Improved architecture

Separating concerns
Remove duplicated code

android/src/main/java/com/henninghall/date_picker/DateBoundary.java

@@ -1,13 +1,15 @@
 package com.henninghall.date_picker;
 
+
 import java.util.Calendar;
+import java.util.TimeZone;
 
 public class DateBoundary {
     private Calendar date;
 
-    DateBoundary(PickerView pickerView, String date) {
+    DateBoundary(TimeZone timezone, String date) {
         if(date == null) return;
-        Calendar cal = Utils.isoToCalendar(date, pickerView.timeZone);
+        Calendar cal = Utils.isoToCalendar(date, timezone);
         this.date = Utils.getTruncatedCalendarOrNull(cal);
     }
 

android/src/main/java/com/henninghall/date_picker/DatePickerManager.java

@@ -1,25 +1,32 @@
 package com.henninghall.date_picker;
 
+
+import com.facebook.react.bridge.Dynamic;
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.common.MapBuilder;
 import com.facebook.react.uimanager.SimpleViewManager;
 import com.facebook.react.uimanager.ThemedReactContext;
-import com.facebook.react.uimanager.annotations.ReactProp;
 import com.facebook.react.uimanager.annotations.ReactPropGroup;
+import com.henninghall.date_picker.props.DateProp;
+import com.henninghall.date_picker.props.FadeToColorProp;
+import com.henninghall.date_picker.props.LocaleProp;
+import com.henninghall.date_picker.props.MaximumDateProp;
+import com.henninghall.date_picker.props.MinimumDateProp;
+import com.henninghall.date_picker.props.MinuteIntervalProp;
+import com.henninghall.date_picker.props.ModeProp;
+import com.henninghall.date_picker.props.TextColorProp;
+import com.henninghall.date_picker.props.UtcProp;
 
 import net.time4j.android.ApplicationStarter;
-import org.apache.commons.lang3.LocaleUtils;
 
+import java.lang.reflect.Method;
 import java.util.Map;
-import java.util.TimeZone;
 
 public class DatePickerManager extends SimpleViewManager<PickerView>  {
 
-  public static final String REACT_CLASS = "DatePickerManager";
+  private static final String REACT_CLASS = "DatePickerManager";
   private static final int SCROLL = 1;
-
   public static ThemedReactContext context;
-  private String date;
 
   @Override
   public String getName() {
@@ -33,69 +40,36 @@ public class DatePickerManager extends SimpleViewManager  {
     return new PickerView();
   }
 
-  @ReactProp(name = "mode")
-  public void setMode(PickerView view, String mode) {
-    Mode m;
-    try {
-      m = Mode.valueOf(mode);
-    } catch (Exception e) {
-      throw new IllegalArgumentException("Invalid mode. Valid modes: 'datetime', 'date', 'time'");
-    }
-    view.setMode(m);
-  }
-
-  @ReactProp(name = "date")
-  public void setDate(PickerView view, String date) {
-    this.date = date;
-  }
-
-  @ReactProp(name = "locale")
-  public void setLocale(PickerView view, String locale) {
-    view.setLocale(LocaleUtils.toLocale(locale.replace('-','_')));
-  }
-
-  @ReactProp(name = "minimumDate")
-  public void setMinimumDate(PickerView view, String date) {
-    view.setMinimumDate(date);
-  }
-
-  @ReactProp(name = "maximumDate")
-  public void setMaximumDate(PickerView view, String date) {
-    view.setMaximumDate(date);
-  }
-
-  @ReactProp(name = "fadeToColor")
-  public void setFadeToColor(PickerView view, String color) {
-    view.style.setFadeToColor(color);
-  }
-
-  @ReactProp(name = "textColor")
-  public void setTextColor(PickerView view, String color) {
-    view.style.setTextColor(color);
-  }
-
-  @ReactProp(name = "minuteInterval")
-  public void setMinuteInterval(PickerView view,  int interval) throws Exception {
-    if (interval < 0 || interval > 59) throw new Exception("Minute interval out of bounds");
-    view.setMinuteInterval(interval);
-  }
+  @ReactPropGroup(names = { DateProp.name, ModeProp.name, LocaleProp.name, MaximumDateProp.name,
+          MinimumDateProp.name, FadeToColorProp.name, TextColorProp.name, UtcProp.name, MinuteIntervalProp.name})
+  public void setProps(PickerView view, int index, Dynamic value) {
+    String[] propNames = getMethodAnnotation("setProps").names();
+    String propName = propNames[index];
+    view.updateProp(propName, value);
 
-  @ReactProp(name = "utc")
-  public void setUtc(PickerView view,  boolean utc) throws Exception {
-    TimeZone timeZone = utc ? TimeZone.getTimeZone("UTC") : TimeZone.getDefault();
-    view.setTimeZone(timeZone);
   }
 
-  @ReactPropGroup(names = {"height", "width"}, customType = "Style")
+  @ReactPropGroup(names = {}, customType = "Style")
   public void setStyle(PickerView view, int index, Integer style) {
-    if(index == 0) view.style.setHeight(style);
+    if(index == 0) {
+      view.updateProp("height", null);
+    }
   }
 
   @Override
   public Map<String, Integer> getCommandsMap() {
-    return MapBuilder.of(
-            "scroll", SCROLL
-    );
+    return MapBuilder.of("scroll", SCROLL);
+  }
+
+  @Override
+  protected void onAfterUpdateTransaction(PickerView pickerView) {
+   super.onAfterUpdateTransaction(pickerView);
+     try{
+       pickerView.update();
+     }
+     catch (Exception e){
+       e.printStackTrace();
+     }
   }
 
   public void receiveCommand(final PickerView view, int command, final ReadableArray args) {
@@ -106,15 +80,6 @@ public class DatePickerManager extends SimpleViewManager  {
     }
   }
 
-  @Override
-  protected void onAfterUpdateTransaction(PickerView view) {
-   super.onAfterUpdateTransaction(view);
-    // updateDisplayValuesIfNeeded() refreshes
-    // which options are available. Should happen before updating the selected date.
-    view.updateDisplayValuesIfNeeded();
-    view.setDate(date);
-  }
-
   public Map getExportedCustomBubblingEventTypeConstants() {
     return MapBuilder.builder()
             .put("dateChange", MapBuilder.of("phasedRegistrationNames",
@@ -123,6 +88,16 @@ public class DatePickerManager extends SimpleViewManager  {
             ).build();
   }
 
+  private ReactPropGroup getMethodAnnotation(String methodName) {
+    Method[] methods = this.getClass().getMethods();
+    Method method = null;
+    for (Method m : methods) {
+      if (m.getName().equals(methodName))
+        method = m;
+    }
+    return method.getAnnotation(ReactPropGroup.class);
+  }
+
 }
 
 

android/src/main/java/com/henninghall/date_picker/EmptyWheelUpdater.java

@@ -1,42 +0,0 @@
-package com.henninghall.date_picker;
-
-import java.util.HashMap;
-import cn.carbswang.android.numberpickerview.library.NumberPickerView;
-
-public class EmptyWheelUpdater {
-
-    private final PickerView pickerView;
-    private final HashMap<Integer, NumberPickerView> views;
-
-    EmptyWheelUpdater(PickerView pickerView) {
-        this.pickerView = pickerView;
-        this.views = getViews();
-    }
-
-    private HashMap<Integer, NumberPickerView> getViews() {
-        HashMap<Integer, NumberPickerView> views = new HashMap<>();
-        for (int id: Utils.emptyWheelIds) {
-            NumberPickerView view = (NumberPickerView) pickerView.findViewById(id);
-            views.put(id, view);
-        }
-        return views;
-    }
-
-    void update() {
-        hideAll();
-        int numberOfVisibleWheels = pickerView.getVisibleWheels().size();
-        int emptyViewsToAdd = numberOfVisibleWheels + 1;
-
-        for (int i = 0; i < emptyViewsToAdd; i++) {
-            int index = i * 2;
-            pickerView.wheelsWrapper.addView(views.get(Utils.emptyWheelIds[i]), index);
-        }
-    }
-
-    private void hideAll() {
-        for (NumberPickerView view: views.values()) {
-            pickerView.wheelsWrapper.removeView(view);
-        }
-    }
-
-}

android/src/main/java/com/henninghall/date_picker/PickerView.java

@@ -1,199 +1,92 @@
 package com.henninghall.date_picker;
 
-import android.os.Build;
 import android.view.View;
-import android.widget.LinearLayout;
 import android.widget.RelativeLayout;
 
-import com.henninghall.date_picker.wheelFunctions.Refresh;
-import com.henninghall.date_picker.wheelFunctions.SetDate;
-import com.henninghall.date_picker.wheelFunctions.UpdateVisibility;
-import com.henninghall.date_picker.wheelFunctions.WheelFunction;
-import com.henninghall.date_picker.wheels.AmPmWheel;
-import com.henninghall.date_picker.wheels.DateWheel;
-import com.henninghall.date_picker.wheels.DayWheel;
-import com.henninghall.date_picker.wheels.HourWheel;
-import com.henninghall.date_picker.wheels.MinutesWheel;
-import com.henninghall.date_picker.wheels.MonthWheel;
-import com.henninghall.date_picker.wheels.Wheel;
-import com.henninghall.date_picker.wheels.YearWheel;
-
-import java.text.SimpleDateFormat;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Calendar;
-import java.util.Collection;
-import java.util.List;
-import java.util.Locale;
-import java.util.TimeZone;
-
-import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+import com.facebook.react.bridge.Dynamic;
+import com.henninghall.date_picker.props.DateProp;
+import com.henninghall.date_picker.props.FadeToColorProp;
+import com.henninghall.date_picker.props.HeightProp;
+import com.henninghall.date_picker.props.LocaleProp;
+import com.henninghall.date_picker.props.ModeProp;
+import com.henninghall.date_picker.props.TextColorProp;
+import com.henninghall.date_picker.ui.UIManager;
 
