iOS自定义时间滚动选择控件

/**
 * 滚轮选择器
 * author lh
 * data 2016/8/20 17:26
 */
public class wheelview extends view {
 
 public static final string tag = "wheelview";
 
 /**
 * 自动回滚到中间的速度
 */
 public static final float speed = 2;
 
 /**
 * 除选中item外，上下各需要显示的备选项数目
 */
 public static final int show_size = 1;
 
 private context context;
 
 private list<string> itemlist;
 private int itemcount;
 
 /**
 * item高度
 */
 private int itemheight = 50;
 
 /**
 * 选中的位置，这个位置是mdatalist的中心位置，一直不变
 */
 private int currentitem;
 
 private paint selectpaint;
 private paint mpaint;
 // 画背景图中单独的画笔
 private paint centerlinepaint;
 
 private float centery;
 private float centerx;
 
 private float mlastdowny;
 /**
 * 滑动的距离
 */
 private float mmovelen = 0;
 private boolean isinit = false;
 private selectlistener mselectlistener;
 private timer timer;
 private mytimertask mtask;
 
 handler updatehandler = new handler() {
 
 @override
 public void handlemessage(message msg) {
  if (math.abs(mmovelen) < speed) {
  // 如果偏移量少于最少偏移量
  mmovelen = 0;
  if (null != timer) {
   timer.cancel();
   timer.purge();
   timer = null;
  }
  if (mtask != null) {
   mtask.cancel();
   mtask = null;
   performselect();
  }
  } else {
  // 这里mmovelen / math.abs(mmovelen)是为了保有mmovelen的正负号，以实现上滚或下滚
  mmovelen = mmovelen - mmovelen / math.abs(mmovelen) * speed;
  }
  invalidate();
 }
 
 };
 
 public wheelview(context context) {
 super(context);
 init(context);
 }
 
 public wheelview(context context, attributeset attrs) {
 super(context, attrs);
 init(context);
 }
 
 public void setonselectlistener(selectlistener listener) {
 mselectlistener = listener;
 }
 
 public void setwheelstyle(int style) {
 itemlist = wheelstyle.getitemlist(context, style);
 if (itemlist != null) {
  itemcount = itemlist.size();
  resetcurrentselect();
  invalidate();
 } else {
  log.i(tag, "item is null");
 }
 }
 
 public void setwheelitemlist(list<string> itemlist) {
 this.itemlist = itemlist;
 if (itemlist != null) {
  itemcount = itemlist.size();
  resetcurrentselect();
 } else {
  log.i(tag, "item is null");
 }
 }
 
 private void resetcurrentselect() {
 if (currentitem < 0) {
  currentitem = 0;
 }
 while (currentitem >= itemcount) {
  currentitem--;
 }
 if (currentitem >= 0 && currentitem < itemcount) {
  invalidate();
 } else {
  log.i(tag, "current item is invalid");
 }
 }
 
 public int getitemcount() {
 return itemcount;
 }
 /**
 * 选择选中的item的index
 * author lh
 * data 2016/9/4 11:09
 */
 public void setcurrentitem(int selected) {
 currentitem = selected;
 resetcurrentselect();
 }
 
 public int getcurrentitem() {
 return currentitem;
 }
 
 @override
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
 super.onmeasure(widthmeasurespec, heightmeasurespec);
 int mviewheight = getmeasuredheight();
 int mviewwidth = getmeasuredwidth();
 centerx = (float) (mviewwidth / 2.0);
 centery = (float) (mviewheight / 2.0);
 
 isinit = true;
 invalidate();
 }
 
 
 private void init(context context) {
 this.context = context;
 
 timer = new timer();
 itemlist = new arraylist<>();
 
 mpaint = new paint(paint.anti_alias_flag);
 mpaint.setstyle(style.fill);
 mpaint.settextalign(align.center);
 mpaint.setcolor(getresources().getcolor(r.color.wheel_unselect_text));
 int size1 = (int) (supportdisplay.getlayoutscale()*22+0.5);
 mpaint.settextsize(size1);
 
 selectpaint = new paint(paint.anti_alias_flag);
 selectpaint.setstyle(style.fill);
 selectpaint.settextalign(align.center);
 selectpaint.setcolor(getresources().getcolor(r.color.color_1a1a1a));
 int size2 = (int) (supportdisplay.getlayoutscale()*24+0.5);
 selectpaint.settextsize(size2);
 
 centerlinepaint = new paint(paint.anti_alias_flag);
 centerlinepaint.setstyle(style.fill);
 centerlinepaint.settextalign(align.center);
 centerlinepaint.setcolor(getresources().getcolor(r.color.wheel_unselect_text));
 
