/**
 * Copyright (C) 2015
 *
 * CycleWheelView.java
 *
 * Description: 
 *
 * Author: Liao Longhui 
 *
 * Ver 1.0, 2015-07-15, Liao Longhui, Create file
 */

package com.example.wheelviewdemo;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

/**
 * 可循環(huán)滾動的選擇器
 * @author Liao Longhui
 *
 */
public class CycleWheelView extends ListView {

 public static final String TAG = CycleWheelView.class.getSimpleName();
 private static final int COLOR_DIVIDER_DEFALUT = Color.parseColor("#747474");
 private static final int HEIGHT_DIVIDER_DEFAULT = 2;
 private static final int COLOR_SOLID_DEFAULT = Color.parseColor("#3e4043");
 private static final int COLOR_SOLID_SELET_DEFAULT = Color.parseColor("#323335");
 private static final int WHEEL_SIZE_DEFAULT = 3;

 private Handler mHandler;

 private CycleWheelViewAdapter mAdapter;

 /**
 * Labels
 */
 private List<String> mLabels;

 /**
 * Color Of Selected Label
 */
 private int mLabelSelectColor = Color.WHITE;

 /**
 * Color Of Unselected Label
 */
 private int mLabelColor = Color.GRAY;

 /**
 * Gradual Alph
 */
 private float mAlphaGradual = 0.7f;

 /**
 * Color Of Divider
 */
 private int dividerColor = COLOR_DIVIDER_DEFALUT;

 /**
 * Height Of Divider
 */
 private int dividerHeight = HEIGHT_DIVIDER_DEFAULT;

 /**
 * Color of Selected Solid
 */
 private int seletedSolidColor = COLOR_SOLID_SELET_DEFAULT;

 /**
 * Color of Unselected Solid
 */
 private int solidColor = COLOR_SOLID_DEFAULT;

 /**
 * Size Of Wheel , it should be odd number like 3 or greater
 */
 private int mWheelSize = WHEEL_SIZE_DEFAULT;

 /**
 * res Id of Wheel Item Layout
 */
 private int mItemLayoutId;

 /**
 * res Id of Label TextView
 */
 private int mItemLabelTvId;

 /**
 * Height of Wheel Item
 */
 private int mItemHeight;

 private boolean cylceEnable;

 private int mCurrentPositon;

 private WheelItemSelectedListener mItemSelectedListener;

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

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

 public CycleWheelView(Context context) {
 super(context);
 }

 private void init() {
 mHandler = new Handler();
 mItemLayoutId = R.layout.item_cyclewheel;
 mItemLabelTvId = R.id.tv_label_item_wheel;
 mAdapter = new CycleWheelViewAdapter();
 setVerticalScrollBarEnabled(false);
 setScrollingCacheEnabled(false);
 setCacheColorHint(Color.TRANSPARENT);
 setFadingEdgeLength(0);
 setOverScrollMode(OVER_SCROLL_NEVER);
 setDividerHeight(0);
 setAdapter(mAdapter);
 setOnScrollListener(new OnScrollListener() {
  @Override
  public void onScrollStateChanged(AbsListView view, int scrollState) {
  if (scrollState == SCROLL_STATE_IDLE) {
   View itemView = getChildAt(0);
   if (itemView != null) {
   float deltaY = itemView.getY();
   if (deltaY == 0) {
    return;
   }
   if (Math.abs(deltaY) < mItemHeight / 2) {
    smoothScrollBy(getDistance(deltaY), 50);
   } else {
    smoothScrollBy(getDistance(mItemHeight + deltaY), 50);
   }
   }
  }
  }

  @Override
  public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
   int totalItemCount) {
  refreshItems();
  }
 });
 }

 private int getDistance(float scrollDistance) {
 if (Math.abs(scrollDistance) <= 2) {
  return (int) scrollDistance;
 } else if (Math.abs(scrollDistance) < 12) {
  return scrollDistance > 0 ? 2 : -2;
 } else {
  return (int) (scrollDistance / 6);
 }
 }

 private void refreshItems() {
 int offset = mWheelSize / 2;
 int firstPosition = getFirstVisiblePosition();
 int position = 0;
 if (getChildAt(0) == null) {
  return;
 }
 if (Math.abs(getChildAt(0).getY()) <= mItemHeight / 2) {
  position = firstPosition + offset;
 } else {
  position = firstPosition + offset + 1;
 }
 if (position == mCurrentPositon) {
  return;
 }
 mCurrentPositon = position;
 if (mItemSelectedListener != null) {
  mItemSelectedListener.onItemSelected(getSelection(), getSelectLabel());
 }
 resetItems(firstPosition, position, offset);
 }