+import java.util.ArrayList;
 
 public class PickerView extends RelativeLayout {
 
-    public LinearLayout wheelsWrapper;
-    public HourWheel hourWheel;
-    public DayWheel dayWheel;
-    public MinutesWheel minutesWheel;
-    public AmPmWheel ampmWheel;
-    public int minuteInterval = 1;
-    public Locale locale;
-    public Mode mode;
-    public Style style;
-    public DateWheel dateWheel;
-    public MonthWheel monthWheel;
-    public YearWheel yearWheel;
-    private WheelOrder wheelOrder;
-    EmptyWheelUpdater emptyWheelUpdater;
-    public boolean requireDisplayValueUpdate = true;
-    public TimeZone timeZone = TimeZone.getDefault();
-    private DateBoundary minDate;
-    private DateBoundary maxDate;
-    private WheelChangeListener onWheelChangeListener = new WheelChangeListenerImpl(this);
+    private final View rootView = inflate(getContext(), R.layout.datepicker_view, this);
+    private final UIManager uiManager;
+    private State state;
+    private ArrayList<String> updatedProps = new ArrayList<>();
 
     public PickerView() {
         super(DatePickerManager.context);
-
-        View rootView = inflate(getContext(), R.layout.datepicker_view, this);
-        style = new Style(this);
-
-        locale = Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP ? Locale.forLanguageTag("en") : Locale.getDefault();
-
-        wheelsWrapper = (LinearLayout) rootView.findViewById(R.id.wheelsWrapper);
-        wheelsWrapper.setWillNotDraw(false);
-
-        yearWheel = new YearWheel( this, R.id.year);
-        monthWheel = new MonthWheel( this, R.id.month);
-        dateWheel = new DateWheel( this, R.id.date);
-        dayWheel = new DayWheel( this, R.id.day);
-        minutesWheel = new MinutesWheel( this, R.id.minutes);
-        ampmWheel = new AmPmWheel(this, R.id.ampm);
-        hourWheel = new HourWheel(this, R.id.hour);
-
-        emptyWheelUpdater = new EmptyWheelUpdater(this);
-        wheelOrder = new WheelOrder(this);
-
-        changeAmPmWhenPassingMidnightOrNoon();
+        state = new State();
+        uiManager = new UIManager(state, this);
     }
 
-    private final Runnable measureAndLayout = new Runnable() {
-        @Override
-        public void run() {
-            measure(
-                    MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
-                    MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.EXACTLY));
-            layout(getLeft(), getTop(), getRight(), getBottom());
-        }
-    };
-
-    private void changeAmPmWhenPassingMidnightOrNoon(){
-        hourWheel.picker.setOnValueChangeListenerInScrolling(new NumberPickerView.OnValueChangeListenerInScrolling() {
-            @Override
-            public void onValueChangeInScrolling(NumberPickerView picker, int oldVal, int newVal) {
-                if(Settings.usesAmPm()){
-                    String oldValue = hourWheel.getValueAtIndex(oldVal);
-                    String newValue = hourWheel.getValueAtIndex(newVal);
-                    boolean passingNoonOrMidnight = (oldValue.equals("12") && newValue.equals("11")) || oldValue.equals("11") && newValue.equals("12");
-                    if (passingNoonOrMidnight) ampmWheel.picker.smoothScrollToValue((ampmWheel.picker.getValue() + 1) % 2,false);
-                }
-            }
-        });
-    }
+    public void update() {
 
+        if(updatedProps.contains(FadeToColorProp.name)) {
+            uiManager.updateFadeToColor();
+        }
 
-    public void setMinimumDate(String date) {
-        minDate = new DateBoundary(this, date);
-        requireDisplayValueUpdate = true;
-    }
-
-    public void setMaximumDate(String date) {
-        maxDate = new DateBoundary(this, date);
-        requireDisplayValueUpdate = true;
-    }
+        if(updatedProps.contains(TextColorProp.name)) {
+            uiManager.updateTextColor();
+        }
 
-    public void setDate(String isoDate) {
-        Calendar cal = Utils.isoToCalendar(isoDate, timeZone);
-        applyOnAllWheels(new SetDate(cal));
-    }
+        if(updatedProps.contains(ModeProp.name)) {
+            uiManager.updateWheelVisibility();
+        }
 
-    public void setLocale(Locale locale) {
-        this.locale = locale;
-        wheelOrder.update(locale);
-        requireDisplayValueUpdate = true;
-    }
+        if(updatedProps.contains(HeightProp.name)) {
+            uiManager.updateHeight();
+        }
 
-    public void setMinuteInterval(int interval) {
-        this.minuteInterval = interval;
-        requireDisplayValueUpdate = true;
-    }
+        if(updatedProps.contains(ModeProp.name) || updatedProps.contains(LocaleProp.name)) {
+            uiManager.updateWheelOrder();
+        }
 
-    // Rounding cal to closest minute interval
-    public Calendar getInitialDate() {
-        Calendar cal = Calendar.getInstance();
-        if(minuteInterval <= 1) return cal;
-        int exactMinute = Integer.valueOf(minutesWheel.format.format(cal.getTime()));
-        int diffSinceLastInterval = exactMinute % minuteInterval;
-        int diffAhead = minuteInterval - diffSinceLastInterval;
-        int diffBehind= -diffSinceLastInterval;
-        boolean closerToPrevious = minuteInterval / 2 > diffSinceLastInterval;
-        int diffToExactValue = closerToPrevious ? diffBehind : diffAhead;
-        cal.add(Calendar.MINUTE, diffToExactValue);
-        return (Calendar) cal.clone();
-    }
+        ArrayList<String> nonRefreshingProps = new ArrayList<String>(){{
+            add(DateProp.name);
+            add(FadeToColorProp.name);
+            add(TextColorProp.name);
+        }};
+        updatedProps.removeAll(nonRefreshingProps);
 
-    private String getDateFormatPattern(){
-        if(mode == Mode.date){
-            return wheelOrder.getVisibleWheel(0).getFormatPattern() + " "
-                    + wheelOrder.getVisibleWheel(1).getFormatPattern() + " "
-                    + wheelOrder.getVisibleWheel(2).getFormatPattern();
+        if(updatedProps.size() != 0) {
+            uiManager.updateDisplayValues();
         }
-        return dayWheel.getFormatPattern();
-    }
-
-    private String getFormatPattern() {
-        return this.getDateFormatPattern() + " "
-                + hourWheel.getFormatPattern() + " "
-                + minutesWheel.getFormatPattern()
-                + ampmWheel.getFormatPattern();
-    }
 
-    public String getDateString() {
-        String dateString = (mode == Mode.date)
-                ? wheelOrder.getVisibleWheel(0).getValue() + " "
-                + wheelOrder.getVisibleWheel(1).getValue() + " "
-                + wheelOrder.getVisibleWheel(2).getValue()
-                : dayWheel.getValue();
-        return dateString
-                + " " + hourWheel.getValue()
-                + " " + minutesWheel.getValue()
-                + ampmWheel.getValue();
-    }
+        uiManager.setWheelsToDate();
 
-    public void setMode(Mode mode) {
-        this.mode = mode;
-        applyOnAllWheels(new UpdateVisibility());
-        wheelOrder.update(locale);
-        requireDisplayValueUpdate = true;
+        updatedProps = new ArrayList<>();
     }
 
-    public Collection<Wheel> getVisibleWheels() {
-        Collection<Wheel> visibleWheels = new ArrayList<>();
-        for (Wheel wheel: getAllWheels()) if (wheel.visible()) visibleWheels.add(wheel);
-        return visibleWheels;
+    public void updateProp(String propName, Dynamic value) {
+        state.setProp(propName, value);
+        updatedProps.add(propName);
     }
 
-    public List<Wheel> getAllWheels(){
-        return new ArrayList<>(Arrays.asList(yearWheel, monthWheel, dateWheel, dayWheel, hourWheel, minutesWheel, ampmWheel));
+    public void scroll(int wheelIndex, int scrollTimes) {
+        uiManager.scroll(wheelIndex, scrollTimes);
     }
 
-    public void applyOnAllWheels(WheelFunction function) {
-        for (Wheel wheel: getAllWheels()) function.apply(wheel);
+    public View getRootView(){
+        return rootView;
     }
 
-    public void applyOnVisibleWheels(WheelFunction function) {
-        for (Wheel wheel: getVisibleWheels()) function.apply(wheel);
-    }
+    private final Runnable measureAndLayout = new Runnable() {
+        @Override
+        public void run() {
+            measure(
+                    MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.EXACTLY),
+                    MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.EXACTLY));
+            layout(getLeft(), getTop(), getRight(), getBottom());
+        }
+    };
 
     @Override
     public void requestLayout() {
@@ -201,45 +94,6 @@ public class PickerView extends RelativeLayout {
         post(measureAndLayout);
     }
 
