fix: client to server modifier press/release

src/lib/deskflow/IKeyState.h

@@ -116,6 +116,16 @@ class IKeyState : public IInterface
   */
   virtual void fakeAllKeysUp() = 0;
 
+  //! Clear stale modifiers
+  /*!
+  Clears stuck modifier state in platform-specific keyboard tracking (e.g. XKB).
+  Default implementation does nothing.
+  */
+  virtual void clearStaleModifiers()
+  {
+    // Default implementation does nothing
+  }
+
   //! Fake ctrl+alt+del
   /*!
   Synthesize a press of ctrl+alt+del.  Return true if processing is

src/lib/deskflow/IPlatformScreen.h

@@ -198,12 +198,13 @@ class IPlatformScreen : public IScreen, public IPrimaryScreen, public ISecondary
   virtual KeyModifierMask pollActiveModifiers() const = 0;
   virtual SInt32 pollActiveGroup() const = 0;
   virtual void pollPressedKeys(KeyButtonSet &pressedKeys) const = 0;
+  virtual void clearStaleModifiers() = 0;
 
+  // Drag-and-drop overrides
   virtual String &getDraggingFilename() = 0;
   virtual void clearDraggingFilename() = 0;
   virtual bool isDraggingStarted() = 0;
   virtual bool isFakeDraggingStarted() = 0;
-
   virtual void fakeDraggingFiles(DragFileList fileList) = 0;
   virtual const String &getDropTarget() const = 0;
 

src/lib/deskflow/KeyState.cpp

@@ -770,6 +770,7 @@ void KeyState::updateKeyState()
   }
 
   // get the current modifier state
+  clearStaleModifiers();
   m_mask = pollActiveModifiers();
 
   // set active modifiers

src/lib/deskflow/PlatformScreen.cpp

@@ -99,6 +99,11 @@ void PlatformScreen::pollPressedKeys(KeyButtonSet &pressedKeys) const
   getKeyState()->pollPressedKeys(pressedKeys);
 }
 
+void PlatformScreen::clearStaleModifiers()
+{
+  getKeyState()->clearStaleModifiers();
+}
+
 bool PlatformScreen::isDraggingStarted()
 {
   if (App::instance().argsBase().m_enableDragDrop) {

src/lib/deskflow/PlatformScreen.h

@@ -74,6 +74,7 @@ class PlatformScreen : public IPlatformScreen
   virtual KeyModifierMask pollActiveModifiers() const;
   virtual SInt32 pollActiveGroup() const;
   virtual void pollPressedKeys(KeyButtonSet &pressedKeys) const;
+  virtual void clearStaleModifiers();
 
   virtual void setDraggingStarted(bool started)
   {

src/lib/platform/EiKeyState.cpp

@@ -321,4 +321,13 @@ void EiKeyState::update_xkb_state(uint32_t keyval, bool is_pressed)
   xkb_state_update_key(xkb_state_, keyval, is_pressed ? XKB_KEY_DOWN : XKB_KEY_UP);
 }
 
+void EiKeyState::clearStaleModifiers()
+{
+  // Recreate the XKB state to clear stuck modifiers that happen when
+  // modifier keys are press on client and released on server
+  if (xkb_state_) {
+    xkb_state_unref(xkb_state_);
+  }
+  xkb_state_ = xkb_state_new(xkb_keymap_);
+}
 } // namespace deskflow

src/lib/platform/EiKeyState.h

@@ -46,6 +46,7 @@ class EiKeyState : public KeyState
   void pollPressedKeys(KeyButtonSet &pressedKeys) const override;
   KeyID map_key_from_keyval(std::uint32_t keyval) const;
   void update_xkb_state(std::uint32_t keyval, bool is_pressed);
+  void clearStaleModifiers() override;
 
 protected:
   // KeyState overrides