 private void resetItems(int firstPosition, int position, int offset){
 for (int i = position - offset - 1; i < position + offset + 1; i++) {
  View itemView = getChildAt(i - firstPosition);
  if (itemView == null) {
  continue;
  }
  TextView labelTv = (TextView) itemView.findViewById(mItemLabelTvId);
  if (position == i) {
  labelTv.setTextColor(mLabelSelectColor);
  itemView.setAlpha(1f);
  } else {
  labelTv.setTextColor(mLabelColor);
  int delta = Math.abs(i - position);
  double alpha = Math.pow(mAlphaGradual, delta);
  itemView.setAlpha((float) alpha);
  }
 }
 }
 
 /**
 * 設(shè)置滾輪的刻度列表
 * 
 * @param labels
 */
 public void setLabels(List<String> labels) {
 mLabels = labels;
 mAdapter.setData(mLabels);
 mAdapter.notifyDataSetChanged();
 initView();
 }

 /**
 * 設(shè)置滾輪滾動監(jiān)聽
 * 
 * @param mItemSelectedListener
 */
 public void setOnWheelItemSelectedListener(WheelItemSelectedListener mItemSelectedListener) {
 this.mItemSelectedListener = mItemSelectedListener;
 }

 /**
 * 獲取滾輪的刻度列表
 * 
 * @return
 */
 public List<String> getLabels() {
 return mLabels;
 }

 /**
 * 設(shè)置滾輪是否為循環(huán)滾動
 * 
 * @param enable true-循環(huán) false-單程
 */

 public void setCycleEnable(boolean enable) {
 if (cylceEnable != enable) {
  cylceEnable = enable;
  mAdapter.notifyDataSetChanged();
  setSelection(getSelection());
 }
 }

 /*
 * 滾動到指定位置
 */
 @Override
 public void setSelection(final int position) {
 mHandler.post(new Runnable() {
  @Override
  public void run() {
  CycleWheelView.super.setSelection(getPosition(position));
  }
 });
 }

 private int getPosition(int positon) {
 if (mLabels == null || mLabels.size() == 0) {
  return 0;
 }
 if (cylceEnable) {
  int d = Integer.MAX_VALUE / 2 / mLabels.size();
  return positon + d * mLabels.size();
 }
 return positon;
 }

 /**
 * 獲取當(dāng)前滾輪位置
 * 
 * @return
 */
 public int getSelection() {
 if (mCurrentPositon == 0) {
  mCurrentPositon = mWheelSize / 2;
 }
 return (mCurrentPositon - mWheelSize / 2) % mLabels.size();
 }

 /**
 * 獲取當(dāng)前滾輪位置的刻度
 * 
 * @return
 */
 public String getSelectLabel() {
 int position = getSelection();
 position = position < 0 ? 0 : position;
 try {
  return mLabels.get(position);
 } catch (Exception e) {
  return "";
 }
 }

 /**
 * 如果需要自定義滾輪每個Item，調(diào)用此方法設(shè)置自定義Item布局，自定義布局中需要一個TextView來顯示滾輪刻度
 * 
 * @param itemResId 布局文件Id
 * @param labelTvId 刻度TextView的資源Id
 */
 public void setWheelItemLayout(int itemResId, int labelTvId) {
 mItemLayoutId = itemResId;
 mItemLabelTvId = labelTvId;
 mAdapter = new CycleWheelViewAdapter();
 mAdapter.setData(mLabels);
 setAdapter(mAdapter);
 initView();
 }

 /**
 * 設(shè)置未選中刻度文字顏色
 * 
 * @param labelColor
 */
 public void setLabelColor(int labelColor) {
 this.mLabelColor = labelColor;
 resetItems(getFirstVisiblePosition(), mCurrentPositon, mWheelSize/2);
 }

 /**
 * 設(shè)置選中刻度文字顏色
 * 
 * @param labelSelectColor
 */
 public void setLabelSelectColor(int labelSelectColor) {
 this.mLabelSelectColor = labelSelectColor;
 resetItems(getFirstVisiblePosition(), mCurrentPositon, mWheelSize/2);
 }

 /**
 * 設(shè)置滾輪刻度透明漸變值
 * 
 * @param alphaGradual
 */
 public void setAlphaGradual(float alphaGradual) {
 this.mAlphaGradual = alphaGradual;
 resetItems(getFirstVisiblePosition(), mCurrentPositon, mWheelSize/2);
 }

