Thank you.
It compiles (tried on arch linux), a touched cbp or cpp file is detected like it should be.
One issue I observe in the "Open files List" is that relative paths are turned into
absolute paths. They should remain relative paths.
As for the code:
#include <wx/fswatcher.h>
seems avoidable in FileExplorer.h if wxFileSystemWatcherEvent and wxFileSystemWatcher* are forward-declared. Compiletime is already not ideal when compiling cb.
Have you considered making
wxFileSystemWatcher *m_fs_watcher;
a std::unique_ptr?
I like the fact that the patch is focussed on the necessary changes. Have you considered a second patch with refactorings e.g. moving initialization of non-static data-members in the ctor body into
a member initializer list or using default member initializers?