Adding a Symbol Layer in Android Studio

Before you can add a symbol layer to the map, you need to follow a few steps. In this article, we will guide you through the process of adding a symbol layer and using it effectively.

Prerequisites

Make sure to complete the steps outlined in the Quickstart: Create an Android app document before proceeding with this tutorial. This will ensure that your Android Studio environment is set up correctly for mapping.

Setting Up the Symbol Layer

To add a symbol layer, you need to take a couple of steps. First, create a new layer by clicking on the 'Add Layer' button in the Map View panel. Then, select the 'Symbol' option from the dropdown menu.

Configuring the Symbol Layer

Once you have added the symbol layer, you can configure it by specifying the filter option. For example, if you want to include MultiPoint features as well, set the filter option of the layer to `any(eq(geometryType(), 'Point'), eq(geometryType(), 'MultiPoint'))`. On the other hand, if you want to limit the layer so that it only renders point geometry features, set the filter option of the layer to `eq(geometryType(), 'Point')`.

Customizing the Symbol Layer

By default, symbol layers will render the coordinates of all geometries in a data source. However, you can customize this behavior by providing your own PNG images for each desired resolution and referencing them in your project.

Using Standard Drawables

Android provides standard drawables that can be used as symbols. For example, you can use the 'sym_keyboard_return' symbol (available in the Android SDK directory: `Sdk/platforms/android-XXX/data/res/`). To use these symbols, simply copy them to your own project and reference them accordingly.

Avoiding Direct References

Google advises against referencing Android resources directly and recommends making a local copy instead. This is because direct references can cause issues when upgrading the Android platform or using different versions of the SDK.

Example Code

Here's an example code snippet that demonstrates how to add a symbol layer:

```java

// Create a new map view

MapView mapView = (MapView) findViewById(R.id.map_view);

// Add a symbol layer to the map

mapView.getMap().addLayer(new SymbolLayer('symbol_layer', 'path/to/symbol/image.png'));

```

In this article, we have demonstrated how to add a symbol layer in Android Studio. By following these steps and customizing the symbol layer as needed, you can effectively use symbols in your mapping applications.

Android studio icon symbol