 /**
 * 設(shè)置滾輪可顯示的刻度數(shù)量，必須為奇數(shù)，且大于等于3
 * 
 * @param wheelSize
 * @throws CycleWheelViewException 滾輪數(shù)量錯誤
 */
 public void setWheelSize(int wheelSize) throws CycleWheelViewException {
 if (wheelSize < 3 || wheelSize % 2 != 1) {
  throw new CycleWheelViewException("Wheel Size Error , Must Be 3,5,7,9...");
 } else {
  mWheelSize = wheelSize;
  initView();
 }
 }
 
 /**
 * 設(shè)置塊的顏色
 * @param unselectedSolidColor 未選中的塊的顏色
 * @param selectedSolidColor 選中的塊的顏色
 */
 public void setSolid(int unselectedSolidColor, int selectedSolidColor){
 this.solidColor = unselectedSolidColor;
 this.seletedSolidColor = selectedSolidColor;
 initView();
 }
 
 /**
 * 設(shè)置分割線樣式
 * @param dividerColor 分割線顏色
 * @param dividerHeight 分割線高度(px)
 */
 public void setDivider(int dividerColor, int dividerHeight){
 this.dividerColor = dividerColor;
 this.dividerHeight = dividerHeight;
 }

 @SuppressWarnings("deprecation")
 private void initView() {
 mItemHeight = measureHeight();
 ViewGroup.LayoutParams lp = getLayoutParams();
 lp.height = mItemHeight * mWheelSize;
 mAdapter.setData(mLabels);
 mAdapter.notifyDataSetChanged();
 Drawable backgroud = new Drawable() {
  @Override
  public void draw(Canvas canvas) {
  int viewWidth = getWidth();
  Paint dividerPaint = new Paint();
  dividerPaint.setColor(dividerColor);
  dividerPaint.setStrokeWidth(dividerHeight);
  Paint seletedSolidPaint = new Paint();
  seletedSolidPaint.setColor(seletedSolidColor);
  Paint solidPaint = new Paint();
  solidPaint.setColor(solidColor);
  canvas.drawRect(0, 0, viewWidth, mItemHeight * (mWheelSize / 2), solidPaint);
  canvas.drawRect(0, mItemHeight * (mWheelSize / 2 + 1), viewWidth, mItemHeight
   * (mWheelSize), solidPaint);
  canvas.drawRect(0, mItemHeight * (mWheelSize / 2), viewWidth, mItemHeight
   * (mWheelSize / 2 + 1), seletedSolidPaint);
  canvas.drawLine(0, mItemHeight * (mWheelSize / 2), viewWidth, mItemHeight
   * (mWheelSize / 2), dividerPaint);
  canvas.drawLine(0, mItemHeight * (mWheelSize / 2 + 1), viewWidth, mItemHeight
   * (mWheelSize / 2 + 1), dividerPaint);
  }

  @Override
  public void setAlpha(int alpha) {
  }

  @Override
  public void setColorFilter(ColorFilter cf) {
  }

  @Override
  public int getOpacity() {
  return 0;
  }
 };
 setBackgroundDrawable(backgroud);
 }

 private int measureHeight() {
 View itemView = LayoutInflater.from(getContext()).inflate(mItemLayoutId, null);
 itemView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
  ViewGroup.LayoutParams.WRAP_CONTENT));
 int w = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
 int h = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
 itemView.measure(w, h);
 int height = itemView.getMeasuredHeight();
 // int width = view.getMeasuredWidth();
 return height;
 }

 public interface WheelItemSelectedListener {
 public void onItemSelected(int position, String label);
 }

 public class CycleWheelViewException extends Exception {
 private static final long serialVersionUID = 1L;

 public CycleWheelViewException(String detailMessage) {
  super(detailMessage);
 }
 }

 public class CycleWheelViewAdapter extends BaseAdapter {

 private List<String> mData = new ArrayList<String>();

 public void setData(List<String> mWheelLabels) {
  mData.clear();
  mData.addAll(mWheelLabels);
 }

 @Override
 public int getCount() {
  if (cylceEnable) {
  return Integer.MAX_VALUE;
  }
  return mData.size() + mWheelSize - 1;
 }