-    public WheelChangeListener getListener() {
-        return onWheelChangeListener;
-    }
-
-    public void updateDisplayValuesIfNeeded() {
-        if(requireDisplayValueUpdate) {
-            applyOnAllWheels(new Refresh());
-            requireDisplayValueUpdate = false;
-        }
-    }
 
-    public void setTimeZone(TimeZone timeZone) {
-        this.timeZone = timeZone;
-        requireDisplayValueUpdate = true;
-    }
-
-    public Calendar getMinimumDate(){
-        if (minDate == null) return null;
-        return minDate.get();
-    }
 
-    public Calendar getMaximumDate(){
-        if (maxDate == null) return null;
-        return maxDate.get();
-    }
-
-    protected SimpleDateFormat getDateFormat() {
-        return new SimpleDateFormat(getFormatPattern(), locale);
-    }
-
-    public void scroll(int wheelIndex, int scrollTimes) {
-        NumberPickerView picker = wheelOrder.getVisibleWheel(wheelIndex).picker;
-        int currentIndex = picker.getValue();
-        int maxValue = picker.getMaxValue();
-        boolean isWrapping = picker.getWrapSelectorWheel();
-        int nextValue = currentIndex + scrollTimes;
-        if(nextValue <= maxValue || isWrapping) {
-            picker.smoothScrollToValue(nextValue % (maxValue + 1));
-        }
-
-    }
 }

android/src/main/java/com/henninghall/date_picker/Settings.java

@@ -1,12 +0,0 @@
-package com.henninghall.date_picker;
-
-
-import android.text.format.DateFormat;
-
-public class Settings {
-
-    public static boolean usesAmPm (){
-        return !DateFormat.is24HourFormat(DatePickerManager.context);
-    }
-
-}

android/src/main/java/com/henninghall/date_picker/State.java

@@ -0,0 +1,206 @@
+package com.henninghall.date_picker;
+
+import android.util.Log;
+
+import com.facebook.react.bridge.Dynamic;
+import com.henninghall.date_picker.models.Mode;
+import com.henninghall.date_picker.models.WheelType;
+import com.henninghall.date_picker.props.DateProp;
+import com.henninghall.date_picker.props.FadeToColorProp;
+import com.henninghall.date_picker.props.HeightProp;
+import com.henninghall.date_picker.props.LocaleProp;
+import com.henninghall.date_picker.props.MaximumDateProp;
+import com.henninghall.date_picker.props.MinimumDateProp;
+import com.henninghall.date_picker.props.MinuteIntervalProp;
+import com.henninghall.date_picker.props.ModeProp;
+import com.henninghall.date_picker.props.Prop;
+import com.henninghall.date_picker.props.TextColorProp;
+import com.henninghall.date_picker.props.UtcProp;
+
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Calendar;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.TimeZone;
+
+public class State {
+
+    private final Prop dateProp = new DateProp();
+    private final Prop modeProp = new ModeProp();
+    private final Prop localeProp = new LocaleProp();
+    private final Prop fadeToColorProp = new FadeToColorProp();
+    private final Prop textColorProp = new TextColorProp();
+    private final Prop minuteIntervalProp = new MinuteIntervalProp();
+    private final Prop minimumDateProp = new MinimumDateProp();
+    private final Prop maximumDateProp = new MaximumDateProp();
+    private final Prop utcProp = new UtcProp();
+    private final Prop heightProp = new HeightProp();
+
+    private final HashMap props = new HashMap<String, Prop>() {{
+        put(DateProp.name, dateProp);
+        put(ModeProp.name, modeProp);
+        put(LocaleProp.name, localeProp);
+        put(FadeToColorProp.name, fadeToColorProp);
+        put(TextColorProp.name, textColorProp);
+        put(MinuteIntervalProp.name, minuteIntervalProp);
+        put(MinimumDateProp.name, minimumDateProp);
+        put(MaximumDateProp.name, maximumDateProp);
+        put(UtcProp.name, utcProp);
+    }};
+
+    private Prop getProp(String name){
+        return (Prop) props.get(name);
+    }
+
+    void setProp(String propName, Dynamic value){
+        getProp(propName).setValue(value);
+    }
+
+    public Mode getMode() {
+        return (Mode) modeProp.getValue();
+    }
+
+    public String getFadeToColor() {
+        return (String) fadeToColorProp.getValue();
+    }
+
+    public String getTextColor() {
+        return (String) textColorProp.getValue();
+    }
+
+    public int getMinuteInterval() {
+        return (int) minuteIntervalProp.getValue();
+    }
+
+    public Locale getLocale() {
+        return (Locale) localeProp.getValue();
+    }
+
+    public Calendar getMinimumDate(){
+        DateBoundary db = new DateBoundary(getTimeZone(), (String) minimumDateProp.getValue());
+        return db.get();
+    }
+
+    public Calendar getMaximumDate(){
+        DateBoundary db = new DateBoundary(getTimeZone(), (String) maximumDateProp.getValue());
+        return db.get();
+    }
+
+    public TimeZone getTimeZone(){
+        boolean utc = (boolean) utcProp.getValue();
+        return utc ? TimeZone.getTimeZone("UTC") : TimeZone.getDefault();
+    }
+
+    public Calendar getDate() {
+        String date = (String) dateProp.getValue();
+        return Utils.isoToCalendar(date, getTimeZone());
+    }
+
+    public Integer getHeight() {
+        return (Integer) heightProp.getValue();
+    }
+
+    public int getShownCount() {
+        int DP_PER_SHOW_SHOW_COUNT = 35;
+        int showCount = getHeight() / DP_PER_SHOW_SHOW_COUNT;
+        int oddShowCount = showCount % 2 == 0 ? showCount + 1 : showCount;
+        return oddShowCount;
+    }
+
+    public ArrayList<WheelType> getOrderedWheels() {
+        String dateTimePattern = LocaleUtils.getDateTimePattern(getLocale());
+        ArrayList<WheelType> unorderedTypes = new ArrayList(Arrays.asList(WheelType.values()));
+        ArrayList<WheelType> orderedWheels = new ArrayList<>();
+
+        // Always put day wheel first
+        unorderedTypes.remove(WheelType.DAY);
+        orderedWheels.add(WheelType.DAY);
+
+        for (char ch : dateTimePattern.toCharArray()){
+            try {
+                WheelType wheelType = Utils.patternCharToWheelType(ch);
+                if (unorderedTypes.contains(wheelType)) {
+                    unorderedTypes.remove(wheelType);
+                    orderedWheels.add(wheelType);
+                }
+            } catch (Exception e) {
+                // ignore unknown pattern chars that not correspond to any wheel type
+            }
+        }
+        // If AM/PM wheel remains it means that the locale does not have AM/PM by default and it
+        // should be put last.
+        if(unorderedTypes.contains(WheelType.AM_PM)){
+            unorderedTypes.remove(WheelType.AM_PM);
+            orderedWheels.add(WheelType.AM_PM);
+        }
+
+        if(!unorderedTypes.isEmpty()) {
+            Log.e(
+                    "RNDatePicker",
+                    unorderedTypes.size() + " wheel types cannot be ordered. Wheel type 0: " + unorderedTypes.get(0));
+        }
+
+        return orderedWheels;
+    }
+
+    public ArrayList<WheelType> getVisibleWheels() {
+        ArrayList<WheelType> visibleWheels = new ArrayList<>();
+        Mode mode = getMode();
+        switch (mode){
+            case datetime: {
+                visibleWheels.add(WheelType.DAY);
+                visibleWheels.add(WheelType.HOUR);
+                visibleWheels.add(WheelType.MINUTE);
+                break;
+            }
+            case time: {
+                visibleWheels.add(WheelType.HOUR);
+                visibleWheels.add(WheelType.MINUTE);
+                break;
+            }
+            case date: {
+                visibleWheels.add(WheelType.YEAR);
+                visibleWheels.add(WheelType.MONTH);
+                visibleWheels.add(WheelType.DATE);
+                break;
+            }
+        }
+        if((mode == Mode.time || mode == Mode.datetime) && Utils.usesAmPm()){
+            visibleWheels.add(WheelType.AM_PM);
+        }
+        return visibleWheels;
+    }
+
+    public ArrayList<WheelType> getOrderedVisibleWheels() {
+        ArrayList<WheelType> orderedWheels = getOrderedWheels();
+        ArrayList<WheelType> visibleWheels = getVisibleWheels();
+        ArrayList<WheelType> visibleOrderedWheels = new ArrayList<>();
+        for (WheelType wheel : orderedWheels){
+            if(visibleWheels.contains(wheel)) visibleOrderedWheels.add(wheel);
+        }
+        return visibleOrderedWheels;
+    }
+
+    // Rounding cal to closest minute interval
+    public Calendar getInitialDate() {
+        Calendar cal = Calendar.getInstance();
+        int minuteInterval = getMinuteInterval();
+        if(minuteInterval <= 1) return cal;
+        SimpleDateFormat minuteFormat = new SimpleDateFormat("mm", getLocale());
+        int exactMinute = Integer.valueOf(minuteFormat.format(cal.getTime()));
+        int diffSinceLastInterval = exactMinute % minuteInterval;
+        int diffAhead = minuteInterval - diffSinceLastInterval;
+        int diffBehind= -diffSinceLastInterval;
+        boolean closerToPrevious = minuteInterval / 2 > diffSinceLastInterval;
+        int diffToExactValue = closerToPrevious ? diffBehind : diffAhead;
+        cal.add(Calendar.MINUTE, diffToExactValue);
+        return (Calendar) cal.clone();
+    }
+
+
+    public WheelType getVisibleWheel(int index) {
+        return getOrderedVisibleWheels().get(index);
+    }
+}

