Merge pull request #62 from irihitech/timeline

Timeline refactoring

demo/Ursa.Demo.Desktop/Ursa.Demo.Desktop.csproj

@@ -6,6 +6,7 @@
         <TargetFramework>net7.0</TargetFramework>
         <Nullable>enable</Nullable>
         <BuiltInComInteropSupport>true</BuiltInComInteropSupport>
+        <AvaloniaUseCompiledBindingsByDefault>false</AvaloniaUseCompiledBindingsByDefault>
     </PropertyGroup>
 
     <PropertyGroup>

demo/Ursa.Demo/Converters/TimelineIconConverter.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Globalization;
+using Avalonia;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+using Avalonia.Media;
+using Ursa.Controls;
+
+namespace Ursa.Demo.Converters;
+
+public class TimelineIconConverter: IValueConverter
+{
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is TimelineItemType t)
+        {
+            return t switch
+            {
+                TimelineItemType.Success => Brushes.Green,
+                TimelineItemType.Ongoing => Brushes.Blue,
+                TimelineItemType.Error => Brushes.Red,
+                _ => Brushes.Gray
+            };
+        }
+        return AvaloniaProperty.UnsetValue;
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        throw new NotImplementedException();
+    }
+}

demo/Ursa.Demo/Pages/IntroductionDemo.axaml

@@ -144,27 +144,29 @@
                                        IPAddress="{Binding Address}" />
                             <u:IPv4Box HorizontalAlignment="Stretch" IsEnabled="False" />
                         </StackPanel>
-                        <u:Timeline Grid.Column="1">
+                        <u:Timeline Grid.Column="1" HorizontalAlignment="Left" Mode="Alternate">
                             <u:TimelineItem
-                                Content="ToDo"
+                                Content="Step 1"
-                                ItemType="Default"
+                                Header="ToDo"
-                                Time="2022-01-01" />
+                                Type="Default"
+                                Time="2023-01-14 09:24:05"/>
                             <u:TimelineItem
-                                Content="Start"
+                                Content="Step 2"
-                                ItemType="Ongoing"
+                                Header="Start"
-                                Time="2022-01-02" />
+                                Position="Right"
+                                Type="Ongoing"
+                                Time="2024-01-04 22:32:58"/>
                             <u:TimelineItem
-                                Content="In between"
+                                Content="Step 3"
-                                ItemType="Success"
+                                Header="In Between"
-                                Time="2022-01-03" />
+                                Type="Warning"
+                                Time="2024-01-05 00:08:29"/>
                             <u:TimelineItem
-                                Content="In between"
+                                Content="Step 4"
-                                ItemType="Warning"
+                                Header="Finished"
-                                Time="2022-01-04" />
+                                Position="Right"
-                            <u:TimelineItem
+                                Type="Success" 
-                                Content="Finished"
+                                Time="2024-01-05 00:27:44"/>
-                                ItemType="Error"
-                                Time="2022-01-05" />
                         </u:Timeline>
                         <StackPanel Grid.Column="2" Spacing="20">
                             <u:ButtonGroup Classes="Primary Solid" ItemsSource="{Binding ButtonGroupItems}" />

