Model-View-Controller Architecture
Example: Real Estate Information
Visualization Tool
CSC 540, Fall 2002
Scenario: Nancy wants to search for houses close to UNCG
under $150K, so she zooms to the area on the map within one
mile from UNCG, then moves the house price slider to 150K,
which filters out the houses over 150K:
DRILL
DOWN
UNCG
80K
100K
120K
140K
160
Max List
Price ($)
Scenario (part 2): Nancy now wants to get details on
each of the remaining houses, so she selects each one
by mouse clicking on it and then presses the “drill
down” button:
DRILL
DOWN
UNCG
80K
100K
120K
140K
160
Max List
Price ($)
Address: 500 Spring Garden
List Price: $130,000
Bedrooms: 2 Bathrooms: 1
Year Built: 1930
X
DRILL
DOWN
UNCG
80K
100K
120K
140K
160
Max List
Price ($)
Scenario (part 3): After looking at the details about each of the
houses under $150K within one mile of UNCG, she discovers
they are too old. She decides to change her overall strategy.
What if she asked for a different view of the data?
GRAPH
UNCG
80K
100K
120K
140K
160
Max List
Price ($)
Scenario (part 4): So she asks for a Cartesian graph with
Miles from UNCG on the horizontal axis and list price ($K)
on the vertical axis. She asks the graph to show houses under 5
miles from UNCG between $140-190K:
Horizontal Axis:
Miles from UNCG
Maximum: 5
Minimum: 0
Vertical Axis:
List Price
Maximum: 190000
Minimum: 140000
A Cartesian graph with Miles from UNCG on the horizontal
axis and list price ($K) on the vertical axis showing houses
under 5 miles from UNCG between $140-190K:
190K
180K
170K
160K
150K
140K
0.5 1 1.5
2
2.5 3 3.5 4
Miles from UNCG
Scenario (part 5): Looking at this view of the data, she quickly
realizes that houses that are very close to campus are too expensive
for her, and she will have better luck by looking at houses 3-4 miles
away:
190K
180K
170K
160K
150K
140K
0.5 1 1.5
2
2.5 3 3.5 4
Miles from UNCG
Scenario (part 6): So she selects the houses that are 3-4 miles away
by enclosing them in a bounding box. Then she asks for a map of
these houses.
190K
180K
Map
170K
160K
150K
140K
0.5 1 1.5
2
2.5 3 3.5 4
Miles from UNCG
The new map shows where the 3 houses are in
relation to UNCG.
UNCG
2 miles:
Scenario (part 7): Now she experiments by
moving filters for price and age until one house is
left, her dream house!
Age
(Years)
0
UNCG
4
80K
100K
120K
140K
160
Max List
Price ($)
Possible MVC Architecture for Real
Estate Information Visualization Tool
MODEL (real
estate data,
query results, &
city street map)
CONTROLLER
(manages user
interaction through
widgits)
CITY MAP VIEW (houses
of interest on map)
DRILL DOWN VIEW
(details about a house)
GRAPH VIEW (Cartesian
graphs of house attributes)