feat: add default template, add sample.

demo/Ursa.Demo/Pages/DrawerDemo.axaml

@@ -13,5 +13,6 @@
     <StackPanel HorizontalAlignment="Left" >
         <u:EnumSelector EnumType="{x:Type common:Position}" Value="{Binding SelectedPosition}"></u:EnumSelector>
         <Button Content="Call Drawer" HorizontalAlignment="Stretch" Command="{Binding OpenDrawerCommand}"></Button>
+        <Button Content="Default Drawer" Command="{Binding OpenDefaultDrawerCommand}"></Button>
     </StackPanel>
 </UserControl>

demo/Ursa.Demo/ViewModels/DrawerDemoViewModel.cs

@@ -13,6 +13,7 @@ namespace Ursa.Demo.ViewModels;
 public partial class DrawerDemoViewModel: ObservableObject
 {
     public ICommand OpenDrawerCommand { get; set; }
+    public ICommand OpenDefaultDrawerCommand { get; set; }
     
     [ObservableProperty] private Position _selectedPosition;
     
@@ -20,6 +21,19 @@ public partial class DrawerDemoViewModel: ObservableObject
     public DrawerDemoViewModel()
     {
         OpenDrawerCommand = new AsyncRelayCommand(OpenDrawer);
+        OpenDefaultDrawerCommand = new AsyncRelayCommand(OpenDefaultDrawer);
+        SelectedPosition = Position.Right;
+    }
+
+    private Task OpenDefaultDrawer()
+    {
+        return Drawer.Show<PlainDialog, PlainDialogViewModel, bool>(new PlainDialogViewModel(), new DefaultDrawerOptions()
+        {
+            Buttons = DialogButton.OKCancel,
+            Position = SelectedPosition,
+            Title = "Please select a date",
+            CanClickOnMaskToClose = false,
+        });
     }
 
     private async Task OpenDrawer()

src/Ursa.Themes.Semi/Controls/Drawer.axaml

@@ -63,4 +63,105 @@
             <Setter Property="BorderThickness" Value="0 1 0 0" />
         </Style>
     </ControlTheme>
+    
+    <ControlTheme x:Key="{x:Type u:DefaultDrawerControl}" TargetType="u:DefaultDrawerControl">
+        <Setter Property="VerticalAlignment" Value="Stretch"></Setter>
+        <Setter Property="HorizontalAlignment" Value="Stretch"></Setter>
+        <Setter Property="Template">
+            <ControlTemplate TargetType="u:DefaultDrawerControl">
+                <Border Name="PART_Root" 
+                        Margin="8 -1 -1 -1"
+                        Padding="0"
+                        HorizontalAlignment="Stretch"
+                        VerticalAlignment="Stretch"
+                        Classes="Shadow"
+                        ClipToBounds="False"
+                        CornerRadius="12 0 0 12"
+                        BorderThickness="1 0 0 0"
+                        IsHitTestVisible="True"
+                        Theme="{DynamicResource CardBorder}">
+                    <Border ClipToBounds="True" CornerRadius="{TemplateBinding CornerRadius}">
+                        <Grid RowDefinitions="Auto, *, Auto">
+                            <ScrollViewer Grid.Row="1">
+                                <ContentPresenter
+                                    Name="PART_ContentPresenter"
+                                    Grid.Row="1"
+                                    Margin="24,8"
+                                    Content="{TemplateBinding Content}" />
+                            </ScrollViewer>
+                            <Grid Grid.Row="0" ColumnDefinitions=" *, Auto">
+                                <TextBlock
+                                    Name="PART_Title"
+                                    Grid.Column="0"
+                                    Margin="24,24,0,0"
+                                    VerticalAlignment="Center"
+                                    FontSize="16"
+                                    FontWeight="Bold"
+                                    IsHitTestVisible="False"
+                                    IsVisible="{TemplateBinding Title,
+                                                                Converter={x:Static ObjectConverters.IsNotNull}}"
+                                    Text="{TemplateBinding Title}"
+                                    TextWrapping="Wrap" />
+                                <Button
+                                    Name="{x:Static u:DrawerControlBase.PART_CloseButton}"
+                                    Grid.Column="1"
+                                    Margin="0,24,24,0"
+                                    DockPanel.Dock="Right"
+                                    Theme="{DynamicResource CloseButton}" />
+                            </Grid>
+                            <StackPanel
+                                Grid.Row="2"
+                                Margin="24,0,24,24"
+                                HorizontalAlignment="Right"
+                                Orientation="Horizontal">
+                                <Button
+                                    Name="{x:Static u:DefaultDialogControl.PART_CancelButton}"
+                                    Margin="8,0,0,0"
+                                    Classes="Tertiary"
+                                    Content="{DynamicResource STRING_MENU_DIALOG_CANCEL}" />
+                                <Button
+                                    Name="{x:Static u:DefaultDialogControl.PART_NoButton}"
+                                    Margin="8,0,0,0"
+                                    Classes="Danger"
+                                    Content="{DynamicResource STRING_MENU_DIALOG_NO}"
+                                    Theme="{DynamicResource SolidButton}" />
+                                <Button
+                                    Name="{x:Static u:DefaultDialogControl.PART_YesButton}"
+                                    Margin="8,0,0,0"
+                                    Classes="Primary"
+                                    Content="{DynamicResource STRING_MENU_DIALOG_YES}"
+                                    Theme="{DynamicResource SolidButton}" />
+                                <Button
+                                    Name="{x:Static u:DefaultDialogControl.PART_OKButton}"
+                                    Margin="8,0,0,0"
+                                    Classes="Primary"
+                                    Content="{DynamicResource STRING_MENU_DIALOG_OK}"
+                                    Theme="{DynamicResource SolidButton}" />
+                            </StackPanel>
+                        </Grid>
+                    </Border>
+                </Border>
+            </ControlTemplate>
+        </Setter>
+        <Style Selector="^[Position=Right] /template/ Border#PART_Root">
+            <Setter Property="Margin" Value="8 0 0 0" />
+            <Setter Property="CornerRadius" Value="12 0 0  12" />
+            <Setter Property="BorderThickness" Value="1 0 0 0" />
+        </Style>
+        <Style Selector="^[Position=Left] /template/ Border#PART_Root">
+            <Setter Property="Margin" Value="0 0 8 0" />
+            <Setter Property="CornerRadius" Value="0 12 12 0" />
+            <Setter Property="BorderThickness" Value="0 0 1 0" />
+        </Style>
+        <Style Selector="^[Position=Top] /template/ Border#PART_Root">
+            <Setter Property="Margin" Value="0 0 0 8" />
+            <Setter Property="CornerRadius" Value="0 0 12 12" />
+            <Setter Property="BorderThickness" Value="0 0 0 1" />
+        </Style>
+        <Style Selector="^[Position=Bottom] /template/ Border#PART_Root">
+            <Setter Property="Margin" Value="0 8 0 0" />
+            <Setter Property="CornerRadius" Value="12 12 0 0" />
+            <Setter Property="BorderThickness" Value="0 1 0 0" />
+        </Style>
+    </ControlTheme>
 </ResourceDictionary>