demo/Ursa.Demo/Pages/TimelineDemo.axaml

@@ -4,55 +4,84 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:selectors="clr-namespace:Ursa.Demo.TemplateSelectors"
     xmlns:u="https://irihi.tech/ursa"
     xmlns:viewModels="clr-namespace:Ursa.Demo.ViewModels"
     d:DesignHeight="450"
     d:DesignWidth="800"
-    x:CompileBindings="False"
+    x:CompileBindings="True"
     x:DataType="viewModels:TimelineDemoViewModel"
     mc:Ignorable="d">
     <UserControl.Resources>
-        <u:TimelineFormatConverter x:Key="FormatConverter" />
+        <ResourceDictionary>
+            <selectors:TimelineIconTemplateSelector x:Key="IconSelector" >
+                <SolidColorBrush x:Key="Default" Color="{DynamicResource SemiGray6Color}"></SolidColorBrush>
+                <SolidColorBrush x:Key="Ongoing" Color="{DynamicResource SemiBlue6Color}"></SolidColorBrush>
+                <SolidColorBrush x:Key="Success" Color="{DynamicResource SemiGreen6Color}"></SolidColorBrush>
+                <SolidColorBrush x:Key="Warning" Color="{DynamicResource SemiOrange6Color}"></SolidColorBrush>
+                <SolidColorBrush x:Key="Error" Color="{DynamicResource SemiRed6Color}"></SolidColorBrush>
+            </selectors:TimelineIconTemplateSelector>
+        </ResourceDictionary>
     </UserControl.Resources>
-    <StackPanel>
+    <WrapPanel>
-        <u:Timeline>
+        <u:Timeline
-            <u:TimelineItem
+            Mode="Alternate"
-                Content="Start"
+            HorizontalAlignment="Left"
-                ItemType="Warning"
+            ContentMemberBinding="{ReflectionBinding Description}"
-                Time="2022-01-01" />
+            HeaderMemberBinding="{ReflectionBinding Header}"
-            <u:TimelineItem
+            IconMemberBinding="{ReflectionBinding ItemType}"
-                Content="In between"
+            IconTemplate="{StaticResource IconSelector}"
-                ItemType="Ongoing"
+            ItemsSource="{Binding Items}"
-                Time="2022-01-02" />
+            TimeMemberBinding="{ReflectionBinding Time}" >
-            <u:TimelineItem
+                
-                Content="Finished"
-                ItemType="Error"
-                Time="2022-01-03" />
-            <u:TimelineItem
-                Content="Finished"
-                IconForeground="Yellow"
-                ItemType="Default"
-                Time="2022-01-03" />
         </u:Timeline>
-        <u:Timeline HorizontalAlignment="Left" ItemsSource="{Binding Items}">
+        <u:Timeline
-            <u:Timeline.ItemTemplate>
+            Mode="Left"
-                <DataTemplate x:DataType="viewModels:TimelineItemViewModel">
+            HorizontalAlignment="Left"
-                    <u:TimelineItem
+            ContentMemberBinding="{ReflectionBinding Description}"
-                        Content="{Binding Content}"
+            HeaderMemberBinding="{ReflectionBinding Header}"
-                        ItemType="{Binding ItemType}"
+            IconMemberBinding="{ReflectionBinding ItemType}"
-                        Time="{Binding Time}"
+            IconTemplate="{StaticResource IconSelector}"
-                        TimeFormat="{Binding TimeFormat}">
+            ItemsSource="{Binding Items}"
-                        <u:TimelineItem.ContentTemplate>
+            TimeMemberBinding="{ReflectionBinding Time}" >
-                            <DataTemplate>
-                                <TextBlock
-                                    MaxWidth="100"
-                                    Text="{Binding}"
-                                    TextWrapping="Wrap" />
-                            </DataTemplate>
-                        </u:TimelineItem.ContentTemplate>
-                    </u:TimelineItem>
-                </DataTemplate>
-            </u:Timeline.ItemTemplate>
         </u:Timeline>
-    </StackPanel>
+        <u:Timeline
+            Mode="Right"
+            HorizontalAlignment="Left"
+            ContentMemberBinding="{ReflectionBinding Description}"
+            HeaderMemberBinding="{ReflectionBinding Header}"
+            IconMemberBinding="{ReflectionBinding ItemType}"
+            IconTemplate="{StaticResource IconSelector}"
+            ItemsSource="{Binding Items}"
+            TimeMemberBinding="{ReflectionBinding Time}" >
+        </u:Timeline>
+        <u:Timeline HorizontalAlignment="Left" Mode="Alternate">
+            <u:TimelineItem
+                Content="Step 1"
+                Header="第一步"
+                Position="Left"
+                Type="Default" />
+            <u:TimelineItem
+                Content="Step 2"
+                Header="第二步"
+                Position="Right"
+                Type="Success" />
+            <u:TimelineItem
+                Content="Step 3"
+                Header="第三步"
+                Position="Separate"
+                Type="Warning" />
+            <u:TimelineItem
+                Content="Step 4"
+                Header="第四步"
+                Position="Separate"
+                Type="Ongoing" />
+            <u:TimelineItem
+                Content="Step 5"
+                Header="第五步"
+                Position="Separate"
+                TimeFormat="yyyy-MM-dd"
+                Type="Error" />
+        </u:Timeline>
+    </WrapPanel>
 </UserControl>

