Display overlays

Overlays are used to provide enhanced, layered information that adds contextual value to a base map, offering users dynamic, interactive, and customized data that can be visualized on top of other map elements.

Disabling overlays​

Overlays can be disabled either by applying a predefined, custom map style created in UNL Studio - where certain overlays are already disabled - or by using the disableOverlay method, as shown below:

• Kotlin
• Java

// Kotlin
val overlayService = OverlayService()
val error = overlayService.disableOverlay(ECommonOverlayId.PublicTransport.value, categoryId = -1)

// Java
OverlayService overlayService = new OverlayService();
int error = overlayService.disableOverlay(ECommonOverlayId.PublicTransport.getValue(), -1);

Passing -1 (default value) as the optional categoryId parameter indicates that we want to disable the entire public transport overlay, rather than targeting a specific category.

The error returned will be success if the overlay was disabled or notFound if no overlay (or overlay category) with the specified ID was found in the applied style.

To disable specific overlays within a category, you'll need to retrieve their unique identifiers (uid) as shown below:

• Kotlin
• Java

// Kotlin
val overlayService = OverlayService()

// Get available overlays with callback
val overlayCollection = overlayService.getAvailableOverlays { error, _ ->
    if (error == UnlError.NoError) {
        // Access overlays through UnlMapView preferences (if available)
    }
}
overlayCollection?.first?.let { collection ->
    if (collection.size > 0) {
        val overlayInfo = collection[0]
        val uid = overlayInfo.uid
        val disableError = overlayService.disableOverlay(uid, -1)
        // Handle the error result
        Log.d("Overlay", "Disable result: $disableError")
    }
}

// Java
OverlayService overlayService = new OverlayService();

// Get available overlays with callback
Pair<List<OverlayInfo>, Integer> overlayCollection = overlayService.getAvailableOverlays((error, result) -> {
    if (error == UnlError.NoError) {
        // Access overlays through UnlMapView preferences (if available)
    }
});
if (overlayCollection != null && overlayCollection.getFirst() != null) {
    List<OverlayInfo> collection = overlayCollection.getFirst();
    if (collection.size() > 0) {
        OverlayInfo overlayInfo = collection.get(0);
        int uid = overlayInfo.getUid();
        int disableError = overlayService.disableOverlay(uid, -1);
        // Handle the error result
        Log.d("Overlay", "Disable result: " + disableError);
    }
}

Enabling overlays​

In a similar way, the overlay can be enabled using the enableOverlay method by providing the overlay id. It also has an optional categoryId parameter, which when left as default, it activates whole overlay rather than a specific category.

• Kotlin
• Java

// Kotlin
val overlayService = OverlayService()
val error = overlayService.enableOverlay(ECommonOverlayId.PublicTransport.value, categoryId = -1)

// Java
OverlayService overlayService = new OverlayService();
int error = overlayService.enableOverlay(ECommonOverlayId.PublicTransport.getValue(), -1);