Android UI仿QQ好友列表分组悬浮效果

package com.xiaos.view;import android.content.Context;import android.graphics.Canvas;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.AbsListView.OnScrollListener;import android.widget.ExpandableListAdapter;import android.widget.ExpandableListView;import android.widget.ExpandableListView.OnGroupClickListener;public class PinnedHeaderExpandableListView extends ExpandableListView implements OnScrollListener,OnGroupClickListener { public PinnedHeaderExpandableListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); registerListener(); } public PinnedHeaderExpandableListView(Context context, AttributeSet attrs) { super(context, attrs); registerListener(); } public PinnedHeaderExpandableListView(Context context) { super(context); registerListener(); } /** * Adapter 接口 . 列表必须实现此接口 . */ public interface HeaderAdapter { public static final int PINNED_HEADER_GONE = 0; public static final int PINNED_HEADER_VISIBLE = 1; public static final int PINNED_HEADER_PUSHED_UP = 2;  /**  * 获取 Header 的状态  * @param groupPosition  * @param childPosition  * @return PINNED_HEADER_GONE,PINNED_HEADER_VISIBLE,PINNED_HEADER_PUSHED_UP 当中之中的一个  */ int getHeaderState(int groupPosition, int childPosition); /**  * 配置 Header, 让 Header 知道显示的内容  * @param header  * @param groupPosition  * @param childPosition  * @param alpha  */ void configureHeader(View header, int groupPosition,int childPosition, int alpha); /**  * 设置组按下的状态   * @param groupPosition  * @param status  */ void setGroupClickStatus(int groupPosition, int status); /**  * 获取组按下的状态  * @param groupPosition  * @return  */ int getGroupClickStatus(int groupPosition); } private static final int MAX_ALPHA = 255; private HeaderAdapter mAdapter; /** * 用于在列表头显示的 View,mHeaderViewVisible 为 true 才可见 */ private View mHeaderView; /** * 列表头是否可见 */ private boolean mHeaderViewVisible; private int mHeaderViewWidth; private int mHeaderViewHeight; public void setHeaderView(View view) { mHeaderView = view; AbsListView.LayoutParams lp = new AbsListView.LayoutParams( ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT); view.setLayoutParams(lp); if (mHeaderView != null) {  setFadingEdgeLength(0); } requestLayout(); } private void registerListener() { setOnScrollListener(this); setOnGroupClickListener(this); } /** * 点击 HeaderView 触发的事件 */ private void headerViewClick() { long packedPosition = getExpandableListPosition(this.getFirstVisiblePosition());  int groupPosition = ExpandableListView.getPackedPositionGroup(packedPosition);  if (mAdapter.getGroupClickStatus(groupPosition) == 1) {  this.collapseGroup(groupPosition);  mAdapter.setGroupClickStatus(groupPosition, 0); } else{  this.expandGroup(groupPosition);  mAdapter.setGroupClickStatus(groupPosition, 1); }  this.setSelectedGroup(groupPosition); } private float mDownX; private float mDownY; /** * 假设 HeaderView 是可见的 , 此函数用于推断是否点击了 HeaderView, 并对做对应的处理 , * 由于 HeaderView 是画上去的 , 所以设置事件监听是无效的 , 仅仅有自行控制 . */ @Override public boolean onTouchEvent(MotionEvent ev) { if (mHeaderViewVisible) {  switch (ev.getAction()) {  case MotionEvent.ACTION_DOWN:  mDownX = ev.getX();  mDownY = ev.getY();  if (mDownX <= mHeaderViewWidth && mDownY <= mHeaderViewHeight) {   return true;  }  break;  case MotionEvent.ACTION_UP:  float x = ev.getX();  float y = ev.getY();  float offsetX = Math.abs(x - mDownX);  float offsetY = Math.abs(y - mDownY);  // 假设 HeaderView 是可见的 , 点击在 HeaderView 内 , 那么触发 headerClick()  if (x <= mHeaderViewWidth && y <= mHeaderViewHeight  && offsetX <= mHeaderViewWidth && offsetY <= mHeaderViewHeight) {   if (mHeaderView != null) {   headerViewClick();   }   return true;  }  break;  default:  break;  } } return super.onTouchEvent(ev); } @Override public void setAdapter(ExpandableListAdapter adapter) { super.setAdapter(adapter); mAdapter = (HeaderAdapter) adapter; } /** *  * 点击了 Group 触发的事件 , 要依据依据当前点击 Group 的状态来 */ @Override public boolean