Filing

About Filing

on the internal store, the external store or both; that is, the user can specify a stores
filter in addition to a labels filter. Figure 15-8 shows the folder tab picker in a view
based on the

protoClockFolderTab

proto.

Choosing a filing filter

To display items according to the user's choice of store, your target view must
supply a

storesFilter

slot. When the target view has a

storesFilter

slot

and more than one store is available, the folder tab views allow the user to specify a
store in addition to a folder from which data items are retrieved for display. For
example, the user might choose to display only entries in the

'business

folder

on the internal store.

When the user chooses any filter from this picker, the system updates the

storesFilter

or

labelsFilter

slot and sends the target view a

NewFilingFilter

message. The argument passed to this method by the system

tells you what changed--the stores filter or the labels filter--but not its new value.

You must supply a

NewFilingFilter

method that examines the

storesFilter

or

labelsFilter

slot and queries your application's soups

appropriately. If the value of the

labelsFilter

slot is

nil

, your

NewFilingFilter

method must display all target items. Similarly, if

the value of the target view's

storesFilter

slot is

nil

, your

NewFilingFilter

method must display items on all available stores.

Your

NewFilingFilter

method must also perform any other actions

necessary to display the appropriate data, such as redrawing views affected by
the new filter value.

You can use the

RegFolderChanged

function to register your own callback

function to be executed when the user adds, deletes, or edits folder names. You
cannot respond adequately to these kinds of changes from within your

NewFilingFilter

or

FileThis

methods alone.