Android - Hijack clicks [closed]

Question

In one of my projects i want to collect something like a click heatmap. Is there any way to do this in Android?

I was thinking about adding a transparent layout above the original layout and "hijack" clicks there and then pass it to the underlying layout. But I can't figure it out.

So, any ideas on how to do this?

Answer 1

i just found the solution myself. It lies in the onInterceptTouchEvent() function. You can override it to intercept all touch events before being handed over to the child views. So i created a layout extending FrameLayout. Surrounded my layout with this layout and thats it :)

Answer 2

Do you just want to capture how many times a specific view is clicked? Or are you wanting the precise pixel coordinates of the touch? If the former, you could just override the onTouchListener for each of them, and increment a counter for that view.

For the latter, I played around a bit with an onTouchListener, and was able to get it to work, but you'll probably have to set an onTouchListener to every view, which shouldn't be a big deal, but just something to keep in mind unless someone has a better way.

Vector2D.java

public class Vector2D {
    private float x;
    private float y;

    public Vector2D(float x, float y) {
        this.x = x;
        this.y = y;
    }

    public void setX(float x) {
        this.x = x;
    }

    public float getX() {
        return this.x;
    }

    public void setY(float y) {
        this.y = y;
    }

    public float getY() {
        return this.y;
    }
}

Main.java

public class Main extends Activity implements OnTouchListener {
    /** Called when the activity is first created. 
     * @return */

    //defined as class variable so it's accessible from onTouch()
    List<Vector2D> points;

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        //adds a new coordinate to the list, 
        //with the X and Y values of the touch
        points.add(new Vector2D(event.getX(), event.getY()));
        Log.d("TOUCH", "X:" + event.getX() + " Y:" + event.getY());
        return true;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test);     

        points = new ArrayList<Vector2D>();       
        final LinearLayout ll = (LinearLayout)findViewById(R.id.linearlayout);
        final TextView pointsList = (TextView)findViewById(R.id.points_list);
        ll.setOnTouchListener(this);
        final Button listPoints = (Button)findViewById(R.id.list_points);
        listPoints.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                StringBuilder sb = new StringBuilder();
                for (Vector2D vector : points) {
                    sb.append(
                        "X:" +vector.getX() + " " + 
                        "Y:" + vector.getY() + "\n");
                }
                pointsList.setText(sb.toString());
            }
        });
    }
}