onGroupClick(ExpandableListView parent,View v,int groupPosition,long id) { if (mAdapter.getGroupClickStatus(groupPosition) == 0) {  mAdapter.setGroupClickStatus(groupPosition, 1);  parent.expandGroup(groupPosition);  //Header自己主动置顶  //parent.setSelectedGroup(groupPosition);   } else if (mAdapter.getGroupClickStatus(groupPosition) == 1) {  mAdapter.setGroupClickStatus(groupPosition, 0);  parent.collapseGroup(groupPosition); } // 返回 true 才干够弹回第一行 , 不知道为什么 return true; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (mHeaderView != null) {  measureChild(mHeaderView, widthMeasureSpec, heightMeasureSpec);  mHeaderViewWidth = mHeaderView.getMeasuredWidth();  mHeaderViewHeight = mHeaderView.getMeasuredHeight(); } } private int mOldState = -1; @Override protected void onLayout(boolean changed, int left, int top, int right,int bottom) { super.onLayout(changed, left, top, right, bottom); final long flatPostion = getExpandableListPosition(getFirstVisiblePosition()); final int groupPos = ExpandableListView.getPackedPositionGroup(flatPostion); final int childPos = ExpandableListView.getPackedPositionChild(flatPostion); int state = mAdapter.getHeaderState(groupPos, childPos); if (mHeaderView != null && mAdapter != null && state != mOldState) {  mOldState = state;  mHeaderView.layout(0, 0, mHeaderViewWidth, mHeaderViewHeight); } configureHeaderView(groupPos, childPos); } public void configureHeaderView(int groupPosition, int childPosition) { if (mHeaderView == null || mAdapter == null || ((ExpandableListAdapter) mAdapter).getGroupCount() == 0) {  return; } int state = mAdapter.getHeaderState(groupPosition, childPosition); switch (state) {  case HeaderAdapter.PINNED_HEADER_GONE: {  mHeaderViewVisible = false;  break;  }   case HeaderAdapter.PINNED_HEADER_VISIBLE: {  mAdapter.configureHeader(mHeaderView, groupPosition,childPosition, MAX_ALPHA);   if (mHeaderView.getTop() != 0){   mHeaderView.layout(0, 0, mHeaderViewWidth, mHeaderViewHeight);  }   mHeaderViewVisible = true;   break;  }   case HeaderAdapter.PINNED_HEADER_PUSHED_UP: {  View firstView = getChildAt(0);  int bottom = firstView.getBottom();   // intitemHeight = firstView.getHeight();  int headerHeight = mHeaderView.getHeight();   int y;   int alpha;   if (bottom < headerHeight) {   y = (bottom - headerHeight);   alpha = MAX_ALPHA * (headerHeight + y) / headerHeight;  } else {   y = 0;   alpha = MAX_ALPHA;  }    mAdapter.configureHeader(mHeaderView, groupPosition,childPosition, alpha);   if (mHeaderView.getTop() != y) {   mHeaderView.layout(0, y, mHeaderViewWidth, mHeaderViewHeight + y);  }   mHeaderViewVisible = true;  break;  } } } @Override /** * 列表界面更新时调用该方法(如滚动时) */ protected void dispatchDraw(Canvas canvas) { super.dispatchDraw(canvas); if (mHeaderViewVisible) {  //分组栏是直接绘制到界面中。而不是增加到ViewGroup中  drawChild(canvas, mHeaderView, getDrawingTime()); } } @Override public void onScroll(AbsListView view, int firstVisibleItem,int visibleItemCount, int totalItemCount) { final long flatPos = getExpandableListPosition(firstVisibleItem); int groupPosition = ExpandableListView.getPackedPositionGroup(flatPos); int childPosition = ExpandableListView.getPackedPositionChild(flatPos);  configureHeaderView(groupPosition, childPosition); } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { }}

package com.xiaos.adapter;import android.content.Context;import android.util.SparseIntArray;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseExpandableListAdapter;import android.widget.ImageView;import android.widget.TextView;import com.xiaos.pinnedheaderexpandable.R;import com.xiaos.view.PinnedHeaderExpandableListView;import com.xiaos.view.PinnedHeaderExpandableListView.HeaderAdapter;public class PinnedHeaderExpandableAdapter extends BaseExpandableListAdapter implements HeaderAdapter{private String[][] childrenData;private String[] groupData;private Context context;private