android/src/main/java/com/henninghall/date_picker/Style.java

@@ -1,61 +0,0 @@
-package com.henninghall.date_picker;
-
-import android.graphics.Color;
-import android.graphics.drawable.GradientDrawable;
-import android.widget.ImageView;
-import com.henninghall.date_picker.wheelFunctions.SetShowCount;
-import com.henninghall.date_picker.wheelFunctions.TextColor;
-
-import cn.carbswang.android.numberpickerview.library.NumberPickerView;
-
-
-class Style {
-    private static int DP_PER_SHOW_SHOW_COUNT = 35;
-
-    private final GradientDrawable gradientBottom;
-    private final GradientDrawable gradientTop;
-    private final PickerView pickerView;
-
-    public Style(PickerView pickerView) {
-        this.pickerView = pickerView;
-        ImageView overlayTop = (ImageView) pickerView.findViewById(R.id.overlay_top);
-        ImageView overlayBottom = (ImageView) pickerView.findViewById(R.id.overlay_bottom);
-        this.gradientTop =  (GradientDrawable) overlayTop.getDrawable();
-        this.gradientBottom =  (GradientDrawable) overlayBottom.getDrawable();
-    }
-
-    public void setFadeToColor(String color) {
-        int alpha = validColor(color) ? 255 : 0;
-        gradientTop.setAlpha(alpha);
-        gradientBottom.setAlpha(alpha);
-        if(validColor(color)) {
-            int startColor = Color.parseColor("#FF"+ color.substring(1));
-            int endColor = Color.parseColor("#00" + color.substring(1));
-            gradientTop.setColors(new int[] {startColor, endColor});
-            gradientBottom.setColors(new int[] {startColor, endColor});
-        }
-    }
-
-    public void setTextColor(String color) {
-        this.pickerView.applyOnAllWheels(new TextColor(color));
-    }
-
-    public void setHeight(int height) {
-        int showCount = height / DP_PER_SHOW_SHOW_COUNT;
-        int oddShowCount = showCount % 2 == 0 ? showCount + 1 : showCount;
-        pickerView.applyOnAllWheels(new SetShowCount(oddShowCount));
-        setShownCountOnEmptyWheels(oddShowCount);
-    }
-
-    private void setShownCountOnEmptyWheels(int shownCount) {
-        for (int id : Utils.emptyWheelIds) {
-            NumberPickerView view = (NumberPickerView) pickerView.findViewById(id);
-            if(view != null) view.setShownCount(shownCount);
-        }
-    }
-
-    private boolean validColor(String color){
-        return color != null && color.length() == 7;
-    }
-
-}

android/src/main/java/com/henninghall/date_picker/Utils.java

@@ -1,8 +1,11 @@
 package com.henninghall.date_picker;
 
 
+import android.text.format.DateFormat;
 import android.text.format.DateUtils;
 
+import com.henninghall.date_picker.models.WheelType;
+
 import net.time4j.PrettyTime;
 
 import java.text.ParseException;
@@ -15,6 +18,10 @@ import java.util.TimeZone;
 
 public class Utils {
 
+    public static boolean usesAmPm(){
+        return !DateFormat.is24HourFormat(DatePickerManager.context);
+    }
+
     public static int[] emptyWheelIds = {
             R.id.emptyStart,
             R.id.empty1,

android/src/main/java/com/henninghall/date_picker/WheelChangeListenerImpl.java

@@ -1,56 +0,0 @@
-package com.henninghall.date_picker;
-
-import com.facebook.react.bridge.Arguments;
-import com.facebook.react.bridge.WritableMap;
-import com.facebook.react.uimanager.events.RCTEventEmitter;
-import com.henninghall.date_picker.wheelFunctions.AnimateToDate;
-import com.henninghall.date_picker.wheels.Wheel;
-
-import java.text.DateFormat;
-import java.text.FieldPosition;
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.Locale;
-import java.util.TimeZone;
-
-public class WheelChangeListenerImpl implements WheelChangeListener {
-
-    private final PickerView pickerView;
-
-    public WheelChangeListenerImpl(PickerView pickerView) {
-        this.pickerView = pickerView;
-    }
-
-    @Override
-    public void onChange(Wheel picker) {
-        WritableMap event = Arguments.createMap();
-        TimeZone timeZone = pickerView.timeZone;
-        SimpleDateFormat dateFormat = pickerView.getDateFormat();
-        Calendar minDate = pickerView.getMinimumDate();
-        Calendar maxDate = pickerView.getMaximumDate();
-        try {
-            dateFormat.setTimeZone(timeZone);
-            Calendar date = Calendar.getInstance(timeZone);
-            String toParse = this.pickerView.getDateString();
-            Date newDate = dateFormat.parse(toParse);
-            date.setTime(newDate);
-
-
-            if (minDate != null && date.before(minDate)) pickerView.applyOnVisibleWheels(
-                    new AnimateToDate(minDate)
-            );
-            else if (maxDate != null && date.after(maxDate)) pickerView.applyOnVisibleWheels(
-                    new AnimateToDate(maxDate)
-            );
-            else {
-                event.putString("date", Utils.dateToIso(date));
-                DatePickerManager.context.getJSModule(RCTEventEmitter.class).receiveEvent(pickerView.getId(), "dateChange", event);
-            }
-        } catch (ParseException e) {
-            e.printStackTrace();
-        }
-    }
-
-}

android/src/main/java/com/henninghall/date_picker/WheelOrder.java

@@ -1,109 +0,0 @@
-package com.henninghall.date_picker;
-
-import com.henninghall.date_picker.wheels.Wheel;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Locale;
-
-public class WheelOrder
-{
-
-    private final HashMap<WheelType, Wheel> wheelPerWheelType;
-    private PickerView pickerView;
-    private ArrayList<WheelType> orderedWheels;
-
-    WheelOrder(final PickerView view) {
-        this.pickerView = view;
-        this.wheelPerWheelType = new HashMap<WheelType, Wheel>() {{
-            put(WheelType.DAY, pickerView.dayWheel);
-            put(WheelType.YEAR, pickerView.yearWheel);
-            put(WheelType.MONTH, pickerView.monthWheel);
-            put(WheelType.DATE, pickerView.dateWheel);
-            put(WheelType.HOUR, pickerView.hourWheel);
-            put(WheelType.MINUTE, pickerView.minutesWheel);
-            put(WheelType.AM_PM, pickerView.ampmWheel);
-        }};
-    }
-
-    private void updateAllWheels(final Locale locale) {
-        try {
-            this.orderedWheels = getOrderedWheels(locale);
-            pickerView.wheelsWrapper.removeAllViews();
-            for (int i = 0; i < wheelPerWheelType.size(); i++) {
-                Wheel w = getWheels(i);
-                if(w.visible()) {
-                    pickerView.wheelsWrapper.addView(w.picker);
-                }
-            }
-
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-
-    void update(final Locale locale) {
-        updateAllWheels(locale);
-        pickerView.emptyWheelUpdater.update();
-    }
-
-    private Wheel getWheels(int index){
-        return wheelPerWheelType.get(orderedWheels.get(index));
-    }
-
-    Wheel getVisibleWheel(int index){
-        return getVisibleWheels().get(index);
-    }
-
-    private ArrayList<Wheel> getVisibleWheels() {
-        ArrayList<Wheel> visibleOrderedWheels = new ArrayList<>();
-        for (WheelType wheelType : orderedWheels){
-            Wheel wheel = wheelPerWheelType.get(wheelType);
-            if(wheel.visible()) {
-                visibleOrderedWheels.add(wheel);
-            }
-        }
-        return visibleOrderedWheels;
-    }
-
-    private ArrayList<WheelType> getOrderedWheels(Locale locale) throws Exception {
-        String dateTimePattern = LocaleUtils.getDateTimePattern(locale);
-        ArrayList<WheelType> unorderedTypes = new ArrayList(Arrays.asList(WheelType.values()));
-        ArrayList<WheelType> orderedWheels = new ArrayList<>();
-
-        // Always put day wheel first
-        unorderedTypes.remove(WheelType.DAY);
-        orderedWheels.add(WheelType.DAY);
-
-        for (char ch : dateTimePattern.toCharArray()){
-            try {
-                WheelType wheelType = Utils.patternCharToWheelType(ch);
-                if (unorderedTypes.contains(wheelType)) {
-                    unorderedTypes.remove(wheelType);
-                    orderedWheels.add(wheelType);
-                }
-            } catch (Exception e) {
-                // ignore unknown pattern chars that not correspond to any wheel type
-            }
-        }
-        // If AM/PM wheel remains it means that the locale does not have AM/PM by default and it
-        // should be put last.
-        if(unorderedTypes.contains(WheelType.AM_PM)){
-            unorderedTypes.remove(WheelType.AM_PM);
-            orderedWheels.add(WheelType.AM_PM);
-        }
-
-        if(!unorderedTypes.isEmpty()) {
-            throw new Exception(unorderedTypes.size() + " wheel types cannot be ordered. Wheel type 0: " + unorderedTypes.get(0));
-        }
-
-        return orderedWheels;
-    }
-
-
-
-
-}
-

android/src/main/java/com/henninghall/date_picker/WheelPosition.java

@@ -1,5 +0,0 @@
-package com.henninghall.date_picker;
-
-public enum WheelPosition {
-    LEFT, RIGHT, MIDDLE
-}

android/src/main/java/com/henninghall/date_picker/Mode.java → android/src/main/java/com/henninghall/date_picker/models/Mode.java