 // 绘制背景
 setbackground(null);
 }
 
 @override
 protected void ondraw(canvas canvas) {
 super.ondraw(canvas);
 if (isinit) {
  drawdata(canvas);
 }
 }
 
 private void drawdata(canvas canvas) {
 // 先绘制选中的text再往上往下绘制其余的text
 if (!itemlist.isempty()) {
  // 绘制中间data
  drawcentertext(canvas);
  // 绘制上方data
  for (int i = 1; i < show_size + 1; i++) {
  drawothertext(canvas, i, -1);
  }
  // 绘制下方data
  for (int i = 1; i < show_size + 1; i++) {
  drawothertext(canvas, i, 1);
  }
 }
 }
 
 private void drawcentertext(canvas canvas) {
 // text居中绘制，注意baseline的计算才能达到居中，y值是text中心坐标
 float y = centery + mmovelen;
 fontmetricsint fmi = selectpaint.getfontmetricsint();
 float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));
 canvas.drawtext(itemlist.get(currentitem), centerx, baseline, selectpaint);
 }
 
 /**
 * 绘制文本
 * author lh
 * data 2016/9/4 11:10
 * @param canvas 画布
 * @param position 距离mcurrentselected的差值
 * @param type 1表示向下绘制，-1表示向上绘制
 */
 private void drawothertext(canvas canvas, int position, int type) {
 int index = currentitem + type * position;
 if (index >= itemcount) {
  index = index - itemcount;
 }
 if (index < 0) {
  index = index + itemcount;
 }
 string text = itemlist.get(index);
 
 int itemheight = getheight() / (show_size * 2 + 1);
 float d = itemheight * position + type * mmovelen;
 float y = centery + type * d;
 
 fontmetricsint fmi = mpaint.getfontmetricsint();
 float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));
 canvas.drawtext(text, centerx, baseline, mpaint);
 }
 
 @override
 public void setbackground(drawable background) {
 background = new drawable() {
  @override
  public void draw(canvas canvas) {
  itemheight = getheight() / (show_size * 2 + 1);
  int width = getwidth();
 
  canvas.drawline(0, itemheight, width, itemheight, centerlinepaint);
  canvas.drawline(0, itemheight * 2, width, itemheight * 2, centerlinepaint);
 
  centerlinepaint.setcolor(getresources().getcolor(r.color.wheel_bg));
  rect toprect = new rect(0, 0, width, itemheight);
  canvas.drawrect(toprect, centerlinepaint);
  rect bottomrect = new rect(0, itemheight * 2, width, itemheight * 3);
  canvas.drawrect(bottomrect, centerlinepaint);
  }
 
  @override
  public void setalpha(int alpha) {
 
  }
 
  @override
  public void setcolorfilter(colorfilter cf) {
 
  }
 
  @override
  public int getopacity() {
  return 0;
  }
 };
 super.setbackground(background);
 }
 
 @override
 public boolean ontouchevent(motionevent event) {
 switch (event.getactionmasked()) {
  case motionevent.action_down:
  dodown(event);
  break;
  case motionevent.action_move:
  domove(event);
  break;
  case motionevent.action_up:
  doup();
  break;
  default:
  break;
 }
 return true;
 }
 
 private void dodown(motionevent event) {
 if (mtask != null) {
  mtask.cancel();
  mtask = null;
 }
 mlastdowny = event.gety();
 }
 
 private void domove(motionevent event) {
 
 mmovelen += (event.gety() - mlastdowny);
 if (mmovelen > itemheight / 2) {
  // 往下滑超过离开距离
  mmovelen = mmovelen - itemheight;
  currentitem--;
  if (currentitem < 0) {
  currentitem = itemcount - 1;
  }
 } else if (mmovelen < -itemheight / 2) {
  // 往上滑超过离开距离
  mmovelen = mmovelen + itemheight;
  currentitem++;
  if (currentitem >= itemcount) {
  currentitem = 0;
  }
 }
 
 mlastdowny = event.gety();
 invalidate();
 }
 
 private void doup() {
 // 抬起手后mcurrentselected的位置由当前位置move到中间选中位置
 if (math.abs(mmovelen) < 0.0001) {
  mmovelen = 0;
  return;
 }
 if (mtask != null) {
  mtask.cancel();
  mtask = null;
 }
 if (null == timer) {
  timer = new timer();
 }
 mtask = new mytimertask(updatehandler);
 timer.schedule(mtask, 0, 10);
 }
 
 class mytimertask extends timertask {
 handler handler;
 
 public mytimertask(handler handler) {
  this.handler = handler;
 }
 
 @override
 public void run() {
  handler.sendmessage(handler.obtainmessage());
 }
 