PinnedHeaderExpandableListView listView;private LayoutInflater inflater;public PinnedHeaderExpandableAdapter(String[][] childrenData,String[] groupData,Context context,PinnedHeaderExpandableListView listView){this.groupData = groupData; this.childrenData = childrenData;this.context = context;this.listView = listView;inflater = LayoutInflater.from(this.context);}@Overridepublic Object getChild(int groupPosition, int childPosition) {return childrenData[groupPosition][childPosition];}@Overridepublic long getChildId(int groupPosition, int childPosition) {return 0;}@Overridepublic View getChildView(int groupPosition, int childPosition,boolean isLastChild, View convertView, ViewGroup parent) {View view = null; if (convertView != null) { view = convertView; } else { view = createChildrenView(); } TextView text = (TextView)view.findViewById(R.id.childto);text.setText(childrenData[groupPosition][childPosition]); return view; }@Overridepublic int getChildrenCount(int groupPosition) {return childrenData[groupPosition].length;}@Overridepublic Object getGroup(int groupPosition) {return groupData[groupPosition];}@Overridepublic int getGroupCount() {return groupData.length;}@Overridepublic long getGroupId(int groupPosition) {return 0;}@Overridepublic View getGroupView(int groupPosition, boolean isExpanded,View convertView, ViewGroup parent) {View view = null; if (convertView != null) { view = convertView; } else { view = createGroupView(); }ImageView iv = (ImageView)view.findViewById(R.id.groupIcon);if (isExpanded) {iv.setImageResource(R.drawable.btn_browser2);}else{iv.setImageResource(R.drawable.btn_browser);}TextView text = (TextView)view.findViewById(R.id.groupto);text.setText(groupData[groupPosition]); return view; }@Overridepublic boolean hasStableIds() {return true;}@Overridepublic boolean isChildSelectable(int groupPosition, int childPosition) {return true;}private View createChildrenView() {return inflater.inflate(R.layout.child, null);}private View createGroupView() {return inflater.inflate(R.layout.group, null);}@Overridepublic int getHeaderState(int groupPosition, int childPosition) {final int childCount = getChildrenCount(groupPosition);if (childPosition == childCount - 1) {return PINNED_HEADER_PUSHED_UP;} else if (childPosition == -1&& !listView.isGroupExpanded(groupPosition)) {return PINNED_HEADER_GONE;} else {return PINNED_HEADER_VISIBLE;}}@Overridepublic void configureHeader(View header, int groupPosition,int childPosition, int alpha) {String groupData = this.groupData[groupPosition];((TextView) header.findViewById(R.id.groupto)).setText(groupData);}private SparseIntArray groupStatusMap = new SparseIntArray();@Overridepublic void setGroupClickStatus(int groupPosition, int status) {groupStatusMap.put(groupPosition, status);}@Overridepublic int getGroupClickStatus(int groupPosition) {if (groupStatusMap.keyAt(groupPosition)>=0) {return groupStatusMap.get(groupPosition);} else {return 0;}}}

package com.xiaos.pinnedheaderexpandable;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.ExpandableListView;import android.widget.ExpandableListView.OnGroupClickListener;import com.xiaos.adapter.PinnedHeaderExpandableAdapter;import com.xiaos.view.PinnedHeaderExpandableListView;public class MainActivity extends Activity{ private PinnedHeaderExpandableListView explistview; private String[][] childrenData = new String[10][10]; private String[] groupData = new String[10]; private int expandFlag = -1;//控制列表的展开  private PinnedHeaderExpandableAdapter adapter;   @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.layout_main); initView(); initData(); }  /** * 初始化VIEW */ private void initView() { explistview = (PinnedHeaderExpandableListView)findViewById(R.id.explistview); } /** * 初始化数据 */ private void initData() { for(int i=0;i<10;i++){  groupData[i] = "分组"+i; }  for(int i=0;i<10;i++){  for(int j=0;j<10;j++){  childrenData[i][j] = "好友"+i+"-"+j;  } } //设置悬浮头部VIEW explistview.setHeaderView(getLayoutInflater().inflate(R.layout.group_head,  explistview, false)); adapter = new PinnedHeaderExpandableAdapter(childrenData, groupData, getApplicationContext(),explistview); explistview.setAdapter(adapter);  //设置单个分组展开 //explistview.setOnGroupClickListener(new GroupClickListener()); }  class GroupClickListener implements OnGroupClickListener{ @Override public boolean onGroupClick(ExpandableListView parent, View v,  int groupPosition, long id) {  if (expandFlag == -1) {  // 展开被选的group  explistview.expandGroup(groupPosition);  // 设置被选中的group置于顶端  explistview.setSelectedGroup(groupPosition);  expandFlag = groupPosition;  } else if (expandFlag == groupPosition) {  explistview.collapseGroup(expandFlag);  expandFlag = -1;  } else {  explistview.collapseGroup(expandFlag);  // 展开被选的group  explistview.expandGroup(groupPosition);  // 设置被选中的group置于顶端  explistview.setSelectedGroup(groupPosition);  expandFlag = groupPosition;  }  return true; } }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="40dip"  android:background="#FFFFFF" >  <ImageView    android:id="@+id/groupIcon"    android:layout_width="40dp"    android:layout_height="40dp"    android:paddingLeft="10dp"    android:src="@null" />  <TextView    android:id="@+id/childto"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingLeft="10dp"    android:paddingTop="10dip"    android:textColor="#000000"    android:textSize="16sp" /></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:orientation="horizontal"   android:background="#B8E6FA"  android:gravity="center_vertical">  <ImageView     android:id="@+id/groupIcon"    android:layout_width="50dp"    android:layout_height="50dp"    android:contentDescription="@null"    android:layout_marginLeft="10dp"    android:src="@drawable/btn_browser2"/>  <TextView    android:id="@+id/groupto"    android:layout_width="match_parent"    android:layout_height="50dp"    android:textColor="#000000"    android:textSize="18sp"     android:gravity="center_vertical|left"/></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:orientation="horizontal"   android:background="#B8E6FA"  android:gravity="center_vertical">  <ImageView     android:id="@+id/groupIcon"    android:layout_width="50dp"    android:layout_height="50dp"    android:contentDescription="@null"    android:layout_marginLeft="10dp"    android:src="@drawable/btn_browser"/>  <TextView    android:id="@+id/groupto"    android:layout_width="match_parent"    android:layout_height="50dp"    android:textColor="#000000"    android:textSize="18sp"     android:gravity="center_vertical|left"/></LinearLayout>

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:background="#F0F0F0"  android:orientation="vertical" >  <com.xiaos.view.PinnedHeaderExpandableListView    android:id="@+id/explistview"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:layout_marginLeft="0.0dip"    android:cacheColorHint="#00000000"    android:choiceMode="singleChoice"    android:drawSelectorOnTop="false"    android:fastScrollEnabled="false"    android:footerDividersEnabled="true"    android:groupIndicator="@null"    android:scrollbars="vertical"    android:scrollingCache="true" /></LinearLayout>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"  package="com.xiaos.pinnedheaderexpandable"  android:versionCode="1"  android:versionName="1.0" >  <uses-sdk    android:minSdkVersion="8"    android:targetSdkVersion="19" />  <application    android:allowBackup="true"    android:icon="@drawable/ic_launcher"    android:label="@string/app_name"    android:theme="@style/AppTheme" >    <activity       android:name=".MainActivity"      android:icon="@drawable/ic_launcher">      <intent-filter>        <action android:name="android.intent.action.MAIN"/>        <category android:name="android.intent.category.LAUNCHER"/>      </intent-filter>    </activity>  </application></manifest>