1. Jim Fawcett CSE775 – Distributed Objects Spring 2007
ActiveX Controls
Jim Fawcett
CSE775 – Distributed Objects
Spring 2007

2. What is an ActiveX Control? Com Component
A COM component
User Interface
Has thread affinity, must live in an STA
Derives from CComObjectRootEx<CComSingleThread-Model>
Creatable class
Derives from CComCoClass
Provides IClassFactory interface

3. What is an ActiveX Control? Properties, callbacks, change notifications
Has stock and custom properties and methods
Implements IDispatch interface
Stock and custom event callbacks
Supports connection points
dispinterface, IConnectionPointContainer, IConnectionPoint, IProvideClassInfo2
Property change notifications
IPropertyNotifySink, connection points

4. What is an ActiveX Control? Control behavior
On-demand rendering of view
IViewObject, IViewObject2, IViewObjectEx
Standard control behavior
IOleControl
In-place activation
IOleObject, IOleInPlaceActiveObject

5. What is an ActiveX Control? Persistence and Drag-and-Drop
Persistence support for containers
IPersistStreamInit, IPersistPropertyBag, IPersistStorage
Drag and Drop support
IDataObject, IDropSource, IDropTarget

6. What is an ActiveX Control? Design-Time Support
Provide property pages
ISpecifyPropertyPages
Property browsing from container
IPerPropertyBrowsing
Arrange properties by category
ICategorizeProperties

7. Control Types “Standard” ActiveX control Composite Control
A container and a control
HTML Control
Uses same webBrowser control as IE

8. What is a Control Container?
Provides a window
Acts as parent for the child COM control
Provides means for user to communicate with control, e.g., button-click, mouse-move, …
Support a set of COM interfaces that control uses to communicate with container

9. What is a Control Container? Basic containment
Control creation
CAxHostWindow has the base classes
CComCoClass
CComObjectRootEx<CComSingleThreadModel>
CWindowImpl
IOleClientSite
IOleInPlaceSiteWindowless
IOleControlSite
IOleContainer
IObjectWintSiteImpl
IServiceProvider
IAdviseSink

10. Container Window
Since the container provides a window for the control, you can do all the usual window things with it by sending windows messages:
Resize and move
Show and hide
CAxWindow provides a QueryControl method to obtain the control’s interface
HRESULT QueryControl(REFIID iid, void** ppUnk);

11. Sinking a Control’s Events
Connection Pointer interfaces
dispinterface, not dual interface, so container can’t just derive from, and implement those source interfaces
IDispatchImpl<nID, T, pdiid>
Derive once of each control
Uses BEGIN_SINK_MAP, SINK_ENTRY, END_SINK_MAP
Call IConnectionPointContainer, IConnectionPoint, IAdvise to establish link
Uses HRESULT AtlAdviseSinkMap(T* pT, bool bAdvise);

12. Sinking Control’s Property Notifications
Control defines IPropertyNotify interface
Request permission to change a property
Notify of a property change
IPropertyNotify is a dual interface
Container just inherits and implements
No need for sink map and IDispatchImpl
Implement STDMETHODIMP OnRequestEdit(DISPID dispID) { return S_OK; } STDMETHODIMP OnChanged(DISPID dispID) { m.bDirty = true; return S_OK; }