Copyright ã1995 by NeXT Computer, Inc.  All Rights Reserved.

Layout

Inherits From:	Object

Declared In:	apps/Preferences.h

Class Description

The Layout class defines the link between the Preferences application and a module that's loaded into the application.  The principal class of the loadable Preference bundle should be a subclass of Layout.  When Preferences loads the bundle, it identifies the View objects to be loaded into the Preferences window by sending this object a view message.  Once the module is loaded, the object is kept apprised of the state of the Preferences application through notification messages such as didHide: and willSelect:.  

These notification messages allow the Layout object to prepare for the named change (for example, willHide:).  However, the value the Layout object returns in response to the message is ignored:  The Layout object can't prevent the change from occurring.  (Also note that being notifications, these methods have one argument, sender, which is a private object within Preferences and should not be accessed.)  

For your loadable module, create a subclass of Layout and override the inherited methods as needed.  For an example of such a subclass, see the Template class files in /NextApps/Preferences.app/Template.bproj.

Instance Variables

id view;

view 	The view that's loaded into the Preferences window.

Method Types

Accessing the root View	- view

Notification of state change	- didHide:
- didUnhide:
- willSelect:
- didSelect:
- willUnselect:
- didUnselect:

Instance Methods

didHide:

- didHide:sender

Received from the Preferences application when the application hides itself.  This gives the Preferences module the opportunity to deallocate resources or do other clean up that might be appropriate (such as removing a timed entry).

See also:  - didUnhide:

didSelect:

- didSelect:sender

Received from the Preferences application just after this module's interface is displayed in the Preferences window.  A willSelect: message precedes this message. 

See also:  - willSelect:, - willUnselect:, - didUnselect:

didUnhide:

- didUnhide:sender

Received from the Preferences application when the application is unhidden.  This gives the Preferences module the opportunity to initialize itself, if necessary.

See also:  - didHide:

didUnselect:

- didUnselect:sender

Received from the Preferences application just after this module's interface ceases to be displayed in the Preferences window.  A willUnselect: message precedes this message.

See also:  - willUnselect:, - willSelect:, - didSelect:

view

- view

Returns the View that's loaded into the Preferences window.  Typically, this View is the root of a view hierarchy containing the buttons and other controls of your Preferences display.

willSelect:

- willSelect:sender

Received from the Preferences application when this module's interface is about to be displayed in the Preferences window.  Immediately following a willSelect: message, the module's top-level View (as returned by the view method) is made a subview of the Preferences window, and then the Layout object receives a didSelect: message.  

See also:  - didSelect:, - willUnselect:, - didUnselect:

willUnselect:

- willUnselect:sender

Received from the Preferences application when the module's top-level View is about to be removed from the view hierarchy in the Preferences window.  Immediately following a willUnselect: message, the module's interface is removed, and then the Layout object receives a didUnselect: message.

See also:  - didUnselect:, - willSelect:, - didSelect: