DatePicker

gistfile1.cs

using System;
using MonoTouch.UIKit;
using System.Drawing;


namespace Core.Controls
{
 public class DatePicker
 {
    #region Head
    public event EventHandler<EventArgs> Changed;
    UIView within;

    // Constructor.
    public DatePicker(UIView within)
    {
      // Setup initial conditions.
      this.within = within;
      Control = new UIDatePicker(RectangleF.Empty){ AutoresizingMask = UIViewAutoresizing.FlexibleWidth };
      Duration = 0.2;

      // Wire up events.
      Control.AddTarget((s, e) => { 
        if (Changed != null) Changed(this, new EventArgs());
      }, 
      UIControlEvent.ValueChanged);
    }
    #endregion

    #region Properties - Public
    public UIDatePicker Control { get; private set; }
    public double Duration { get; set; }
    public bool IsShowing { get; private set; }
    public bool IsAnimating { get; private set; }
    public DateTime Date
    {
      get{ return Control.Date; }
      set{ Control.Date = value; }
    }
    #endregion

    #region Methods - Public
    public bool Toggle(Action onComplete = null)
    {
      if (IsShowing) {
        return Hide(onComplete);
      } else {
        return Show(onComplete);
      }
    }

    public bool Show(Action onComplete = null)
    {
      // Setup initial conditions.
      if(IsShowing || IsAnimating) return false;

      // Insert the date-picker off the bottom of the screen.
      Control.Frame = offScreenBounds();
      within.AddSubview(Control);

      // Animate on screen.
      IsAnimating = true;
      UIView.AnimateNotify(
        Duration, 
        animation:() => {
          Control.Frame = onScreenBounds();
        },
        completion: (finished) => {
          // Done.
          IsAnimating = false;
          IsShowing = true;
          if (onComplete != null) onComplete();
      });

      // Finish up.
      return true;
    }


    public bool Hide(Action onComplete = null)
    {
      // Setup initial conditions.
      if(!IsShowing || IsAnimating) return false;

      // Animate off screen.
      IsAnimating = true;
      UIView.AnimateNotify(
        Duration, 
        animation:() => {
          Control.Frame = offScreenBounds();
        },
        completion: (finished) => {
          // Done.
          IsAnimating = false;
          IsShowing = false;
          Control.RemoveFromSuperview();
          if (onComplete != null) onComplete();
      });

      // Finish up.
      return true;
    }
    #endregion

    #region Internal
    private SizeF size(){ return new SizeF(within.Frame.Width, Control.Frame.Height); }

    private RectangleF offScreenBounds()
    {
      return new RectangleF (new PointF(0, within.Frame.Height), size());
    }

    private RectangleF onScreenBounds()
    {
      var top = within.Frame.Height - Control.Frame.Height;
      return new RectangleF (new PointF(0, top), size());
    }
    #endregion
  }
}