Markers

A marker is a visual representation (such as an icon or a geometry, like a polyline or polygon) placed at a specific geographic location on a map to indicate an important point of interest, event, or location.

Markers can represent temporary or user-specified points on the map, such as user-defined locations, waypoints, or temporary annotations. While they are often represented by icons, they can also take the form of more complex geometries, like lines or shapes, depending on the context or requirements.

Markers typically contain only basic metadata, such as their position, title, or description, without extensive associated details.

By default, the map does not include any visual elements categorized as markers. Users have the ability to create and add markers to the map as needed.

Instantiating Markers​

Markers can be instantiated via:

1. Default Initialization : UnlMarker() creates a basic marker object.
2. With UnlCoordinatesList : UnlMarker(coordinates: UnlCoordinatesList) initializes a marker at specified geographic coordinates
3. With UnlCoordinates and radius in meters : UnlMarker(coordinates: UnlCoordinates, radius: Int) creates a circular marker centered at the given coordinates with a defined radius.
4. With UnlCoordinates, horizontal radius, and vertical radius in meters : UnlMarker(coordinates: UnlCoordinates, horizRadius: Int, vertRadius: Int) creates a rectangle marker centered at the specified coordinates with defined horizontal and vertical radii.

🚨 Danger

Creating a marker does not automatically display it on the map. Ensure you set its coordinates and attach it to the desired map. Refer to the Display markers guide for detailed instructions.

Types of Markers​

There are 3 types of markers:

• Point markers (each part is a group of points - array of coordinates)
• Polyline markers (each part is a polyline - array of coordinates)
• Polygon markers (each part is a polygon - array of coordinates)

The marker has methods for managing and manipulating markers on a map, including operations such as adding, updating, and deleting coordinates or parts.

A marker can be rendered in multiple ways on the map, either through default settings or user-specified rendering options:

• An image icon
• A polygon drawn with custom collors for border and shape.
• A polyline having an associated image at each point

Point marker

Polyline marker with point markers at each point

Polygon marker

Customization options​

Markers offer extensive customization options through UnlMarkerRenderSettings class and UnlMarkerCollectionRenderSettings, enabling developers to tailor their appearance and behavior. Customizable features include:

• Colors: Modify the fill color, contour color, and text color to match the desired style.
• Sizes: Adjust dimensions such as line width, label size, and margins to fit specific requirements.
• Labeling and Positioning: Define custom labeling modes, reposition item or group labels, and adjust the alignment of labels and images relative to geographic coordinates.
• Grouping Behavior: Configure how multiple markers are grouped when located in proximity.
• Icons: Customize icons for individual markers or groups, including options for image fit and alignment.
• Polyline and Polygon Textures: Apply unique textures to polylines and polygons for enhanced visualization.

Interaction with Markers​

Selecting markers​

Markers are selectable by default, meaning user interactions, such as taps or clicks, can identify specific markers programmatically (e.g., through the function mapview.cursorSelectionMarkers()).

💡 Tip

When cursor is hovering over a grouped marker cluster, the mapview.cursorSelectionMarkers() method will return the MarkerMatchList with a group head marker. See more about group head markers at UnlMarker Clustering.

The result is a MarkerMatchList. The UnlMarkerMatch item contains detailed information about the match:

• the matched marker: UnlMarker
• the marker's type: EMarkerMatchType
• the matched marker's index: Int in collection
• the matched markerCollection: UnlMarkerCollection of the marker
• the matched marker's segment: Int
• the matched position coordinates: UnlCoordinates
• the distance: Int from the matched position to the cursor position in meters

Searching markers​

Markers are not searchable.

Calculating route with marker​

Markers are not designed for route calculation.

💡 Tip

To enable route calculation and navigation, create a new landmark using the relevant coordinates of the marker and a representative name and use that object for routing.

Marker​

Name	Type	Description
id	Long	Unique identifier for the marker.
name	String	Name of the marker.
type	EMarkerType	Type of the marker (Point, Polyline, Polygon).
area	RectangleGeographicArea	The geographic area covered by the marker.
partCount	Int	Number of parts in the marker.
getCoordinates()	UnlCoordinatesList	Returns the coordinates of the marker.
setCoordinates(coordinates: UnlCoordinatesList)	Unit	Sets the coordinates of the marker.
set(center: UnlCoordinates, radius: Int)	Unit	Sets the marker as a circle with the specified center and radius in meters.
set(center: UnlCoordinates, horizontalRadius: Int, verticalRadius: Int)	Unit	Sets the marker as an ellipse with the specified center and horizontal/vertical radii in meters.
set(corner1: UnlCoordinates, corner2: UnlCoordinates)	Unit	Sets the marker as a rectangle defined by two corner coordinates.
add(coordinates: UnlCoordinates, index: Int, part: Int)	Unit	Adds coordinates to the marker at the specified index and part.
add(latitude: Double, longitude: Double, index: Int, part: Int)	Unit	Adds coordinates to the marker using latitude and longitude values at the specified index and part.

MarkerCollection​

The UnlMarkerCollection class is the main collection holding markers. All the markers within a collection have the same type and are styled in the same way.

Name	Type	Description
name	String	The name of the marker collection.
size	Int	Returns the number of markers in the collection.
type	EMarkerType	Retrieves the type of the marker collection.
area	RectangleGeographicArea	The geographic area enclosing all markers in the collection.
markers	ArrayList\?	The list of markers in the collection.
add(marker:UnlMarker,index:Int)	Unit	Adds a marker to the collection at a specific index (default is the end of the collection).
del(index: Int)	Unit	Deletes a marker from the collection by index.
clear()	Unit	Deletes all markers from the collection.
getMarkerAt(index:Int)	UnlMarker	Returns the marker at a specific index or an empty marker if the index is invalid.
getMarkerById(markerId:Long)	UnlMarker	Retrieves a marker by its unique ID.
getPointsGroupHead(groupId:Long)	UnlMarker	Retrieves the head of a points group for a given marker ID.
getPointsGroupComponents(groupId:Long)	ArrayList\?	Retrieves the components of a points group by its ID.
save(buffer: DataBuffer)	Int	Serializes the collection and adds it to a DataBuffer.