如何从屏幕左端检测 android slide/swipe 菜单事件?

How to detect android slide/swipe menu event from the left end of screen?

我没有滑块 menu/drawer,但我想使用滑块事件,在该事件中,应用程序通常会从屏幕左侧显示一个抽屉。当用户做这个手势时,我需要做一些不同的任务。

这个活动可以收听吗?如果是的话怎么办?

import android.app.Activity;
import android.util.Log;
import android.view.MotionEvent;

public class SlidableActivity extends Activity {
    protected static final String TAG = "SlidableActivity";
    private static final int ACTION_TYPE_DEFAULT = 0;
    private static final int ACTION_TYPE_UP = 1;
    private static final int ACTION_TYPE_RIGHT = 2;
    private static final int ACTION_TYPE_DOWN = 3;
    private static final int ACTION_TYPE_LEFT = 4;
    private static final int SLIDE_RANGE = 100;
    private float mTouchStartPointX;
    private float mTouchStartPointY;
    private int mActionType = ACTION_TYPE_DEFAULT;

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int x = (int) event.getRawX();
        int y = (int) event.getRawY();
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            mTouchStartPointX = event.getRawX();
            mTouchStartPointY = event.getRawY();
            break;
        case MotionEvent.ACTION_MOVE:
            if (mTouchStartPointX - x > SLIDE_RANGE) {
                mActionType = ACTION_TYPE_LEFT;
            } else if (x - mTouchStartPointX > SLIDE_RANGE) {
                mActionType = ACTION_TYPE_RIGHT;
            } else if (mTouchStartPointY - y > SLIDE_RANGE) {
                mActionType = ACTION_TYPE_UP;
            } else if (y - mTouchStartPointY > SLIDE_RANGE) {
                mActionType = ACTION_TYPE_DOWN;
            }
            break;
        case MotionEvent.ACTION_UP:
            if (mActionType == ACTION_TYPE_UP) {
                slideUp();
            } else if (mActionType == ACTION_TYPE_RIGHT) {
                slideToRight();
            } else if (mActionType == ACTION_TYPE_DOWN) {
                slideDown();
            } else if (mActionType == ACTION_TYPE_LEFT) {
                slideToLeft();
            }
            break;
        default:
            break;
        }
        return true;
    }

    protected void slideToLeft() {
        Log.d(TAG, "slideToLeft() was called.");
    }

    protected void slideToRight() {
        Log.d(TAG, "slideToRight() was called.");
    }

    protected void slideUp() {
        Log.d(TAG, "slideUp() was called.");
    }

    protected void slideDown() {
        Log.d(TAG, "slideDown() was called.");
    }
}

检查这个 link