05-830, User Interface
Software, Spring, 1997
Lecture 6, February 5,
Copyright © 1997 - Brad
Lecture . . .
(Show Videos of HyperCard use, Macromind use, IBs from the IB tape,
- Just show what looks like
- Note: differentiate from term "rapid prototyping"
- Some support for behavior: typically changing screens
- Like a movie of the interaction
- Goal: see some of interface very quickly (hours)
- Often no possibility of migrating to real application
- May not use "real" widgets
- "Low Fidelity" Techniques
- Just use paper and/or overheads
- Experimenter "plays computer"
- Ask the user "what would you do now"
- Experimenter shows the computer's expected response
- Very cheap and easy and gets surprisingly good results
- Find out if users understand organization, how to find desired operations,
if understand menu names, etc.
- Easy to change between sessions
- Can make a movie of the paper using a regular video camera
- To demonstrate/explain the interface
- For Character Screens
- 24x80 DOS, often no mouse
- Especially for forms-based applications
- Examples: Bricklin's Demo (PC), Protoscreens for PCs from
- Specify characters for each position of screen, or a "character graphics"
- Can specify fields that are editable text
- Can specify that clicking on an area causes changing to a new screen.
- Also menus
- Card Programs
- Examples: HyperCard and SuperCard for Mac; Toolbook and OWL's
GUIDE for PCs
- Early Research systems:
- Menulay: vector screens, widgets, sounds, text, output C code
- Trillium: Xerox copier interfaces; interpreted Lisp
- Sequence of cards
- Paint program (not "draw")
- Draw pictures on each card
- May be multiple layers
- Buttons can transition to another card
- Single window
- Buttons can start running a script ("HyperTalk")
- Script can move objects, change cards, animate, compute, etc.
- Code management: who changes what; finding the script
- Not good for dynamically created graphics
- Complete control of individual pixels
- Graphic designers have complete control
- Design new widgets
- Can be "real" application if sufficient power/speed
- Animation Programs
- Example: MacroMind Director
- Also control individual pixels
- Individual paintings can be specified as animation elements
- E.g., characters
- Each can be instantiated, moved, etc.
- Good control over timing, synchronization
- Scripting language
- Can program that when a mouse button is clicked in an area, start
an animation or transition.
- Scripting language even more primitive than HyperTalk
- Good for "Future Scenarios" when want good fidelity with real look.
- Obviously not for final (real) interface.
- Lay out widgets to make dialog boxes, menus.
- Have a palette or menu of kinds of widgets
- Place with mouse
- Connect call-backs with each widget
- Generates C code directly or intermediate language
- Sometimes connected to an intepreter so can execute call-backs.
- If not, some call-backs can be simulated, e.g. transition to
window; pop-up error.
- Layout mechanisms
- usually a complication
- X's row and columns stuff
- Galaxy's struts and springs
- store information in special files rather than in source code
- positions, colors, text labels, etc.
- allow for easier modification for users, internationalization, etc.
- Usually don't support:
- Error checking of values, e.g. for text input fields
- Greying of widgets depending on values and other widgets
- Default values of widgets
- Dynamic changing of widgets (e.g., add more items)
- Dynamic changing layers (groups) of widgets (visibility) depending
on values and other widgets
- Any dynamically created graphical objects.
- Large commercial market
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