@@ -1,4 +1,4 @@
-package com.henninghall.date_picker;
+package com.henninghall.date_picker.models;
 
 public enum Mode {
     date, time, datetime

android/src/main/java/com/henninghall/date_picker/WheelType.java → android/src/main/java/com/henninghall/date_picker/models/WheelType.java

@@ -1,4 +1,4 @@
-package com.henninghall.date_picker;
+package com.henninghall.date_picker.models;
 
 public enum WheelType {
     DAY, DATE, MONTH, YEAR, HOUR, MINUTE, AM_PM

android/src/main/java/com/henninghall/date_picker/props/DateProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public class DateProp extends Prop<String> {
+    public static final String name = "date";
+
+    @Override
+    public String toValue(Dynamic value){
+        return value.asString();
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/FadeToColorProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public class FadeToColorProp extends Prop<String> {
+    public static final String name = "fadeToColor";
+    
+    @Override
+    public String toValue(Dynamic value){
+        return value.asString();
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/HeightProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+import com.henninghall.date_picker.models.Mode;
+
+public class HeightProp extends Prop<Integer> {
+    public static final String name = "height";
+
+    @Override
+    public Integer toValue(Dynamic value){
+        return value.asInt();
+    }
+}

android/src/main/java/com/henninghall/date_picker/props/LocaleProp.java

@@ -0,0 +1,28 @@
+package com.henninghall.date_picker.props;
+
+import android.os.Build;
+
+import com.facebook.react.bridge.Dynamic;
+
+import org.apache.commons.lang3.LocaleUtils;
+
+import java.util.Locale;
+
+public class LocaleProp extends Prop<Locale> {
+    public static final String name = "locale";
+
+    public LocaleProp(){
+        super(
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP
+                ? Locale.forLanguageTag("en")
+                : Locale.getDefault()
+        );
+    }
+
+    @Override
+    public Locale toValue(Dynamic value){
+        return LocaleUtils.toLocale(value.asString().replace('-','_'));
+    }
+
+}
+

android/src/main/java/com/henninghall/date_picker/props/MaximumDateProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public class MaximumDateProp extends Prop<String> {
+    public static final String name = "maximumDate";
+    
+    @Override
+    public String toValue(Dynamic value){
+        return value.asString();
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/MinimumDateProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public class MinimumDateProp extends Prop<String> {
+    public static final String name = "minimumDate";
+
+    @Override
+    public String toValue(Dynamic value){
+        return value.asString();
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/MinuteIntervalProp.java

@@ -0,0 +1,17 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+import com.henninghall.date_picker.models.Mode;
+
+public class MinuteIntervalProp extends Prop<Integer> {
+    public static final String name = "minuteInterval";
+
+    public MinuteIntervalProp(){
+        super(1);
+    }
+
+    public Integer toValue(Dynamic value){
+        return value.asInt();
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/ModeProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+import com.henninghall.date_picker.models.Mode;
+
+public class ModeProp extends Prop<Mode> {
+    public static final String name = "mode";
+
+    @Override
+    public Mode toValue(Dynamic value){
+        return Mode.valueOf(value.asString());
+    }
+}

android/src/main/java/com/henninghall/date_picker/props/Prop.java

@@ -0,0 +1,28 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public abstract class Prop<T> {
+    private T value;
+
+    public Prop() { }
+
+    public Prop(T defaultValue) {
+        value = defaultValue;
+    }
+
+    abstract T toValue(Dynamic value);
+
+    public void setValue(Dynamic value){
+        this.value = toValue(value);
+    }
+
+    public void setValue(T value){
+        this.value = value;
+    }
+
+    public T getValue(){
+        return value;
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/TextColorProp.java

@@ -0,0 +1,13 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public class TextColorProp extends Prop<String> {
+    public static final String name = "textColor";
+    
+    @Override
+    public String toValue(Dynamic value){
+        return value.asString();
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/props/UtcProp.java

@@ -0,0 +1,12 @@
+package com.henninghall.date_picker.props;
+
+import com.facebook.react.bridge.Dynamic;
+
+public class UtcProp extends Prop<Boolean> {
+    public static final String name = "utc";
+
+    @Override
+    Boolean toValue(Dynamic value) {
+        return value.asBoolean();
+    }
+}

android/src/main/java/com/henninghall/date_picker/ui/EmptyWheels.java

@@ -0,0 +1,45 @@
+package com.henninghall.date_picker.ui;
+
+import android.view.View;
+
+import com.henninghall.date_picker.PickerView;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+
+import java.util.HashMap;
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
+public class EmptyWheels {
+
+    private final HashMap<Integer, NumberPickerView> views;
+    private final Wheels wheels;
+    private View rootView;
+    private State state;
+
+    EmptyWheels(View rootView, Wheels wheels, State state) {
+        this.wheels = wheels;
+        this.rootView = rootView;
+        this.state = state;
+        this.views = getViews();
+    }
+
+    private HashMap<Integer, NumberPickerView> getViews() {
+        HashMap<Integer, NumberPickerView> views = new HashMap<>();
+        for (int id: Utils.emptyWheelIds) {
+            NumberPickerView view = (NumberPickerView) rootView.findViewById(id);
+            views.put(id, view);
+        }
+        return views;
+    }
+
+    void add() {
+        int numberOfVisibleWheels = state.getVisibleWheels().size();
+        int emptyViewsToAdd = numberOfVisibleWheels + 1;
+        for (int i = 0; i < emptyViewsToAdd; i++) {
+            int index = i * 2;
+            wheels.addWheel(views.get(Utils.emptyWheelIds[i]), index);
+        }
+    }
+
+
+}

android/src/main/java/com/henninghall/date_picker/ui/FadingOverlay.java

@@ -0,0 +1,42 @@
+package com.henninghall.date_picker.ui;
+
+import android.graphics.Color;
+import android.graphics.drawable.GradientDrawable;
+import android.view.View;
+import android.widget.ImageView;
+
+import com.henninghall.date_picker.R;
+import com.henninghall.date_picker.State;
+
+public class FadingOverlay {
+
+    private final GradientDrawable gradientTop;
+    private final GradientDrawable gradientBottom;
+    private final State state;
+
+    public FadingOverlay(State state, View rootView) {
+        this.state = state;
+        ImageView overlayTop = (ImageView) rootView.findViewById(R.id.overlay_top);
+        ImageView overlayBottom = (ImageView) rootView.findViewById(R.id.overlay_bottom);
+        gradientTop =  (GradientDrawable) overlayTop.getDrawable();
+        gradientBottom =  (GradientDrawable) overlayBottom.getDrawable();
+    }
+
+    public void updateColor(){
+        String color = state.getFadeToColor();
+        int alpha = validColor(color) ? 255 : 0;
+        gradientTop.setAlpha(alpha);
+        gradientBottom.setAlpha(alpha);
+        if(validColor(color)) {
+            int startColor = Color.parseColor("#FF"+ color.substring(1));
+            int endColor = Color.parseColor("#00" + color.substring(1));
+            gradientTop.setColors(new int[] {startColor, endColor});
+            gradientBottom.setColors(new int[] {startColor, endColor});
+        }
+    }
+
+    private boolean validColor(String color){
+        return color != null && color.length() == 7;
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/ui/UIManager.java

@@ -0,0 +1,87 @@
+package com.henninghall.date_picker.ui;
+
+import android.view.View;
+
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+import com.henninghall.date_picker.wheelFunctions.AnimateToDate;
+import com.henninghall.date_picker.wheelFunctions.Refresh;
+import com.henninghall.date_picker.wheelFunctions.SetDate;
+import com.henninghall.date_picker.wheelFunctions.SetShowCount;
+import com.henninghall.date_picker.wheelFunctions.TextColor;
+import com.henninghall.date_picker.wheelFunctions.UpdateVisibility;
+import com.henninghall.date_picker.wheels.Wheel;
+
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
+public class UIManager {
+    private final State state;
+    private final View rootView;
+    private Wheels wheels;
+    private FadingOverlay fadingOverlay;
+    private WheelScroller wheelScroller = new WheelScroller();
+
+    public UIManager(State state, View rootView){
+        this.rootView = rootView;
+        this.state = state;
+        wheels = new Wheels(state, rootView, this);
+        fadingOverlay = new FadingOverlay(state, rootView);
+    }
+
+    public void updateWheelVisibility(){
+        wheels.applyOnAll(new UpdateVisibility());
+    }
+
+    public void updateTextColor(){
+        wheels.applyOnAll(new TextColor(state.getTextColor()));
+    }
+
+    public void updateFadeToColor(){
+        fadingOverlay.updateColor();
+    }
+
+    public void updateHeight(){
+        int shownCount = state.getShownCount();
+        wheels.applyOnAll(new SetShowCount(shownCount));
+        setShownCountOnEmptyWheels(shownCount);
+    }
+
+    public void updateWheelOrder() {
+        wheels.removeAll();
+        wheels.addInOrder();
+        wheels.addEmpty();
+    }
+
+    public void updateDisplayValues(){
+        wheels.applyOnAll(new Refresh());
+    }
+
+    public void setWheelsToDate(){
+        wheels.applyOnAll(new SetDate(state.getDate()));
+    }
+
+    public void scroll(int wheelIndex, int scrollTimes) {
+        Wheel wheel = wheels.getWheel(state.getOrderedVisibleWheels().get(wheelIndex));
+        wheelScroller.scroll(wheel,scrollTimes);
+    }
+
+    SimpleDateFormat getDateFormat() {
+        return new SimpleDateFormat(wheels.getFormatPattern(), state.getLocale());
+    }
+
+    void animateToDate(Calendar date) {
+        wheels.applyOnVisible(new AnimateToDate(date));
+    }
+
+    private void setShownCountOnEmptyWheels(int shownCount) {
+        for (int id : Utils.emptyWheelIds) {
+            NumberPickerView view = (NumberPickerView) rootView.findViewById(id);
+            if(view != null) view.setShownCount(shownCount);
+        }
+    }
+
+
+}

android/src/main/java/com/henninghall/date_picker/WheelChangeListener.java → android/src/main/java/com/henninghall/date_picker/ui/WheelChangeListener.java

