Examples

Styling heatmaps

activity_multiple_heatmap_styling
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:mapbox="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.mapbox.mapboxsdk.maps.MapView
android:id="@id/mapView"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/switch_heatmap_style_fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|right"
android:layout_marginBottom="16dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:srcCompat="@drawable/ic_swap_horiz_white_24dp"
mapbox:fabSize="normal" />
</FrameLayout>
MultipleHeatmapStylingActivity
package com.mapbox.mapboxandroiddemo.examples.dds;
import android.os.Bundle;
import android.view.View;
import com.mapbox.mapboxandroiddemo.R;
import com.mapbox.mapboxsdk.Mapbox;
import com.mapbox.mapboxsdk.camera.CameraPosition;
import com.mapbox.mapboxsdk.camera.CameraUpdateFactory;
import com.mapbox.mapboxsdk.geometry.LatLng;
import com.mapbox.mapboxsdk.maps.MapView;
import com.mapbox.mapboxsdk.maps.MapboxMap;
import com.mapbox.mapboxsdk.maps.OnMapReadyCallback;
import com.mapbox.mapboxsdk.maps.Style;
import com.mapbox.mapboxsdk.style.expressions.Expression;
import com.mapbox.mapboxsdk.style.layers.HeatmapLayer;
import com.mapbox.mapboxsdk.style.layers.Layer;
import com.mapbox.mapboxsdk.style.sources.GeoJsonSource;
import java.net.URI;
import java.net.URISyntaxException;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import timber.log.Timber;
import static com.mapbox.mapboxsdk.style.expressions.Expression.heatmapDensity;
import static com.mapbox.mapboxsdk.style.expressions.Expression.interpolate;
import static com.mapbox.mapboxsdk.style.expressions.Expression.linear;
import static com.mapbox.mapboxsdk.style.expressions.Expression.literal;
import static com.mapbox.mapboxsdk.style.expressions.Expression.rgb;
import static com.mapbox.mapboxsdk.style.expressions.Expression.rgba;
import static com.mapbox.mapboxsdk.style.expressions.Expression.zoom;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.heatmapColor;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.heatmapIntensity;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.heatmapOpacity;
import static com.mapbox.mapboxsdk.style.layers.PropertyFactory.heatmapRadius;
public class MultipleHeatmapStylingActivity extends AppCompatActivity
implements OnMapReadyCallback {
private static final String HEATMAP_SOURCE_ID = "HEATMAP_SOURCE_ID";
private static final String HEATMAP_LAYER_ID = "HEATMAP_LAYER_ID";
private MapView mapView;
private MapboxMap mapboxMap;
private Expression[] listOfHeatmapColors;
private Expression[] listOfHeatmapRadiusStops;
private Float[] listOfHeatmapIntensityStops;
private int index;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
index = 0;
// Mapbox access token is configured here. This needs to be called either in your application
// object or in the same activity which contains the mapview.
Mapbox.getInstance(this, getString(R.string.access_token));
setContentView(R.layout.activity_multiple_heatmap_styling);
mapView = findViewById(R.id.mapView);
mapView.onCreate(savedInstanceState);
mapView.getMapAsync(this);
}
@Override
public void onMapReady(@NonNull final MapboxMap mapboxMap) {
MultipleHeatmapStylingActivity.this.mapboxMap = mapboxMap;
mapboxMap.setStyle(Style.LIGHT, new Style.OnStyleLoaded() {
@Override
public void onStyleLoaded(@NonNull final Style style) {
CameraPosition cameraPositionForFragmentMap = new CameraPosition.Builder()
.target(new LatLng(34.056684, -118.254002))
.zoom(11.047)
.build();
mapboxMap.animateCamera(
CameraUpdateFactory.newCameraPosition(cameraPositionForFragmentMap), 2600);
try {
style.addSource(new GeoJsonSource(HEATMAP_SOURCE_ID, new URI("asset://la_heatmap_styling_points.geojson")));
} catch (URISyntaxException exception) {
Timber.d(exception);
}
initHeatmapColors();
initHeatmapRadiusStops();
initHeatmapIntensityStops();
addHeatmapLayer(style);
findViewById(R.id.switch_heatmap_style_fab).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
index++;
if (index == listOfHeatmapColors.length - 1) {
index = 0;
}
Layer heatmapLayer = style.getLayer(HEATMAP_LAYER_ID);
if (heatmapLayer != null) {
heatmapLayer.setProperties(
heatmapColor(listOfHeatmapColors[index]),
heatmapRadius(listOfHeatmapRadiusStops[index]),
heatmapIntensity(listOfHeatmapIntensityStops[index])
);
}
}
});
}
});
}
private void addHeatmapLayer(@NonNull Style loadedMapStyle) {
// Create the heatmap layer
HeatmapLayer layer = new HeatmapLayer(HEATMAP_LAYER_ID, HEATMAP_SOURCE_ID);
// Heatmap layer disappears at whatever zoom level is set as the maximum
layer.setMaxZoom(18);
layer.setProperties(
// Color ramp for heatmap. Domain is 0 (low) to 1 (high).
