reorganize logic for date/time dropdown

Author: VictoriousRaptor

Flow.Launcher/SettingWindow.xaml

@@ -1815,6 +1815,7 @@
                                                     </Grid.RowDefinitions>
                                                     <Border Grid.Row="0">
                                                         <TextBox
+                                                            x:Name="QueryTextBox"
                                                             IsReadOnly="True"
                                                             Style="{DynamicResource QueryBoxStyle}"
                                                             Text="{DynamicResource hiThere}" />
@@ -2170,7 +2171,8 @@
                                                                 VerticalAlignment="Center"
                                                                 FontSize="14"
                                                                 ItemsSource="{Binding TimeFormatDisplayList}"
-                                                                SelectedIndex="{Binding TimeFormatIndex, Mode=OneTime}"
+                                                                SelectedIndex="{Binding TimeFormatIndex, Mode=OneWayToSource}"
+                                                                DropDownOpened="RefreshDateTimeList"
                                                                 SelectionChanged="PreviewClockAndDate" />
                                                             <ui:ToggleSwitch
                                                                 IsOn="{Binding UseClock, Mode=TwoWay}"
@@ -2208,7 +2210,8 @@
                                                                 VerticalAlignment="Center"
                                                                 FontSize="14"
                                                                 ItemsSource="{Binding DateFormatDisplayList}"
-                                                                SelectedIndex="{Binding DateFormatIndex, Mode=OneTime}"
+                                                                SelectedIndex="{Binding DateFormatIndex, Mode=OneWayToSource}"
+                                                                DropDownOpened="RefreshDateTimeList"
                                                                 SelectionChanged="PreviewClockAndDate" />
                                                             <ui:ToggleSwitch
                                                                 IsOn="{Binding UseDate, Mode=TwoWay}"

Flow.Launcher/SettingWindow.xaml.cs

@@ -45,6 +45,8 @@ public SettingWindow(IPublicAPI api, SettingWindowViewModel viewModel)
             API = api;
             InitializePosition();
             InitializeComponent();
+
+            RefreshDateTimeListLogic(viewModel.DateFormatIndex, viewModel.TimeFormatIndex);
         }
 
         #region General
@@ -517,19 +519,6 @@ private void PluginStore_OnKeyDown(object sender, KeyEventArgs e)
 
         private void PreviewClockAndDate(object sender, RoutedEventArgs e)
         {
-            if (DateFormat != null && TimeFormat != null)
-            {
-                if (DateFormat.SelectedIndex == -1 || TimeFormat.SelectedIndex == -1)
-                {
-                    return;
-                }
-                viewModel.UpdateDateTimeDisplayList(DateFormat.SelectedIndex, TimeFormat.SelectedIndex);
-                DateFormat.Items.Refresh();
-                TimeFormat.Items.Refresh(); // selected = -1
-                // todo avoid recursion
-                DateFormat.SelectedIndex = viewModel.DateFormatIndex;
-                TimeFormat.SelectedIndex = viewModel.TimeFormatIndex;
-            }
             ClockDisplay();
         }
 
@@ -605,5 +594,23 @@ private void StoreListItem_Click(object sender, RoutedEventArgs e)
             };
 
         }
+
+        private void RefreshDateTimeList(object sender, EventArgs e)
+        {
+            RefreshDateTimeListLogic(DateFormat.SelectedIndex, TimeFormat.SelectedIndex);
+        }
+
+        private void RefreshDateTimeListLogic(int dateIndex, int timeIndex)
+        {
+            viewModel.UpdateDateTimeDisplayList();
+            RefreshComboBox(DateFormat, dateIndex);
+            RefreshComboBox(TimeFormat, timeIndex);
+        }
+
+        private static void RefreshComboBox(System.Windows.Controls.ComboBox box, int index)
+        {
+            box.Items.Refresh();
+            box.SelectedIndex = index;
+        }
     }
 }

Flow.Launcher/ViewModel/SettingWindowViewModel.cs

@@ -482,8 +482,11 @@ public int TimeFormatIndex
             get => timeFormatIndex;
             set
             {
-                timeFormatIndex = value;
-                Settings.TimeFormat = TimeFormatList[TimeFormatIndex];
+                if (value != -1)
+                {
+                    timeFormatIndex = value;
+                    Settings.TimeFormat = TimeFormatList[value];
+                }
             }
         }
 
@@ -493,26 +496,20 @@ public int DateFormatIndex
             get => dateFormatIndex;
             set 
             { 
-                dateFormatIndex = value; 
-                Settings.DateFormat = DateFormatList[DateFormatIndex]; 
+                if (value != -1)
+                {
+                    dateFormatIndex = value;
+                    Settings.DateFormat = DateFormatList[value];
+                }
             }
         }
 
         public List<string> TimeFormatDisplayList { get; set; } = null;
 
         public List<string> DateFormatDisplayList { get; set; } = null;
 
-        public void UpdateSettingsDateTimeFormat()
+        public void UpdateDateTimeDisplayList()
         {
-            Settings.DateFormat = DateFormatList[DateFormatIndex];
-            Settings.TimeFormat = TimeFormatList[TimeFormatIndex];
-        }
-
-        public void UpdateDateTimeDisplayList(int dateIndex, int timeIndex)
-        {
-            DateFormatIndex = dateIndex;
-            TimeFormatIndex = timeIndex;
-
             for (int i = 0; i < TimeFormatList.Count; ++i)
             {
                 TimeFormatDisplayList[i] = DateTime.Now.ToString(TimeFormatList[i], CultureInfo.CurrentCulture);
@@ -522,8 +519,6 @@ public void UpdateDateTimeDisplayList(int dateIndex, int timeIndex)
             {
                 DateFormatDisplayList[i] = DateTime.Now.ToString(DateFormatList[i], CultureInfo.CurrentCulture);
             }
-
-            //UpdateSettingsDateTimeFormat();
         }
 
         public double WindowWidthSize