Number of decimal places and breakpoints in measure and draw tool

[asemoller]

Is your feature request related to a problem? Please describe.
We're having some concerns regarding the number of decimal places and breakpoints shown in the measure and draw tool. We would like if number of decimal places and breakpoints could be an option in the config file.

For example, we would like to have these settings:

• 1 decimal place for lenghts of less than 10 m (we never want to show accuracy in centimetre)
• no decimal place for lenghts shown in m and exceeding 10 m
• 2 decimal places for lenghts shown in km (high and low)
• no decimal place for areas shown in kvm
• 2 decimal places for areas shown in ha and is less than 10 ha
• 1 decimal places for areas shown in ha and is larger than 10 ha
• 2 decimal places for areas shown in kvkm (high and low)

We're aware that others may think differently so that's why we want it to be an option, if it's possible.

Related issues: #881 and #1617.

[tonnyandersson]

I think the main challenge is to figure out how to do this in a way that isn't a complete *insert expletive* nightmare from an admin, developer or user perspective.

Came up with this for your length example:

[
  {
    "breakpoint": 10, // If less than...
    "divisor": 1, // Divide length in meters with...
    "precision": 1, // Number of decimals
    "unit": "m" // Duh...
  },
  {
    "breakpoint": 1000,
    "divisor": 1,
    "precision": 0,
    "unit": "m"
  },
  {
    "breakpoint": "Infinity",
    "divisor": 1000,
    "precision": 2,
    "unit":" km"
  }
]

Makes sense? I dunno.

EDIT: Parameters could be shortened to...

[
  [10, 1, 1, "m"],
  [1000, 1, 0, "m"],
  ["Infinity", 1000, 2, "km"]
]

...to save space, at the expense of readablilty.