1 files changed, 141 insertions, 0 deletions

diff --git a/Xamarin.Forms.Platform.Android/AppCompat/PickerRenderer.cs b/Xamarin.Forms.Platform.Android/AppCompat/PickerRenderer.cs
new file mode 100644
index 00000000..d59d9f6e
--- /dev/null
+++ b/Xamarin.Forms.Platform.Android/AppCompat/PickerRenderer.cs
@@ -0,0 +1,141 @@
+using System;
+using System.ComponentModel;
+using System.Linq;
+using Android.App;
+using Android.Text;
+using Android.Widget;
+using Object = Java.Lang.Object;
+
+namespace Xamarin.Forms.Platform.Android.AppCompat
+{
+	public class PickerRenderer : ViewRenderer<Picker, EditText>
+	{
+		AlertDialog _dialog;
+		bool _disposed;
+
+		public PickerRenderer()
+		{
+			AutoPackage = false;
+		}
+
+		protected override EditText CreateNativeControl()
+		{
+			return new EditText(Context);
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing && !_disposed)
+			{
+				_disposed = true;
+
+				((ObservableList<string>)Element.Items).CollectionChanged -= RowsCollectionChanged;
+			}
+
+			base.Dispose(disposing);
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
+		{
+			if (e.OldElement != null)
+				((ObservableList<string>)e.OldElement.Items).CollectionChanged -= RowsCollectionChanged;
+
+			if (e.NewElement != null)
+			{
+				((ObservableList<string>)e.NewElement.Items).CollectionChanged += RowsCollectionChanged;
+				if (Control == null)
+				{
+					EditText textField = CreateNativeControl();
+					textField.Focusable = false;
+					textField.Clickable = true;
+					textField.Tag = this;
+					textField.InputType = InputTypes.Null;
+					textField.SetOnClickListener(PickerListener.Instance);
+					SetNativeControl(textField);
+				}
+				UpdatePicker();
+			}
+
+			base.OnElementChanged(e);
+		}
+
+		protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
+		{
+			base.OnElementPropertyChanged(sender, e);
+
+			if (e.PropertyName == Picker.TitleProperty.PropertyName)
+				UpdatePicker();
+			if (e.PropertyName == Picker.SelectedIndexProperty.PropertyName)
+				UpdatePicker();
+		}
+
+		internal override void OnFocusChangeRequested(object sender, VisualElement.FocusRequestArgs e)
+		{
+			base.OnFocusChangeRequested(sender, e);
+
+			if (e.Focus)
+				OnClick();
+			else if (_dialog != null)
+			{
+				_dialog.Hide();
+				((IElementController)Element).SetValueFromRenderer(VisualElement.IsFocusedPropertyKey, false);
+				Control.ClearFocus();
+				_dialog = null;
+			}
+		}
+
+		void OnClick()
+		{
+			Picker model = Element;
+			using(var builder = new AlertDialog.Builder(Context))
+			{
+				builder.SetTitle(model.Title ?? "");
+				string[] items = model.Items.ToArray();
+				builder.SetItems(items, (s, e) => ((IElementController)model).SetValueFromRenderer(Picker.SelectedIndexProperty, e.Which));
+
+				builder.SetNegativeButton(global::Android.Resource.String.Cancel, (o, args) => { });
+
+				_dialog = builder.Create();
+			}
+
+			_dialog.SetCanceledOnTouchOutside(true);
+			_dialog.DismissEvent += (sender, args) =>
+			{
+				_dialog.Dispose();
+				_dialog = null;
+			};
+
+			_dialog.Show();
+		}
+
+		void RowsCollectionChanged(object sender, EventArgs e)
+		{
+			UpdatePicker();
+		}
+
+		void UpdatePicker()
+		{
+			Control.Hint = Element.Title;
+
+			if (Element.SelectedIndex == -1 || Element.Items == null)
+				Control.Text = null;
+			else
+				Control.Text = Element.Items[Element.SelectedIndex];
+		}
+
+		class PickerListener : Object, IOnClickListener
+		{
+			#region Statics
+
+			public static readonly PickerListener Instance = new PickerListener();
+
+			#endregion
+
+			public void OnClick(global::Android.Views.View v)
+			{
+				var renderer = v.Tag as PickerRenderer;
+				renderer?.OnClick();
+			}
+		}
+	}
+}
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