android Maps API v2 with custom markers

I want to make maps with custom markers. In API v2 I can set icon, title, etc for markers. But I want to display title with marker at the first onset. Now title displays only when I taping the marker. In v1 was overlays, but in v2 I didn't found anything similar.

Edited: Maybe I was not clear enough. Something like Marker.showInfoWindow() in API works only for one marker. I can't show info windows for all of my markers at the same time. Anyway I need to show titles for all of my markers, without waiting while user will tap on it.

Solution 1:

I have also stumbled upon this problem. V2 API is a step forward, two steps back. Google, please add an overridable 'draw' method on the Marker or GoogleMap classes so we can customize the drawing ourselves.

A possible solution is to generate the bitmap on the fly and attach it to the marker. i.e. Create a canvas, insert the marker bitmap, draw the text next to the marker. This involves some painful calculations (the appropriate canvas size with the marker bitmap and the text next to each other). Unfortunately, there's no setIcon method in Marker, so every time the text changes, a new marker has to be created. It may be fine if you just have a marker on the map, but with dozens of markers, this may not be feasible. Also there may be memory issue on creating those bitmaps dynamically. A sample code (with just the text):

Bitmap.Config conf = Bitmap.Config.ARGB_8888; 
Bitmap bmp = Bitmap.createBitmap(200, 50, conf); 
Canvas canvas = new Canvas(bmp);

canvas.drawText("TEXT", 0, 50, paint); // paint defines the text color, stroke width, size
mMap.addMarker(new MarkerOptions()
                                .position(clickedPosition)
                                //.icon(BitmapDescriptorFactory.fromResource(R.drawable.marker2))
                                .icon(BitmapDescriptorFactory.fromBitmap(bmp))
                                .anchor(0.5f, 1)
                                    );

Hopefully, Google will add the appropriate methods so we can do this easily. Damn, I really like the new Map rotate feature in V2 API.

Solution 2:

Finally did it. So what you do is have a background image (in my case i just use a blue rectangle). Create a marker like so:

Marker myLocMarker = map.addMarker(new MarkerOptions()
            .position(myLocation)
            .icon(BitmapDescriptorFactory.fromBitmap(writeTextOnDrawable(R.drawable.bluebox, "your text goes here"))));

Notice the writeTextOnDrawable() Method:

private Bitmap writeTextOnDrawable(int drawableId, String text) {

    Bitmap bm = BitmapFactory.decodeResource(getResources(), drawableId)
            .copy(Bitmap.Config.ARGB_8888, true);

    Typeface tf = Typeface.create("Helvetica", Typeface.BOLD);

    Paint paint = new Paint();
    paint.setStyle(Style.FILL);
    paint.setColor(Color.WHITE);
    paint.setTypeface(tf);
    paint.setTextAlign(Align.CENTER);
    paint.setTextSize(convertToPixels(context, 11));

    Rect textRect = new Rect();
    paint.getTextBounds(text, 0, text.length(), textRect);

    Canvas canvas = new Canvas(bm);

    //If the text is bigger than the canvas , reduce the font size
    if(textRect.width() >= (canvas.getWidth() - 4))     //the padding on either sides is considered as 4, so as to appropriately fit in the text
        paint.setTextSize(convertToPixels(context, 7));        //Scaling needs to be used for different dpi's

    //Calculate the positions
    int xPos = (canvas.getWidth() / 2) - 2;     //-2 is for regulating the x position offset

    //"- ((paint.descent() + paint.ascent()) / 2)" is the distance from the baseline to the center.
    int yPos = (int) ((canvas.getHeight() / 2) - ((paint.descent() + paint.ascent()) / 2)) ;  

    canvas.drawText(text, xPos, yPos, paint);

    return  bm;
}



public static int convertToPixels(Context context, int nDP)
{
    final float conversionScale = context.getResources().getDisplayMetrics().density;

    return (int) ((nDP * conversionScale) + 0.5f) ;

}

Thanks to Arun George: Add text to image in android programmatically

Solution 3:

Seems like your question was finally answered at a Google I/O session.

Have a look at http://googlemaps.github.io/android-maps-utils/

It has:

Marker clustering — handles the display of a large number of points

Heat maps — display a large number of points as a heat map

IconGenerator — display text on your Markers (see screenshot)

Very importantly it can be modified on any thread so handling many markers is a breeze