(GH-3746) Introduce ClockSelectedTimeChanged and CalendarSelectedDate…

…Changed

src/MahApps.Metro/Controls/TimePicker/DateTimePicker.cs

@@ -45,6 +45,11 @@ static DateTimePicker()
             IsClockVisibleProperty.OverrideMetadata(typeof(DateTimePicker), new PropertyMetadata(OnClockVisibilityChanged));
         }
 
+        public DateTimePicker()
+        {
+            this.SetCurrentValue(DisplayDateProperty, DateTime.Today);
+        }
+
         /// <inheritdoc />
         protected override void FocusElementAfterIsDropDownOpenChanged()
         {
@@ -151,7 +156,7 @@ public override void OnApplyTemplate()
             {
                 _calendar.PreviewKeyDown -= this.CalendarPreviewKeyDown;
                 _calendar.DisplayDateChanged -= this.CalendarDisplayDateChanged;
-                _calendar.SelectedDatesChanged -= CalendarSelectedDateChanged;
+                _calendar.SelectedDatesChanged -= this.CalendarSelectedDateChanged;
                 _calendar.PreviewMouseUp -= CalendarPreviewMouseUp;
             }
 
@@ -163,7 +168,7 @@ public override void OnApplyTemplate()
             {
                 _calendar.PreviewKeyDown += this.CalendarPreviewKeyDown;
                 _calendar.DisplayDateChanged += this.CalendarDisplayDateChanged;
-                _calendar.SelectedDatesChanged += CalendarSelectedDateChanged;
+                _calendar.SelectedDatesChanged += this.CalendarSelectedDateChanged;
                 _calendar.PreviewMouseUp += CalendarPreviewMouseUp;
 
                 _calendar.SetBinding(Calendar.SelectedDateProperty, GetBinding(SelectedDateTimeProperty));
@@ -175,7 +180,7 @@ public override void OnApplyTemplate()
                 _calendar.SetBinding(FlowDirectionProperty, GetBinding(FlowDirectionProperty));
             }
 
-            SetDatePartValues();
+            //SetDatePartValues();
         }
 
         private static void CalendarPreviewMouseUp(object sender, MouseButtonEventArgs e)
@@ -257,13 +262,6 @@ protected override string GetValueForTextBox()
             return valueForTextBox;
         }
 
-        protected override void OnRangeBaseValueChanged(object sender, SelectionChangedEventArgs e)
-        {
-            base.OnRangeBaseValueChanged(sender, e);
-
-            SetDatePartValues();
-        }
-
         protected override void OnTextBoxLostFocus(object sender, RoutedEventArgs e)
         {
             if (!(sender is DatePickerTextBox textBox))
@@ -311,14 +309,36 @@ private static void OnClockVisibilityChanged(DependencyObject d, DependencyPrope
             d.CoerceValue(OrientationProperty);
         }
 
-        private static void CalendarSelectedDateChanged(object sender, SelectionChangedEventArgs e)
+        private void CalendarSelectedDateChanged(object sender, SelectionChangedEventArgs e)
         {
+            if (e.AddedItems.Count > 0 && this.SelectedDateTime.HasValue && DateTime.Compare((DateTime)e.AddedItems[0], this.SelectedDateTime.Value) != 0)
+            {
+                this.SetCurrentValue(SelectedDateTimeProperty, (DateTime?)e.AddedItems[0] + this.GetSelectedTimeFromGUI());
+            }
+            else
+            {
+                if (e.AddedItems.Count == 0)
+                {
+                    this.SetCurrentValue(SelectedDateTimeProperty, (DateTime?)null);
+                    return;
+                }
+
+                if (!this.SelectedDateTime.HasValue)
+                {
+                    if (e.AddedItems.Count > 0)
+                    {
+                        this.SetCurrentValue(SelectedDateTimeProperty, (DateTime?)e.AddedItems[0] + this.GetSelectedTimeFromGUI());
+                    }
+                }
+            }
+
+            /*
             var dateTimePicker = (DateTimePicker)((Calendar)sender).TemplatedParent;
 
