Move keyboard handling to separate classes

common/rfb/CConnection.cxx

@@ -40,6 +40,10 @@
 #include <rfb/CConnection.h>
 #include <rfb/util.h>
 
+#define XK_MISCELLANY
+#define XK_XKB_KEYS
+#include <rfb/keysymdef.h>
+
 #include <rfb/LogWriter.h>
 
 #include <rdr/InStream.h>
@@ -693,6 +697,89 @@ void CConnection::sendClipboardData(const char* data)
   }
 }
 
+void CConnection::sendKeyPress(int systemKeyCode,
+                               uint32_t keyCode, uint32_t keySym)
+{
+  // For the first few years, there wasn't a good consensus on what the
+  // Windows keys should be mapped to for X11. So we need to help out a
+  // bit and map all variants to the same key...
+  switch (keySym) {
+  case XK_Hyper_L:
+    keySym = XK_Super_L;
+    break;
+  case XK_Hyper_R:
+    keySym = XK_Super_R;
+    break;
+  // There has been several variants for Shift-Tab over the years.
+  // RFB states that we should always send a normal tab.
+  case XK_ISO_Left_Tab:
+    keySym = XK_Tab;
+    break;
+  }
+
+#ifdef __APPLE__
+  // Alt on OS X behaves more like AltGr on other systems, and to get
+  // sane behaviour we should translate things in that manner for the
+  // remote VNC server. However that means we lose the ability to use
+  // Alt as a shortcut modifier. Do what RealVNC does and hijack the
+  // left command key as an Alt replacement.
+  switch (keySym) {
+  case XK_Super_L:
+    keySym = XK_Alt_L;
+    break;
+  case XK_Super_R:
+    keySym = XK_Super_L;
+    break;
+  case XK_Alt_L:
+    keySym = XK_Mode_switch;
+    break;
+  case XK_Alt_R:
+    keySym = XK_ISO_Level3_Shift;
+    break;
+  }
+#endif
+
+  // Because of the way keyboards work, we cannot expect to have the same
+  // symbol on release as when pressed. This breaks the VNC protocol however,
+  // so we need to keep track of what keysym a key _code_ generated on press
+  // and send the same on release.
+  downKeys[systemKeyCode].keyCode = keyCode;
+  downKeys[systemKeyCode].keySym = keySym;
+
+  vlog.debug("Key pressed: %d => 0x%02x / XK_%s (0x%04x)",
+             systemKeyCode, keyCode, KeySymName(keySym), keySym);
+
+  writer()->writeKeyEvent(keySym, keyCode, true);
+}
+
+void CConnection::sendKeyRelease(int systemKeyCode)
+{
+  DownMap::iterator iter;
+
+  iter = downKeys.find(systemKeyCode);
+  if (iter == downKeys.end()) {
+    // These occur somewhat frequently so let's not spam them unless
+    // logging is turned up.
+    vlog.debug("Unexpected release of key code %d", systemKeyCode);
+    return;
+  }
+
+  vlog.debug("Key released: %d => 0x%02x / XK_%s (0x%04x)",
+             systemKeyCode, iter->second.keyCode,
+             KeySymName(iter->second.keySym), iter->second.keySym);
+
+  writer()->writeKeyEvent(iter->second.keySym,
+                          iter->second.keyCode, false);
+
+  downKeys.erase(iter);
+}
+
+void CConnection::releaseAllKeys()
+{
+  while (!downKeys.empty())
+    sendKeyRelease(downKeys.begin()->first);
+}
+
 void CConnection::refreshFramebuffer()
 {
   forceNonincremental = true;

common/rfb/CConnection.h

@@ -24,6 +24,7 @@
 #ifndef __RFB_CCONNECTION_H__
 #define __RFB_CCONNECTION_H__
 
+#include <map>
 #include <string>
 
 #include <rfb/CMsgHandler.h>
@@ -196,6 +197,18 @@ namespace rfb {
     // clipboard via handleClipboardRequest().
     virtual void sendClipboardData(const char* data);
 
