SAND Internet Browser
This is only a page that launches the applet. The main page with all the
information is here.
This applet requires Java 1.4 or higher. Thus, if you have not done so
already, you will need to download and install the latest plug-in from Sun.
A Browser window is divided into several panels stacked vertically. These
are (from top to bottom):
This SAND Internet Browser was brought to you by Frantisek
Brabec. Please send comments, suggestions and bug reports to firstname.lastname@example.org.
- The command area, containing menus and buttons for several actions:
and Next retrieve the first/next tuple satisfying the currently
set scan order and predicate; File provides various basic operations
such as Open or Close [the current relation] or Quit [the
browser]; Display presents a menu of several activities connected
to the graphical display, such as clearing it or drawing spatial features;
allows changes of drawing attributes such as line or fill color.
The Scan order panel contains a button that triggers the exhibition
of several ``pop-up'' dialog boxes, and a message area that displays the
currently selected scan order parameters. Each dialog box corresponds
to parameters to be used when the relation is being scanned with the help
of one of the indices defined for it.
The Conditions panel allows specification of a predicate to be used
to evaluate the query (the predicate must follow the syntactic rules of
The info panel indicates the current line and fill colors (the colors that
will be used next time the user chooses any displaying operation from the
menu). It also contains a choice which allows the user to change
the current relation (the relation that all the queries are executed with
The graphical display panel is the drawing area where spatial
features are input and output. At any given moment of the interaction,
the current value of the relation's spatial attribute is displayed
in this area and highlighted by an orange rectangle. Most of the other
user interface components which hold a spatial feature value support
input by drawing on the graphical display. The display can also be panned
(with the help of the horizontal and vertical scrollbars) and zoomed in
The zoom in and zoom out operations are available through left and
middle click respectively, the right click finds the nearest object to
the location of the click from the current relation and makes it the current
The info line will show various messages during the browser execution.
The tuple display panel contains a series of labeled entry boxes,
one for each attribute in the schema of the relation. These are updated
to reflect the value of the current tuple.
The layer display lists all the layers available for this relation.
Clicking on the individual entries in this list toggles displaying of the
respective layers in the graphical display area on and off.