How to extends ResourceProxy interface in osmdroid?

yea, i know, another thread about changing icons in osmdroid. But there isn't any good explanation available !

I made lot of research and it is a frequently asked topic. Why not make a clear answer at this point for all user who need to specify their own resources ?

All stuff available is to "Have a look at ResourceProxy.java" or "Pass the bitmap to constructor". No way, it doesn't work for me, I don't even know how a simple interface could find my drawable in my res folder ! I tried to pass some .PNG files with the same names as osmdroid (like "person.png") but when I run the app I have still the default resource.

Can someone explain clearly how to write "our own ResourceProxy" step by step ? Not brievely like that because I followed the steps and didn't manage to success.

I know that osmdroid was fixed recently in github but the .aar is older than the fix. Here you can find the Resource Proxy class.

Solution

When you create in an instance of the MapView, you need to pass in a reference to a implementation of "ResourceProxy". By default, it loads the "DefaultResourceProxyImpl". To override, create a new class that extends DefaultResourceProxyImpl and then you can override getBitmap and getDrawable. There is actually is an example that overrides the DefaultResourceProxyImpl here:

https://github.com/osmdroid/osmdroid/blob/master/OpenStreetMapViewer/src/main/java/org/osmdroid/ResourceProxyImpl.java

Just for you, I'm working on including such an example with the osmdroid example app. It's going to look something like this

 public class CustomResourceProxy extends DefaultResourceProxyImpl {

      private final Context mContext;
      public CustomResourceProxy(Context pContext) {
           super(pContext);
        mContext = pContext;
      }

      @Override
    public Bitmap getBitmap(final bitmap pResId) {
        switch (pResId){
                case person:
                     //your image goes here!!!
                     return BitmapFactory.decodeResource(mContext.getResources(),org.osmdroid.example.R.drawable.sfgpuci);

           }
           return super.getBitmap(pResId);
    }

    @Override
    public Drawable getDrawable(final bitmap pResId) {
        switch (pResId){
                case person:
                     //your image goes here!!!
                     return mContext.getResources().getDrawable(org.osmdroid.example.R.drawable.sfgpuci);
           }
           return super.getDrawable(pResId);
    }

 }

Edit: done See https://github.com/osmdroid/osmdroid/blob/master/OpenStreetMapViewer/src/main/java/org/osmdroid/CustomResourceProxy.java

Edit: Edit: Wiki updated, see https://github.com/osmdroid/osmdroid/wiki/How-to-use-the-osmdroid-library