// Begin color ramp at 0-stop with a 0-transparency color to create a blur-like effect.
heatmapColor(listOfHeatmapColors[index]),
// Increase the heatmap color weight weight by zoom level
// heatmap-intensity is a multiplier on top of heatmap-weight
heatmapIntensity(listOfHeatmapIntensityStops[index]),
// Adjust the heatmap radius by zoom level
heatmapRadius(listOfHeatmapRadiusStops[index]
),
heatmapOpacity(1f)
);
// Add the heatmap layer to the map and above the "water-label" layer
loadedMapStyle.addLayerAbove(layer, "waterway-label");
}
@Override
protected void onStart() {
super.onStart();
mapView.onStart();
}
@Override
protected void onResume() {
super.onResume();
mapView.onResume();
}
@Override
protected void onPause() {
super.onPause();
mapView.onPause();
}
@Override
protected void onStop() {
super.onStop();
mapView.onStop();
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mapView.onSaveInstanceState(outState);
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
@Override
public void onDestroy() {
super.onDestroy();
mapView.onDestroy();
}
private void initHeatmapColors() {
listOfHeatmapColors = new Expression[] {
// 0
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.25), rgba(224, 176, 63, 0.5),
literal(0.5), rgb(247, 252, 84),
literal(0.75), rgb(186, 59, 30),
literal(0.9), rgb(255, 0, 0)
),
// 1
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(255, 255, 255, 0.4),
literal(0.25), rgba(4, 179, 183, 1.0),
literal(0.5), rgba(204, 211, 61, 1.0),
literal(0.75), rgba(252, 167, 55, 1.0),
literal(1), rgba(255, 78, 70, 1.0)
),
// 2
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(12, 182, 253, 0.0),
literal(0.25), rgba(87, 17, 229, 0.5),
literal(0.5), rgba(255, 0, 0, 1.0),
literal(0.75), rgba(229, 134, 15, 0.5),
literal(1), rgba(230, 255, 55, 0.6)
),
// 3
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(135, 255, 135, 0.2),
literal(0.5), rgba(255, 99, 0, 0.5),
literal(1), rgba(47, 21, 197, 0.2)
),
// 4
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(4, 0, 0, 0.2),
literal(0.25), rgba(229, 12, 1, 1.0),
literal(0.30), rgba(244, 114, 1, 1.0),
literal(0.40), rgba(255, 205, 12, 1.0),
literal(0.50), rgba(255, 229, 121, 1.0),
literal(1), rgba(255, 253, 244, 1.0)
),
// 5
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.05), rgba(0, 0, 0, 0.05),
literal(0.4), rgba(254, 142, 2, 0.7),
literal(0.5), rgba(255, 165, 5, 0.8),
literal(0.8), rgba(255, 187, 4, 0.9),
literal(0.95), rgba(255, 228, 173, 0.8),
literal(1), rgba(255, 253, 244, .8)
),
//6
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.3), rgba(82, 72, 151, 0.4),
literal(0.4), rgba(138, 202, 160, 1.0),
literal(0.5), rgba(246, 139, 76, 0.9),
literal(0.9), rgba(252, 246, 182, 0.8),
literal(1), rgba(255, 255, 255, 0.8)
),
//7
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.1), rgba(0, 2, 114, .1),
literal(0.2), rgba(0, 6, 219, .15),
literal(0.3), rgba(0, 74, 255, .2),
literal(0.4), rgba(0, 202, 255, .25),
literal(0.5), rgba(73, 255, 154, .3),
literal(0.6), rgba(171, 255, 59, .35),
literal(0.7), rgba(255, 197, 3, .4),
literal(0.8), rgba(255, 82, 1, 0.7),
