我想让飞的手势检测工作在我的Android应用程序。

我有一个GridLayout,包含9个ImageViews。来源可以在这里找到:罗曼家伙的网格布局。

我从Romain Guy的Photostream应用程序中获取的文件只做了轻微的修改。

对于简单的点击情况,我只需要为每个ImageView设置onClickListener,我添加为实现View.OnClickListener的主要活动。实现能够识别投掷的东西似乎要复杂得多。我猜这是因为它可能跨越不同的观点?

If my activity implements OnGestureListener I don't know how to set that as the gesture listener for the Grid or the Image views that I add. public class SelectFilterActivity extends Activity implements View.OnClickListener, OnGestureListener { ... If my activity implements OnTouchListener then I have no onFling method to override (it has two events as parameters allowing me to determine if the fling was noteworthy). public class SelectFilterActivity extends Activity implements View.OnClickListener, OnTouchListener { ... If I make a custom View, like GestureImageView that extends ImageView I don't know how to tell the activity that a fling has occurred from the view. In any case, I tried this and the methods weren't called when I touched the screen.

我真的需要一个跨视图工作的具体例子。我应该在什么时候以及如何附加这个侦听器?我还需要能够检测单个点击。

// Gesture detection
mGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {

    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        int dx = (int) (e2.getX() - e1.getX());
        // don't accept the fling if it's too short
        // as it may conflict with a button push
        if (Math.abs(dx) > MAJOR_MOVE && Math.abs(velocityX) > Math.absvelocityY)) {
            if (velocityX > 0) {
                moveRight();
            } else {
                moveLeft();
            }
            return true;
        } else {
            return false;
        }
    }
});

是否有可能在我的屏幕上方放置一个透明的视图来捕捉投掷?

如果我选择不从XML膨胀我的子图像视图,我可以通过手势检测器作为构造函数参数到我创建的ImageView的新子类吗?

这是一个非常简单的活动,我试图让飞动检测工作:SelectFilterActivity(改编自photostream)。

我一直在看这些资料:

检测手势-教程 SDK文档 计算器的代码

到目前为止,什么都没用,我希望能得到一些指导。


当前回答

上面的一个答案提到了处理不同的像素密度,但建议手动计算滑动参数。值得注意的是,你可以使用ViewConfiguration类从系统中获得合理的缩放值:

final ViewConfiguration vc = ViewConfiguration.get(getContext());
final int swipeMinDistance = vc.getScaledPagingTouchSlop();
final int swipeThresholdVelocity = vc.getScaledMinimumFlingVelocity();
final int swipeMaxOffPath = vc.getScaledTouchSlop();
// (there is also vc.getScaledMaximumFlingVelocity() one could check against)

我注意到,使用这些值可以使应用程序和系统其他部分之间的“感觉”更加一致。

其他回答

感谢幕府将军,他的代码我适应了我的情况。

让你的活动像往常一样实现onclicklistener:

public class SelectFilterActivity extends Activity implements OnClickListener {

  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;
  private GestureDetector gestureDetector;
  View.OnTouchListener gestureListener;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    /* ... */

    // Gesture detection
    gestureDetector = new GestureDetector(this, new MyGestureDetector());
    gestureListener = new View.OnTouchListener() {
      public boolean onTouch(View v, MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
      }
    };

  }

  class MyGestureDetector extends SimpleOnGestureListener {
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
      try {
        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) {
          Toast.makeText(SelectFilterActivity.this, "Left Swipe", Toast.LENGTH_SHORT).show();
        } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
          Toast.makeText(SelectFilterActivity.this, "Right Swipe", Toast.LENGTH_SHORT).show();
        }
      } catch (Exception e) {
         // nothing
      }
      return false;
    }

    @Override
    public boolean onDown(MotionEvent e) {
      return true;
    }
  }
}

将你的手势监听器附加到你添加到主布局中的所有视图上;

// Do this for each view added to the grid
imageView.setOnClickListener(SelectFilterActivity.this); 
imageView.setOnTouchListener(gestureListener);

敬畏地看着你被覆盖的方法被击中,包括activity的onClick(View v)和手势监听器的onFling。

public void onClick(View v) {
  Filter f = (Filter) v.getTag();
  FilterFullscreenActivity.show(this, input, f);
}