@@ -1,4 +1,4 @@
-package com.henninghall.date_picker;
+package com.henninghall.date_picker.ui;
 
 import com.henninghall.date_picker.wheels.Wheel;
 

android/src/main/java/com/henninghall/date_picker/ui/WheelChangeListenerImpl.java

@@ -0,0 +1,60 @@
+package com.henninghall.date_picker.ui;
+
+import android.view.View;
+
+import com.facebook.react.bridge.Arguments;
+import com.facebook.react.bridge.WritableMap;
+import com.facebook.react.uimanager.events.RCTEventEmitter;
+import com.henninghall.date_picker.DatePickerManager;
+import com.henninghall.date_picker.PickerView;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+import com.henninghall.date_picker.wheels.Wheel;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.TimeZone;
+
+public class WheelChangeListenerImpl implements WheelChangeListener {
+
+    private final Wheels wheels;
+    private final State state;
+    private final UIManager uiManager;
+    private final View rootView;
+
+    public WheelChangeListenerImpl(Wheels wheels, State state, UIManager uiManager, View rootView) {
+        this.wheels = wheels;
+        this.uiManager = uiManager;
+        this.state = state;
+        this.rootView = rootView;
+    }
+
+    @Override
+    public void onChange(Wheel picker) {
+        WritableMap event = Arguments.createMap();
+        TimeZone timeZone = state.getTimeZone();
+        SimpleDateFormat dateFormat = uiManager.getDateFormat();
+        Calendar minDate = state.getMinimumDate();
+        Calendar maxDate = state.getMaximumDate();
+        try {
+            dateFormat.setTimeZone(timeZone);
+            Calendar date = Calendar.getInstance(timeZone);
+            String toParse = wheels.getDateString();
+            Date newDate = dateFormat.parse(toParse);
+            date.setTime(newDate);
+
+            if (minDate != null && date.before(minDate)) uiManager.animateToDate(minDate);
+            else if (maxDate != null && date.after(maxDate)) uiManager.animateToDate(maxDate);
+            else {
+                event.putString("date", Utils.dateToIso(date));
+                DatePickerManager.context.getJSModule(RCTEventEmitter.class)
+                        .receiveEvent(rootView.getId(), "dateChange", event);
+            }
+        } catch (ParseException e) {
+            e.printStackTrace();
+        }
+    }
+
+}

android/src/main/java/com/henninghall/date_picker/ui/WheelScroller.java

@@ -0,0 +1,19 @@
+package com.henninghall.date_picker.ui;
+
+import com.henninghall.date_picker.wheels.Wheel;
+
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
+public class WheelScroller {
+
+    public void scroll(Wheel wheel, int scrollTimes) {
+        NumberPickerView picker = wheel.picker;
+        int currentIndex = picker.getValue();
+        int maxValue = picker.getMaxValue();
+        boolean isWrapping = picker.getWrapSelectorWheel();
+        int nextValue = currentIndex + scrollTimes;
+        if(nextValue <= maxValue || isWrapping) {
+            picker.smoothScrollToValue(nextValue % (maxValue + 1));
+        }
+    }
+}

android/src/main/java/com/henninghall/date_picker/ui/Wheels.java

@@ -0,0 +1,186 @@
+package com.henninghall.date_picker.ui;
+
+import android.view.View;
+import android.widget.LinearLayout;
+
+import com.henninghall.date_picker.R;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+import com.henninghall.date_picker.models.WheelType;
+import com.henninghall.date_picker.models.Mode;
+import com.henninghall.date_picker.wheelFunctions.AddOnChangeListener;
+import com.henninghall.date_picker.wheelFunctions.WheelFunction;
+import com.henninghall.date_picker.wheels.AmPmWheel;
+import com.henninghall.date_picker.wheels.DateWheel;
+import com.henninghall.date_picker.wheels.DayWheel;
+import com.henninghall.date_picker.wheels.HourWheel;
+import com.henninghall.date_picker.wheels.MinutesWheel;
+import com.henninghall.date_picker.wheels.MonthWheel;
+import com.henninghall.date_picker.wheels.Wheel;
+import com.henninghall.date_picker.wheels.YearWheel;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
+public class Wheels {
+
+    private final State state;
+    private HourWheel hourWheel;
+    private DayWheel dayWheel;
+    private MinutesWheel minutesWheel;
+    private AmPmWheel ampmWheel;
+    private DateWheel dateWheel;
+    private MonthWheel monthWheel;
+    private YearWheel yearWheel;
+    private View rootView;
+    private final LinearLayout wheelsWrapper;
+    private final EmptyWheels emptyWheels;
+
+    private HashMap<WheelType, Wheel> wheelPerWheelType;
+    private UIManager uiManager;
+
+    Wheels(State state, View rootView, UIManager uiManager){
+        this.state = state;
+        this.rootView = rootView;
+        this.uiManager = uiManager;
+        wheelsWrapper = (LinearLayout) rootView.findViewById(R.id.wheelsWrapper);
+        wheelsWrapper.setWillNotDraw(false);
+
+        yearWheel = new YearWheel(getPickerWithId(R.id.year), state);
+        monthWheel = new MonthWheel(getPickerWithId(R.id.month), state);
+        dateWheel = new DateWheel(getPickerWithId(R.id.date), state);
+        dayWheel = new DayWheel(getPickerWithId(R.id.day), state);
+        minutesWheel = new MinutesWheel(getPickerWithId(R.id.minutes), state);
+        ampmWheel = new AmPmWheel(getPickerWithId(R.id.ampm), state);
+        hourWheel = new HourWheel(getPickerWithId(R.id.hour), state);
+        wheelPerWheelType = getWheelPerType();
+
+        changeAmPmWhenPassingMidnightOrNoon();
+        addOnChangeListener();
+        emptyWheels = new EmptyWheels(rootView,this,state);
+    }
+
+    private void addOnChangeListener(){
+        WheelChangeListener onWheelChangeListener = new WheelChangeListenerImpl(this, state, uiManager, rootView);
+        applyOnAll(new AddOnChangeListener(onWheelChangeListener));
+    }
+
+    private NumberPickerView getPickerWithId(int id){
+        return (NumberPickerView) rootView.findViewById(id);
+    }
+
+    private Collection<Wheel> getVisible() {
+        ArrayList<WheelType> wheelTypes = state.getVisibleWheels();
+        Collection<Wheel> wheels = new ArrayList<>();
+        for (WheelType type: wheelTypes){
+            wheels.add(getWheel(type));
+        }
+        return wheels;
+    }
+
+    void applyOnAll(WheelFunction function) {
+        for (Wheel wheel: getAll()) function.apply(wheel);
+    }
+
+    void applyOnVisible(WheelFunction function) {
+        for (Wheel wheel: getVisible()) function.apply(wheel);
+    }
+
+    Wheel getWheel(WheelType type){
+        return wheelPerWheelType.get(type);
+    }
+
+    void addInOrder(){
+        ArrayList<WheelType> wheels = state.getOrderedVisibleWheels();
+        for (WheelType wheelType : wheels) {
+            Wheel wheel = getWheel(wheelType);
+            addWheel(wheel.picker);
+        }
+    }
+
+    private ArrayList<Wheel> getOrderedWheels(){
+        ArrayList<Wheel> list = new ArrayList<>();
+        for (WheelType type : state.getOrderedVisibleWheels()) {
+            list.add(getWheel(type));
+        }
+        return list;
+    }
+
+    void addWheel(View wheel) { wheelsWrapper.addView(wheel); }
+
+    void addWheel(View wheel, int index) { wheelsWrapper.addView(wheel,index); }
+
+    void removeAll() {
+        wheelsWrapper.removeAllViews();
+    }
+
+    private void changeAmPmWhenPassingMidnightOrNoon() {
+        hourWheel.picker.setOnValueChangeListenerInScrolling(new NumberPickerView.OnValueChangeListenerInScrolling() {
+            @Override
+            public void onValueChangeInScrolling(NumberPickerView picker, int oldVal, int newVal) {
+                if(Utils.usesAmPm()){
+                    String oldValue = hourWheel.getValueAtIndex(oldVal);
+                    String newValue = hourWheel.getValueAtIndex(newVal);
+                    boolean passingNoonOrMidnight = (oldValue.equals("12") && newValue.equals("11")) || oldValue.equals("11") && newValue.equals("12");
+                    if (passingNoonOrMidnight) ampmWheel.picker.smoothScrollToValue((ampmWheel.picker.getValue() + 1) % 2,false);
+                }
+            }
+        });
+    }
+
+    private List<Wheel> getAll(){
+        return new ArrayList<>(Arrays.asList(yearWheel, monthWheel, dateWheel, dayWheel, hourWheel, minutesWheel, ampmWheel));
+    }
+
+    private String getDateFormatPattern(){
+        ArrayList<Wheel> wheels = getOrderedWheels();
+        if(state.getMode() == Mode.date){
+            return wheels.get(0).getFormatPattern() + " "
+                    + wheels.get(1).getFormatPattern() + " "
+                    + wheels.get(2).getFormatPattern();
+        }
+        return dayWheel.getFormatPattern();
+    }
+
+    public String getFormatPattern() {
+        return this.getDateFormatPattern() + " "
+                + hourWheel.getFormatPattern() + " "
+                + minutesWheel.getFormatPattern()
+                + ampmWheel.getFormatPattern();
+    }
+
+    String getDateString() {
+        ArrayList<Wheel> wheels = getOrderedWheels();
+
+        String dateString = (state.getMode() == Mode.date)
+                ? wheels.get(0).getValue() + " "
+                + wheels.get(1).getValue() + " "
+                + wheels.get(2).getValue()
+                : dayWheel.getValue();
+        return dateString
+                + " " + hourWheel.getValue()
+                + " " + minutesWheel.getValue()
+                + ampmWheel.getValue();
+    }
+
+    private HashMap<WheelType, Wheel> getWheelPerType(){
+        return new HashMap<WheelType, Wheel>() {{
+            put(WheelType.DAY, dayWheel);
+            put(WheelType.YEAR, yearWheel);
+            put(WheelType.MONTH,monthWheel);
+            put(WheelType.DATE, dateWheel);
+            put(WheelType.HOUR, hourWheel);
+            put(WheelType.MINUTE, minutesWheel);
+            put(WheelType.AM_PM, ampmWheel);
+        }};
+    }
+
+    void addEmpty() {
+        emptyWheels.add();
+    }
+}

