public static FeatureCollection ToFeatureCollection(this FAnnotation annotation)
{
var list = new List <Feature>();
if (annotation is PointAnnotation)
{
var pa = (PointAnnotation)annotation;
list.Add(pa.ToFeature());
}
else if (annotation is PolylineAnnotation)
{
var pa = (PolylineAnnotation)annotation;
list.Add(pa.ToFeature());
}
else if (annotation is MultiPolylineAnnotation)
{
var pa = (MultiPolylineAnnotation)annotation;
list.Add(pa.ToFeature());
}
return(FeatureCollection.FromFeatures(list.ToArray()));
}
/// <summary>
/// This has a problem, if the same pin updates a couple of times a second pin might jump suddenly to the
/// 2nd to latest position then smooth animate to the latest position, but I think this is ok logically since
/// By the time it's animating its final animation position is not really up to date.
/// </summary>
/// <param name="pin">Pin.</param>
private void animateLocationChange(Pin pin)
{
#region Simultaneous pin update
System.Threading.Tasks.Task.Run(async() => {
// If there exist a pin that caused this update
if (isPinAnimating)
{
return;
}
// Wait for pin position assignment in the same call
isPinAnimating = true;
// Get all pins with the same key and same flat value (animatable pins)
var pinsWithSimilarKey = xMap.pins.Where(
(Pin arg) => arg.IsCenterAndFlat == pin.IsCenterAndFlat).ToArray();
Device.BeginInvokeOnMainThread(() => {
var geoJsonSource = (GeoJsonSource)nMap.GetSource(mapLockedPinsSourceKey);
var visibleMovablePinCount = pinsWithSimilarKey.Count(p => p.isVisible);
var currentHeadingCollection = new double[visibleMovablePinCount];
var features = new Feature[visibleMovablePinCount];
// Update the entire frame
MapBox.Extensions.MapExtensions.animatePin(
(double d) => {
System.Threading.Tasks.Task.Run(() => {
for (int i = 0; i < visibleMovablePinCount; i++)
{
var p = pinsWithSimilarKey[i];
Position theCurrentAnimationJump = p.position;
double theCurrentHeading = p.heading;
// Only update the pin if it is the pin that cause this animation call
// OR the if it actually requested for a position update before this current animation has not been finished
if (pin == p || p.requestForUpdate)
{
theCurrentAnimationJump = SphericalUtil.interpolate(p.previousPinPosition, p.position, d);
theCurrentHeading = SphericalUtil.computeHeading(p.previousPinPosition, p.position);
}
currentHeadingCollection[i] = theCurrentHeading;
var feature = Feature.FromGeometry(
Com.Mapbox.Geojson.Point.FromLngLat(theCurrentAnimationJump.longitude,
theCurrentAnimationJump.latitude));
feature.AddStringProperty(MapboxRenderer.pin_image_key, p.image);
feature.AddNumberProperty(MapboxRenderer.pin_rotation_key, (Java.Lang.Number)theCurrentHeading);
feature.AddNumberProperty(MapboxRenderer.pin_size_key, (Java.Lang.Number)p.imageScaleFactor);
feature.AddStringProperty(MapboxRenderer.pin_id_key, p.id);
// Add to the new animation frame
features[i] = feature;
}
// Extension method bypass, fromFeatures accepts IList as parameter
var featureCollection = FeatureCollection.FromFeatures(features);
// Update the entire layer
Device.BeginInvokeOnMainThread(() => geoJsonSource.SetGeoJson(featureCollection));
});
},
async(d, b) => {
// DO NOT REMOVE, this is essential for the simultaneous pin location update to work
await System.Threading.Tasks.Task.Delay(500);
isPinAnimating = false;
// Stabilize the pins, at this moment all the pins are updated
for (int i = 0; i < visibleMovablePinCount; i++)
{
var p = pinsWithSimilarKey[i];
// To avoid triggering heading property change event
p.PropertyChanged -= Pin_PropertyChanged;
p.requestForUpdate = false;
p.heading = currentHeadingCollection[i];
p.PropertyChanged += Pin_PropertyChanged;
}
}, 500);
});
});
#endregion
}
public static FeatureCollection toFeatureCollection(this IEnumerable <Feature> features)
{
return(FeatureCollection.FromFeatures(features.ToArray()));
}