Android programming ListView head ViewPager AD polling graph effect

This article describes the Android programming ListView head ViewPager advertising polling graph effect. To share for your reference, the details are as follows:

I looked at some software of others before and found that the advertising graph was not quite the same as that of ViewPager when I polled it. Later, I also checked 1. Because of the time problem, I found some materials and practiced 1 myself.

1. In order to solve the ListView header plus ViewPager sliding conflict problem, we must customize ListView and rewrite the onInterceptTouchEvent method. The ListView code is as follows:

package com.example.testa; 
import android.content.Context; 
import android.util.AttributeSet; 
import android.view.MotionEvent; 
import android.widget.ListView; 
public class DefinedListView extends ListView { 
 public DefinedListView(Context context) { 
  super(context); 
 } 
 public DefinedListView(Context context, AttributeSet attrs) { 
  super(context, attrs); 
 } 
 public DefinedListView(Context context, AttributeSet attrs, int defStyle) {
  super(context, attrs, defStyle); 
 } 
 private float xDistance, yDistance, xLast, yLast; 
 @Override 
 public boolean onInterceptTouchEvent(MotionEvent ev) { 
  switch (ev.getAction()) { 
   case MotionEvent.ACTION_DOWN: 
    xDistance = yDistance = 0f; 
    xLast = ev.getX(); 
    yLast = ev.getY(); 
    break; 
   case MotionEvent.ACTION_MOVE: 
    final float curX = ev.getX(); 
    final float curY = ev.getY(); 
    xDistance += Math.abs(curX - xLast); 
    yDistance += Math.abs(curY - yLast); 
    xLast = curX; 
    yLast = curY; 
    if (xDistance > yDistance) { 
     return false; 
    } 
  } 
  return super.onInterceptTouchEvent(ev); 
 } 
}

2. In order to slow down the speed of advertising polling, we must reset the Scroller of ViewPager. The customized Scroller is as follows:

package com.example.testa; 
import java.lang.reflect.Field; 
import android.annotation.SuppressLint; 
import android.content.Context; 
import android.os.Handler; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.view.ViewPager; 
import android.view.LayoutInflater; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.View.OnTouchListener; 
import android.view.animation.Interpolator; 
import android.widget.Scroller; 
public class DefinedScroller extends Scroller { 
 private int DURATION_TIME = 1000; 
 private boolean shouldAutoScroll = true; 
 private ViewPager viewPager = null; 
 @SuppressLint("HandlerLeak") 
 private final Handler handler = new Handler() { 
  public void handleMessage(android.os.Message msg) { 
   if (shouldAutoScroll) { 
    viewPager.setCurrentItem(viewPager.getCurrentItem() + 1); 
    handler.sendEmptyMessageDelayed(0, 2000); 
   } 
  }; 
 }; 
 public DefinedScroller(Context context) { 
  super(context); 
 } 
 public DefinedScroller(Context context, Interpolator interpolator) { 
  super(context, interpolator); 
 } 
 private View initViewPager(Context context) { 
  View view = LayoutInflater.from(context).inflate(R.layout.view_pager_layout, null);
  this.viewPager = (ViewPager) view.findViewById(R.id.viewpager);
  this.viewPager.setOffscreenPageLimit(2); 
  this.viewPager.setAdapter(new MyFragmentPagerAdapter(((FragmentActivity) context).getSupportFragmentManager())); 
  return view; 
 } 
 public ViewPager getViewPager() { 
  return viewPager; 
 } 
 public View initView(Context context) { 
  View view = initViewPager(context); 
  this.viewPager.setOnTouchListener(new OnTouchListener() { 
   @Override 
   public boolean onTouch(View v, MotionEvent event) { 
    if (event.getAction() == MotionEvent.ACTION_UP) { 
     shouldAutoScroll = true; 
     handler.sendEmptyMessageDelayed(0, 2000); 
    } else { 
     handler.removeMessages(0); 
     shouldAutoScroll = false; 
    } 
    return false; 
   } 
  }); 
  try { 
   Field mScroller = ViewPager.class.getDeclaredField("mScroller"); 
   mScroller.setAccessible(true); 
   mScroller.set(viewPager, this); 
  } catch (NoSuchFieldException e) { 
  } catch (IllegalArgumentException e) { 
  } catch (IllegalAccessException e) { 
  } 
  handler.sendEmptyMessageDelayed(0, 2000); 
  return view; 
 } 
 public void setShouldAutoScroll() { 
  handler.removeMessages(0); 
  if (viewPager.isShown()) { 
   shouldAutoScroll = true; 
   handler.sendEmptyMessageDelayed(0, 2000); 
  } else { 
   shouldAutoScroll = false; 
  } 
 } 
 @Override 
 public void startScroll(int startX, int startY, int dx, int dy, int duration) { 
  super.startScroll(startX, startY, dx, dy, shouldAutoScroll ? DURATION_TIME : duration); 
 } 
}