android/src/main/java/com/henninghall/date_picker/wheelFunctions/AddOnChangeListener.java

@@ -0,0 +1,27 @@
+package com.henninghall.date_picker.wheelFunctions;
+
+import com.henninghall.date_picker.ui.WheelChangeListener;
+import com.henninghall.date_picker.wheels.Wheel;
+
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
+public class AddOnChangeListener implements WheelFunction {
+
+    private final WheelChangeListener onChangeListener;
+
+    public AddOnChangeListener(WheelChangeListener onChangeListener){
+        this.onChangeListener = onChangeListener;
+    }
+
+    @Override
+    public void apply(final Wheel wheel) {
+        wheel.picker.setOnValueChangedListener(new NumberPickerView.OnValueChangeListener() {
+            @Override
+            public void onValueChange(NumberPickerView picker, int oldVal, int newVal) {
+                onChangeListener.onChange(wheel);
+            }
+        });
+    }
+}
+
+

android/src/main/java/com/henninghall/date_picker/wheels/AmPmWheel.java

@@ -2,18 +2,20 @@ package com.henninghall.date_picker.wheels;
 
 import android.graphics.Paint;
 
-import com.henninghall.date_picker.Mode;
-import com.henninghall.date_picker.PickerView;
-import com.henninghall.date_picker.Settings;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+import com.henninghall.date_picker.models.Mode;
 
 import java.util.ArrayList;
 import java.util.Calendar;
 
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
 
 public class AmPmWheel extends Wheel {
 
-    public AmPmWheel(PickerView pickerView, int id) {
-        super(pickerView, id);
+    public AmPmWheel(final NumberPickerView picker, State state) {
+        super(picker, state);
     }
 
     @Override
@@ -31,12 +33,12 @@ public class AmPmWheel extends Wheel {
 
     @Override
     public boolean visible() {
-        return Settings.usesAmPm() && pickerView.mode != Mode.date;
+        return Utils.usesAmPm() && state.getMode() != Mode.date;
     }
 
     @Override
     public String getFormatPattern() {
-        return Settings.usesAmPm() ? " a " : "";
+        return Utils.usesAmPm() ? " a " : "";
     }
 
     @Override

android/src/main/java/com/henninghall/date_picker/wheels/DateWheel.java

@@ -1,17 +1,17 @@
 package com.henninghall.date_picker.wheels;
 
 import android.graphics.Paint;
-import android.text.format.DateUtils;
 
-import java.text.DateFormat;
-import java.text.SimpleDateFormat;
 import java.util.*;
 import com.henninghall.date_picker.*;
+import com.henninghall.date_picker.models.Mode;
+
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
 
 public class DateWheel extends Wheel
 {
-    public DateWheel(final PickerView pickerView, final int id) {
-        super(pickerView, id);
+    public DateWheel(final NumberPickerView picker, final State id) {
+        super(picker, id);
     }
 
 
@@ -32,12 +32,12 @@ public class DateWheel extends Wheel
 
     @Override
     public boolean visible() {
-        return this.pickerView.mode == Mode.date;
+        return state.getMode() == Mode.date;
     }
 
     @Override
     public String getFormatPattern() {
-        return LocaleUtils.getPatternIncluding("d", pickerView.locale);
+        return LocaleUtils.getPatternIncluding("d", state.getLocale());
     }
 
     @Override

android/src/main/java/com/henninghall/date_picker/wheels/DayWheel.java

@@ -4,7 +4,8 @@ import android.graphics.Paint;
 import android.text.TextUtils;
 
 import com.henninghall.date_picker.LocaleUtils;
-import com.henninghall.date_picker.Mode;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.models.Mode;
 import com.henninghall.date_picker.PickerView;
 import com.henninghall.date_picker.Utils;
 
@@ -12,15 +13,17 @@ import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Date;
 
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
 
 public class DayWheel extends Wheel {
 
     private String todayValue;
+    private static int defaultNumberOfDays = Calendar.getInstance().getActualMaximum(Calendar.DAY_OF_YEAR);
 
-    public DayWheel(PickerView pickerView, int id) {
-        super(pickerView, id);
+    public DayWheel(NumberPickerView picker, State state) {
+        super(picker, state);
     }
-    private static int defaultNumberOfDays = Calendar.getInstance().getActualMaximum(Calendar.DAY_OF_YEAR);
 
     @Override
     public ArrayList<String> getValues() {
@@ -40,8 +43,8 @@ public class DayWheel extends Wheel {
 
     private Calendar getStartCal(){
         Calendar cal;
-        Calendar max = pickerView.getMaximumDate();
-        Calendar min = pickerView.getMinimumDate();
+        Calendar max = state.getMaximumDate();
+        Calendar min = state.getMinimumDate();
         if (min != null) {
             cal = (Calendar) min.clone();
             resetToMidnight(cal);
@@ -50,7 +53,7 @@ public class DayWheel extends Wheel {
             resetToMidnight(cal);
             cal.add(Calendar.DATE, -cal.getActualMaximum(Calendar.DAY_OF_YEAR) / 2);
         } else {
-            cal = (Calendar) pickerView.getInitialDate().clone();
+            cal = (Calendar) state.getInitialDate().clone();
             cal.add(Calendar.DATE, -defaultNumberOfDays / 2);
         }
         return cal;
@@ -58,8 +61,8 @@ public class DayWheel extends Wheel {
 
     private Calendar getEndCal(){
         Calendar cal;
-        Calendar max = pickerView.getMaximumDate();
-        Calendar min = pickerView.getMinimumDate();
+        Calendar max = state.getMaximumDate();
+        Calendar min = state.getMinimumDate();
         if (max != null) {
             cal = (Calendar) max.clone();
             resetToMidnight(cal);
@@ -68,7 +71,7 @@ public class DayWheel extends Wheel {
             resetToMidnight(cal);
             cal.add(Calendar.DATE, cal.getActualMaximum(Calendar.DAY_OF_YEAR) / 2);
         } else {
-            cal = (Calendar) pickerView.getInitialDate().clone();
+            cal = (Calendar) state.getInitialDate().clone();
             cal.setTime(new Date());
             cal.add(Calendar.DATE, defaultNumberOfDays / 2);
         }
@@ -88,13 +91,13 @@ public class DayWheel extends Wheel {
 
     @Override
     public boolean visible() {
-        return pickerView.mode == Mode.datetime;
+        return state.getMode() == Mode.datetime;
     }
 
 
     @Override
     public String getFormatPattern() {
-        return LocaleUtils.getDatePattern(pickerView.locale)
+        return LocaleUtils.getDatePattern(state.getLocale())
                 .replace("EEEE", "EEE")
                 .replace("MMMM", "MMM");
     }
@@ -113,7 +116,7 @@ public class DayWheel extends Wheel {
     }
 
     private String toTodayString(String value) {
-        String todayString = Utils.printToday(pickerView.locale);
+        String todayString = Utils.printToday(state.getLocale());
         boolean shouldBeCapitalized = Character.isUpperCase(value.charAt(0));
         return shouldBeCapitalized
                 ? Utils.capitalize(todayString)
@@ -122,7 +125,7 @@ public class DayWheel extends Wheel {
 
     private String removeYear(String value) {
         ArrayList<String> pieces = Utils.splitOnSpace(value);
-        pieces.remove(LocaleUtils.getFullPatternPos("y", pickerView.locale));
+        pieces.remove(LocaleUtils.getFullPatternPos("y", state.getLocale()));
         return TextUtils.join(" ", pieces);
     }
 

android/src/main/java/com/henninghall/date_picker/wheels/HourWheel.java

@@ -2,25 +2,26 @@ package com.henninghall.date_picker.wheels;
 
 import android.graphics.Paint;
 
