From 6dc869b9e5b35c1ac129e4543c7fc6ee7395143c Mon Sep 17 00:00:00 2001
From: "Frank A. Krueger" <fak@praeclarum.org>
Date: Sun, 26 Nov 2017 10:32:55 -0800
Subject: [PATCH] Add DatePickerRenderer

---
 Ooui.Forms/Exports.cs                      |   1 +
 Ooui.Forms/Renderers/DatePickerRenderer.cs | 111 +++++++++++++++++++++
 Samples/DisplayAlertPage.xaml              |   5 +-
 Samples/DisplayAlertPage.xaml.cs           |   2 +-
 4 files changed, 116 insertions(+), 3 deletions(-)
 create mode 100644 Ooui.Forms/Renderers/DatePickerRenderer.cs

diff --git a/Ooui.Forms/Exports.cs b/Ooui.Forms/Exports.cs
index bc179cd..c231e3d 100644
--- a/Ooui.Forms/Exports.cs
+++ b/Ooui.Forms/Exports.cs
@@ -8,6 +8,7 @@ using Xamarin.Forms.Internals;
 [assembly: ExportRenderer (typeof (ActivityIndicator), typeof (ActivityIndicatorRenderer))]
 [assembly: ExportRenderer (typeof (BoxView), typeof (BoxRenderer))]
 [assembly: ExportRenderer (typeof (Button), typeof (ButtonRenderer))]
+[assembly: ExportRenderer (typeof (DatePicker), typeof (DatePickerRenderer))]
 [assembly: ExportRenderer (typeof (Entry), typeof (EntryRenderer))]
 [assembly: ExportRenderer (typeof (Label), typeof (LabelRenderer))]
 [assembly: ExportRenderer (typeof (ProgressBar), typeof (ProgressBarRenderer))]
diff --git a/Ooui.Forms/Renderers/DatePickerRenderer.cs b/Ooui.Forms/Renderers/DatePickerRenderer.cs
new file mode 100644
index 0000000..79bb422
--- /dev/null
+++ b/Ooui.Forms/Renderers/DatePickerRenderer.cs
@@ -0,0 +1,111 @@
+using System;
+using System.ComponentModel;
+using Xamarin.Forms;
+using Ooui.Forms.Extensions;
+
+namespace Ooui.Forms.Renderers
+{
+    public class DatePickerRenderer : ViewRenderer<DatePicker, Input>
+    {
+        bool _disposed;
+
+        IElementController ElementController => Element as IElementController;
+
+        public override SizeRequest GetDesiredSize (double widthConstraint, double heightConstraint)
+        {
+            var size = "00/00/0000".MeasureSize ("", 16.0, FontAttributes.None);
+            size = new Size (size.Width, size.Height * 1.428 + 14);
+            return new SizeRequest (size, size);
+        }
+
+        protected override void OnElementChanged (ElementChangedEventArgs<DatePicker> e)
+        {
+            base.OnElementChanged (e);
+
+            if (e.NewElement == null)
+                return;
+
+            if (Control == null) {
+                var entry = new Input {
+                    ClassName = "form-control",
+                    Type = InputType.Date,
+                };
+
+                entry.Inputted += OnStarted;
+                entry.Changed += OnEnded;
+
+                SetNativeControl (entry);
+            }
+
+            UpdateDateFromModel (false);
+            UpdateMaximumDate ();
+            UpdateMinimumDate ();
+            UpdateTextColor ();
+            UpdateFlowDirection ();
+        }
+
+        protected override void OnElementPropertyChanged (object sender, PropertyChangedEventArgs e)
+        {
+            base.OnElementPropertyChanged (sender, e);
+
+            if (e.PropertyName == DatePicker.DateProperty.PropertyName || e.PropertyName == DatePicker.FormatProperty.PropertyName)
+                UpdateDateFromModel (true);
+            else if (e.PropertyName == DatePicker.MinimumDateProperty.PropertyName)
+                UpdateMinimumDate ();
+            else if (e.PropertyName == DatePicker.MaximumDateProperty.PropertyName)
+                UpdateMaximumDate ();
+            else if (e.PropertyName == DatePicker.TextColorProperty.PropertyName || e.PropertyName == VisualElement.IsEnabledProperty.PropertyName)
+                UpdateTextColor ();
+        }
+
+        void OnEnded (object sender, EventArgs eventArgs)
+        {
+            DateTime.TryParseExact (Control.Value, "yyyy-MM-dd", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.AssumeUniversal, out var date);
+            ElementController?.SetValueFromRenderer (DatePicker.DateProperty, date);
+            ElementController?.SetValueFromRenderer (VisualElement.IsFocusedPropertyKey, false);
+        }
+
+        void OnStarted (object sender, EventArgs eventArgs)
+        {
+            ElementController?.SetValueFromRenderer (VisualElement.IsFocusedPropertyKey, true);
+        }
+
+        void UpdateDateFromModel (bool animate)
+        {
+            Control.Value = Element.Date.ToString ("yyyy-MM-dd");
+        }
+
+        void UpdateFlowDirection ()
+        {
+        }
+
+        void UpdateMaximumDate ()
+        {
+        }
+
+        void UpdateMinimumDate ()
+        {
+        }
+
+        void UpdateTextColor ()
+        {
+        }
+
+        protected override void Dispose (bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            _disposed = true;
+
+            if (disposing) {
+                if (Control != null) {
+                    Control.Inputted -= OnStarted;
+                    Control.Changed -= OnEnded;
+                }
+            }
+
+            base.Dispose (disposing);
+        }
+    }
+}
diff --git a/Samples/DisplayAlertPage.xaml b/Samples/DisplayAlertPage.xaml
index b5deb93..fd29d53 100644
--- a/Samples/DisplayAlertPage.xaml
+++ b/Samples/DisplayAlertPage.xaml
@@ -4,10 +4,11 @@
              x:Class="Samples.DisplayAlertPage">
     <ContentPage.Content>
         <StackLayout>
-            <Label Text="Welcome to DisplayAlert Sample!" />
+            <Label Text="Welcome to DisplayAlert Sample!" FontSize="32" FontAttributes="Bold" Margin="10,10,10,50" />
             <ActivityIndicator x:Name="activity" />
             <ProgressBar x:Name="progress" />
-            <Button Text="Tap for Display Alert"
+            <DatePicker x:Name="datePicker" />
+            <Button Text="Tap to Display Alert"
                     Clicked="OnButtonClicked" />
         </StackLayout>
     </ContentPage.Content>
diff --git a/Samples/DisplayAlertPage.xaml.cs b/Samples/DisplayAlertPage.xaml.cs
index 8ebd945..719568d 100644
--- a/Samples/DisplayAlertPage.xaml.cs
+++ b/Samples/DisplayAlertPage.xaml.cs
@@ -18,7 +18,7 @@ namespace Samples
         {
             activity.IsRunning = true;
             progress.Progress = 0.5;
-            var result = await DisplayAlert("Alert Message", "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero. Sed cursus ante dapibus diam. Sed nisi. Nulla quis sem at nibh elementum imperdiet. Duis sagittis ipsum. Praesent mauris. Fusce nec tellus sed augue semper porta. Mauris massa.", "YES", "NO");
+            var result = await DisplayAlert($"Alert @ {datePicker.Date}", "This is a test of the dialog. Is it working?", "YES", "NO");
             await DisplayAlert("Alert Response", $"You selected value: {result}", "OK");
             activity.IsRunning = false;
             progress.Progress = 1.0;