NSDocumentController is a class that
controls a set of NSDocuments for an application.
As an application delegate, it responds to the typical
File Menu commands for opening and creating new
documents, and making sure all documents have
been saved when an application quits. It also
registers itself for the
NSWorkspaceWillPowerOffNotification.
Note that NSDocumentController isn't truly the
application delegate, but it works in a similar
way. You can still have your own application delegate
- but beware, if it responds to the same methods as
NSDocumentController, your delegate
methods will get called, not the
NSDocumentController's.
NSDocumentController also manages
document types and the related NSDocument
subclasses that handle them. This information
comes from the custom info property list
({ApplicationName}Info.plist)
loaded when NSDocumentController is initialized. The
property list contains an array of dictionarys
with the key NSTypes. Each dictionary contains a set
of keys:
NSDocumentClass - The name of the
subclass
NSName - Short name of the document type
NSHumanReadableName - Longer document
type name
NSUnixExtensions - Array of strings
NSDOSExtensions - Array of strings
NSIcon - Icon name for these documents
NSRole - Viewer or Editor
You can use NSDocumentController to get a list of all
open documents, the current document (The one whose
window is Key) and other information about these
documents. It also remembers the most recently
opened documents (through the user default key
NSRecentDocuments)..
You can subclass NSDocumentController to customize the
behavior of certain aspects of the class, but it
is very rare that you would need to do this.
Uses
-runModalOpenPanel:forTypes:
to allow the user to select files to open (after
initializing the NSOpenPanel). Returns the
list of files as URLs that the user has selected.
Iterates through all the open documents and asks
each one in turn if it can close using
[NSDocument -canCloseDocument]
. If the document returns YES, then it is closed.
Returns the current directory. This method first
checks if there is a current document using the
-currentDocument
method. If this returns a document and the document
has a filename, this method returns the directory this
file is located in. Otherwise it returns the directory
of the most recently opened document or the user's home
directory if no document has been opened before.
Returns the names of the NSDocument subclasses
handling documents in this application. This will
be nil or empty if this is not a document
based application.
Uses
-runModalOpenPanel:forTypes:
to allow the user to select files to open (after
initializing the NSOpenPanel). Returns the
list of files that the user has selected.
If there are any unsaved documents, this method displays
an alert panel asking if the user wants to review the
unsaved documents. If the user agrees to review the
documents, this method calls
-closeAllDocuments
to close each document (prompting to save a document if
it is dirty). If cancellable is
YES, then the user is not allowed to
cancel this request, otherwise this method will
return NO if the user presses the
Cancel button. Otherwise returns YES
after all documents have been closed (or if there are
no unsaved documents.)