Center a raster marker (Android API Google Maps v2)

Question

When I add a marker from a custom bitmap, the marker does not center at the specified point.

I add it like this:

// ID tramo final int tramoId = tr.getId(); // Nodos final Nodo[] nodos = tr.getNodos(); final PolylineOptions p = new PolylineOptions(); MarkerOptions m = new MarkerOptions(); // Seteamos posicion de linea y marker m.position(semisuma(nodos)); for (final Nodo n : nodos) { p.add(n.getLatLng()); } // Color de linea y marker BitmapDescriptor icon = null; if (tr.getCapacidad() == 0) { p.color(0xFF000000); m = null; } else if (tr.getCapacidad() - tr.getPlazasOcupadas() == 0) { p.color(0xEEFF0000); final TextDrawable drawable = new TextDrawable(0, 0xEEFF0000, 0xFFFFFFFF); icon = BitmapDescriptorFactory.fromBitmap(fromDrawable(drawable)); } else { p.color(0xEE00FFFF); final TextDrawable drawable = new TextDrawable(0, 0xEE00FFFF, 0xFFFFFFFF); icon = BitmapDescriptorFactory.fromBitmap(fromDrawable(drawable)); } if (m != null) { m.title(String.valueOf(tramoId)); m.icon(icon); } if (polylinesTramo.get(idTramo) != null) { polylinesTramo.get(idTramo).remove(); } if (markersTramo.get(idTramo) != null) { markersTramo.get(idTramo).remove(); } polylinesTramo.put(idTramo, map.getMap().addPolyline(p)); if (marker != null) { markersTramo.put(idTramo, map.getMap().addMarker(m)); } 

This is the TextDrawable code:

 package com.cidaut.blueparking.ui; import android.graphics.Canvas; import android.graphics.ColorFilter; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.drawable.Drawable; public class TextDrawable extends Drawable { private final String text; private final Paint paint; private final int centroX = 13; private final int centroY = 16; private final float textSize; private final float whereToDrawX; private final int bgColor; public TextDrawable(final int text, final int bgColor, final int textColor) { this(String.valueOf(text), bgColor, textColor); } public TextDrawable(final String text, final int bgColor, final int textColor) { this.text = text; this.bgColor = bgColor; this.paint = new Paint(); paint.setColor(textColor); paint.setTextSize(14f); paint.setAntiAlias(true); paint.setFakeBoldText(true); paint.setStyle(Paint.Style.FILL); paint.setTextAlign(Paint.Align.LEFT); textSize = paint.measureText(text); whereToDrawX = centroX - (textSize / 2); } @Override public void draw(final Canvas canvas) { canvas.drawColor(bgColor); canvas.drawText(text, whereToDrawX, centroY, paint); } @Override public void setAlpha(final int alpha) { paint.setAlpha(alpha); } @Override public void setColorFilter(final ColorFilter cf) { paint.setColorFilter(cf); } @Override public int getOpacity() { return PixelFormat.TRANSLUCENT; } } 

and here fromDrawable method

 protected Bitmap fromDrawable(final Drawable drawable) { final Bitmap bitmap = Bitmap.createBitmap(25, 25, Config.ARGB_8888); final Canvas canvas = new Canvas(bitmap); drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight()); drawable.draw(canvas); return bitmap; } 

What should I add to my code to get markers with centers in their positions?

Answer 1

Just set the anchor point for the marker to 0.5 and 0.5 (the middle of your icon).

 ... MarkerOptions m = new MarkerOptions(); m.anchor(0.5f, 0.5f); ... 

The default binding value is (0.5f, 1.0f). You can read the marker here.

Answer 2

If you are using a Marker , you will need to repair the anchor to center the image. As the documentation says: "Anchor: the point on the image that will be placed at the LatLng position of the marker. This default value is 50% to the left of the image and at the bottom of the image."

You might want to consider using GroundOverlay instead of Marker if you want the image centered in the center. See GroundOverlay . "The default anchor is 50% of the top of the image and 50% to the left of the image."