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POandroid maps circle overlay, dynamically change radius?
 

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  1. POandroid maps circle overlay, dynamically change radius?
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    <p>I have a MapView in my app and am drawing a few circle overlays on this map. Everything is working fine, but when I zoom on the map, the overlay radius does not change. I have tried searching forums and google for a solution but could not find one that worked for me. Does anyone have any ideas?</p> <p>Here is my code:</p> <p>HelloGoogleMaps.java (main activity)</p> <pre><code>package com.adam.maps; import java.util.Iterator; import java.util.List; import android.content.Context; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.view.MotionEvent; import android.view.View; import android.view.View.OnTouchListener; import android.widget.AbsoluteLayout; import android.widget.RelativeLayout; import android.widget.Toast; import android.widget.ZoomButtonsController.OnZoomListener; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapActivity; import com.google.android.maps.MapController; import com.google.android.maps.MapView; public class HelloGoogleMaps extends MapActivity { //create new LocationManager //and LocationListener objects LocationManager lm; LocationListener locationListener; OnZoomListener listener; //create a new MapView //and MapController object MapView mapView; MapController mc; RelativeLayout parent; int num = 4; //LoopRegion region[] = new LoopRegion[num]; //LoopRegion border[] = new LoopRegion[num]; float regionX[] = {(float) 42.91556645193364, (float) 42.9151598328247, (float) 43.00110298764482, (float) 43.00054196511636}; float regionY[] = {(float) -78.87073255078127, (float) -78.8714594294243, (float) -78.78354466454317, (float) -78.78226256863405}; int regionR[] = {100, 70, 150, 75}; GeoPoint regionC[] = new GeoPoint[num]; CustomOverlay overlay[] = new CustomOverlay[num]; CustomOverlay overlayLoc; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Toast.makeText(getBaseContext(), "Welcome to 'sound clusters'" , Toast.LENGTH_LONG).show(); //---use the LocationManager class to obtain GPS locations--- lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE); locationListener = new MyLocationListener(); lm.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, locationListener); //set our mapViewer object to our "mapview" namespace in the xml layout file //this allows us to set the zoom control "ON" in our view mapView = (MapView) findViewById(R.id.mapview); //this will enable zoom controls, and put it on the screen mapView.setBuiltInZoomControls(true); //--------------------------------------------------------// parent = (RelativeLayout) findViewById(R.id.parent); //-------this is part of creating an overlay icon------------------------------- /*List&lt;Overlay&gt; mapOverlays = mapView.getOverlays(); Drawable drawable = this.getResources().getDrawable(R.drawable.icon); CustomItemizedOverlay itemizedOverlay = new CustomItemizedOverlay(drawable, this);*/ //------------------------------------------------------------------------------ // Create new Overlay for (int i = 0; i &lt; num; i++){ regionC[i] = new GeoPoint( (int) (regionX[i] * 1E6), (int) (regionY[i] * 1E6)); int newRadius = (int) feetToPixels(mapView.getZoomLevel(), regionR[i]); overlay[i] = new CustomOverlay(regionC[i], newRadius); mapView.getOverlays().add(overlay[i]); } //-------this is part of creating an overlay icon------------------------------- /*OverlayItem overlayitem = new OverlayItem(point, "Hello", "I'm in Athens, Greece!"); itemizedOverlay.addOverlay(overlayitem); mapOverlays.add(itemizedOverlay);*/ //------------------------------------------------------------------------------ mc = mapView.getController(); mc.setZoom(20); mapView.setSatellite(true); Toast.makeText(getBaseContext(), "Zoom level: " + mapView.getZoomLevel(), Toast.LENGTH_SHORT).show(); } //not sure what this does, but Google says you need it----// @Override protected boolean isRouteDisplayed() { return false; } //--------------------------------------------------------// private class MyLocationListener implements LocationListener { //@Override public void onLocationChanged(Location loc) { if (loc != null) { List overlays = mapView.getOverlays(); // first remove old overlay if (overlays.size() &gt; 0) { for (Iterator iterator = overlays.iterator(); iterator .hasNext();) { iterator.next(); iterator.remove(); } } GeoPoint p = new GeoPoint( (int) (loc.getLatitude() * 1E6), (int) (loc.getLongitude() * 1E6)); overlayLoc = new CustomOverlay(p, 5); mapView.getOverlays().add(overlayLoc); for (int i = 0; i &lt; num; i++){ mapView.getOverlays().add(overlay[i]); } //mc.animateTo(p); //mc.setZoom(16); mapView.invalidate(); } } //@Override public void onProviderDisabled(String provider) { // TODO Auto-generated method stub } //@Override public void onProviderEnabled(String provider) { // TODO Auto-generated method stub } //@Override public void onStatusChanged(String provider, int status, Bundle extras) { // TODO Auto-generated method stub } } //custom functions-------------------------------------------------------------------- private static final double equatorFeet = 131479920; private double feetToPixels(int zoomLevel, int feet) { double equatorPixels = 256; for (int i = 1; i &lt; zoomLevel; i++) { equatorPixels = equatorPixels * 2; } double pixelPerFoot = equatorPixels / equatorFeet; return feet * pixelPerFoot; } //------------------------------------------------------------------------------------ } </code></pre> <p>And the Overlay class CustomOverlay.java</p> <pre><code>package com.adam.maps; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Point; import com.google.android.maps.GeoPoint; import com.google.android.maps.MapView; import com.google.android.maps.Overlay; import com.google.android.maps.Projection; public class CustomOverlay extends Overlay { private GeoPoint geopoint; private int rad; public CustomOverlay(GeoPoint point, int radius) { geopoint = point; rad = radius; } @Override public void draw(Canvas canvas, MapView mapView, boolean shadow) { // Transform geo-position to Point on canvas Projection projection = mapView.getProjection(); Point point = new Point(); //store the transformed geopoint into a point with pixel values projection.toPixels(geopoint, point); /*// text "My Location" Paint text = new Paint(); text.setAntiAlias(true); text.setColor(Color.BLUE); text.setTextSize(12); text.setTypeface(Typeface.MONOSPACE);*/ // the circle to mark the spot Paint circlePaint = new Paint(); circlePaint.setAntiAlias(true); //fill region circlePaint.setColor(Color.RED); circlePaint.setAlpha(90); circlePaint.setStyle(Paint.Style.FILL); canvas.drawCircle(point.x, point.y, rad, circlePaint); //border region circlePaint.setColor(Color.WHITE); circlePaint.setAlpha(255); circlePaint.setStyle(Paint.Style.STROKE); circlePaint.setStrokeWidth(3); canvas.drawCircle(point.x, point.y, rad, circlePaint); /*canvas.drawText("My Location", point.x + 3 * CIRCLERADIUS, point.y + 3 * CIRCLERADIUS, text);*/ } } </code></pre> <p>Thank you in advance for your help!</p>
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