在视图上添加多个手势，不起作用

问题描述

我正在尝试向视图添加多个手势。我已经成功地让它们分开工作，但是当我合并时，最终只有一个工作，我做错了什么？

我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,float veLocityX,float veLocityY) {
                

                return true;
            }
        }

将两者合二为一：

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));

将它们组合起来后，只有第一个手势最终起作用 (gestureDetector)。我怎样才能让两者都收听视图？

组合它们时，在 onScale 中执行 pinch 操作时永远不会调用 gestureScale 方法。但是当我不包含其他手势时，它会单独工作。

解决方法

您需要将所有手势封装在一个 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
    }
}));