Define the Update Hint

The first task is to define the update hint.

To define the update hint

• Add the following two #define values to ContainerDoc.h, prior to the class declaration:

  #define HINT_UPDATE_WINDOW            0
  #define HINT_UPDATE_ITEM                1
  

  The two #define HINT_ values are used for the LPARAM lHint value passed to CContainerView::OnUpdate, which you’ll create in the next step. The first hint value, HINT_UPDATE_WINDOW, has the framework’s default lHint value of 0, which means “no hint”: in other words, it is an instruction to invalidate the entire client area of the view. The second, HINT_UPDATE_ITEM, is used to invalidate the rectangle of the view’s client area occupied by the COleClientItem object. That rectangle is passed to OnUpdate using the pHint parameter.