31-08-2016, 04:46 PM
1451901966-symbianospresentation130320032226phpapp02.ppt (Size: 761 KB / Downloads: 4)
UI Framework Layer
The topmost layer of Symbian OS provides the frameworks and libraries for constructing a user interface, including the basic class hierarchies for user interface controls, and other frameworks and utilities, including concrete widget classes used by interface components.
UI Application Framework Collection
The Uikon: component provides a concrete framework for user interface and application creation. Applications, typically, should not derive directly from Uikon classes. Instead, they should derive from equivalent classes provided by the variant user interface, because these provide the appropriate look and feel and other device-specific behavior. However, applications implement virtual methods inherited from Uikon and call inherited methods.
The Control Environment (CONE) : provides a control hierarchy and environment. It provides policy-free abstract controls and control context, as the basis for interaction between the user and the application. It includes the application interface to user and keyboard events and View Server encapsulation.
The FEP Base component provides base classes for creating FEPs. FEPs selectively intercept and preprocess user input events, which are returned to the system as simplified events for handling by applications, to enable keyboard mapping, multitap keyboard input, handwriting recognition, voice recognition and other input preprocessing.
The UI Look and Feel component defines the look-and-feel properties of the user interface. It defines standard methods (i.e. an API) for which user interface customizers provide an implementation in the UikLaf library of a variant user interface. The role of the user interface LAF component is to provide other parts of the application framework with a way of requesting look-and-feel information from a variant user interface, including the layout and behavior of windows; which bitmaps and fonts to use; and the location of various resource files.
The Uikon Error Resolver Plug-in is a resource file that maps system error numbers to helpful error-text strings, which a variant user interface extends and customizes. Errors are flagged when a user interface thread leaves normal execution inside the active scheduler of an application.
The Application Services Layer
The Application Services layer provides support independent of the user interface for applications on Symbian OS. These services divide into three broad groupings:
System level services : system-level services used by all applications, for example the Application Architecture or Text Handling
Application Framework
Application Launch Services
Multimedia Protocols.
Application services and engines: services that support generic types of application and application-like services, for example personal productivity applications.
Data Sync Services
Device Management
Client Provisioning
PIM App Services: services based on more generic but application-centric technologies, for example mail, messaging and browsing.
Other Application Services
Office Application Engines