“抛舞”后的舞蹈是可选的,但也是鼓励的。

我稍微修改和修复了Thomas Fankhauser的解决方案

整个系统由两个文件组成,SwipeInterface和ActivitySwipeDetector


SwipeInterface.java

import android.view.View;

public interface SwipeInterface {

    public void bottom2top(View v);

    public void left2right(View v);

    public void right2left(View v);

    public void top2bottom(View v);

}

探测器

import android.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class ActivitySwipeDetector implements View.OnTouchListener {

    static final String logTag = "ActivitySwipeDetector";
    private SwipeInterface activity;
    static final int MIN_DISTANCE = 100;
    private float downX, downY, upX, upY;

    public ActivitySwipeDetector(SwipeInterface activity){
        this.activity = activity;
    }

    public void onRightToLeftSwipe(View v){
        Log.i(logTag, "RightToLeftSwipe!");
        activity.right2left(v);
    }

    public void onLeftToRightSwipe(View v){
        Log.i(logTag, "LeftToRightSwipe!");
        activity.left2right(v);
    }

    public void onTopToBottomSwipe(View v){
        Log.i(logTag, "onTopToBottomSwipe!");
        activity.top2bottom(v);
    }

    public void onBottomToTopSwipe(View v){
        Log.i(logTag, "onBottomToTopSwipe!");
        activity.bottom2top(v);
    }

    public boolean onTouch(View v, MotionEvent event) {
        switch(event.getAction()){
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

            // swipe horizontal?
            if(Math.abs(deltaX) > MIN_DISTANCE){
                // left or right
                if(deltaX < 0) { this.onLeftToRightSwipe(v); return true; }
                if(deltaX > 0) { this.onRightToLeftSwipe(v); return true; }
            }
            else {
                Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
            }

            // swipe vertical?
            if(Math.abs(deltaY) > MIN_DISTANCE){
                // top or down
                if(deltaY < 0) { this.onTopToBottomSwipe(v); return true; }
                if(deltaY > 0) { this.onBottomToTopSwipe(v); return true; }
            }
            else {
                Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                v.performClick();
            }
        }
        }
        return false;
    }

}

它是这样使用的:

ActivitySwipeDetector swipe = new ActivitySwipeDetector(this);
LinearLayout swipe_layout = (LinearLayout) findViewById(R.id.swipe_layout);
swipe_layout.setOnTouchListener(swipe);

在实现Activity时,你需要实现来自SwipeInterface的方法,你可以找到在哪个视图上调用了Swipe事件。

@Override
public void left2right(View v) {
    switch(v.getId()){
        case R.id.swipe_layout:
            // do your stuff here
        break;
    }       
}

在web(和本页)上有一些主张使用ViewConfiguration.getScaledTouchSlop()为SWIPE_MIN_DISTANCE设置一个设备缩放值。

getScaledTouchSlop()用于“滚动阈值”距离,而不是滑动距离。滚动阈值距离必须小于“页面之间的摆动”阈值距离。例如,这个函数在我的三星GS2上返回12个像素,而本页引用的示例大约是100个像素。

与API级别8 (Android 2.2, Froyo),你有getScaledPagingTouchSlop(),用于页面滑动。 在我的设备上,它返回24(像素)。所以如果你的API级别< 8,我认为“2 * getScaledTouchSlop()”应该是“标准”的滑动阈值。 但是我的小屏幕应用程序的用户告诉我,它太少了……在我的应用程序中,你可以垂直滚动,水平切换页面。有了建议的值,他们有时会改变页面,而不是滚动。

我知道现在回答已经太晚了,但我仍然在发布ListView的滑动检测,如何在ListView项目中使用滑动触摸侦听器。

参考:Exterminator13(本页答案之一)

创建一个ActivitySwipeDetector.class

package com.example.wocketapp;

import android.content.Context;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;

public class ActivitySwipeDetector implements View.OnTouchListener 
{
    static final String logTag = "SwipeDetector";
    private SwipeInterface activity;
    private float downX, downY;
    private long timeDown;
    private final float MIN_DISTANCE;
    private final int VELOCITY;
    private final float MAX_OFF_PATH;

    public ActivitySwipeDetector(Context context, SwipeInterface activity)
    {
        this.activity = activity;
        final ViewConfiguration vc = ViewConfiguration.get(context);
        DisplayMetrics dm = context.getResources().getDisplayMetrics();
        MIN_DISTANCE = vc.getScaledPagingTouchSlop() * dm.density;
        VELOCITY = vc.getScaledMinimumFlingVelocity();
        MAX_OFF_PATH = MIN_DISTANCE * 2;
    }

