rfb_win32: Use scan codes if available

If scan codes are available using QEMU Extended Keyboard Messages
from clients, use that to inject scancodes directly into the
system using the SendInput API.

No conversion is needed as Windows uses the same scancode encoding.

Signed-off-by: Rahul Kale <Rahul.Kale@barco.com>
Signed-off-by: Peter Korsgaard <peter.korsgaard@barco.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/win/rfb_win32/SInput.cxx b/win/rfb_win32/SInput.cxx
index 15ef4b06..f6075c16 100644
--- a/win/rfb_win32/SInput.cxx
+++ b/win/rfb_win32/SInput.cxx
@@ -134,6 +134,9 @@ win32::SPointer::pointerEvent(const Point& pos, int buttonmask)
 BoolParameter rfb::win32::SKeyboard::deadKeyAware("DeadKeyAware",
   "Whether to assume the viewer has already interpreted dead key sequences "
   "into latin-1 characters", true);
+BoolParameter rfb::win32::SKeyboard::rawKeyboard("RawKeyboard",
+  "Send keyboard events straight through and avoid mapping them to the "
+  "current keyboard layout", false);
 
 // The keysymToAscii table transforms a couple of awkward keysyms into their
 // ASCII equivalents.
@@ -229,6 +232,31 @@ inline void doKeyboardEvent(BYTE vkCode, DWORD flags) {
   keybd_event(vkCode, MapVirtualKey(vkCode, 0), flags, 0);
 }
 
+inline void doScanCodeEvent(BYTE scancode, bool down) {
+  INPUT evt;
+
+  evt.type = INPUT_KEYBOARD;
+  evt.ki.wVk = 0;
+  evt.ki.dwFlags = KEYEVENTF_SCANCODE;
+
+  if (!down)
+    evt.ki.dwFlags |= KEYEVENTF_KEYUP;
+
+  if (scancode & 0x80) {
+    evt.ki.dwFlags |= KEYEVENTF_EXTENDEDKEY;
+    scancode &= ~0x80;
+  }
+
+  evt.ki.wScan = scancode;
+  evt.ki.dwExtraInfo = 0;
+  evt.ki.time = 0;
+  vlog.debug("SendInput ScanCode: 0x%x Flags: 0x%lx %s", scancode,
+             evt.ki.dwFlags, down ? "Down" : "Up");
+
+  if (SendInput(1, &evt, sizeof(evt)) != 1)
+    vlog.error("SendInput %lu", GetLastError());
+}
+
 // KeyStateModifier is a class which helps simplify generating a "fake" press
 // or release of shift, ctrl, alt, etc.  An instance of the class is created
 // for every key which may need to be pressed or released.  Then either press()
@@ -323,6 +351,13 @@ win32::SKeyboard::SKeyboard()
 
 void win32::SKeyboard::keyEvent(rdr::U32 keysym, rdr::U32 keycode, bool down)
 {
+  // If scan code is available use that directly as windows uses
+  // compatible scancodes
+  if (keycode && rawKeyboard) {
+    doScanCodeEvent(keycode, down);
+    return;
+  }
+
   for (unsigned int i = 0; i < sizeof(keysymToAscii) / sizeof(keysymToAscii_t); i++) {
     if (keysymToAscii[i].keysym == keysym) {
       keysym = keysymToAscii[i].ascii;