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。
Thomas Fankhauser和Marek Sebera提出的我的解决方案版本(不处理垂直滑动):
SwipeInterface.java
import android.view.View;
public interface SwipeInterface {
public void onLeftToRight(View v);
public void onRightToLeft(View v);
}
ActivitySwipeDetector.java
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 = "ActivitySwipeDetector";
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();
return true;
}
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.i(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) {
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)));
}
}
}
return false;
}
}