demo/Ursa.Demo/TemplateSelectors/TimelineIconTemplateSelector.cs

@@ -0,0 +1,34 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Shapes;
+using Avalonia.Controls.Templates;
+using Avalonia.Media;
+using Ursa.Controls;
+
+namespace Ursa.Demo.TemplateSelectors;
+
+public class TimelineIconTemplateSelector: ResourceDictionary, IDataTemplate
+{
+    
+    public Control? Build(object? param)
+    {
+        if (param is TimelineItemType t)
+        {
+            string s = t.ToString();
+            if (ContainsKey(s))
+            {
+                object? o = this[s];
+                if (o is SolidColorBrush c)
+                {
+                    var ellipse = new Ellipse() { Width = 12, Height = 12, Fill = c };
+                    return ellipse;
+                }
+            }
+        }
+        return null;
+    }
+
+    public bool Match(object? data)
+    {
+        return data is TimelineItemType;
+    }
+}

demo/Ursa.Demo/ViewModels/TimelineDemoViewModel.cs

@@ -11,41 +11,24 @@ public class TimelineDemoViewModel: ViewModelBase
         new()
         {
             Time = DateTime.Now,
-            TimeFormat = "yyyy-MM-dd HH:mm:ss",
             Description = "Item 1",
-            Content = "First",
+            Header = "审核中",
             ItemType = TimelineItemType.Success,
         },
         new()
         {
             Time = DateTime.Now,
-            TimeFormat = "HH:mm:ss",
             Description = "Item 2",
-            Content = "Content 2",
+            Header = "发布成功",
-            ItemType = TimelineItemType.Success,
-        },
-        new()
-        {
-            Time = DateTime.Now,
-            TimeFormat = "HH:mm:ss",
-            Description = "Item 3",
-            Content = "Content 3",
             ItemType = TimelineItemType.Ongoing,
         },
         new()
         {
             Time = DateTime.Now,
-            TimeFormat = "HH:mm:ss",
+            Description = "Item 3",
-            Description = "Item 4",
+            Header = "审核失败",
-            Content = "Content 4"
+            ItemType = TimelineItemType.Error,
-        },
+        }
-        new()
-        {
-            Time = DateTime.Now,
-            TimeFormat = "HH:mm:ss",
-            Description = "Item 5",
-            Content = "Content 5"
-        },
     };
 }
 
@@ -54,6 +37,6 @@ public class TimelineItemViewModel: ObservableObject
     public DateTime Time { get; set; }
     public string? TimeFormat { get; set; }
     public string? Description { get; set; }    
-    public string? Content { get; set; }
+    public string? Header { get; set; }
     public TimelineItemType ItemType { get; set; }
 }

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

@@ -6,9 +6,9 @@
     <Design.PreviewWith>
         <StackPanel Width="100" Spacing="20">
             <u:Timeline>
-                <u:TimelineItem Content="Hello" Time="2022-01-01" />
+                <u:TimelineItem Content="Hello" />
-                <u:TimelineItem Content="World" Time="2022-02-01" />
+                <u:TimelineItem Content="World" />
-                <u:TimelineItem Content="!" Time="2022-03-01" />
+                <u:TimelineItem Content="!" />
                 <u:TimelineItem />
             </u:Timeline>
         </StackPanel>
@@ -26,104 +26,172 @@
     <converters:TimelineItemTypeToIconForegroundConverter
         x:Key="ForegroundConverter"
         DefaultBrush="{DynamicResource DefaultTimelineIconForeground}"
+        ErrorBrush="{DynamicResource ErrorTimelineIconForeground}"
         OngoingBrush="{DynamicResource OngoingTimelineIconForeground}"
         SuccessBrush="{DynamicResource SuccessTimelineIconForeground}"
-        WarningBrush="{DynamicResource WarningTimelineIconForeground}"
+        WarningBrush="{DynamicResource WarningTimelineIconForeground}" />
-        ErrorBrush="{DynamicResource ErrorTimelineIconForeground}" />
 
