Information Technology Reference
In-Depth Information
a 2D vector graphic as its view, called 'webble'. It is possible to create Web-
based compound documents including dynamic graphic components represented
as composite webbles. The Webble World brings in flexible representations of
media objects.
2.2 Meme Media Architecture
Meme media objects wraps each knowledge resource in computers, such as text,
image, tool, or services, as a two dimensional visual object. In IntelligentPad
system, such a media object is called a 'pad'. Each pad has a card-like view on
the screen and a standard set of operations like 'move', 'resize', 'copy', 'paste',
and 'peel'. Users can easily copy a pad, paste a pad onto another, and peel a
pad from a composite pad through mouse operations. A pad can be pasted onto
another pad to define both a physical containment relationship and a functional
linkage between them.
Figure 1 shows the user interface of a composite pad and its functional linkage
structure. When pad
P
3 is pasted onto another pad
P
1, the pad
P
3 becomes a
child of
P
1, and
P
1 becomes the parent of
P
3. No pad may have more than one
parent pad. Pads can be pasted together to define various types of multimedia
documents and application tools. Each pad provides a list of interfaces that
maintain its state data, called 'slots'. From users' point of view, a slot works as
a connection jack of a pad. Users can functionally connect each child pad to one
of the slots of its parent pad. Only a single connection can be defined between
a parent and its child.
slot
P
3
Pasting &
Connecting
P
1
P
2
P
3
Slot Connection
P
2
P
3
P
1
(a) User Interface
(b) Connection Structure
Fig. 1.
A composite pad and its slot connection structure in IntelligentPad
In IntelligentPad, each pad consists of three basic components: model, view,
and controller. Model-View-Controller pattern is originally from the Smalltalk-
80's GUI component architecture [9]. In the IntelligentPad, the structure of
MVC is slightly different from the original structure (Fig. 2). There is no direct
connection between the model and the controller. Here, a model is responsible
for managing data and domain logics for operating the data. A view is working