literal(0.9), rgba(196, 0, 1, 0.8),
literal(0.95), rgba(121, 0, 0, 0.8)
),
// 8
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.1), rgba(0, 2, 114, .1),
literal(0.2), rgba(0, 6, 219, .15),
literal(0.3), rgba(0, 74, 255, .2),
literal(0.4), rgba(0, 202, 255, .25),
literal(0.5), rgba(73, 255, 154, .3),
literal(0.6), rgba(171, 255, 59, .35),
literal(0.7), rgba(255, 197, 3, .4),
literal(0.8), rgba(255, 82, 1, 0.7),
literal(0.9), rgba(196, 0, 1, 0.8),
literal(0.95), rgba(121, 0, 0, 0.8)
),
// 9
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.1), rgba(0, 2, 114, .1),
literal(0.2), rgba(0, 6, 219, .15),
literal(0.3), rgba(0, 74, 255, .2),
literal(0.4), rgba(0, 202, 255, .25),
literal(0.5), rgba(73, 255, 154, .3),
literal(0.6), rgba(171, 255, 59, .35),
literal(0.7), rgba(255, 197, 3, .4),
literal(0.8), rgba(255, 82, 1, 0.7),
literal(0.9), rgba(196, 0, 1, 0.8),
literal(0.95), rgba(121, 0, 0, 0.8)
),
// 10
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.01),
literal(0.1), rgba(0, 2, 114, .1),
literal(0.2), rgba(0, 6, 219, .15),
literal(0.3), rgba(0, 74, 255, .2),
literal(0.4), rgba(0, 202, 255, .25),
literal(0.5), rgba(73, 255, 154, .3),
literal(0.6), rgba(171, 255, 59, .35),
literal(0.7), rgba(255, 197, 3, .4),
literal(0.8), rgba(255, 82, 1, 0.7),
literal(0.9), rgba(196, 0, 1, 0.8),
literal(0.95), rgba(121, 0, 0, 0.8)
),
// 11
interpolate(
linear(), heatmapDensity(),
literal(0.01), rgba(0, 0, 0, 0.25),
literal(0.25), rgba(229, 12, 1, .7),
literal(0.30), rgba(244, 114, 1, .7),
literal(0.40), rgba(255, 205, 12, .7),
literal(0.50), rgba(255, 229, 121, .8),
literal(1), rgba(255, 253, 244, .8)
)
};
}
private void initHeatmapRadiusStops() {
listOfHeatmapRadiusStops = new Expression[] {
// 0
interpolate(
linear(), zoom(),
literal(6), literal(50),
literal(20), literal(100)
),
// 1
interpolate(
linear(), zoom(),
literal(12), literal(70),
literal(20), literal(100)
),
// 2
interpolate(
linear(), zoom(),
literal(1), literal(7),
literal(5), literal(50)
),
// 3
interpolate(
linear(), zoom(),
literal(1), literal(7),
literal(5), literal(50)
),
// 4
interpolate(
linear(), zoom(),
literal(1), literal(7),
literal(5), literal(50)
),
// 5
interpolate(
linear(), zoom(),
literal(1), literal(7),
literal(15), literal(200)
),
// 6
interpolate(
linear(), zoom(),
literal(1), literal(10),
literal(8), literal(70)
),
// 7
interpolate(
linear(), zoom(),
literal(1), literal(10),
literal(8), literal(200)
),
// 8
interpolate(
linear(), zoom(),
literal(1), literal(10),
literal(8), literal(200)
),
// 9
interpolate(
linear(), zoom(),
literal(1), literal(10),
literal(8), literal(200)
),
// 10
interpolate(
linear(), zoom(),
literal(1), literal(10),
literal(8), literal(200)
),
// 11
interpolate(
linear(), zoom(),
literal(1), literal(10),
literal(8), literal(200)
),
};
}
private void initHeatmapIntensityStops() {
listOfHeatmapIntensityStops = new Float[] {
// 0
0.6f,
// 1
0.3f,
// 2
1f,
// 3
1f,
// 4
1f,
// 5
1f,
// 6
1.5f,
// 7
0.8f,
// 8
0.25f,
// 9
0.8f,
// 10
0.25f,
// 11
0.5f
};
}
}
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