# Options

To dictate & restrict what the map can and should do, regardless of its contents, it needs some guidance!

It provides options that can be categorized into three main parts:

* [Initial positioning](#initial-positioning)\
  Defines the location of the map when it is first loaded
* [Permanent rules](#permanent-rules)\
  Defines restrictions that last throughout the map's lifetime
* [Event handling](https://docs.fleaflet.dev/v7/usage/programmatic-interaction/listen-to-events)\
  Defines methods that are called on specific map events

{% embed url="<https://pub.dev/documentation/flutter_map/latest/flutter_map/MapOptions-class.html>" %}

## Initial Positioning

{% hint style="info" %}
Changing these properties after the map has already been built for the first time will have no effect: they only apply on initialisation.

To control the map programatically, use a `MapController`: [controllers-and-cameras](https://docs.fleaflet.dev/v7/usage/programmatic-interaction/controllers-and-cameras "mention").
{% endhint %}

One part of `MapOptions` responsibilities is to define how the map should be positioned when first loaded. There's two ways to do this (that are incompatible):

* `initialCenter` (`LatLng`) & `initialZoom`
* `initialCameraFit`
  * by bounds (circumscribed[^1]): `CameraFit.bounds`
  * by bounds (inscribed[^2]): `CameraFit.insideBounds`
  * by coordinates (circumscribed[^3]): `CameraFit.coordinates`

It is possible to also set the map's `initialRotation` in degrees, if you don't want it North (0°) facing initially.

If rotation is enabled/allowed, if using `initialCameraFit`, prefer defining it by coordinates for a more intended/tight fit.

## Permanent Rules

One part of `MapOptions` responsibilities is to define the restrictions and limitations of the map and what users can/cannot do with it.

Some of the options are described elsewhere in this documentation, in context. In addition, the API docs show all the available options, and below is a partial list of options:

* `cameraConstraint`
  * camera bounds inside bounds: `CameraConstraint.bounds`
  * camera center inside bounds: `CameraConstraint.center`
  * *unconstrained (default): `CameraConstraint.unconstrained`*
* `maxZoom` and `minZoom`\
  Sets a hard limit on the maximum and minimum amounts that the map can be zoomed
* [`interactionOptions`](https://docs.fleaflet.dev/v7/usage/options/interaction-options)\
  Configures the gestures that the user can use to interact with the map - for example, disable rotation or configure cursor/keyboard rotation

{% hint style="success" %}
Instead of `maxZoom` (or in addition to), consider setting `maxNativeZoom` per `TileLayer` instead, to allow tiles to scale (and lose quality) on the final zoom level, instead of setting a hard limit.
{% endhint %}

## Custom CRS

FM does have some support for using alternative CRSs.&#x20;

{% content-ref url="options/custom-crss" %}
[custom-crss](https://docs.fleaflet.dev/v7/usage/options/custom-crss)
{% endcontent-ref %}

[^1]: Bounds inside camera

[^2]: Camera inside bounds

[^3]: Coordinates inside camera, as tightly as possible