与Android的边框手势

Question

我正在开发一个应用程序(在Galaxy Nexus上),我注意到当你从屏幕底部滑动到屏幕上时谷歌实施了"Google Now"应用程序(Chrome浏览器也做了一段时间,而不是确定它是否仍然存在).我一直在环顾四周,但一直无法确定他们是如何做到这一点的.有没有一种简单的方法来处理从挡板而不是屏幕开始的手势？

我检查了开发人员页面以供参考,但我能找到的唯一文章是:

http://developer.android.com/design/patterns/gestures.html

有没有其他地方可以获得这些信息？

[编辑]

我一直在尝试基于Lain_B的方法获得边缘手势非常失败,但无法使其工作.这是我用来尝试检测手势的代码,但是logcat总是输出零...

public class MainActivity extends Activity implements OnGestureListener {

private GestureDetector myGesture;

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

    myGesture = new GestureDetector(getBaseContext(),
            (OnGestureListener) this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    Log.e("Flags Touch", "Flags: " + event.getEdgeFlags());
    return myGesture.onTouchEvent(event);
}

@Override
public boolean onDown(MotionEvent e) {
    Log.e("Flags", "Flags: " + e.getEdgeFlags());
    Log.e("Event", "onDown");
    // TODO Auto-generated method stub
    return false;
}

@Override
public void onLongPress(MotionEvent e) {
    Log.e("Event", "onLongPress");
    // TODO Auto-generated method stub

}

@Override
public void onShowPress(MotionEvent e) {
    Log.e("Flags", "Flags: " + e.getEdgeFlags());
    Log.e("Event", "onShowPress");
    // TODO Auto-generated method stub

}

@Override
public boolean onSingleTapUp(MotionEvent e) {
    Log.e("Event", "onSingleTapUp");
    // TODO Auto-generated method stub
    return false;
}

@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
        float distanceY) {
    // Log.e("Event", "onScroll");
    return false;
}

// these constants are used for onFling
private static final int SWIPE_MIN_DISTANCE = 120;
private static final int SWIPE_MAX_OFF_PATH = 250;
private static final int SWIPE_THRESHOLD_VELOCITY = 200;

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

    Log.e("Event", "onFling");
    Log.e("Flags", "Flags: " + e1.getEdgeFlags());

    if (e1.getEdgeFlags() == MotionEvent.EDGE_LEFT) {
        // code to handle swipe from left edge
        Log.e("!!!!!", "Edge fling!");
    }

    try {
        // do not do anything if the swipe does not reach a certain length
        // of distance
        if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
            return false;

        // right to left swipe
        if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
                && Math.abs(velocityX) < SWIPE_THRESHOLD_VELOCITY) {

        }
        // left to right swipe
        else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                && Math.abs(velocityX) < SWIPE_THRESHOLD_VELOCITY) {

        }
    } catch (Exception e) {
        // nothing
    }
    return false;

}
}

[编辑2]

使用Lain_B的请求输出...

(使用Nexus 7)...从挡板上最远的左侧点开始,向右滑动到中间(ish).

08-16 16:44:13.674: I/Fling(16702): Flags: 0
08-16 16:44:13.674: I/Fling(16702): e1: 2.5 711.5152
08-16 16:44:13.674: I/Fling(16702): e2: 215.4591 717.08105

从屏幕中心点滑动,离开屏幕(向右侧)

08-16 16:46:37.364: I/Fling(16702): Flags: 0
08-16 16:46:37.364: I/Fling(16702): e1: 392.5 758.1818
08-16 16:46:37.364: I/Fling(16702): e2: 783.4375 743.3334

Answer 1

我认为MotionEvent.getEdgeFlags()正是你要找的.然后,您可以将返回的值与EDGE_LEFT,EDGE_RIGHT等进行比较,以查看触摸的边缘.

if( event1.getEdgeFlags()&MotionEvent.EDGE_LEFT != 0 ){
    //code to handle swipe from left edge
}

要么

if( e1.getX() < 5.0f ){
    //handle swipe from left edge
}

Answer 2

依赖MotionEvent.getEdgeFlags是错误的.有关详细信息,请参阅此讨论:https://groups.google.com/forum/？fromgroups =#!topic/android- Developers/ZNjpzbkxeNM

从概念上讲,要检测边缘滑动,您需要检测拖动/滚动事件,并确保向下事件的原始"x"坐标距边缘一定距离.

最简单的方法是使用GestureDetector来检测拖动/滚动.幸运的是,SimpleOnGestureListener的onScroll方法拥有您需要的一切.

这样的事情(如果你使用的是配置了SimpleOnGestureListener的GestureDetector):

 public boolean onScroll (MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {

        if (e1.getX() < SOME_DISTANCE_FROM_SCREEN) {
           //your code  
           return true;
        }
        return false;
 }