
 struct input_manager {
     struct controller *controller;
     struct video_buffer *video_buffer;
     struct screen *screen;
+    enum text_events_pref text_events_pref;
 };
 
 void

app/src/main.c

@@ -11,6 +11,7 @@
 #include "config.h"
 #include "compat.h"
 #include "log.h"
+#include "input_manager.h"
 #include "recorder.h"
 
 struct args {
@@ -67,6 +68,18 @@ static void usage(const char *arg0) {
         "        Set the TCP port the client listens on.\n"
         "        Default is %d.\n"
         "\n"
+        "    --prefer-text-events mode\n"
+        "        Configure how key/text events are forwarded to the Android\n"
+        "        device.\n"
+        "        Possible values are:\n"
+        "          always:\n"
+        "            Every text is sent as text. (default)\n"
+        "          non-alpha:\n"
+        "            Only letters are sent as a sequence of key events, other\n"
+        "            characters are sent as text.\n"
+        "          never:\n"
+        "            Every text is sent as a sequence of key events.\n"
+        "\n"
         "    --push-target path\n"
         "        Set the target directory for pushing files to the device by\n"
         "        drag & drop. It is passed as-is to \"adb push\".\n"
@@ -294,9 +307,33 @@ guess_record_format(const char *filename) {
     return 0;
 }
 
+static bool
+parse_prefer_text_events(const char *optarg,
+                         enum text_events_pref *pref) {
+    if (!strcmp(optarg, "always")) {
+        *pref = PREFER_TEXT_EVENTS_ALWAYS;
+        return true;
+    }
+
+    if (!strcmp(optarg, "non-alpha")) {
+        *pref = PREFER_TEXT_EVENTS_NON_ALPHA;
+        return true;
+    }
+
+    if (!strcmp(optarg, "never")) {
+        *pref = PREFER_TEXT_EVENTS_NEVER;
+        return true;
+    }
+
+    LOGE("Unsupported text events preference: %s"
+         "(expected 'always', 'non-alpha' or 'never')", optarg);
+    return false;
+}
+
 #define OPT_RENDER_EXPIRED_FRAMES 1000
 #define OPT_WINDOW_TITLE          1001
 #define OPT_PUSH_TARGET           1002
+#define OPT_PREFER_TEXT_EVENTS    1003
 
 static bool
 parse_args(struct args *args, int argc, char *argv[]) {
@@ -319,6 +356,8 @@ parse_args(struct args *args, int argc, char *argv[]) {
         {"serial",                required_argument, NULL, 's'},
         {"show-touches",          no_argument,       NULL, 't'},
         {"turn-screen-off",       no_argument,       NULL, 'S'},
+        {"prefer-text-events",    required_argument, NULL,
+                                                 OPT_PREFER_TEXT_EVENTS},
         {"version",               no_argument,       NULL, 'v'},
         {"window-title",          required_argument, NULL,
                                                  OPT_WINDOW_TITLE},
@@ -393,6 +432,12 @@ parse_args(struct args *args, int argc, char *argv[]) {
             case OPT_PUSH_TARGET:
                 opts->push_target = optarg;
                 break;
+            case OPT_PREFER_TEXT_EVENTS:
+                if (!parse_prefer_text_events(optarg,
+                                              &opts->text_events_pref)) {
+                    return false;
+                }
+                break;
             default:
                 // getopt prints the error message on stderr
                 return false;

app/src/scrcpy.c

@@ -42,6 +42,7 @@ static struct input_manager input_manager = {
     .controller = &controller,
     .video_buffer = &video_buffer,
     .screen = &screen,
+    .text_events_pref = 0, // initialized later
 };
 
 // init SDL and set appropriate hints
@@ -414,6 +415,8 @@ scrcpy(const struct scrcpy_options *options) {
         show_touches_waited = true;
     }
 
+    input_manager.text_events_pref = options->text_events_pref;
+
     ret = event_loop(options->display, options->control);
     LOGD("quit...");
 

app/src/scrcpy.h

@@ -5,6 +5,7 @@
 #include <stdint.h>
 
 #include "config.h"
+#include "input_manager.h"
 #include "recorder.h"
 
 struct scrcpy_options {
@@ -14,6 +15,7 @@ struct scrcpy_options {
     const char *window_title;
     const char *push_target;
     enum recorder_format record_format;
+    enum text_events_pref text_events_pref;
     uint16_t port;
     uint16_t max_size;
     uint32_t bit_rate;
@@ -33,6 +35,7 @@ struct scrcpy_options {
     .window_title = NULL, \
     .push_target = NULL, \
     .record_format = RECORDER_FORMAT_AUTO, \
+    .text_events_pref = PREFER_TEXT_EVENTS_ALWAYS, \
     .port = DEFAULT_LOCAL_PORT, \
     .max_size = DEFAULT_LOCAL_PORT, \
     .bit_rate = DEFAULT_BIT_RATE, \