Identify triple tap on custom view

Question

I want to draw circle, whenever user taps on a custom view, and based on tap count circle color changes.

Single Tap : YELLOW CIRCLE
Double Tap : GREEN CIRCLE
Tri         


        

Answer 1

This code will do what you need. I simplified your class.

import java.util.ArrayList;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.graphics.RectF;
import android.os.CountDownTimer;
import android.view.MotionEvent;
import android.view.View;

public class TripleTapView extends View {

    // Set the tap delay in milliseconds
    protected static final long TAP_MAX_DELAY = 500L;
    // Radius to capture tap within bound
    private final static int RADIUS = 30;
    // Store all points with tap count
    public ArrayList<CustomPoint> _points = new ArrayList<CustomPoint>();

    Context _context;
    Paint _paint;

    TapCounter _tapCounter = new TapCounter(TAP_MAX_DELAY, TAP_MAX_DELAY);

    public TripleTapView(Context context) {
        super(context);
        _context = context;

        _paint = new Paint();
        _paint.setAntiAlias(true);
        _paint.setDither(true);
        _paint.setStyle(Paint.Style.FILL);
        _paint.setStrokeJoin(Paint.Join.ROUND);
        _paint.setStrokeCap(Paint.Cap.ROUND);
        _paint.setStrokeWidth(2);
    }

    @Override
    protected void onDraw(final Canvas canvas) {
        super.onDraw(canvas);
        for (CustomPoint point_temp : _points) {
            // For changing tap circle color based on tap count
            switch (point_temp.count) {
            case 1:
                _paint.setColor(Color.YELLOW);
                break;
            case 2:
                _paint.setColor(Color.GREEN);
                break;
            case 3:
                _paint.setColor(Color.RED);
                break;
            }
            canvas.drawCircle(point_temp.point.x, point_temp.point.y, 10,
                    _paint);
        }
    }

    private RectF _lastTapArea;
    private int _lastTapCount = 0;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            _tapCounter.resetCounter();
            float x = event.getX();
            float y = event.getY();

            if (_lastTapArea != null) {
                if (_lastTapArea.contains(x, y)) {
                    if (_lastTapCount < 3) {
                        _lastTapCount++;
                    } else {
                        addPoint(_lastTapArea.centerX(),
                                _lastTapArea.centerY(), _lastTapCount);
                        _lastTapCount = 1;
                    }
                } else {
                    addPoint(_lastTapArea.centerX(), _lastTapArea.centerY(),
                            _lastTapCount);
                    _lastTapCount = 1;
                    _lastTapArea = new RectF(x - RADIUS, y - RADIUS,
                            x + RADIUS, y + RADIUS);
                }
            } else {
                _lastTapCount = 1;
                _lastTapArea = new RectF(x - RADIUS, y - RADIUS, x + RADIUS, y
                        + RADIUS);
            }

            return true;
        }

        return false;
    }

    void addPoint(float x, float y, int tapCount) {
        _points.add(new CustomPoint(new PointF(x, y), tapCount));
        invalidate();
    }

    class TapCounter extends CountDownTimer {

        public TapCounter(long millisInFuture, long countDownInterval) {
            super(millisInFuture, countDownInterval);
        }

        @Override
        public void onFinish() {
            if (_lastTapArea != null) {
                if (_lastTapCount > 0)
                    addPoint(_lastTapArea.centerX(), _lastTapArea.centerY(),
                            _lastTapCount);

                _lastTapCount = 0;
                _lastTapArea = null;
            }
        }

        @Override
        public void onTick(long millisUntilFinished) {
        }

        public void resetCounter() {
            start();
        }
    }
}