A map theme is a collection of all layer styles, zoom levels,
symbols, and how zooming affects each map configuration. For
example, you can specify a set of visual properties in the Map
Style Property Sheet, such as whether elements are visible or not,
the transparency level, and the color, line thickness, or label
for each layer. You can then associate these properties with a
selected zoom level and when a zoom operation crosses the zoom
threshold, the next style set is applied dynamically. In other
words, you can display a style set per scale range, (see Setting
dynamic styles). There is no limit to the number of zoom levels
that you can define that trigger a change in the appearance of a
map.
For example, in a map of an entire country,
the cities could display at a zoom level that shows the whole
country. When zooming in, you can see only street and building map
layers, and when zooming out only the motorways and cities.
Symbols can also be added to a map and
contribute to the overall theme, but this must be done outside of
the Map Builder. Symbols are placed in their own layers and can be
set to visible or invisible.
For more information about how to add symbols to a map, refer to
the JViews
Diagrammer document Using the Designer