DirectionsPolyline class abstract
Polyline encoding is a lossy compression algorithm that allows you to store a series of coordinates as a single string. Point coordinates are encoded using signed values. If you only have a few static points, you may also wish to use the interactive polyline encoding utility. The encoding process converts a binary value into a series of character codes for ASCII characters using the familiar base64 encoding scheme: to ensure proper display of these characters, encoded values are summed with 63 (the ASCII character '?') before converting them into ASCII. The algorithm also checks for additional character codes for a given point by checking the least significant bit of each byte group; if this bit is set to 1, the point is not yet fully formed and additional data must follow. Additionally, to conserve space, points only include the offset from the previous point (except of course for the first point). All points are encoded in Base64 as signed integers, as latitudes and longitudes are signed values. The encoding format within a polyline needs to represent two coordinates representing latitude and longitude to a reasonable precision. Given a maximum longitude of +/- 180 degrees to a precision of 5 decimal places (180.00000 to -180.00000), this results in the need for a 32 bit signed binary integer value.
Properties:
- points - A single string representation of the polyline.
Constructors
- DirectionsPolyline([void updates(DirectionsPolylineBuilder b)])
-
factory
Properties
Methods
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
rebuild(
dynamic updates(DirectionsPolylineBuilder)) → DirectionsPolyline -
Rebuilds the instance.
inherited
-
toBuilder(
) → DirectionsPolylineBuilder -
Converts the instance to a builder
B.inherited -
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Static Properties
-
serializer
→ Serializer<
DirectionsPolyline> -
no setter