     <ControlTheme x:Key="{x:Type u:TimelineItem}" TargetType="u:TimelineItem">
+        <Setter Property="HorizontalAlignment" Value="Left" />
+        <Setter Property="VerticalAlignment" Value="Top" />
         <Setter Property="u:TimelineItem.Template">
             <ControlTemplate TargetType="u:TimelineItem">
-                <Grid ColumnDefinitions="Auto, *" RowDefinitions="*, Auto, *">
+                <Grid
+                    Name="PART_RootGrid"
+                    ColumnDefinitions="Auto, Auto, Auto"
+                    RowDefinitions="Auto, Auto, Auto">
+                    <!--  Icon and Axis  -->
                     <Grid
+                        Name="PART_IconAxisRoot"
                         Grid.Row="0"
-                        Grid.RowSpan="2"
+                        Grid.RowSpan="3"
-                        Grid.Column="0"
+                        Grid.Column="1"
-                        RowDefinitions="Auto, Auto, *">
+                        RowDefinitions="Auto, *">
-                        <Rectangle
+                        <Panel Grid.Row="0" Name="{x:Static u:TimelineItem.PART_Icon}">
-                            Grid.Row="0"
+                            <ContentPresenter
-                            Grid.Column="0"
+                                Margin="8"
-                            Width="1"
-                            Height="8"
-                            HorizontalAlignment="Center"
-                            VerticalAlignment="Top"
-                            Classes="start"
-                            Fill="{DynamicResource TimelineLineBrush}" />
-                        <Panel Grid.Row="1">
-                            <Ellipse
-                                Name="PART_Indicator"
-                                Width="8"
-                                Height="8"
-                                Margin="2"
                                 HorizontalAlignment="Center"
-                                VerticalAlignment="Top"
+                                VerticalAlignment="Center"
-                                Fill="{DynamicResource DefaultTimelineIconForeground}" />
+                                Content="{TemplateBinding Icon}"
+                                ContentTemplate="{TemplateBinding IconTemplate}" />
+                            <Ellipse
+                                Name="PART_DefaultIcon"
+                                Width="12"
+                                Height="12"
+                                Margin="8"
+                                IsVisible="False"
+                                Fill="Gray" />
                         </Panel>
                         <Rectangle
-                            Grid.Row="2"
+                            Grid.Row="1"
-                            Grid.Column="0"
+                            Width="2"
-                            Width="1"
                             HorizontalAlignment="Center"
                             VerticalAlignment="Stretch"
                             Classes="end"
                             Fill="{DynamicResource TimelineLineBrush}" />
                     </Grid>
-                    <Rectangle
-                        Grid.Row="2"
-                        Grid.Column="0"
-                        Width="1"
-                        HorizontalAlignment="Center"
-                        VerticalAlignment="Stretch"
-                        Classes="end"
-                        Fill="{DynamicResource TimelineLineBrush}" />
                     <ContentPresenter
+                        Name="{x:Static u:TimelineItem.PART_Header}"
                         Grid.Row="0"
-                        Grid.Column="1"
+                        Grid.Column="2"
-                        HorizontalAlignment="Stretch"
+                        Margin="8,4"
-                        VerticalAlignment="Bottom"
+                        VerticalAlignment="Top"
-                        Foreground="Gray">
+                        Content="{TemplateBinding Header}"
-                        <ContentPresenter.Content>
