如何将图像（标记）放置在圆圈内并使它们可单击/可触摸？

Question

What I want to do:

It should be something like a radar. I send my geocoords to an API and get "people" back, and also their distance to me.

I have a round image as background, my radar screen, and I want to place a marker(another Image) on that image for every person I got back from the API. In the center is my position and depending on the distance and direction, that marker should be placed.

While the radar is a circle I can´t work with normal coordinates(they would be a rectangle). So my first question is, can you give me a pest practice or any advice how to do this? Placing Bitmaps over Bitmaps? But How to place them inside that circle?

On top of that, i want that markers to be clicked/touchable. If two or more markers are really near togehter, so that you cant touch/click them seperatly, I need a way to find out, which markers are clicked/touched. Or maybe in other words, which markers are placed inside the touched/clicked area.

How should I implement this?

Maybe android offers something I don´t think of (hopefully).

Thanks in advance!!!

Answer 1

I would create a custom view that fits your your case... for example:

public class RadarView extends View {
    @Override
    protected void onDraw(Canvas canvas) {
        // draw the background
        // draw each dots.
    }
}

Of course the view will have to have a list of all the dots to press, as well as their positions.