The key is the startScroll method

3. Other test classes,

(1) TestFragment:

package com.example.testa; 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
public class TestFragment extends Fragment { 
 public int imageResource = 0; 
 public static TestFragment newInstance(int imageResource) { 
  TestFragment newFragment = new TestFragment(); 
  newFragment.imageResource = imageResource; 
  return newFragment; 
 } 
 @Override 
 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
  View view = inflater.inflate(R.layout.pager_layout, null); 
  ImageView textView = (ImageView) view.findViewById(R.id.image); 
  textView.setImageResource(imageResource); 
  return view; 
 } 
}

(2) Adapter class of ViewPager:

package com.example.testa; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentStatePagerAdapter; 
public class MyFragmentPagerAdapter extends FragmentStatePagerAdapter { 
 public MyFragmentPagerAdapter(FragmentManager fm) { 
  super(fm); 
 } 
 @Override 
 public int getCount() { 
  return Integer.MAX_VALUE; 
 } 
 @Override 
 public Fragment getItem(int arg0) { 
  switch (arg0 % 4) { 
   case 0: 
    return TestFragment.newInstance(R.drawable.a1); 
   case 1: 
    return TestFragment.newInstance(R.drawable.default_wh); 
   case 2: 
    return TestFragment.newInstance(R.drawable.default_ww); 
   case 3: 
    return TestFragment.newInstance(R.drawable.test); 
   default: 
    return TestFragment.newInstance(R.drawable.a1); 
  } 
 } 
}

(3) Activity for testing:

package com.example.testa; 
import java.util.ArrayList; 
import java.util.List; 
import android.os.Bundle; 
import android.support.v4.app.FragmentActivity; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AbsListView; 
import android.widget.AbsListView.OnScrollListener; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.BaseAdapter; 
import android.widget.TextView; 
public class MainActivity extends FragmentActivity { 
 private DefinedListView listView = null; 
 private List<String> list = null; 
 private DefinedScroller definedScroller = null; 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
  listView = (DefinedListView) findViewById(R.id.listview); 
  initListData(); 
  initViewPager(); 
  listView.setAdapter(new ListAdapter()); 
  listView.setOnItemClickListener(new OnItemClickListener() { 
   @Override 
   public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
    definedScroller.getViewPager().setCurrentItem(definedScroller.getViewPager().getCurrentItem() + 1); 
   } 
  }); 
  listView.setOnScrollListener(new OnScrollListener() { 
   @Override 
   public void onScrollStateChanged(AbsListView view, int scrollState) { 
    if (scrollState == SCROLL_STATE_IDLE) { 
     definedScroller.setShouldAutoScroll(); 
    } 
   } 
   @Override 
   public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { 
   } 
  }); 
 } 
 private void initListData() { 
  list = new ArrayList<String>(); 
  for (int i = 1; i <= 20; ++i) { 
   list.add("test" + i); 
  } 
 } 
 private void initViewPager() { 
  definedScroller = new DefinedScroller(this); 
  listView.addHeaderView(definedScroller.initView(this)); 
 } 
 private class ListAdapter extends BaseAdapter { 
  @Override 
  public int getCount() { 
   return list.size(); 
  } 
  @Override 
  public Object getItem(int position) { 
   return list.get(position); 
  } 
  @Override 
  public long getItemId(int position) { 
   return position; 
  } 
  @Override 
  public View getView(int position, View convertView, ViewGroup parent) {
   TextView textView = (TextView) LayoutInflater.from(MainActivity.this).inflate(R.layout.text_view_layout, 
     null); 
   textView.setPadding(20, 20, 20, 20); 
   textView.setText(list.get(position)); 
   return textView; 
  } 
 } 
}

4. Forget about layout files

Some of the above is seen in other places, for a long time, forget where to see, can not write on the source address, please forgive me.

I hope this article has been helpful for Android programming.