-import com.henninghall.date_picker.Mode;
-import com.henninghall.date_picker.PickerView;
-import com.henninghall.date_picker.Settings;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+import com.henninghall.date_picker.models.Mode;
 
 import java.util.ArrayList;
 import java.util.Calendar;
 
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
 public class HourWheel extends Wheel {
 
-    public HourWheel(PickerView pickerView, int id) {
-        super(pickerView, id);
+    public HourWheel(NumberPickerView picker, State id) {
+        super(picker, id);
     }
 
-
     @Override
     public ArrayList<String> getValues() {
         Calendar cal = Calendar.getInstance();
         ArrayList<String> values = new ArrayList<>();
-        int numberOfHours = Settings.usesAmPm() ? 12 : 24;
+        int numberOfHours = Utils.usesAmPm() ? 12 : 24;
 
         for(int i=0; i<numberOfHours; i++) {
             values.add(format.format(cal.getTime()));
@@ -31,12 +32,12 @@ public class HourWheel extends Wheel {
 
     @Override
     public boolean visible() {
-        return pickerView.mode != Mode.date;
+        return state.getMode() != Mode.date;
     }
 
     @Override
     public String getFormatPattern() {
-        return Settings.usesAmPm() ? "h": "HH";
+        return Utils.usesAmPm() ? "h": "HH";
     }
 
     @Override

android/src/main/java/com/henninghall/date_picker/wheels/MinutesWheel.java

@@ -2,17 +2,19 @@ package com.henninghall.date_picker.wheels;
 
 import android.graphics.Paint;
 
-import com.henninghall.date_picker.Mode;
-import com.henninghall.date_picker.PickerView;
-import com.henninghall.date_picker.Settings;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.Utils;
+import com.henninghall.date_picker.models.Mode;
 
 import java.util.ArrayList;
 import java.util.Calendar;
 
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
 public class MinutesWheel extends Wheel {
 
-    public MinutesWheel(PickerView pickerView, int id) {
-        super(pickerView, id);
+    public MinutesWheel(NumberPickerView picker, State id) {
+        super(picker, id);
     }
 
     @Override
@@ -21,9 +23,9 @@ public class MinutesWheel extends Wheel {
         ArrayList<String> values = new ArrayList<>();
 
         cal.set(Calendar.MINUTE, 0);
-        for(int i=0; i<60; i = i + pickerView.minuteInterval) {
+        for(int i=0; i<60; i = i + state.getMinuteInterval()) {
             values.add(format.format(cal.getTime()));
-            cal.add(Calendar.MINUTE, pickerView.minuteInterval);
+            cal.add(Calendar.MINUTE, state.getMinuteInterval());
         }
 
         return values;
@@ -31,7 +33,7 @@ public class MinutesWheel extends Wheel {
 
     @Override
     public boolean visible() {
-        return pickerView.mode != Mode.date;
+        return state.getMode() != Mode.date;
     }
 
     @Override
@@ -41,7 +43,7 @@ public class MinutesWheel extends Wheel {
 
     @Override
     public Paint.Align getTextAlign() {
-        return Settings.usesAmPm() ? Paint.Align.RIGHT: Paint.Align.LEFT;
+        return Utils.usesAmPm() ? Paint.Align.RIGHT: Paint.Align.LEFT;
     }
 
 }

android/src/main/java/com/henninghall/date_picker/wheels/MonthWheel.java

@@ -4,10 +4,13 @@ import android.graphics.Paint;
 
 import java.util.*;
 import com.henninghall.date_picker.*;
+import com.henninghall.date_picker.models.Mode;
+
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
 
 public class MonthWheel extends Wheel
 {
-    public MonthWheel(final PickerView pickerView, final int id) {
+    public MonthWheel(final NumberPickerView pickerView, final State id) {
         super(pickerView, id);
     }
 
@@ -27,7 +30,7 @@ public class MonthWheel extends Wheel
 
     @Override
     public boolean visible() {
-        return this.pickerView.mode == Mode.date;
+        return state.getMode() == Mode.date;
     }
 
     @Override

android/src/main/java/com/henninghall/date_picker/wheels/Wheel.java

@@ -4,7 +4,7 @@ import android.graphics.Paint;
 import android.view.View;
 
 import cn.carbswang.android.numberpickerview.library.NumberPickerView;
-import com.henninghall.date_picker.PickerView;
+import com.henninghall.date_picker.State;
 
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
@@ -13,9 +13,7 @@ import java.util.Locale;
 
 public abstract class Wheel {
 
-    private final Wheel self;
-    public final int id;
-    public PickerView pickerView;
+    protected final State state;
     private Calendar userSetValue;
 
     public abstract boolean visible();
@@ -27,27 +25,19 @@ public abstract class Wheel {
         return value;
     }
 
-    ArrayList<String> values = new ArrayList<>();
+    private ArrayList<String> values = new ArrayList<>();
     public NumberPickerView picker;
     public SimpleDateFormat format;
 
-    public Wheel(final PickerView pickerView, final int id) {
-        this.id = id;
-        this.self = this;
-        this.pickerView = pickerView;
-        this.picker = (NumberPickerView) pickerView.findViewById(id);
-        this.format = new SimpleDateFormat(getFormatPattern(), pickerView.locale);
+    public Wheel(NumberPickerView picker, State state) {
+        this.state = state;
+        this.picker = picker;
+        this.format = new SimpleDateFormat(getFormatPattern(), state.getLocale());
         picker.setTextAlign(getTextAlign());
-        picker.setOnValueChangedListener(new NumberPickerView.OnValueChangeListener() {
-            @Override
-            public void onValueChange(NumberPickerView picker, int oldVal, int newVal) {
-                pickerView.getListener().onChange(self);
-            }
-        });
     }
 
     private int getIndexOfDate(Calendar date){
-        format.setTimeZone(pickerView.timeZone);
+        format.setTimeZone(state.getTimeZone());
         return values.indexOf(format.format(date.getTime()));
     }
 
@@ -69,7 +59,7 @@ public abstract class Wheel {
     }
 
     public void setValue(Calendar date) {
-        format.setTimeZone(pickerView.timeZone);
+        format.setTimeZone(state.getTimeZone());
         this.userSetValue = date;
         int index = getIndexOfDate(date);
 
@@ -81,7 +71,7 @@ public abstract class Wheel {
     }
 
     public void refresh() {
-        this.format = new SimpleDateFormat(getFormatPattern(), pickerView.locale);
+        this.format = new SimpleDateFormat(getFormatPattern(), state.getLocale());
         if (!this.visible()) return;
         init();
     }
@@ -112,7 +102,7 @@ public abstract class Wheel {
     }
 
     String getLocaleString(Calendar cal) {
-        return getString(cal, this.pickerView.locale);
+        return getString(cal, this.state.getLocale());
     }
 
     private String getString(Calendar cal, Locale locale){

android/src/main/java/com/henninghall/date_picker/wheels/YearWheel.java

@@ -3,19 +3,22 @@ package com.henninghall.date_picker.wheels;
 import android.graphics.Paint;
 
 import com.henninghall.date_picker.LocaleUtils;
-import com.henninghall.date_picker.Mode;
+import com.henninghall.date_picker.State;
+import com.henninghall.date_picker.models.Mode;
 import com.henninghall.date_picker.PickerView;
 
 import java.util.ArrayList;
 import java.util.Calendar;
 
+import cn.carbswang.android.numberpickerview.library.NumberPickerView;
+
 public class YearWheel extends Wheel
 {
     private int defaultStartYear;
     private int defaultEndYear;
 
-    public YearWheel(final PickerView pickerView, final int id) {
-        super(pickerView, id);
+    public YearWheel(final NumberPickerView picker, final State id) {
+        super(picker, id);
         this.defaultStartYear = 1900;
         this.defaultEndYear = 2100;
     }
@@ -40,22 +43,22 @@ public class YearWheel extends Wheel
     }
 
     private int getEndYear() {
-        if (this.pickerView.getMaximumDate() == null) {
+        if (state.getMaximumDate() == null) {
             return this.defaultEndYear;
         }
-        return this.pickerView.getMaximumDate().get(Calendar.YEAR);
+        return state.getMaximumDate().get(Calendar.YEAR);
     }
 
     private int getStartYear() {
-        if (this.pickerView.getMinimumDate() == null) {
+        if (state.getMinimumDate() == null) {
             return this.defaultStartYear;
         }
-        return this.pickerView.getMinimumDate().get(Calendar.YEAR);
+        return state.getMinimumDate().get(Calendar.YEAR);
     }
 
     @Override
     public boolean visible() {
-        return this.pickerView.mode == Mode.date;
+        return state.getMode() == Mode.date;
     }
 
     @Override
@@ -65,7 +68,7 @@ public class YearWheel extends Wheel
 
     @Override
     public String getFormatPattern() {
-        return LocaleUtils.getPatternIncluding("y", pickerView.locale);
+        return LocaleUtils.getPatternIncluding("y", state.getLocale());
     }
 
 }