From 2ccea8fe1ebc15c437cef074df38eb76388695d8 Mon Sep 17 00:00:00 2001
From: rabbitism <popmessiah@hotmail.com>
Date: Thu, 16 May 2024 22:48:46 +0800
Subject: [PATCH] feat: make panel format nullable. Update display text on
 display format change.

---
 src/Ursa/Controls/DateTimePicker/TimePicker.cs         | 10 ++++++++++
 .../Controls/DateTimePicker/TimePickerPresenter.cs     |  4 ++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/Ursa/Controls/DateTimePicker/TimePicker.cs b/src/Ursa/Controls/DateTimePicker/TimePicker.cs
index 983e3d2..1383bac 100644
--- a/src/Ursa/Controls/DateTimePicker/TimePicker.cs
+++ b/src/Ursa/Controls/DateTimePicker/TimePicker.cs
@@ -39,6 +39,16 @@ public class TimePicker : TimePickerBase, IClearControl
     {
         SelectedTimeProperty.Changed.AddClassHandler<TimePicker, TimeSpan?>((picker, args) =>
             picker.OnSelectionChanged(args));
+        DisplayFormatProperty.Changed.AddClassHandler<TimePicker, string?>((picker, args) => picker.OnDisplayFormatChanged(args));
+    }
+
+    private void OnDisplayFormatChanged(AvaloniaPropertyChangedEventArgs<string?> args)
+    {
+        if (_textBox is null) return;
+        var time = SelectedTime;
+        var date = new DateTime( 1, 1, 1, time.Value.Hours, time.Value.Minutes, time.Value.Seconds);
+        var text = date.ToString(DisplayFormat);
+        _textBox.Text = text;
     }
 
     public string? Watermark
diff --git a/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs b/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs
index dedf751..0f8db96 100644
--- a/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs
+++ b/src/Ursa/Controls/DateTimePicker/TimePickerPresenter.cs
@@ -130,12 +130,12 @@ public class TimePickerPresenter : TemplatedControl
     private void OnPanelFormatChanged(AvaloniaPropertyChangedEventArgs<string> args)
     {
         var format = args.NewValue.Value;
-
         UpdatePanelLayout(format);
     }
 
-    private void UpdatePanelLayout(string panelFormat)
+    private void UpdatePanelLayout(string? panelFormat)
     {
+        if (panelFormat is null) return;
         var parts = panelFormat.Split(new[] { ' ', '-', ':' }, StringSplitOptions.RemoveEmptyEntries);
         var panels = new List<Control?>();
         foreach (var part in parts)