Ruby FFI (x86) bindings to essential COM related Windows APIs
- convenient DSL for binding COM interface definitions
IUIFramework = COMInterface[IUnknown,
'F4F0385D-6872-43a8-AD09-4C339CB3F5C5',
Initialize: [[:pointer, :pointer], :long],
Destroy: [[], :long],
LoadUI: [[:pointer, :buffer_in], :long],
GetView: [[:uint, :pointer, :pointer], :long],
GetUICommandProperty: [[:uint, :pointer, :pointer], :long],
SetUICommandProperty: [[:uint, :pointer, :pointer], :long],
InvalidateUICommand: [[:uint, :int, :pointer], :long],
FlushPendingInvalidations: [[], :long],
SetModes: [[:int], :long]
]
UIFramework = COMFactory[IUIFramework, '926749fa-2615-4987-8845-c33e65f2b957']
IUIApplication = COMInterface[IUnknown,
'D428903C-729A-491d-910D-682A08FF2522',
OnViewChanged: [[:uint, :int, :pointer, :int, :int], :long],
OnCreateUICommand: [[:uint, :int, :pointer], :long],
OnDestroyUICommand: [[:uint, :int, :pointer], :long]
]
IUIApplicationImpl = COMCallback[IUIApplication]
- straightforward usage of the resulting Ruby classes
class UIA < IUIApplicationImpl
# uich is an instance of IUICommandHandlerImpl subclass (bindings and definition omitted for brevity)
def initialize(uich)
@uich = uich
super() # wire COM stuff
end
attr_reader :uich
# COM interface method implementations
def OnCreateUICommand(*args)
uich.QueryInterface(uich.class::IID, args[-1])
S_OK
end
end
uif = UIFramework.new # system COM object implementing the IUIFramework interface
uia = UIA.new(uich) # Ruby COM object implementing the IUIApplication interface
- transparent interop with code expecting COM interface pointers
uif.Initialize(hwnd, uia)
Classes starting with capital I are wrappers around raw COM interface pointers inheriting from COMInterface_
(e.g. IUIApplication
). They contain COMVptr_
and COMVtbl_
(FFI::Struct
implementations) instances wired to the corresponding COM interface implementation base and virtual table pointers and are (usually) not directly instantiated by application code.
Classes not starting with capital I are COM factories (obtain COM interface implementations using CoCreateInstance
) inheriting from the corresponding COM interface class (e.g. UIFramework
is a factory for creating instances of IUIFramework
). They are directly instantiated by application code and create system COM objects implementing the corresponding interface.
Classes starting with capital I and ending with Impl are COM callbacks inheriting from the corresponding COM interface class (e.g. IUIApplicationImpl
is a base class for implementing the IUIApplication
interface in Ruby). They are usually subclassed, implement (some) of the corresponding COM interface methods and then instantiated by application code.
All kinds of classes can be freely subclassed and used regardless of their COM duties (just don't forget to call super appropriately in the subclass #initialize
method). COMInterface_
(their common base) implements #to_ptr
(returning the corresponding COMVptr_
instance pointer), so the instances can be directly passed to code expecting COM interface pointers. In a scenario where the COM stuff is used as instance variables of some other class, but it is desirable for the class instances to be passed transparently to code expecting COM interface pointers, just define #to_ptr
calling the appropriate COM object #to_ptr
.
gem install windows_com
See examples folder (the UIRibbon example requires windows_gui gem)