+    // sendKeyPress()/sendKeyRelease() send keyboard events to the
+    // server
+    void sendKeyPress(int systemKeyCode, uint32_t keyCode, uint32_t keySym);
+    void sendKeyRelease(int systemKeyCode);
+
+    // releaseAllKeys() sends keyboard release events to the server for
+    // all keys that are currently pressed down by this client,
+    // avoiding keys getting stuck. This can be useful if the client
+    // loses keyboard focus or otherwise no longer gets keyboard events
+    // from the system.
+    void releaseAllKeys();
+
     // refreshFramebuffer() forces a complete refresh of the entire
     // framebuffer
     void refreshFramebuffer();
@@ -313,6 +326,13 @@ namespace rfb {
     bool hasRemoteClipboard;
     bool hasLocalClipboard;
     bool unsolicitedClipboardAttempt;
+
+    struct DownKey {
+        uint32_t keyCode;
+        uint32_t keySym;
+    };
+    typedef std::map<int, DownKey> DownMap;
+    DownMap downKeys;
   };
 }
 #endif

vncviewer/CMakeLists.txt

@@ -18,7 +18,6 @@ add_executable(vncviewer
   PlatformPixelBuffer.cxx
   Viewport.cxx
   parameters.cxx
-  keysym2ucs.c
   touch.cxx
   MonitorIndicesParameter.cxx
   vncviewer.cxx)
@@ -37,17 +36,15 @@ endif()
 
 if(WIN32)
   target_sources(vncviewer PRIVATE Win32TouchHandler.cxx win32.c)
-elseif(APPLE)
-  target_sources(vncviewer PRIVATE cocoa.mm osx_to_qnum.c)
-else()
-  target_sources(vncviewer PRIVATE GestureHandler.cxx XInputTouchHandler.cxx xkb_to_qnum.c)
-endif()
-
-if(WIN32)
+  target_sources(vncviewer PRIVATE KeyboardWin32.cxx keysym2ucs.c)
   target_sources(vncviewer PRIVATE Surface_Win32.cxx)
 elseif(APPLE)
+  target_sources(vncviewer PRIVATE cocoa.mm)
+  target_sources(vncviewer PRIVATE KeyboardMacOS.mm osx_to_qnum.c keysym2ucs.c)
   target_sources(vncviewer PRIVATE Surface_OSX.cxx)
 else()
+  target_sources(vncviewer PRIVATE GestureHandler.cxx XInputTouchHandler.cxx)
+  target_sources(vncviewer PRIVATE KeyboardX11.cxx xkb_to_qnum.c)
   target_sources(vncviewer PRIVATE Surface_X11.cxx)
 endif()
 

vncviewer/Keyboard.h

@@ -0,0 +1,49 @@
+/* Copyright 2011-2021 Pierre Ossman <ossman@cendio.se> for Cendio AB
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#ifndef __KEYBOARD_H__
+#define __KEYBOARD_H__
+
+#include <stdint.h>
+
+class KeyboardHandler
+{
+public:
+  virtual void handleKeyPress(int systemKeyCode,
+                              uint32_t keyCode, uint32_t keySym) = 0;
+  virtual void handleKeyRelease(int systemKeyCode) = 0;
+};
+
+class Keyboard
+{
+public:
+  Keyboard(KeyboardHandler* handler_) : handler(handler_) {};
+  virtual ~Keyboard() {};
+
+  virtual bool handleEvent(const void* event) = 0;
+
+  virtual void reset() {};
+
+  virtual unsigned getLEDState() = 0;
+  virtual void setLEDState(unsigned state) = 0;
+
+protected:
+  KeyboardHandler* handler;
+};
+
+#endif

vncviewer/KeyboardMacOS.h

@@ -0,0 +1,60 @@
+/* Copyright 2011-2021 Pierre Ossman <ossman@cendio.se> for Cendio AB
+ * 
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+#ifndef __KEYBOARDMACOS_H__
+#define __KEYBOARDMACOS_H__
+
+#include "Keyboard.h"
+
+#ifdef __OBJC__
+@class NSEvent;
+@class NSString;
+#else
+class NSEvent;
+class NSString;
+#endif
+
+class KeyboardMacOS : public Keyboard
+{
+public:
+  KeyboardMacOS(KeyboardHandler* handler);
+  virtual ~KeyboardMacOS();
+
+  bool handleEvent(const void* event) override;
+
+  unsigned getLEDState() override;
+  void setLEDState(unsigned state) override;
+
+  // Special helper on macOS
+  static bool isKeyboardSync(const void* event);
+
+protected:
+  bool isKeyboardEvent(const NSEvent* nsevent);
+  bool isKeyPress(const NSEvent* nsevent);
+  uint32_t translateSystemKeyCode(int systemKeyCode);
+  unsigned getSystemKeyCode(const NSEvent* nsevent);
+
+  NSString* keyTranslate(unsigned keyCode, unsigned modifierFlags);
+  uint32_t translateEventKeysym(const NSEvent* nsevent);
+
+  int openHID(unsigned int* ioc);
+  int getModifierLockState(int modifier, bool* on);
+  int setModifierLockState(int modifier, bool on);
+};
+
+#endif