+                        ContentTemplate="{TemplateBinding HeaderTemplate}"
+                        FontSize="14"
+                        Foreground="{DynamicResource SemiGrey9}" />
+                    <ContentPresenter
+                        Name="{x:Static u:TimelineItem.PART_Content}"
+                        Grid.Row="1"
+                        Grid.Column="2"
+                        Margin="8,2"
+                        VerticalAlignment="Top"
+                        Content="{TemplateBinding Content}"
+                        ContentTemplate="{TemplateBinding ContentTemplate}"
+                        TextElement.FontSize="12"
+                        TextElement.Foreground="Gray" />
+                    <TextBlock
+                        Name="{x:Static u:TimelineItem.PART_Time}"
+                        Grid.Row="0"
+                        Grid.Column="0"
+                        Margin="8,2"
+                        VerticalAlignment="Top"
+                        FontSize="12"
+                        Foreground="Gray"
+                        TextWrapping="Wrap">
+                        <TextBlock.Text>
                             <MultiBinding Converter="{StaticResource FormatConverter}">
                                 <Binding Path="Time" RelativeSource="{RelativeSource TemplatedParent}" />
                                 <Binding Path="TimeFormat" RelativeSource="{RelativeSource TemplatedParent}" />
                             </MultiBinding>
-                        </ContentPresenter.Content>
+                        </TextBlock.Text>
-                    </ContentPresenter>
+                    </TextBlock>
-                    <ContentPresenter
-                        Name="content"
-                        Grid.Row="1"
-                        Grid.Column="1"
-                        Margin="0,0,0,16"
-                        HorizontalAlignment="Left"
-                        VerticalAlignment="Center"
-                        Content="{TemplateBinding Content}"
-                        ContentTemplate="{TemplateBinding ContentTemplate}" />
                 </Grid>
             </ControlTemplate>
         </Setter>
-        <Style Selector="^:first /template/ Rectangle.start">
-            <Setter Property="Rectangle.Fill" Value="Transparent" />
-        </Style>
         <Style Selector="^:last /template/ Rectangle.end">
             <Setter Property="Rectangle.Fill" Value="Transparent" />
         </Style>
-        <Style Selector="^:none /template/ Ellipse#PART_Indicator">
+        <Style Selector="^:empty-icon /template/ Ellipse#PART_DefaultIcon">
-            <Setter Property="Ellipse.Fill" Value="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=u:TimelineItem}, Path=IconForeground}" />
+            <Setter Property="IsVisible" Value="True"/>
         </Style>
-        <Style Selector="^:not(:none):default /template/ Ellipse#PART_Indicator">
+        <Style Selector="^:empty-icon[Type=Default] /template/ Ellipse#PART_DefaultIcon">
-            <Setter Property="Ellipse.Fill" Value="{DynamicResource DefaultTimelineIconForeground}" />
+            <Setter Property="Fill" Value="{DynamicResource SemiGrey6}"/>
         </Style>
-        <Style Selector="^:not(:none):ongoing /template/ Ellipse#PART_Indicator">
+        <Style Selector="^:empty-icon[Type=Error] /template/ Ellipse#PART_DefaultIcon">
-            <Setter Property="Ellipse.Fill" Value="{DynamicResource OngoingTimelineIconForeground}" />
+            <Setter Property="Fill" Value="{DynamicResource SemiRed6}"/>
         </Style>
-        <Style Selector="^:not(:none):success /template/ Ellipse#PART_Indicator">
+        <Style Selector="^:empty-icon[Type=Ongoing] /template/ Ellipse#PART_DefaultIcon">
-            <Setter Property="Ellipse.Fill" Value="{DynamicResource SuccessTimelineIconForeground}" />
+            <Setter Property="Fill" Value="{DynamicResource SemiBlue6}"/>
         </Style>
-        <Style Selector="^:not(:none):warning /template/ Ellipse#PART_Indicator">
+        <Style Selector="^:empty-icon[Type=Success] /template/ Ellipse#PART_DefaultIcon">
