问题
I want to add a pulse ring animation on blue dot current user location in Android google mapFragment (like Uber).
Can anybody help me with this thing?
回答1:
I have found a solution to add pulsating animation to a marker. Here is the map part, Here variable "map" denotes your map.
private Circle lastUserCircle;
private long pulseDuration = 1000;
private ValueAnimator lastPulseAnimator;
private void addPulsatingEffect(LatLng userLatlng){
if(lastPulseAnimator != null){
lastPulseAnimator.cancel();
Log.d("onLocationUpdated: ","cancelled" );
}
if(lastUserCircle != null)
lastUserCircle.setCenter(userLatlng);
lastPulseAnimator = valueAnimate(userLocation.getAccuracy(), pulseDuration, new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
if(lastUserCircle != null)
lastUserCircle.setRadius((Float) animation.getAnimatedValue());
else {
lastUserCircle = map.addCircle(new CircleOptions()
.center(userLatlng)
.radius((Float) animation.getAnimatedValue())
.strokeColor(Color.RED)
.fillColor(Color.BLUE));
}
}
});
}
protected ValueAnimator valueAnimate(float accuracy,long duration, ValueAnimator.AnimatorUpdateListener updateListener){
Log.d( "valueAnimate: ", "called");
ValueAnimator va = ValueAnimator.ofFloat(0,accuracy);
va.setDuration(duration);
va.addUpdateListener(updateListener);
va.setRepeatCount(ValueAnimator.INFINITE);
va.setRepeatMode(ValueAnimator.RESTART);
va.start();
return va;
}
You have to call this on location updates by adding PositionChangedListener. You can easily find that in Google map docs. After that, for each update call the above method.
Fixing the pulse radius to somewhat same value, so that it's neither too big, nor too small
Write this method
protected float getDisplayPulseRadius(float radius) {
float diff = (map.getMaxZoomLevel() - map.getCameraPosition().zoom);
if (diff < 3)
return radius;
if (diff < 3.7)
return radius * (diff / 2);
if (diff < 4.5)
return (radius * diff);
if (diff < 5.5)
return (radius * diff) * 1.5f;
if (diff < 7)
return (radius * diff) * 2f;
if (diff < 7.8)
return (radius * diff) * 3.5f;
if (diff < 8.5)
return (float) (radius * diff) * 5;
if (diff < 10)
return (radius * diff) * 10f;
if (diff < 12)
return (radius * diff) * 18f;
if (diff < 13)
return (radius * diff) * 28f;
if (diff < 16)
return (radius * diff) * 40f;
if (diff < 18)
return (radius * diff) * 60;
return (radius * diff) * 80;
}
And change this line
userLocation.getAccuracy()
to
getDisplayPulseRadius(userLocation.getAccuracy()
And also
.radius((Float) animation.getAnimatedValue())
to
.radius(getDisplayPulseRadius((Float) animation.getAnimatedValue()))
If you want an effect like the color fades to transparent when it gets big, you can use this just in the next line where you are setting the radius inside the animator
circle.setFillColor(adjustAlpha(pulseAroundMeFillColor, 1 - animation.getAnimatedFraction()));
private int adjustAlpha(int color, float factor) {
int alpha = Math.round(Color.alpha(color) * factor);
int red = Color.red(color);
int green = Color.green(color);
int blue = Color.blue(color);
return Color.argb(alpha, red, green, blue);
}
回答2:
import android.animation.ValueAnimator
import android.graphics.Color
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import com.google.android.gms.maps.CameraUpdateFactory
import com.google.android.gms.maps.GoogleMap
import com.google.android.gms.maps.MapFragment
import com.google.android.gms.maps.model.Circle
import com.google.android.gms.maps.model.CircleOptions
import com.google.android.gms.maps.model.LatLng
import com.google.android.gms.maps.model.MarkerOptions
class MainActivity : AppCompatActivity() {
private val pulseCount = 4
private val animationDuration = (pulseCount + 1) * 1000
private val SAN_FRANCISCO_LOCATION = LatLng(37.7749295, -122.4194155)
private var gMap: GoogleMap? = null
private var circles = Array<Circle?>(pulseCount, { null })
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
(fragmentManager.findFragmentById(R.id.mpFrgmnt) as MapFragment).getMapAsync { map ->
gMap = map
setCurrentLocation()
}
}
private fun setCurrentLocation() {
gMap?.let { gMap ->
gMap.moveCamera(CameraUpdateFactory.newLatLngZoom(SAN_FRANCISCO_LOCATION, 17f))
gMap.animateCamera(CameraUpdateFactory.zoomIn())
gMap.animateCamera(CameraUpdateFactory.zoomTo(17f), animationDuration, null)
gMap.addMarker(MarkerOptions().position(SAN_FRANCISCO_LOCATION).title("San Francisco !"))
val from = 0
val to = 100
val fraction = 255 / to
for (i in 0 until pulseCount) {
addPulseAnimator(gMap, circles, SAN_FRANCISCO_LOCATION, from, to, fraction, i)
}
}
}
private fun addPulseAnimator(gMap: GoogleMap, circles: Array<Circle?>, latLng: LatLng, from: Int, to: Int, colorFraction: Int, currentPosition: Int) {
val valueAnimator = ValueAnimator.ofInt(from, to)
valueAnimator.duration = animationDuration.toLong()
valueAnimator.repeatCount = ValueAnimator.INFINITE
valueAnimator.repeatMode = ValueAnimator.RESTART
valueAnimator.startDelay = currentPosition * 1000L
valueAnimator.addUpdateListener { valueAnimator ->
val radius = valueAnimator.animatedValue as Int
circles[currentPosition]?.let { circle ->
circle.center = latLng
circle.radius = radius.toDouble()
circle.fillColor = Color.argb((to - radius) * colorFraction, 48, 118, 254)
circle.strokeWidth = 0f
} ?: run {
circles[currentPosition] = gMap.addCircle(CircleOptions()
.center(latLng)
.radius(radius.toDouble())
.fillColor(Color.argb((to - radius) * colorFraction, 48, 118, 254))
.strokeWidth(0f))
}
}
valueAnimator.start()
}
}
来源：https://stackoverflow.com/questions/41672994/pulse-ring-animation-around-a-google-maps-marker-in-android