-            /* Without deactivating changing SelectedTime would callbase.OnSelectedTimeChanged.
-             * This would write too and this would result in duplicate writing.
-             * More problematic would be instead that a short amount of time SelectedTime would be as value in TextBox
-             */
+            // Without deactivating changing SelectedTime would callbase.OnSelectedTimeChanged.
+            // This would write too and this would result in duplicate writing.
+            // More problematic would be instead that a short amount of time SelectedTime would be as value in TextBox
+
             dateTimePicker._deactivateWriteValueToTextBox = true;
 
             var dt =  e.AddedItems.Count > 0 ? (DateTime?)e.AddedItems[0] : default;
@@ -334,6 +354,17 @@ private static void CalendarSelectedDateChanged(object sender, SelectionChangedE
             dateTimePicker._deactivateWriteValueToTextBox = false;
 
             dateTimePicker.WriteValueToTextBox();
+            */
+        }
+
+        protected override void ClockSelectedTimeChanged(object sender, SelectionChangedEventArgs e)
+        {
+            var time = this.GetSelectedTimeFromGUI() ?? TimeSpan.Zero;
+            var date = SelectedDateTime ?? DateTime.Today;
+
+            this.SetCurrentValue(SelectedDateTimeProperty, date.Date + time);
+
+            //SetDatePartValues();
         }
 
         private DateTime? GetSelectedDateTimeFromGUI()

src/MahApps.Metro/Controls/TimePicker/TimePicker.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Windows;
+using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
 using System.Windows.Threading;
 
@@ -40,6 +41,14 @@ protected override void FocusElementAfterIsDropDownOpenChanged()
                 });
         }
 
+        protected override void ClockSelectedTimeChanged(object sender, SelectionChangedEventArgs e)
+        {
+            var time = this.GetSelectedTimeFromGUI() ?? TimeSpan.Zero;
+            var date = SelectedDateTime ?? DateTime.Today;
+
+            this.SetCurrentValue(SelectedDateTimeProperty, date.Date + time);
+        }
+
         protected override void OnTextBoxLostFocus(object sender, RoutedEventArgs e)
         {
             if (!(sender is DatePickerTextBox textBox))

src/MahApps.Metro/Controls/TimePicker/TimePickerBase.cs

@@ -519,13 +519,7 @@ protected virtual string GetValueForTextBox()
 
         protected abstract void OnTextBoxLostFocus(object sender, RoutedEventArgs e);
 
-        protected virtual void OnRangeBaseValueChanged(object sender, SelectionChangedEventArgs e)
-        {
-            // If we do not have a date yet we should use Today instead of DateTime.Min
-            var newDateTime = SelectedDateTime ?? DateTime.Today;
-
-            this.SetCurrentValue(SelectedDateTimeProperty, newDateTime.Date + this.GetSelectedTimeFromGUI());
-        }
+        protected abstract void ClockSelectedTimeChanged(object sender, SelectionChangedEventArgs e);
 
         protected virtual void OnSelectedTimeChanged(TimePickerBaseSelectionChangedEventArgs<DateTime?> e)
         {
@@ -739,7 +733,7 @@ private void TimePickerSelectionChanged(object sender, SelectionChangedEventArgs
         {
             if (!_deactivateRangeBaseEvent)
             {
-                OnRangeBaseValueChanged(sender, e);
+                this.ClockSelectedTimeChanged(sender, e);
             }
         }
 
@@ -876,7 +870,7 @@ private static void SetDefaultTimeOfDayValue(Selector selector)
                     return new TimeSpan(hours, minutes, seconds);
                 }
 
-                return this.SelectedDateTime.GetValueOrDefault().TimeOfDay;
+                return null; //this.SelectedDateTime.GetValueOrDefault().TimeOfDay;
             }
         }