src/Ursa/Controls/Drawer/DefaultDrawerControl.cs

@@ -59,9 +59,68 @@ public class DefaultDrawerControl: DrawerControlBase
         _okButton = e.NameScope.Find<Button>(PART_OKButton);
         _cancelButton = e.NameScope.Find<Button>(PART_CancelButton);
         EventHelper.RegisterClickEvent(OnDefaultButtonClick, _yesButton, _noButton, _okButton, _cancelButton);
+        SetButtonVisibility();
+    }
+    
+    private void SetButtonVisibility()
+    {
+        bool isCloseButtonVisible = DataContext is IDialogContext || Buttons != DialogButton.YesNo;
+        SetVisibility(_closeButton, isCloseButtonVisible);
+        switch (Buttons)
+        {
+            case DialogButton.None:
+                SetVisibility(_okButton, false);
+                SetVisibility(_cancelButton, false);
+                SetVisibility(_yesButton, false);
+                SetVisibility(_noButton, false);
+                break;
+            case DialogButton.OK:
+                SetVisibility(_okButton, true);
+                SetVisibility(_cancelButton, false);
+                SetVisibility(_yesButton, false);
+                SetVisibility(_noButton, false);
+                break;
+            case DialogButton.OKCancel:
+                SetVisibility(_okButton, true);
+                SetVisibility(_cancelButton, true);
+                SetVisibility(_yesButton, false);
+                SetVisibility(_noButton, false);
+                break;
+            case DialogButton.YesNo:
+                SetVisibility(_okButton, false);
+                SetVisibility(_cancelButton, false);
+                SetVisibility(_yesButton, true);
+                SetVisibility(_noButton, true);
+                break;
+            case DialogButton.YesNoCancel:
+                SetVisibility(_okButton, false);
+                SetVisibility(_cancelButton, true);
+                SetVisibility(_yesButton, true);
+                SetVisibility(_noButton, true);
+                break;
+        }
     }
     
     private void OnDefaultButtonClick(object? sender, RoutedEventArgs e)
     {
+        if (sender is Button button)
+        {
+            if (button == _okButton)
+            {
+                OnElementClosing(this, DialogResult.OK);
+            }
+            else if (button == _cancelButton)
+            {
+                OnElementClosing(this, DialogResult.Cancel);
+            }
+            else if (button == _yesButton)
+            {
+                OnElementClosing(this, DialogResult.Yes);
+            }
+            else if (button == _noButton)
+            {
+                OnElementClosing(this, DialogResult.No);
+            }
+        }
     }
 }