Android系统联系人全特效实现(上)分组导航和挤压动画(附源码)

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:id="@+id/contacts_list_view"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:fadingEdge="none" >
</ListView>
<LinearLayout
android:id="@+id/title_layout"
android:layout_width="fill_parent"
android:layout_height="18dip"
android:layout_alignParentTop="true"
android:background="#303030" >
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginLeft="10dip"
android:textColor="#ffffff"
android:textSize="13sp" />
</LinearLayout>
</RelativeLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:id="@+id/sort_key_layout"
android:layout_width="fill_parent"
android:layout_height="18dip"
android:background="#303030" >
<TextView
android:id="@+id/sort_key"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginLeft="10dip"
android:textColor="#ffffff"
android:textSize="13sp" />
</LinearLayout>
<LinearLayout
android:id="@+id/name_layout"
android:layout_width="fill_parent"
android:layout_height="50dip" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginLeft="10dip"
android:layout_marginRight="10dip"
android:src="@drawable/icon" />
<TextView
android:id="@+id/name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:textColor="#ffffff"
android:textSize="22sp" />
</LinearLayout>
</LinearLayout>

public class Contact {
/**
* 联系人姓名
*/
private String name;
/**
* 排序字母
*/
private String sortKey;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSortKey() {
return sortKey;
}
public void setSortKey(String sortKey) {
this.sortKey = sortKey;
}
}

public class ContactAdapter extends ArrayAdapter<Contact> {
/**
* 需要渲染的item布局文件
*/
private int resource;
/**
* 字母表分组工具
*/
private SectionIndexer mIndexer;
public ContactAdapter(Context context, int textViewResourceId, List<Contact> objects) {
super(context, textViewResourceId, objects);
resource = textViewResourceId;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Contact contact = getItem(position);
LinearLayout layout = null;
if (convertView == null) {
layout = (LinearLayout) LayoutInflater.from(getContext()).inflate(resource, null);
} else {
layout = (LinearLayout) convertView;
}
TextView name = (TextView) layout.findViewById(R.id.name);
LinearLayout sortKeyLayout = (LinearLayout) layout.findViewById(R.id.sort_key_layout);
TextView sortKey = (TextView) layout.findViewById(R.id.sort_key);
name.setText(contact.getName());
int section = mIndexer.getSectionForPosition(position);
if (position == mIndexer.getPositionForSection(section)) {
sortKey.setText(contact.getSortKey());
sortKeyLayout.setVisibility(View.VISIBLE);
} else {
sortKeyLayout.setVisibility(View.GONE);
}
return layout;
}
/**
* 给当前适配器传入一个分组工具。
*
* @param indexer
*/
public void setIndexer(SectionIndexer indexer) {
mIndexer = indexer;
}
}

public class MainActivity extends Activity {
/**
* 分组的布局
*/
private LinearLayout titleLayout;
/**
* 分组上显示的字母
*/
private TextView title;
/**
* 联系人ListView
*/
private ListView contactsListView;
/**
* 联系人列表适配器
*/
private ContactAdapter adapter;
/**
* 用于进行字母表分组
*/
private AlphabetIndexer indexer;
/**
* 存储所有手机中的联系人
*/
private List<Contact> contacts = new ArrayList<Contact>();
/**
* 定义字母表的排序规则
*/
private String alphabet = "#ABCDEFGHIJKLMNOPQRSTUVWXYZ";
/**
* 上次第一个可见元素，用于滚动时记录标识。
*/
private int lastFirstVisibleItem = -1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
adapter = new ContactAdapter(this, R.layout.contact_item, contacts);
titleLayout = (LinearLayout) findViewById(R.id.title_layout);
title = (TextView) findViewById(R.id.title);
contactsListView = (ListView) findViewById(R.id.contacts_list_view);
Uri uri = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;
Cursor cursor = getContentResolver().query(uri,
new String[] { "display_name", "sort_key" }, null, null, "sort_key");
if (cursor.moveToFirst()) {
do {
String name = cursor.getString(0);
String sortKey = getSortKey(cursor.getString(1));
Contact contact = new Contact();
contact.setName(name);
contact.setSortKey(sortKey);
contacts.add(contact);
} while (cursor.moveToNext());
}
startManagingCursor(cursor);
indexer = new AlphabetIndexer(cursor, 1, alphabet);
adapter.setIndexer(indexer);
if (contacts.size() > 0) {
setupContactsListView();
}
}
/**
* 为联系人ListView设置监听事件，根据当前的滑动状态来改变分组的显示位置，从而实现挤压动画的效果。
*/
private void setupContactsListView() {
contactsListView.setAdapter(adapter);
contactsListView.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
int totalItemCount) {
int section = indexer.getSectionForPosition(firstVisibleItem);
int nextSecPosition = indexer.getPositionForSection(section + 1);
if (firstVisibleItem != lastFirstVisibleItem) {
MarginLayoutParams params = (MarginLayoutParams) titleLayout.getLayoutParams();
params.topMargin = 0;
titleLayout.setLayoutParams(params);
title.setText(String.valueOf(alphabet.charAt(section)));
}
if (nextSecPosition == firstVisibleItem + 1) {
View childView = view.getChildAt(0);
if (childView != null) {
int titleHeight = titleLayout.getHeight();
int bottom = childView.getBottom();
MarginLayoutParams params = (MarginLayoutParams) titleLayout
.getLayoutParams();
if (bottom < titleHeight) {
float pushedDistance = bottom - titleHeight;
params.topMargin = (int) pushedDistance;
titleLayout.setLayoutParams(params);
} else {
if (params.topMargin != 0) {
params.topMargin = 0;
titleLayout.setLayoutParams(params);
}
}
}
}
lastFirstVisibleItem = firstVisibleItem;
}
});
}
/**
* 获取sort key的首个字符，如果是英文字母就直接返回，否则返回#。
*
* @param sortKeyString
* 数据库中读取出的sort key
* @return 英文字母或者#
*/
private String getSortKey(String sortKeyString) {
String key = sortKeyString.substring(0, 1).toUpperCase();
if (key.matches("[A-Z]")) {
return key;
}
return "#";
}
}

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