Android 滚动视图手势监听器

Question

我需要在用户向上滚动时隐藏错误，并在用户向下滚动时显示回来。

代码如下：

ScrollView scrollViewContainer = (ScrollView) rootView.findViewById(R.id.scrollViewContainer);
mGestureDetector = new GestureDetector(scrollViewContainer.getContext(), new OnGestureListener() {
     @Override        
    public boolean onDown(MotionEvent e) {
         System.out.println("GestureDetector --> onDown");                           
        return true;
    }

    @Override
    public void onShowPress(MotionEvent e) {
        System.out.println("GestureDetector --> onShowPress");
         // TODO Auto-generated method stub
        for (int i = 0; i < editTextList.size(); i++) {
            String error = editTextError.get(i);
            editTextList.get(i).setError(error);
        }           
    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        System.out.println("GestureDetector --> onSingleTapUp");
        for (int i = 0; i < editTextList.size(); i++) {
            //list with errors 
     String error = editTextError.get(i);
        //list with edit text   
          editTextList.get(i).setError(error);
            editTextList.get(i).setFocusableInTouchMode(true);
        }
        return false;
    }

    @Override
    public void onLongPress(MotionEvent e) {
         // TODO Auto-generated method stub
        System.out.println("GestureDetector --> onLongPressTapUp");
        for (int i = 0; i < editTextList.size(); i++) {
            String error = editTextError.get(i);
            editTextList.get(i).setError(error);
                        }
                    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        LogS.i("GestureDetector --> onFling");
         // TODO Auto-generated method stub
        for (FloatLabeledEditText floatLabeledEditText : editTextList) {
            floatLabeledEditText.setError(null);                }
        return false;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        LogS.i("GestureDetector --> onScroll");
        for (FloatLabeledEditText floatLabeledEditText : editTextList) {
            floatLabeledEditText.setError(null);
            floatLabeledEditText.setFocusableInTouchMode(false);
            }
        return false;
    }
});

mGestureListener = new View.OnTouchListener() {
    public boolean onTouch(View v, MotionEvent event) {

        if (mGestureDetector.onTouchEvent(event)) {
            return true;
        }

        if(event.getAction() == MotionEvent.ACTION_UP) {
            if(mIsScrolling ) {
                System.out.println("OnTouchListener --> onTouch ACTION_UP");
                for (FloatLabeledEditText floatLabeledEditText :    editTextList) {
                    floatLabeledEditText.setError(null);                    
                    }
                Log.d("OnTouchListener --> onTouch ACTION_UP");
                mIsScrolling  = false;
                        }
        }

        if(event.getAction() == MotionEvent.ACTION_DOWN) {
            if(mIsScrolling ) {
                System.out.println("OnTouchListener --> onTouch ACTION_Down");
                for (FloatLabeledEditText floatLabeledEditText : editTextList) {
                floatLabeledEditText.setError(null);    
                    }
                mIsScrolling  = false;

            }
        }

        return false;
    }
};

scrollViewContainer.setOnTouchListener(mGestureListener);

Answer 1

activity_scroll_layout.xml

  <?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/scrv"
    android:layout_width="match_parent"
    android:layout_height="fill_parent"
    android:fillViewport="true"
    android:scrollbars="none" >
 
    <LinearLayout
        android:id="@+id/container2"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:background="#1E1E1E"
        android:baselineAligned="false"
        android:orientation="vertical" >
 
        <LinearLayout
            android:id="@+id/top"
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:background="@android:color/black"
            android:baselineAligned="false"
            android:orientation="vertical" >
        </LinearLayout>
 
        <LinearLayout
            android:id="@+id/middle"
            android:layout_width="match_parent"
            android:layout_height="100dp"
            android:background="@android:color/white"
            android:baselineAligned="false"
            android:orientation="vertical" >
 
            <Button
                android:id="@+id/button"
                style="?android:attr/buttonStyleSmall"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Button" />
        </LinearLayout>
 
        <LinearLayout
            android:id="@+id/bottom"
            android:layout_width="match_parent"
            android:layout_height="200dp"
            android:background="@android:color/darker_gray"
            android:baselineAligned="false"
            android:orientation="vertical" >
        </LinearLayout>
    </LinearLayout>
 