    public void onRightToLeftSwipe(View v) 
    {
        Log.i(logTag, "RightToLeftSwipe!");
        activity.onRightToLeft(v);
    }

    public void onLeftToRightSwipe(View v) 
    {
        Log.i(logTag, "LeftToRightSwipe!");
        activity.onLeftToRight(v);
    }

    public boolean onTouch(View v, MotionEvent event) 
    {
        switch (event.getAction()) 
        {
            case MotionEvent.ACTION_DOWN:
            {
                Log.d("onTouch", "ACTION_DOWN");
                timeDown = System.currentTimeMillis();
                downX = event.getX();
                downY = event.getY();
                v.getParent().requestDisallowInterceptTouchEvent(false);
                return true;
            }

        case MotionEvent.ACTION_MOVE:
            {
                float y_up = event.getY();
                float deltaY = y_up - downY;
                float absDeltaYMove = Math.abs(deltaY);

                if (absDeltaYMove > 60) 
                {
                    v.getParent().requestDisallowInterceptTouchEvent(false);
                } 
                else
                {
                    v.getParent().requestDisallowInterceptTouchEvent(true);
                }
            }

            break;

            case MotionEvent.ACTION_UP: 
            {
                Log.d("onTouch", "ACTION_UP");
                long timeUp = System.currentTimeMillis();
                float upX = event.getX();
                float upY = event.getY();

                float deltaX = downX - upX;
                float absDeltaX = Math.abs(deltaX);
                float deltaY = downY - upY;
                float absDeltaY = Math.abs(deltaY);

                long time = timeUp - timeDown;

                if (absDeltaY > MAX_OFF_PATH) 
                {
                    Log.e(logTag, String.format(
                            "absDeltaY=%.2f, MAX_OFF_PATH=%.2f", absDeltaY,
                            MAX_OFF_PATH));
                    return v.performClick();
                }

                final long M_SEC = 1000;
                if (absDeltaX > MIN_DISTANCE && absDeltaX > time * VELOCITY / M_SEC) 
                {
                     v.getParent().requestDisallowInterceptTouchEvent(true);
                    if (deltaX < 0) 
                    {
                        this.onLeftToRightSwipe(v);
                        return true;
                    }
                    if (deltaX > 0) 
                    {
                        this.onRightToLeftSwipe(v);
                        return true;
                    }
                }
                else 
                {
                    Log.i(logTag,
                            String.format(
                                    "absDeltaX=%.2f, MIN_DISTANCE=%.2f, absDeltaX > MIN_DISTANCE=%b",
                                    absDeltaX, MIN_DISTANCE,
                                    (absDeltaX > MIN_DISTANCE)));
                    Log.i(logTag,
                            String.format(
                                    "absDeltaX=%.2f, time=%d, VELOCITY=%d, time*VELOCITY/M_SEC=%d, absDeltaX > time * VELOCITY / M_SEC=%b",
                                    absDeltaX, time, VELOCITY, time * VELOCITY
                                            / M_SEC, (absDeltaX > time * VELOCITY
                                            / M_SEC)));
                }

                 v.getParent().requestDisallowInterceptTouchEvent(false);

            }
        }
        return false;
    }
    public interface SwipeInterface 
    {

        public void onLeftToRight(View v);

        public void onRightToLeft(View v);
    }

}

从你的activity类中调用它,就像这样:

yourLayout.setOnTouchListener(new ActivitySwipeDetector(this, your_activity.this));

别忘了实现SwipeInterface,它会给你两个@override方法:

    @Override
    public void onLeftToRight(View v) 
    {
        Log.e("TAG", "L to R");
    }

    @Override
    public void onRightToLeft(View v) 
    {
        Log.e("TAG", "R to L");
    }

上面的滑动手势检测代码非常有用!但是,您可能希望通过使用以下相对值(REL_SWIPE)而不是绝对值(SWIPE_)来使该解决方案密度不可知。

DisplayMetrics dm = getResources().getDisplayMetrics();

int REL_SWIPE_MIN_DISTANCE = (int)(SWIPE_MIN_DISTANCE * dm.densityDpi / 160.0f);
int REL_SWIPE_MAX_OFF_PATH = (int)(SWIPE_MAX_OFF_PATH * dm.densityDpi / 160.0f);
int REL_SWIPE_THRESHOLD_VELOCITY = (int)(SWIPE_THRESHOLD_VELOCITY * dm.densityDpi / 160.0f);