The document discusses user interfaces (UI) and their components. A UI simplifies user interaction with applications by managing commands and data exchange. As applications grew larger, UIs were needed to track functionality and educate users. A UI has two main components: a dialog manager that handles conversations between the user and application, and a presentation manager that displays application data. The document then covers various ways of implementing command dialogs, presenting data, providing online help, and developing UIs using management systems.

2.  Role: Simplifying interaction of a user with an
application.
 Two aspects:
◦ 1. Issuing Commands.
◦ 2. Exchange of Data.
 Requirement of UI?
◦ Before requirement was small & hence small
applications.
◦ But now, applications have become so large that one
programmer‟s team do not know any thing about other
programmer‟s team working on same application.
◦ UI will keep track of information of functionalities &
educating users for those applications.

3.  Two components:
◦ 1.Dialog Manager
◦ 2.Presentation Manager
 1. Dialog Manager:
◦ Manages conversation between user & application.
◦ Prompts user for command.
◦ Transmits command to application.
 2. Presentation Manager:
◦ Displays data produced by the application in
appropriate manner on screen.

4.  User Interface Covers Following Topics:
 1. Command Dialogs
-Principle of command dialog design
 2. Presentation of Data
 3. Online Help
-Hypertext
 4. Structure of User Interface
 5. UIMS-User Interface Management Systems
-MenuLay
-HyperCard

5.  Commands are issued to an application
through a command dialog.
 Three ways to implement command dialogs
are:
◦ 1. Command Languages
◦ 2. Command Menus
◦ 3. Direct Manipulation

6. 1. Command Languages:
 Similar to command languages for OS.
 Primitive Command Languages support:
◦ Imperative commands
◦ Syntax: <action><parameters>
 Sophisticated Command Language support:
◦ Imperative commands (eg: instructions, statements)
◦ Declarative commands (eg: algorithms)
 Have their own syntax and semantics
 Problem with command language is?
◦ Need to learn syntax before using the application.
◦ Needs large time and efforts.
 Solution?
 On line help. How?
◦ Reduces syntax memorizing efforts.
◦ But, than too it needs some efforts initially to use it.

7. 2. Command Menus:
 Basic functionalities of application are reflected
in menu choices.
 Provides obvious advantage.
 Hierarchy of menus explain functionality of
applications. Eg. File, edit, view
 Use can be simplified by “pull down” menu
utilities. eg. C, vb(toolbar)
3. Direct Manipulation System:
 Provides user with a visual display of universe of
application. i.e. C Help, MSDN(for vb, online).
 Display shows important objects in universe.
 Actions or operations over objects are indicated
using pointing devices eg. Cursor or mouse.
 Eg: Spread Sheet

8.  Principles of Command Dialog Design: These set of
principles ensures effectiveness of command dialogs.
◦ 1. Ease of Use
◦ 2. Consistency in command structure
◦ 3. Immediate feedback on user commands
◦ 4. Error Handling
◦ 5. On line help to avoid memorizing command details.
◦ 6. Undo Facility
◦ 7. Shortcuts for experienced users.
 Command menus score over command languages on
principles 1,2 & 5.
 Command languages score over command menus on
principles 7.
 But that limitation is eliminated by „type ahead‟
facility (menu shortcuts) which is the aid to
experienced users.
 Recent trend is in development of direct manipulation
system in graphics.

9.  Data for an application can be input through
free form typing.
 Alternative option is form filling approach
which is good for large volume of data.
 Application results representation: Tables.
 Summery results representation: Graphs, pie
chart, etc.

10.  Important to promote & sustain interest in use of an
application.
 It minimizes efforts of initial learning of commands.
 Avoids using printed doc (books) to solve every
doubts.
 Forms:
◦ Online explanations,
◦ Demonstrations,
◦ Tutorials
,◦ Manuals.
 Important aspect: fast access to efficient location of
desirable information.
 Eg: Hypertext

11.  Hypertext:
 Visualizes document consisting of
hierarchical arrangement of information.
 Provides variety of means to locate required
information.
 Forms:
◦ Tables & Indexes
◦ String searching functions
◦ Means to navigate within documents
◦ Backtracking facilities
 Effectiveness depends on efficiency of
organization.

12.  Two Components:
 1. Presentation Manager: Responsible for
◦ Managing user‟s screen,
◦ Accepting data,
◦ Presenting results.
 2. Dialog Manager: Responsible for
◦ Interpreting user command
◦ Implementing them by invoking related modules
◦ Error messages
◦ Online Functions
◦ Organizing changes in view.

13. Application
Code
Presentation
Manager
Dialog
Manager
Graphics
Package
--------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------
Use
r
User
Interface
User
Interface

14.  Automates the generation of user interfaces.
 Input to UIMS?
 Specification of presentation & dialog
semantics.
 Output of UIMS?
 Presentation and dialog managers of UI resp.
 Types of Dialog Managers:
◦ Grammar
◦ Event Descriptions
◦ Finite State Machines

15.  Grammar:
◦ Syntax & Semantics of commands are specified.
◦ Interface gets activated when user starts writing programs.
◦ EgYACC
 Event Based Approach:
◦ Uses visual model of interface
◦ Screen with ICON is displayed to user.
◦ Event is generated by selecting icon.
◦ Eg: VB
 Drawback of Grammar & Event Based Approach?
 Lack the notion of sequence of actions
 Solution?
 Finite State Machine:
◦ Associate finite state machine with each states of machines.
◦ Has additional power to co-ordinate concurrent activities in
different windows.
◦ Eg: SCADA for PLC controller‟s programming

16. Menulay:
 Is an early UIMS
 Consist of set of icons.
 Set of semantic actions are specified for each
icon.
 Action is performed when the icon is
selected.
 System generates following:
◦ Set of Icon_Tables(name,description) of icon.
◦ Set of events and functions.
 Same as VB.

17. Hypercard:
 This UIMS is object oriented & event oriented given by
Apple.
 A card: has associated screen layout and background.
 Contains buttons & fields.
 Button can be selected by mouse.
 Fields can be edited.
 Hypercard is thus a hierarchy of cards called stack.
 UI behavior is specified by associating
◦ An action in form of HyperTalk,
◦ Button
◦ Field
◦ Card.
 Hierarchy of cards determine sequence of actions
performed.
 Thus, follows interpretive schematic for
implementing a UI.