Describe route optimization feature

[Lineflyer]

See:
cgeo/cgeo#13974 and cgeo/cgeo#14027

Proposal:
Such kind of feature might be best explained using an example and describe the needed actions with screenshots.

Open questions (for me):
AFAICS this was a two-step implementation:

1. All routes were considered round-trip (routing back to start after last point of the route)
2. Adding a linear route feature (non round-trip)

For case 2 I am not sure how it actually works UI-wise or how we distinguish between case 1 and 2.

@moving-bits
Can you add a brief feature explanation here (or maybe even start sketching a page in the manual)?

[moving-bits]

FYI: We had changed the implementation along the way, since we have the option to add the same point multiple times to an individual route. Now route optimization will always be in linear mode. If you like to have a roundtrip calculation, you'll need to add your starting point as final point of your route additionally.

I can try to sketch a feature description in the manual. (May take a couple of days, though.)

[moving-bits]

@Lineflyer
Here's a proposal regarding individual routes, route optimization, routes & tracks:

I propose to add a new menu entry in the "coordinates and navigation" section, named "routes and tracks". The page should explain what individual routes are, and how they are created / modified / deleted / optimized, as well as explain how to handle routes and tracks using the routes & tracks menu.

individual route

• create your own line of caches you want to follow on a specific trip
• individual routes are marked by a blue line (default value) connection the geo items of the route
• add a geo item by long-pressing on a cache or waypoint and selecting "append to route" or "prepend to route" (if available)
• add a freely selected address to the individual route by long-pressing on a free space of the map and selecting "append to route" / "prepend to route"
• you can remove geo items from your route by long-pressing on this geo item and selecting "remove from start / end / position x"

what are individual routes for?

• displays a line of geo items you want to follow during a geocaching trip
• length of this route will be displayed in the upper right corner of the map's screen
• select "set route start as target" in one of the two bottom menus in the map to draw an additional navigation line from your current position to the route's start. The distance for this will be displayed in the map's upper right corner as well, so you can always see how much to go to your next target, and what length the rest of the route has
• whenever you have visited a geo item, you can remove it from your route, and blue line as well as distance info will update accordingly, so you can always see the remaining route

editing and optimizing an individual route

• open the routing menu at the map's bottom and select the edit symbol (pencil) in the "individual route" line
• a list of all your geo items in your individual route will appear
• you can change the order by drag & drop of the "hamburger" symbols beside each entry. Don't forget to save the route by pressing the checkmark symbol at the top, if you want to accept the changes
• by long-tapping any of the entries you can select this entry as new starting point of your route. All following entries including this one will be moved to the top of the route, the others move down, keeping the order of entries within each of the two groups.
• by using the "two arrows" symbol at the top you can reverse the route
• by using the "magic wand" symbol at the top you can let c:geo let reorder the entries to optimize for shorter distance. First and last entry will stay, all entries in between may be reordered for a shorter route length. (This is an experimental function ... - use text from message box -)

the route & tracks menu

• tap on the "curly lines" button at the bottom of the map to open the route & tracks menu. This button will only be displayed if there is currently an individual route or at least one track. Without this button you can use the "Routes / tracks" menu entry to open the route & tracks menu
• this menu allows you to
  • for individual routes:
    • load or store an individual route
    • edit an individual route (see above)
    • update all caches of an individual route
    • enable/disable display of an individual route
    • set map focus to the individual route
    • remove an individual route
  • for tracks/routes (GPX)
    • load a route/track from GPX file
    • select a color to display a certain route/track with
    • enable/disable display per route/track
    • set map focus to a specific route/track
    • remove specific route/track from map
  • clear all manual targets (removes the navigation line)