android - 在 View 上添加多个手势，不起作用

Question

我正在尝试将多个手势添加到一个 View 中。我已经成功地让它们分别工作，但是当我组合时，只有一个最终工作，我做错了什么？

我要添加的第一个手势是 Scale Gesture:

public class MyScaleGestures implements View.OnTouchListener, ScaleGestureDetector.OnScaleGestureListener {
        private View view;
        private ScaleGestureDetector gestureScale;
        private float scaleFactor = 1;
        private boolean inScale = false;

        public MyScaleGestures (Context c){ gestureScale = new ScaleGestureDetector(c, this); }

        @Override
        public boolean onTouch(View view, MotionEvent event) {
            this.view = view;
            gestureScale.onTouchEvent(event);
            return true;
        }

        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            scaleFactor *= detector.getScaleFactor();
            Log.d(TAG, "onScale: " + scaleFactor);
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);
            return true;
        }

        @Override
        public boolean onScaleBegin(ScaleGestureDetector detector) {
            return true;
        }

        @Override
        public void onScaleEnd(ScaleGestureDetector detector) { inScale = false; }
    }

我的第二个手势是 SimpleOnGestureListener:

 private class FlingGestureDetector extends GestureDetector.SimpleOnGestureListener {
            @Override
            public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
                

                return true;
            }

            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                

                return true;
            }
        }

将两者合并为一类:

public class OnSwipeTouchListener implements View.OnTouchListener, ScaleGestureDetector.OnScaleGestureListener {

        private final GestureDetector gestureDetector;
        private ScaleGestureDetector gestureScale;

        private OnSwipeTouchListener(Context context) {
            gestureDetector = new GestureDetector(context, new FlingGestureDetector());
            gestureScale = new ScaleGestureDetector(context, this);
        }

        public boolean onTouch(View v, MotionEvent event) {
            gestureDetector.onTouchEvent(event);
            gestureScale.onTouchEvent(event);
            return true;
        }

        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            Log.d(TAG, "onScale: " + detector.getScaleFactor());
            return false;
        }

并使用它:

sceneView.setOnTouchListener(new OnSwipeTouchListener(this));

将它们组合后，第一个手势中只有一个最终起作用 (gestureDetector)。我怎样才能让两者都听取 View ？

将它们组合在一起时，在 gestureScale 中执行 pinch Action 时，永远不会调用 onScale 方法。但当我不包括其他手势时，它会单独工作。

Answer 1

您需要将所有手势包装在一个 OnTouchListener 类中并实现您的逻辑。

在下面的示例中，我错过了所有参数。并且您应该根据您的要求提供所有这些。

import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;

class MyGesture implements View.OnTouchListener {
    private View view;
    private MyDetector myDetector;

    private ScaleGestureDetector scaleDetector;
    private GestureDetector gestureDetector;

    public MyGesture(View view, MyDetector myDetector) {
        this.view = view;
        this.myDetector = myDetector;

        initialGestures();
    }

    private void initialGestures() {
        scaleDetector = new ScaleGestureDetector(
                view.getContext(),
                new ScaleGestureDetector.SimpleOnScaleGestureListener() {
                    @Override
                    public boolean onScale(ScaleGestureDetector detector) {
                        myDetector.onScale();
                        return true;
                    }
                });

        gestureDetector = new GestureDetector(
                view.getContext(),
                new GestureDetector.SimpleOnGestureListener() {
                    @Override
                    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                        myDetector.onFling();
                        return false;
                    }
                });
    }


    @Override
    public boolean onTouch(View v, MotionEvent event) {
        gestureDetector.onTouchEvent(event);
        scaleDetector.onTouchEvent(event);
        return true;
    }


    interface MyDetector {
        void onScale();

        void onFling();
    }
}

并使用它:

myView.setOnTouchListener(new MyGesture(myView, new MyGesture.MyDetector() {
    @Override
    public void onScale() {
        // do sth
    }

    @Override
    public void onFling() {
        // do sth
    }
}));