HexagonView

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.View;


public class HexagonView extends View {
    static final float SQRT3 = (float) Math.sqrt(3);
    static final int TILES_NEEDED = 4;
    float r = 100;

    Path hexagon;
    Paint[] paints;

    public HexagonView(Context context) {
        super(context);
        init();
    }

    public HexagonView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public HexagonView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    public void init() {
        hexagon = new Path();
        double step = (2 * Math.PI) / 6; // Tau / 6 = 60°
        double angle;
        for (int i = 0; i < 6; i++) {
            angle = step * i;
            if (hexagon.isEmpty()) {
                hexagon.moveTo((float) (r * Math.cos(angle)), (float) (r * Math.sin(angle)));
            } else {
                hexagon.lineTo((float) (r * Math.cos(angle)), (float) (r * Math.sin(angle)));
            }
        }
        paints = new Paint[TILES_NEEDED];
        for (int i = 0, s = paints.length; i < s; i++) {
            paints[i] = new Paint();
            paints[i].setAntiAlias(true);
            paints[i].setColor(getColor(i));
        }
    }

    public int getColor(int i) {
        switch (i) {
            case 0:
                return Color.BLUE;
            case 1:
                return Color.GREEN;
            case 2:
                return Color.RED;
            case 3:
                return Color.CYAN;
        }
        return Color.BLACK;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        float xshift = 3 * r;
        float yshift = 2 * SQRT3 * r;
        for (int p = 0; p < TILES_NEEDED; p++) {
            float ry = -yshift * p / 4f;
            ry -= yshift;
            do {
                ry += yshift;
                float rx = -xshift * p / 2f;
                rx -= xshift;
                do {
                    rx += xshift;
                    canvas.save();
                    canvas.translate(rx, ry);
                    canvas.drawPath(hexagon, paints[p]);
                    canvas.restore();

                } while (rx <= canvas.getWidth());
            } while (ry <= canvas.getHeight());
        }
    }
}