The document discusses the process of designing view layer classes in a user interface. It involves: 1) Identifying view layer objects during analysis by examining use cases and interaction diagrams. 2) Designing individual view layer objects by applying design principles to best support the application functions and provide a usable interface. 3) Prototyping, testing usability, and refining the view layer interface through iterative design.

1. Unit 5
View layer : Designing interface
objects

2. Introduction
• UI(user interface)
– Main goal of UI is to display and obtain needed
information in an accessible , efficient manner
– UI design is a creative process

3. Designing view layer classes
• UI layer consists of
– objects with which user interacts
– Objects needed to manage or control UI
• Responsibility of view layer objects
– Input :responding to user interaction
• Translating user’s action into an appropriate response
– Output :displaying or printing business objects

4. Process of designing view layer classes
• It has 4 major activities
– Macro level UI design process: (identifying view layer object)
• Takes place during analysis phase
• Identifying classes that interact with human actors by analysing use
cases
• sequence and collaboration diagram helps to identify UI classes
– Micro level UI design activities
• Designing the view layer objects by applying design axioms and
corollaries
– Decide how to use and extend the components so they best support
application specific functions and provide the most usable interface
• Prototyping the view layer interface
– Useful in the early design process
– Testing usability and user satisfaction
– Refining and iterating the design

5. Macro level design process
The class
interacts with a
human actor
Zoom in by utilizing
sequence or collaboration
diagrams
Identify the interface
Next class objects for the class
refine and
iterate
The class
Define the relationships doesn’t
among the view objects interacts with
the human
actor

6. Relationship among view objects,
business objects, access objects
View objects
Business objects
Access objects

7. Micro level design process
Apply micro level UI
design rules and GUI
guidelines to each
interface object identified
to develop the UI
Next interface
objects refine
and iterate
Done

8. Design rules
• Making the interface simple ( application of corollary 2)
– Ex:
• Car engine is complex
• But driver interface remains simple
– User must be able to work with our screen without asking much
questions
– Factors affecting UI
• Dead lines
• Comparative evaluations
• Addition features
• Shortcuts
– Things to be considered while designing UI
• Additional features affect performance, complexity
• Fixing problem, after the release of product is difficult