TM4L Viewer
The TM4L
project includes two tools that support respectively the creation and maintenance, and
visualizing and browsing of educational Topic Maps: the TM4L Editor and TM4L
Viewer.
TM4L
Viewer is
based on the TM4J Topic Map navigator -
TMNav, thus it
includes open
source software developed by the
TM4J Project.
It is currently based on:
TMNav - Version: TMNav 0.2.8.1
Panckoucke - Version: Panckoucke 0.3.1
- To run TM4L you need Java JRE or SDK, version 1.4 or above. You can get Java from
Sun's Java download page.
- Display resolution required: 1024 x 768 pixels.
The
TM4L Viewer distribution file includes everything you need to run the Viewer (except the Java Runtime Environment).
You can download it from the link to the Download Page above.
- Download tm4lViewer-0.1-bin.zip
- Unzip the package.
- Run it:
- On Windows: double click runtm4lV.bat.
- On Unix/Linux: double click runtm4lV.sh.
Note. In some cases Window installations may require JRE in C:\ directory.
To open a Topic Map in the
TM4L Viewer, open the File
menu and select "Open Topic Map". In the opened dialog use the "Browse" button
to find and select the Topic Map file. The name of the loaded Topic Map file
will appear in the "Topic Maps" panel of the Viewer's window. You can have
several Topic Maps opened.
To close or reload a Topic Map,
select its name in the "Topic Maps" panel and right-click it. A pop-up menu will
be displayed, from which you can select "Close" or "Reload" to complete these
operations.
You should reload a Topic Map file
after any update of the corresponding Topic Map (in the TM4L Editor).
You can merge two Topic Maps.
When merging, any topics that have the same
subject are
merged, and any duplicate associations are removed.
When two topics are
merged, the result is a single topic whose characteristics are the union of the
characteristics of the original topics, with duplicates removed.
Two topics have the same
subject if:
- They have one or more subject indicators in common
- They reify the same addressable subject, or
- They have the same base name in the same scope.
After opening a Topic Map, six
useful indexes are available in the Indexes panel of the Viewer's window
(through a
dropdown list):
- Subject Topics
- Relationships
- Topic Types
- Relationship Types
- Resource Types
- Themes.
These indexes provide the
starting point for browsing the loaded Topic Map. When you select an item from
an index (topic, relationship, etc.), the corresponding Topic Map object will be
displayed in the "Tree View" and "Graph/Text View" panels of the Viewer's
window.
A topic type is a category to which sets of topics belong. Topic types are used to group topics
in classes. Just as topics can be grouped according to type, so can relations between topics be grouped
according to their type using relation types. Note that both topic types and relation types are
also topics.
The "Tree View" and
"Graph/Text View" panels of the Viewer's window display the currently selected
Topic Maps object(s). If you select a topic or an association, all the
information in the Topic Map about the selected object will be displayed in
those two panels in a different view (see below). If you select a topic
type, association type, or resource type in the corresponding index (in the
Index panel), all objects (instances) of that type will be listed in both the "Tree
View" and "Graph/Text View" panels.
You
can
change the view in the two "View" panels: right-click anywhere in the panel,
select the "View" item in the popup menu, and then in the popup sub-menu select
the type of view you want to set in the corresponding panel. Choosing a new view should
update the display in the panel immediately. Note that you can resize the panels
as needed.
The TM4L Viewer supports three types of view:
Graph View, Text View and Tree View.
The Graph View displays all
the information related to the selected Topic Map object as a graph. When there
is too much information related to the object, the visualization becomes rather crowded.
For that reason the graph doesn't show the resources associated with a topic.
You can see them in the "Tree View". Also, you can choose to have displayed or
not displayed the labels of the graph arcs (which give information about the
type of the relations connecting the topics presented by the corresponding graph nodes).
Right-click within the panel and select "Don't label arcs" / ""Label arcs".
Note that the arc labels do help in
understanding the relationships between the displayed Topic Maps objects. For
example, an arc
labeled by both the “I” icon
and the string
“instance”,
indicates that all end-nodes are instances of the center-node. In
other words, the center-node is a parent topic of the end-nodes. But when an
arc is only labeled by the icon
“I”,
this
indicates that the center-node is an instance of the end-node.
The Text View
displays all the characteristics of a topic or a relationship in different sections.
The Tree View displays
all the information related to the selected Topic Map object as
a hierarchical tree (just as any file browser). In most cases,
the result will be meaningful. The topics are indicated by green
"T”
icons. The root of the tree shows
the current (selected) topic. The topics displayed immediately below it
(indicated by the "P" icon) are related to the selected topic and play roles
(indicated by the "R" icon) in the corresponding relationships. All children of
the selected topic are listed under the "Instances". All resources are indicated
by the "O" icon and are possibly preceded by the resource type.
Typically you start the Topic Map navigation by selecting
an object from one of the TM indexes (in the Indexes panel). When you select an
item, for example, a topic or relationship, it will be displayed in the "Tree
View" and the "Graph/Text View"
panels.
You can navigate through the Topic Map, by selecting an
object related to the currently displayed one to be displayed next. To do so,
right-click the wanted object in the "Tree View" or "Graph/Text View" panel . A
popup menu will be displayed presenting two choices: "Show node in" and "View".
The "View" option was already explained.
The "Show node in" option allows you to specify which
should be the "target" panel in which the requited object will be displayed.
Suppose you have right-clicked on a topic in the "Tree View" panel. If you
select again "Tree View" from the "Show node in" popup menu, the information
about the selected object will replace the information currently displayed
there. If you select the "Graph/Text View", the object will be displayed in the
other View panel, keeping the tree the same. In this way you can browse one by
one all objects related to the object currently displayed in the "Tree View"
panel, without loosing the focus. Note that any of the two View panels can be
chosen as a target panel.
The
"Open
in browser" option in the popup menu allow you to open a resource in your
default Web browser. This way you can visit the Web pages related to the topic
on focus..
Each View
panel maintains a history of the TM objects that you have seen so far in this
particular panel. Use the back and
forward buttons, located in the upper toolbar of each of the View panels
to navigate through the History list.
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