</ScrollView>

ScrollLayoutActivity

import android.os.Bundle;
import android.app.Activity;
import android.util.DisplayMetrics;
import android.util.Log;    
import android.view.GestureDetector;    
import android.view.GestureDetector.SimpleOnGestureListener;    
import android.view.MotionEvent;    
import android.widget.LinearLayout;    
import android.widget.ScrollView;    
import android.widget.Toast;  

    public class ScrollLayoutActivity extends Activity {

 private static String TAG = ScrollLayoutActivity.class.getSimpleName();

 private LinearLayout mTopLayout;
 private LinearLayout mMiddleLayout;
 private LinearLayout mBottomLayout;

 private ScrollView mScrollView;

 private boolean possitionTop;
 private boolean possitionMiddle = true;

 int mLayoutHeight;
 float mDeviceHeight;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_testlayouts);

  DisplayMetrics displayMetrics = new DisplayMetrics();
  getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);

  // final float height=displayMetrics.heightPixels/displayMetrics.xdpi;

  // device height in pixels
  mDeviceHeight = displayMetrics.heightPixels;
  mLayoutHeight = (int) mDeviceHeight / 3;

  mScrollView = (ScrollView) findViewById(R.id.scrv);

  mTopLayout = (LinearLayout) findViewById(R.id.top);
  mMiddleLayout = (LinearLayout) findViewById(R.id.middle);
  mBottomLayout = (LinearLayout) findViewById(R.id.bottom);

  mTopLayout.setLayoutParams(new LinearLayout.LayoutParams(mTopLayout
    .getLayoutParams().width, mLayoutHeight));
  mBottomLayout.setLayoutParams(new LinearLayout.LayoutParams(
    mBottomLayout.getLayoutParams().width, mLayoutHeight));
  mMiddleLayout.setLayoutParams(new LinearLayout.LayoutParams(
    mMiddleLayout.getLayoutParams().width, (int) mDeviceHeight));

  mScrollView.setHorizontalFadingEdgeEnabled(false);
  mScrollView.setVerticalFadingEdgeEnabled(false);
  mScrollView.post(new Runnable() {
   public void run() {
    mScrollView.scrollTo(0, mLayoutHeight);
   }
  });

  // findViewById(R.id.button).setOnClickListener(new
  // View.OnClickListener() {
  //
  // @Override
  // public void onClick(View v) {
  // Toast.makeText(ScrollLayoutActivity.this, "height : " +
  // mDeviceHeight, Toast.LENGTH_SHORT).show();
  // }
  // });

  Toast.makeText(this, "Device Height : " + mDeviceHeight,
    Toast.LENGTH_SHORT).show();

 }

 public boolean dispatchTouchEvent(MotionEvent ev) {
  return mGestureDetector.onTouchEvent(ev);
 }

 SimpleOnGestureListener simpleOnGestureListener = new SimpleOnGestureListener() {
  @Override
  public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
    float velocityY) {
   String swipe = "";
   float sensitvity = 100;

   if ((e1.getX() - e2.getX()) > sensitvity) {
    swipe += "Swipe Left\n";
   } else if ((e2.getX() - e1.getX()) > sensitvity) {
    swipe += "Swipe Right\n";
   } else {
    swipe += "\n";
   }

   if ((e1.getY() - e2.getY()) > sensitvity) {
    swipe += "Swipe Up\n";
    if (!possitionMiddle && possitionTop) {
     mScrollView.scrollBy(0, mLayoutHeight);
     possitionTop = false;
     possitionMiddle = true;
    } else if (possitionMiddle && !possitionTop) {
     mScrollView.fullScroll(ScrollView.FOCUS_DOWN);
     possitionTop = false;
     possitionMiddle = false;
    }
   } else if ((e2.getY() - e1.getY()) > sensitvity) {
    swipe += "Swipe Down\n";
    if (possitionMiddle && !possitionTop) {
     mScrollView.fullScroll(ScrollView.FOCUS_UP);
     possitionTop = true;
     possitionMiddle = false;
    }
    if (!possitionMiddle && !possitionTop) {
     mScrollView
       .scrollTo(mScrollView.getBottom(), mLayoutHeight);
     possitionTop = false;
     possitionMiddle = true;
    }
   } else {
    swipe += "\n";
   }
   Log.d(TAG, swipe);
   return super.onFling(e1, e2, velocityX, velocityY);
  }

 };

 GestureDetector mGestureDetector = new GestureDetector(
   simpleOnGestureListener);
}

Answer 2

您可以检查某个视图是否可见，然后显示/隐藏错误。 这就是你要找的吗？