Struct VectorReaderIter

pub struct VectorReaderIter { /* private fields */ }

Reads the layers and features of a vector tile.

To create a new VectorReaderIter, use VectorReader::iterate().

A vector tile consists of named layers, which contain features. Each feature has an ID, a geometry, and a set of key/value tags. The meanings of the IDs and tags depends on the data source that the tile came from. The OpenMapTiles schema is a common schema for vector tiles.

To read all layers in a tile, use layer_count() and read_layer(). If you know the name of the layer you want, you can also use read_layer_by_name(). Once the iterator is reading a layer, you can call next_feature() in a loop to read all the features in the layer.

A VectorReaderIter is not thread-safe, but iterators created from the same VectorReader can be used in different threads.

See the Mapbox Vector Tile specification for more information about the vector tile format.

Properties

reader

Readable | Writeable | Construct Only

Implements

[trait@glib::ObjectExt]

GLib type: GObject with reference counted clone semantics.

Implementations

impl VectorReaderIter

pub fn feature_contains_point(&self, x: f64, y: f64) -> bool

Determines whether the current feature contains the given point.

The point must be specified in tile space. See layer_extent() to get the range of the coordinates.

Only polygon or multipolygon features can contain a point. For all other feature types, this function returns false.

If the point is on the border of the polygon, this function may return either true or false.

Returns

true if the feature contains the point, false otherwise.

pub fn feature_geometry_type(&self) -> GeometryType

Gets the geometry type of the current feature.

Returns

The geometry type of the current feature.

pub fn feature_id(&self) -> u64

Gets the ID of the current feature.

Returns

The ID of the current feature.

pub fn feature_keys(&self) -> Vec<GString>

Gets the keys of the tags of the current feature.

Returns

The keys of the tags of the current feature.

pub fn feature_point(&self) -> Option<(f64, f64)>

Gets the coordinates of the current feature in tile space, if the feature is a single point.

See layer_extent() to get the range of the coordinates.

It is an error to call this function if the feature is not a single point. Use feature_geometry_type() to check the feature’s geometry type.

Returns

true if the feature is a point, false otherwise.

x

The x coordinate of the point.

y

The y coordinate of the point.

pub fn feature_tag(&self, key: &str) -> Option<Value>

Gets the value of the tag with the given key.

key

The key of the tag to get.

Returns

true if the tag was found, false otherwise.

value

The value of the tag.

pub fn layer_count(&self) -> u32

Gets the number of layers in the vector tile.

Returns

The number of layers.

pub fn layer_extent(&self) -> u32

Gets the extent for coordinates in the current layer.

0 represents the top and left edges of the tile, and this value represents the bottom and right edges. Feature geometries may extend outside of this range, since tiles often include some margin.

Tiles do not contain metadata about the location of the tile within the world, so it is up to the caller to know the tile’s coordinates and convert latitude/longitude to tile-space coordinates.

Returns

The layer’s extent

pub fn layer_feature_count(&self) -> u32

Gets the number of features in the current layer.

You can loop over all features in the current layer by calling read_feature() with each index from 0 to the feature count, but it might be easier to use next_feature() instead.

Returns

The number of features in the current layer.

pub fn layer_name(&self) -> Option<GString>

Gets the name of the current layer.

Returns

The name of the current layer.

pub fn reader(&self) -> Option<VectorReader>

Gets the reader that the iterator is iterating over.

Returns

The reader that the iterator is iterating over.

pub fn next_feature(&self) -> bool

Advances the iterator to the next feature in the current layer.

Returns

true if there is a next feature, false otherwise.

pub fn read_feature(&self, index: i32)

Moves the iterator to the feature at the given index in the current layer.

You can get the number of features in the current layer with layer_feature_count().

index

The index of the feature to read.

pub fn read_layer(&self, index: i32)

Sets the current layer of the reader to the layer at the given index.

index

The index of the layer to read.

pub fn read_layer_by_name(&self, name: &str) -> bool

Moves the iterator to the layer with the given name, if present.

If the layer is not found, the current layer will be set to None and the function will return false. Layers are typically omitted if they are empty, so don’t assume that a layer in the schema will always be present.

The iterator’s current feature will be None after calling this function; use next_feature() to advance to the first feature in the layer.

Returns

true if the layer was found, false otherwise.

Trait Implementations

impl Clone for VectorReaderIter

fn clone(&self) -> Self

Makes a clone of this shared reference.

This increments the strong reference count of the object. Dropping the object will decrement it again.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for VectorReaderIter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for VectorReaderIter

type ParamSpec = ParamSpecObject

type SetValue = VectorReaderIter

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(&str) -> ParamSpecObjectBuilder<'_, VectorReaderIter>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for VectorReaderIter

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Hashes the memory address of this object.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for VectorReaderIter

fn cmp(&self, other: &Self) -> Ordering

Comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl ParentClassIs for VectorReaderIter

type Parent = Object

impl<OT: ObjectType> PartialEq<OT> for VectorReaderIter

fn eq(&self, other: &OT) -> bool

Equality for two GObjects.

Two GObjects are equal if their memory addresses are equal.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for VectorReaderIter

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

Partial comparison for two GObjects.

Compares the memory addresses of the provided objects.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for VectorReaderIter

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for VectorReaderIter