-            <Setter Property="Ellipse.Fill" Value="{DynamicResource WarningTimelineIconForeground}" />
+            <Setter Property="Fill" Value="{DynamicResource SemiGreen6}"/>
         </Style>
-        <Style Selector="^:not(:none):error /template/ Ellipse#PART_Indicator">
+        <Style Selector="^:empty-icon[Type=Warning] /template/ Ellipse#PART_DefaultIcon">
-            <Setter Property="Ellipse.Fill" Value="{DynamicResource ErrorTimelineIconForeground}" />
+            <Setter Property="Fill" Value="{DynamicResource SemiOrange6}"/>
+        </Style>
+        <Style Selector="^:all-left">
+            <Style Selector="^ /template/ ContentPresenter#PART_Header">
+                <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Grid.Column" Value="2" />
+                <Setter Property="HorizontalContentAlignment" Value="Left" />
+                <Setter Property="HorizontalAlignment" Value="Left" />
+            </Style>
+            <Style Selector="^ /template/ ContentPresenter#PART_Content">
+                <Setter Property="Grid.Row" Value="1" />
+                <Setter Property="Grid.Column" Value="2" />
+                <Setter Property="HorizontalContentAlignment" Value="Left" />
+                <Setter Property="HorizontalAlignment" Value="Left" />
+            </Style>
+            <Style Selector="^ /template/ TextBlock#PART_Time">
+                <Setter Property="Grid.Row" Value="2" />
+                <Setter Property="Grid.Column" Value="2" />
+                <Setter Property="TextAlignment" Value="Left" />
+                <Setter Property="HorizontalAlignment" Value="Left" />
+                <Setter Property="Margin" Value="8 2 8 12"></Setter>
+            </Style>
+        </Style>
+        <Style Selector="^:all-right">
+            <Style Selector="^ /template/ ContentPresenter#PART_Header">
+                <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Grid.Column" Value="0" />
+                <Setter Property="HorizontalContentAlignment" Value="Right" />
+                <Setter Property="HorizontalAlignment" Value="Right" />
+            </Style>
+            <Style Selector="^ /template/ ContentPresenter#PART_Content">
+                <Setter Property="Grid.Row" Value="1" />
+                <Setter Property="Grid.Column" Value="0" />
+                <Setter Property="HorizontalContentAlignment" Value="Right" />
+                <Setter Property="HorizontalAlignment" Value="Right" />
+            </Style>
+            <Style Selector="^ /template/ TextBlock#PART_Time">
+                <Setter Property="Grid.Row" Value="2" />
+                <Setter Property="Grid.Column" Value="0" />
+                <Setter Property="TextAlignment" Value="Right" />
+                <Setter Property="HorizontalAlignment" Value="Right" />
+                <Setter Property="Margin" Value="8 2 8 12"></Setter>
+            </Style>
+        </Style>
+        <Style Selector="^:separate">
+            <Style Selector="^ /template/ ContentPresenter#PART_Header">
+                <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Grid.Column" Value="2" />
+                <Setter Property="HorizontalContentAlignment" Value="Left" />
+                <Setter Property="HorizontalAlignment" Value="Left" />
+            </Style>
+            <Style Selector="^ /template/ ContentPresenter#PART_Content">
+                <Setter Property="Grid.Row" Value="1" />
+                <Setter Property="Grid.Column" Value="2" />
+                <Setter Property="HorizontalContentAlignment" Value="Left" />
+                <Setter Property="HorizontalAlignment" Value="Left" />
+                <Setter Property="Margin" Value="8 2 8 12"></Setter>
+            </Style>
+            <Style Selector="^ /template/ TextBlock#PART_Time">
+                <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Grid.Column" Value="0" />
+                <Setter Property="TextAlignment" Value="Right" />
+                <Setter Property="HorizontalAlignment" Value="Right" />
+            </Style>
         </Style>
     </ControlTheme>
 </ResourceDictionary>

