安卓侧面滑动组件设计

要想做一个跟通讯录类似的在右侧实现滑动，

看看界面

下面看一下实现的代码：

friend.xml

<?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="@color/background"
    android:orientation="vertical" >
    
    <include layout="@layout/friend_header"/>
    
    <RelativeLayout 
        android:orientation="vertical"
        android:layout_width="fill_parent"  
        android:layout_height="fill_parent">
        
    <ListView android:id="@+id/list_view" 
		android:layout_height="wrap_content" 
		android:layout_width="fill_parent"
		android:scrollbars="none"
		android:cacheColorHint="@color/white"
		></ListView>
    
    <com.example.widget.MyLetterListView
    	android:id="@+id/my_list_view" 
		android:background="@drawable/corner"  
		android:layout_width="30dip" 
		android:layout_height="fill_parent"
		android:layout_alignParentRight="true" />
    
    </RelativeLayout>
</LinearLayout> 

friend_header.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
   	android:layout_width="fill_parent"
   	android:layout_height="wrap_content"
   	android:paddingLeft="2dip"
   	android:paddingRight="2dip"
   	android:gravity="center_vertical"
   	android:orientation="horizontal"
   	android:background="@drawable/widget_bar_bg">
   	<TextView 
   		android:id="@+id/friend_search_head_title"
   		style="@style/detail_head_title"
   		android:layout_gravity="center"
   		android:clickable="true"
   		android:textSize="20sp"
   		android:text="@string/my_friend"
   		></TextView>
 
   		<ImageView
   		android:id="@+id/friend_center_back"
	   	android:layout_width="wrap_content" 
	   	android:layout_height="wrap_content" 
	   	android:layout_gravity="right|center"
	   	android:clickable="true"
	   	android:textColor="@color/white"
	   	android:background="@drawable/add_friend" 
	   	></ImageView>
   		
</FrameLayout>

这里主要把组件构建出来，滑动功能还没有实现

MyLetterListView.java

package com.example.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

public class MyLetterListView extends View
{
	OnTouchingLetterChangedListener onTouchingLetterChangedListener;
	String[] b = {"@","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","#"};
	int choose = -1;
	Paint paint = new Paint();
	boolean showBkg = false;

	public MyLetterListView(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		
	}

	public MyLetterListView(Context context, AttributeSet attrs) {
		super(context, attrs);
		
	}

	public MyLetterListView(Context context) {
		super(context);
	}
	
	protected void onDraw(Canvas canvas) {
		super.onDraw(canvas);
		if(showBkg){
		    canvas.drawColor(Color.parseColor("#40000000"));
		}
		
	    int height = getHeight();
	    int width = getWidth();
	    int singleHeight = height / b.length;
	    for(int i=0;i<b.length;i++){
	       paint.setColor(Color.BLACK);
	       paint.setTypeface(Typeface.DEFAULT_BOLD);
	       paint.setAntiAlias(true);
	       if(i == choose){
	    	   paint.setColor(Color.parseColor("#3399ff"));
	    	   paint.setFakeBoldText(true);
	       }
	       float xPos = width/2  - paint.measureText(b[i])/2;
	       float yPos = singleHeight * i + singleHeight;
	       
	       canvas.drawText(b[i], xPos, yPos, paint);
	       
	       paint.reset();
	    }
	   
	}
	
	@Override
	public boolean dispatchTouchEvent(MotionEvent event) {
		final int action = event.getAction();
	    final float y = event.getY();
	    final float x = event.getX();
	    final int oldChoose = choose;
	    final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;
	    final int c = (int) (y/getHeight()*b.length);
	    
		switch (action) {
			case MotionEvent.ACTION_DOWN:
				showBkg = true;
				if(oldChoose != c && listener != null){
					if(c > 0 && c< b.length){
						listener.onTouchingLetterChanged(b[c],y,x);
						choose = c;
						invalidate();
					}
				}
				
				break;
			case MotionEvent.ACTION_MOVE:
				if(oldChoose != c && listener != null){
					if(c > 0 && c< b.length){
						listener.onTouchingLetterChanged(b[c],y,x);
						choose = c;
						invalidate();
					}
				}
				break;
			case MotionEvent.ACTION_UP:
				showBkg = false;
				choose = -1;
				listener.onTouchingLetterEnd();
				invalidate();
				break;
		}
		return true;
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		return super.onTouchEvent(event);
	}

	public void setOnTouchingLetterChangedListener(OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
		this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
	}

	public interface OnTouchingLetterChangedListener{
		public void onTouchingLetterEnd();
		public void onTouchingLetterChanged(String s,float y,float x);
	}
}