 @Override
 public Object getItem(int position) {
  return "";
 }

 @Override
 public long getItemId(int position) {
  return position;
 }

 @Override
 public boolean isEnabled(int position) {
  return false;
 }

 @Override
 public View getView(int position, View convertView, ViewGroup parent) {
  if (convertView == null) {
  convertView = LayoutInflater.from(getContext()).inflate(mItemLayoutId, null);
  }
  TextView textView = (TextView) convertView.findViewById(mItemLabelTvId);
  if (position < mWheelSize / 2
   || (!cylceEnable && position >= mData.size() + mWheelSize / 2)) {
  textView.setText("");
  convertView.setVisibility(View.INVISIBLE);
  } else {
  textView.setText(mData.get((position - mWheelSize / 2) % mData.size()));
  convertView.setVisibility(View.VISIBLE);
  }
  return convertView;
 }
 }
}

public class MainActivity extends Activity {
 private CycleWheelView cycleWheelView0,cycleWheelView1, cycleWheelView2;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 cycleWheelView0 = (CycleWheelView) findViewById(R.id.cycleWheelView);
 List<String> labels = new ArrayList<>();
 for (int i = 0; i < 12; i++) {
  labels.add("" + i);
 }
 cycleWheelView0.setLabels(labels);
 cycleWheelView0.setAlphaGradual(0.5f);
 cycleWheelView0.setOnWheelItemSelectedListener(new WheelItemSelectedListener() {
  @Override
  public void onItemSelected(int position, String label) {
  Log.d("test", label);
  }
 });
 
 cycleWheelView1 = (CycleWheelView) findViewById(R.id.cycleWheelView1);
 List<String> labels1 = new ArrayList<>();
 for (int i = 0; i < 24; i++) {
  labels1.add("" + i);
 }
 cycleWheelView1.setLabels(labels1);
 try {
  cycleWheelView1.setWheelSize(5);
 } catch (CycleWheelViewException e) {
  e.printStackTrace();
 }
 cycleWheelView1.setSelection(2);
 cycleWheelView1.setWheelItemLayout(R.layout.item_cyclewheel_custom, R.id.tv_label_item_wheel_custom);
 cycleWheelView1.setOnWheelItemSelectedListener(new WheelItemSelectedListener() {
  @Override
  public void onItemSelected(int position, String label) {
  Log.d("test", label);
  }
 });

 cycleWheelView2 = (CycleWheelView) findViewById(R.id.cycleWheelView2);
 List<String> labels2 = new ArrayList<>();
 for (int i = 0; i < 60; i++) {
  labels2.add("" + i);
 }
 cycleWheelView2.setLabels(labels2);
 try {
  cycleWheelView2.setWheelSize(7);
 } catch (CycleWheelViewException e) {
  e.printStackTrace();
 }
 cycleWheelView2.setCycleEnable(true);
 cycleWheelView2.setSelection(30);
 cycleWheelView2.setAlphaGradual(0.6f);
 cycleWheelView2.setDivider(Color.parseColor("#abcdef"), 2);
 cycleWheelView2.setSolid(Color.WHITE,Color.WHITE);
 cycleWheelView2.setLabelColor(Color.BLUE);
 cycleWheelView2.setLabelSelectColor(Color.RED);
 cycleWheelView2.setOnWheelItemSelectedListener(new WheelItemSelectedListener() {
  @Override
  public void onItemSelected(int position, String label) {
  Log.d("test", label);
  }
 });

 }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:padding="16dp"
 android:background="@android:color/transparent" >

 <TextView
 android:id="@+id/tv_label_item_wheel"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:textSize="20sp"
 android:singleLine="true"
 android:layout_centerHorizontal="true"
 android:layout_centerVertical="true" />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:padding="16dp"
 android:background="@android:color/transparent" >

 <TextView
 android:id="@+id/tv_label_item_wheel_custom"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:singleLine="true"
 android:layout_alignParentLeft="true"
 android:layout_centerVertical="true" />

 <ImageView
 android:layout_width="25dp"
 android:layout_height="25dp"
 android:layout_centerVertical="true"
 android:layout_alignParentRight="true"
 android:src="@drawable/ic_launcher" />

</RelativeLayout>

<LinearLayout 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="horizontal" >

 <com.example.wheelviewdemo.CycleWheelView
 android:id="@+id/cycleWheelView"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:layout_weight="1" >
 </com.example.wheelviewdemo.CycleWheelView>
 
 <com.example.wheelviewdemo.CycleWheelView
 android:id="@+id/cycleWheelView1"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:layout_weight="1" >
 </com.example.wheelviewdemo.CycleWheelView>

 <com.example.wheelviewdemo.CycleWheelView
 android:id="@+id/cycleWheelView2"
 android:layout_width="0dp"
 android:layout_height="wrap_content"
 android:layout_weight="1" >
 </com.example.wheelviewdemo.CycleWheelView>
 
</LinearLayout>