Android imitation WeChat chat bubble effect implementation idea

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:andro
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#f0f0e0" >
<RelativeLayout
android:
android:layout_width="fill_parent"
android:layout_alignParentTop="true"
android:layout_height="wrap_content">
<TextView
android:layout_width="fill_parent"
android:layout_height="44dp"
android:gravity="center"
android:textSize="18sp"
android:background="#486a9a"
android:textColor="@android:color/white"
android:text="Chat"/>
</RelativeLayout>
<RelativeLayout
android:
android:layout_alignParentBottom="true"
android:layout_width="fill_parent"
android:background="#486a9a"
android:paddingTop="5dp"
android:layout_height="wrap_content">
<Button
android:
android:layout_width="70dp"
android:layout_height="50dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="10dp"
android:text="Send" />
<EditText
android:
android:layout_width="fill_parent"
android:layout_height="50dp"
android:layout_centerVertical="true"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_toLeftOf="@id/btn_send"
android:textSize="16sp"/>
</RelativeLayout>
<ListView
android:
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="@id/rl_bottom"
android:layout_below="@id/rl_top"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginTop="10dp"
android:cacheColorHint="#00000000"
android:divider="@null"
android:listSelector="#00000000"
android:dividerHeight="3dp"
android:scrollbars="none"/>
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:andro
android:layout_width="fill_parent"
android:orientation="vertical"
android:paddingBottom="5dp"
android:layout_height="wrap_content" >
<TextView
android:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:background="#bfbfbf"
android:paddingTop="2dp"
android:paddingBottom="2dp"
android:paddingLeft="4dp"
android:paddingRight="4dp"
android:textColor="#ffffff"
android:textSize="12sp" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp" >
<ImageView
android:
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:background="@drawable/mypic"
android:focusable="false" />
<TextView
android:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="5dp"
android:layout_toRightOf="@+id/iv_user_image"
android:background="@drawable/chatfrom_bg"
android:gravity="left|center"
android:clickable="true"
android:focusable="true"
android:lineSpacingExtra="2dp"
android:minHeight="50dp"
android:textColor="#ff000000"
android:textSize="14sp" />
</RelativeLayout>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:andro
android:layout_width="fill_parent"
android:orientation="vertical"
android:paddingBottom="5dp"
android:layout_height="wrap_content" >
<TextView
android:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#bfbfbf"
android:layout_gravity="center_horizontal"
android:paddingTop="2dp"
android:paddingBottom="2dp"
android:paddingLeft="4dp"
android:paddingRight="4dp"
android:textColor="#ffffff"
android:textSize="12sp" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp" >
<ImageView
android:
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:background="@drawable/mypic"
android:focusable="false" />
<TextView
android:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginRight="5dp"
android:layout_toLeftOf="@+id/iv_user_image"
android:background="@drawable/chatto_bg"
android:gravity="left|center"
android:clickable="true"
android:focusable="true"
android:lineSpacingExtra="2dp"
android:textColor="#ff000000"
android:textSize="14sp" />
</RelativeLayout>
</LinearLayout>

public class ChatEntity {
private int userImage;
private String content;
private String chatTime;
private boolean isComeMsg;
public int getUserImage() {
return userImage;
}
public void setUserImage(int userImage) {
= userImage;
}
public String getContent() {
return content;
}
public void setContent(String content) {
= content;
}
public String getChatTime() {
return chatTime;
}
public void setChatTime(String chatTime) {
= chatTime;
}
public boolean isComeMsg() {
return isComeMsg;
}
public void setComeMsg(boolean isComeMsg) {
= isComeMsg;
}
}

public class ChatDemoActivity extends Activity {
private Button sendButton = null;
private EditText contentEditText = null;
private ListView chatListView = null;
private List<ChatEntity> chatList = null;
private ChatAdapter chatAdapter = null;
@Override
public void onCreate(Bundle savedInstanceState) {
(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView();
contentEditText = (EditText) (.et_content);
sendButton = (Button) (.btn_send);
chatListView = (ListView) ();
chatList = new ArrayList<ChatEntity>();
ChatEntity chatEntity = null;
for (int i = 0; i < 2; i++) {
chatEntity = new ChatEntity();
if (i % 2 == 0) {
(false);
("Hello");
("2012-09-20 15:12:32");
}else {
(true);
("Hello,nice to meet you!");
("2012-09-20 15:13:32");
}
(chatEntity);
}
chatAdapter = new ChatAdapter(this,chatList);
(chatAdapter);
(new OnClickListener() {
@Override
public void onClick(View v) {
if (!().toString().equals("")) {
//Send a message
send();
}else {
(, "Content is empty", Toast.LENGTH_SHORT).show();
}
}
});
}
private void send(){
ChatEntity chatEntity = new ChatEntity();
("2012-09-20 15:16:34");
(().toString());
(false);
(chatEntity);
();
(() - 1);
("");
}
private class ChatAdapter extends BaseAdapter{
private Context context = null;
private List<ChatEntity> chatList = null;
private LayoutInflater inflater = null;
private int COME_MSG = 0;
private int TO_MSG = 1;
public ChatAdapter(Context context,List<ChatEntity> chatList){
= context;
= chatList;
inflater = ();
}
@Override
public int getCount() {
return ();
}
@Override
public Object getItem(int position) {
return (position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public int getItemViewType(int position) {
// Differentiate the types of the two views and label two different variables to represent their respective types
ChatEntity entity = (position);
if (())
{
return COME_MSG;
}else{
return TO_MSG;
}
}
@Override
public int getViewTypeCount() {
// This method returns 1 by default. If you want the listview item to be the same, it returns 1. We have two styles here, return 2
return 2;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ChatHolder chatHolder = null;
if (convertView == null) {
chatHolder = new ChatHolder();
if ((position).isComeMsg()) {
convertView = (.chat_from_item, null);
}else {
convertView = (.chat_to_item, null);
}
= (TextView) (.tv_time);
= (TextView) (.tv_content);
= (ImageView) (.iv_user_image);
(chatHolder);
}else {
chatHolder = (ChatHolder)();
}
((position).getChatTime());
((position).getContent());
((position).getUserImage());
return convertView;
}
private class ChatHolder{
private TextView timeTextView;
private ImageView userImageView;
private TextView contentTextView;
}
}
}