 }
 
 private void performselect() {
 if (mselectlistener != null) {
  mselectlistener.onselect(currentitem, itemlist.get(currentitem));
 } else {
  log.i(tag, "null listener");
 }
 }
 
 public interface selectlistener {
 void onselect(int index, string text);
 }
 
}

/**
 * 时间选择样式
 * author lh
 * data 2016/9/4 11:05
 */
public class wheelstyle {
 
 public static final int minyear = 1980;
 public static final int maxyear = 2020;
 
 /**
 * wheel style hour
 */
 public static final int style_hour = 1;
 /**
 * wheel style minute
 */
 public static final int style_minute = 2;
 /**
 * wheel style year
 */
 public static final int style_year = 3;
 /**
 * wheel style month
 */
 public static final int style_month = 4;
 /**
 * wheel style day
 */
 public static final int style_day = 5;
 /**
 * wheel style simple day
 */
 public static final int style_simple_day = 6;
 /**
 * wheel style set warn
 */
 public static final int style_set_warn = 7;
 /**
 * wheel style work answer
 */
 public static final int style_work_answer = 8;
 
 private wheelstyle() {
 }
 
 public static list<string> getitemlist(context context, int style) {
 if (style == style_hour) {
  return createhourstring();
 } else if (style == style_minute) {
  return createminutestring();
 } else if (style == style_year) {
  return createyearstring();
 } else if (style == style_month) {
  return createmonthstring();
 } else if (style == style_day) {
  return createdaystring();
 } else if (style == style_simple_day) {
  return createsimpledaystring();
 } else if (style == style_set_warn) {
  return createsetwarntimestring();
 } else {
  throw new illegalargumentexception("style is illegal");
 }
 }
 
 private static list<string> createhourstring() {
 list<string> wheelstring = new arraylist<>();
 for (int i = 0; i < 24; i++) {
  wheelstring.add(string.format("%02d" + "时", i));
 }
 return wheelstring;
 }
 
 private static list<string> createminutestring() {
 list<string> wheelstring = new arraylist<>();
 for (int i = 0; i < 60; i++) {
  wheelstring.add(string.format("%02d" + "分", i));
 }
 return wheelstring;
 }
 
 private static list<string> createyearstring() {
 list<string> wheelstring = new arraylist<>();
 for (int i = minyear; i <= maxyear; i++) {
  wheelstring.add(integer.tostring(i));
 }
 return wheelstring;
 }
 
 private static list<string> createmonthstring() {
 list<string> wheelstring = new arraylist<>();
 for (int i = 1; i <= 12; i++) {
  wheelstring.add(string.format("%02d" + "月", i));
 }
 return wheelstring;
 }
 
 private static list<string> createdaystring() {
 list<string> wheelstring = new arraylist<>();
 for (int i = 1; i <= 31; i++) {
  wheelstring.add(string.format("%02d" + "日", i));
 }
 return wheelstring;
 }
 
 private static list<string> createsimpledaystring() {
 list<string> wheelstring = new arraylist<>();
 wheelstring.add("一天后");
 wheelstring.add("两天后");
 wheelstring.add("三天后");
 return wheelstring;
 }
 
 private static list<string> createsetwarntimestring() {
 list<string> wheelstring = new arraylist<>();
 wheelstring.add("30分钟");
 wheelstring.add("60分钟");
 wheelstring.add("90分钟");
 wheelstring.add("120分钟");
 return wheelstring;
 }
 /**
 * 计算闰月
 *
 * @param month
 * @return
 */
 private static boolean isleapmonth(int month) {
 return month == 1 || month == 3 || month == 5 || month == 7
  || month == 8 || month == 10 || month == 12;
 }
 
 /**
 * 计算闰年
 *
 * @param year
 * @return
 */
 private static boolean isleapyear(int year) {
 return (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
 }
}

<com.example.view.timeview.wheelview
  android:id="@+id/select_time_simple_wheel"
  android:layout_width="match_parent"
  android:layout_height="150dp"
  android:layout_marginleft="20dp"
  android:layout_marginright="20dp"
  android:layout_weight="1" />