From f595d16cde7c7cc6749df4d913666e51375534fd Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Wed, 20 Oct 2021 22:04:11 +0200
Subject: [PATCH] wip

---
 app/src/hid_keyboard.c  | 48 ++++++++++++++++++++++++++++++++++++++++-
 app/src/hid_keyboard.h  |  6 +++++-
 app/src/input_manager.c |  2 ++
 app/src/scrcpy.c        | 16 +++++++++++++-
 4 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/app/src/hid_keyboard.c b/app/src/hid_keyboard.c
index b66676b1..9bc1ee87 100644
--- a/app/src/hid_keyboard.c
+++ b/app/src/hid_keyboard.c
@@ -33,6 +33,9 @@
 #define HID_KEYBOARD_RESERVED 0x00
 #define HID_KEYBOARD_ERROR_ROLL_OVER 0x01
 
+#define SC_SCANCODE_CAPSLOCK 57
+#define SC_SCANCODE_NUMLOCK 83
+
 /**
  * For HID over AOAv2, only report descriptor is needed.
  *
@@ -170,6 +173,43 @@ sdl_keymod_to_hid_modifiers(SDL_Keymod mod) {
     return modifiers;
 }
 
+static bool
+send_mod_lock_state(struct hid_keyboard *kb, unsigned lock_mod) {
+    assert(!(lock_mod & ~SC_MOD_MASK));
+    if (!lock_mod) {
+        // Nothing to do
+        return true;
+    }
+
+    struct hid_event hid_event;
+    hid_event.from_accessory_id = HID_KEYBOARD_ACCESSORY_ID;
+    hid_event.buffer = create_hid_keyboard_event();
+    if (!hid_event.buffer) {
+        return false;
+    }
+    hid_event.size = HID_KEYBOARD_EVENT_SIZE;
+
+    unsigned i = 0;
+    if (lock_mod & SC_MOD_CAPSLOCK) {
+        hid_event.buffer[HID_KEYBOARD_INDEX_KEYS + i] = SC_SCANCODE_CAPSLOCK;
+        ++i;
+    }
+    if (lock_mod & SC_MOD_NUMLOCK) {
+        hid_event.buffer[HID_KEYBOARD_INDEX_KEYS + i] = SC_SCANCODE_NUMLOCK;
+        ++i;
+    }
+
+//    for (int i = 0; i < HID_KEYBOARD_EVENT_SIZE; ++i)
+//        printf("%02x ", hid_event->buffer[i]);
+//    printf("\n");
+
+    if (!aoa_push_hid_event(kb->aoa, &hid_event)) {
+        LOGW("Could request HID event");
+    }
+
+    return true;
+}
+
 static bool
 convert_hid_keyboard_event(struct hid_keyboard *kb, struct hid_event *hid_event,
                            const SDL_KeyboardEvent *event) {
@@ -276,9 +316,11 @@ sc_key_processor_process_text(struct sc_key_processor *kp,
 }
 
 bool
-hid_keyboard_init(struct hid_keyboard *kb, struct aoa *aoa) {
+hid_keyboard_init(struct hid_keyboard *kb, struct aoa *aoa, unsigned lock_mod) {
     kb->aoa = aoa;
 
+    // FIXME In practice, sending CAPS_LOCK immediately after fails with a Pipe
+    // error but we must know immediately if this fails or not
     bool ok = aoa_setup_hid(aoa, HID_KEYBOARD_ACCESSORY_ID,
                             keyboard_report_desc,
                             ARRAY_LEN(keyboard_report_desc));
@@ -297,6 +339,10 @@ hid_keyboard_init(struct hid_keyboard *kb, struct aoa *aoa) {
 
     kb->key_processor.ops = &ops;
 
+    // FIXME to avoid pipe error
+    usleep(100000);
+    send_mod_lock_state(kb, lock_mod);
+
     return true;
 }
 
diff --git a/app/src/hid_keyboard.h b/app/src/hid_keyboard.h
index b57070aa..606ee3c3 100644
--- a/app/src/hid_keyboard.h
+++ b/app/src/hid_keyboard.h
@@ -16,6 +16,10 @@
 // 0x65 is Application, typically AT-101 Keyboard ends here.
 #define HID_KEYBOARD_KEYS 0x66
 
+#define SC_MOD_MASK 0x3
+#define SC_MOD_CAPSLOCK 0x1
+#define SC_MOD_NUMLOCK 0x2
+
 /**
  * HID keyboard events are sequence-based, every time keyboard state changes
  * it sends an array of currently pressed keys, the host is responsible for
@@ -36,7 +40,7 @@ struct hid_keyboard {
 };
 
 bool
-hid_keyboard_init(struct hid_keyboard *kb, struct aoa *aoa);
+hid_keyboard_init(struct hid_keyboard *kb, struct aoa *aoa, unsigned lock_mod);
 
 void
 hid_keyboard_destroy(struct hid_keyboard *kb);
diff --git a/app/src/input_manager.c b/app/src/input_manager.c
index bba3c998..e82ae67a 100644
--- a/app/src/input_manager.c
+++ b/app/src/input_manager.c
@@ -376,6 +376,8 @@ input_manager_process_key(struct input_manager *im,
 
     bool smod = is_shortcut_mod(im, mod);
 
+    LOGD("=== %x", (int) mod);
+
     if (down && !repeat) {
         if (keycode == im->last_keycode && mod == im->last_mod) {
             ++im->key_repeat;
diff --git a/app/src/scrcpy.c b/app/src/scrcpy.c
index 2a51b111..1d7d982a 100644
--- a/app/src/scrcpy.c
+++ b/app/src/scrcpy.c
@@ -254,6 +254,18 @@ stream_on_eos(struct stream *stream, void *userdata) {
     SDL_PushEvent(&stop_event);
 }
 
+static unsigned
+to_sc_mod(SDL_Keymod sdl_mod) {
+    unsigned mod = 0;
+    if (sdl_mod & KMOD_CAPS) {
+        mod |= SC_MOD_CAPSLOCK;
+    }
+    if (sdl_mod & KMOD_NUM) {
+        mod |= SC_MOD_NUMLOCK;
+    }
+    return mod;
+}
+
 bool
 scrcpy(struct scrcpy_options *options) {
     static struct scrcpy scrcpy;
@@ -462,7 +474,9 @@ scrcpy(struct scrcpy_options *options) {
                 goto aoa_hid_end;
             }
 
-            if (!hid_keyboard_init(&s->keyboard_hid, &s->aoa)) {
+            // FIXME: SDL_GetModState() always returns 0 here :/
+            unsigned mod = to_sc_mod(SDL_GetModState());
+            if (!hid_keyboard_init(&s->keyboard_hid, &s->aoa, mod)) {
                 aoa_join(&s->aoa);
                 aoa_stop(&s->aoa);
                 aoa_destroy(&s->aoa);