This section is divided into several topics:
- The Map Hierarchy: Sorting Things Out
- The Map Directory: Take Your Pick
- Adding And Removing Maps: Easy Come, Easy Go
The Map Hierarchy: Sorting Things Out
Quo Vadis maps are built around a hierarchical, modular model. Every map is independent of every other map, but each map contains data which allows Quo Vadis to place it into a universal hierarchy in which “parent” maps can contain other “child” maps. For example, a United States map can contain state maps, and a state map can contain county maps, and a county map can contain city maps, and so on...
NOTE: Currently, only city and county maps are available. References to other types of maps are only included to help explain the functionality of the map hierarchy.
All the maps installed in your PDA follow this scheme, with maps being sorted alphabetically within a parent map. However, it is possible to have a hierarchy in which maps don’t visually appear to be alphabetically sorted. This happens if there are multiple maps which don’t have parent maps installed. For example, if you have installed a California state map, and two cities in California, say, San Francisco and Palo Alto, as well as a map of Albuquerque, New Mexico, then the maps would be sorted as follows:
You would likely expect Albuquerque to be placed before California, but since you haven’t installed a state map of New Mexico, the map appears to be in the wrong place because it doesn’t have its parent map. Otherwise, the order would have made sense, since it would have looked like this:
So, if you now added a map of Paris, France, it would be placed
before California, because France is alphabetically ahead of the
United States, and so on. Countries are sorted on the same level
as other countries, states against states, cities against cities
and so forth. There is no inter-level sorting. This approach may
be modified in a future version of Quo Vadis to accommodate alphabetized
sorting of maps mixed at different hierarchical levels.
Also, note that map data is not replicated within each parent
map. That is, if you only had a map of California installed, you
would be able to see an overview of the state, its highways, and
so forth, but you would not be able to zoom in and see any county
or city details. You would have to install the specific cities
that interest you. If this approach were not taken, then every
map that was higher in the hierarchy would get bigger and bigger,
and would take up lots of memory in your PDA, which is probably
not what you want. In fact, you wouldn’t even be able to store
a map of California with every single city’s details, since you
would likely need at least 50MB of free memory (we’re all looking
forward to that...maybe next year!)
U.S. maps are currently divided into incorporated cities and counties,
based on U.S. government-specific categories. All map data which
does not fall within any incorporated city’s bounds is placed
into a county map. Another way to say this is: There are city
maps, and county maps of “all the remainder stuff” not part of
any incorporated city. Therefore, when travelling between cities,
it is usually better to install the county map, because it may
contain data that helps link the cities together. Otherwise, you
might see a “gap” between non-adjacent cities, where a road segment
suddenly belongs to the county, and not to either of the two cities.
This approach gives you the flexibility of storing only the cities
which you are likely to need or visit while saving memory space
by eliminating the need to store the remaining non-essential road
data.
The Map Directory: Take Your Pick
The Map Directory is what is used to display and interact with your existing Map Hierarchy. A sample is shown below:
 |
In this example, the map of San Mateo County spatially contains the maps of the cities shown in the list. Note that it is itself a map module, and has its own memory size which is not the total of all the contained cities, as you might think. Maps may also be deleted from the directory via the menu options (see below). To view a map, simply select one from the list and tap on the View button. Quo Vadis will then try to select an initial zoom level to display the entire map. |
Adding And Removing Maps: Easy Come, Easy Go
Maps can be added by simply following the same steps outlined in the Installation section.
To remove a map, select the map in the directory by tapping on
its name, then tap on the Menu button to activate the Map Directory’s Menu bar, as illustrated
here. To delete the selected map, tap the Delete Map menu option. Similarly, to delete all maps, tap the Delete All Maps menu option. Maps that are deleted cannot be recovered except
by reinstalling them as mentioned previously. Please note that you need to keep
at least one map to use Quo Vadis. If you delete all maps, Quo
Vadis will exit since you won’t be able to do anything any more
without a map. You typically only want to do this when you have
no more room in your PDA, and you want to install a large set
of new map modules for another area.You can install as many map modules as will fit in your PDA’s memory. Map modules vary in size from less than 5K for a tiny city to as much as 800K for really large cities or counties, for example. You can view the file map module sizes in the online map library. Currently, there is no provision for “breaking up” such large maps into pieces smaller than those described in the hierarchical model above.