src/Ursa/Controls/Timeline/Timeline.cs

@@ -1,56 +1,220 @@
 using System.Collections.Specialized;
-using System.Runtime.CompilerServices;
-using System.Runtime.InteropServices.ComTypes;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Generators;
 using Avalonia.Controls.Presenters;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
+using Avalonia.Data;
+using Avalonia.Layout;
+using Avalonia.Metadata;
 
 namespace Ursa.Controls;
 
 public class Timeline: ItemsControl
 {
+    private static readonly FuncTemplate<Panel?> DefaultPanel = new((Func<Panel>)(() => new TimelinePanel()));
     
-    public static readonly StyledProperty<IDataTemplate?> ItemDescriptionTemplateProperty = AvaloniaProperty.Register<Timeline, IDataTemplate?>(
+    public static readonly StyledProperty<IBinding?> IconMemberBindingProperty = AvaloniaProperty.Register<Timeline, IBinding?>(
-        nameof(ItemDescriptionTemplate));
+        nameof(IconMemberBinding));
 
-    public IDataTemplate? ItemDescriptionTemplate
+    [AssignBinding]
+    [InheritDataTypeFromItems(nameof(ItemsSource))]
+    public IBinding? IconMemberBinding
     {
-        get => GetValue(ItemDescriptionTemplateProperty);
+        get => GetValue(IconMemberBindingProperty);
-        set => SetValue(ItemDescriptionTemplateProperty, value);
+        set => SetValue(IconMemberBindingProperty, value);
     }
 
-    public Timeline()
+    public static readonly StyledProperty<IBinding?> HeaderMemberBindingProperty = AvaloniaProperty.Register<Timeline, IBinding?>(
+        nameof(HeaderMemberBinding));
+
+    [AssignBinding]
+    [InheritDataTypeFromItems(nameof(ItemsSource))]
+    public IBinding? HeaderMemberBinding
     {
-        ItemsView.CollectionChanged+=ItemsViewOnCollectionChanged;
+        get => GetValue(HeaderMemberBindingProperty);
+        set => SetValue(HeaderMemberBindingProperty, value);
     }
 
-    private void ItemsViewOnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
+    public static readonly StyledProperty<IBinding?> ContentMemberBindingProperty = AvaloniaProperty.Register<Timeline, IBinding?>(
+        nameof(ContentMemberBinding));
+    
+    [AssignBinding]
+    [InheritDataTypeFromItems(nameof(ItemsSource))]
+    public IBinding? ContentMemberBinding
     {
-        RefreshTimelineItems();
+        get => GetValue(ContentMemberBindingProperty);
+        set => SetValue(ContentMemberBindingProperty, value);
     }
     
-    protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+
+    public static readonly StyledProperty<IDataTemplate?> IconTemplateProperty = AvaloniaProperty.Register<Timeline, IDataTemplate?>(
+        nameof(IconTemplate));
+
+    [InheritDataTypeFromItems(nameof(ItemsSource))]
+    public IDataTemplate? IconTemplate
     {
-        base.OnPropertyChanged(change);
+        get => GetValue(IconTemplateProperty);
-        RefreshTimelineItems();
+        set => SetValue(IconTemplateProperty, value);
     }
 
-    private void RefreshTimelineItems()
+    public static readonly StyledProperty<IDataTemplate?> DescriptionTemplateProperty = AvaloniaProperty.Register<Timeline, IDataTemplate?>(
+        nameof(DescriptionTemplate));
+
+    [InheritDataTypeFromItems(nameof(ItemsSource))]
+    public IDataTemplate? DescriptionTemplate
     {
-        for (int i = 0; i < this.LogicalChildren.Count; i++)
+        get => GetValue(DescriptionTemplateProperty);
+        set => SetValue(DescriptionTemplateProperty, value);
+    }
+
+    public static readonly StyledProperty<IBinding?> TimeMemberBindingProperty = AvaloniaProperty.Register<Timeline, IBinding?>(
+        nameof(TimeMemberBinding));
+
+    [AssignBinding]
+    [InheritDataTypeFromItems(nameof(ItemsSource))]
+    public IBinding? TimeMemberBinding
+    {
+        get => GetValue(TimeMemberBindingProperty);
+        set => SetValue(TimeMemberBindingProperty, value);
+    }
+
+    public static readonly StyledProperty<string?> TimeFormatProperty = AvaloniaProperty.Register<Timeline, string?>(
+        nameof(TimeFormat), defaultValue:"yyyy-MM-dd HH:mm:ss");
+
+    public string? TimeFormat
+    {
+        get => GetValue(TimeFormatProperty);
+        set => SetValue(TimeFormatProperty, value);
+    }
+    
+
+    public static readonly StyledProperty<TimelineDisplayMode> ModeProperty = AvaloniaProperty.Register<Timeline, TimelineDisplayMode>(
+        nameof(Mode));
+
+    public TimelineDisplayMode Mode
+    {
+        get => GetValue(ModeProperty);
+        set => SetValue(ModeProperty, value);
+    }
+
+    static Timeline()
+    {
+        ItemsPanelProperty.OverrideDefaultValue<Timeline>(DefaultPanel);
+        ModeProperty.Changed.AddClassHandler<Timeline, TimelineDisplayMode>((t, e) => { t.OnDisplayModeChanged(e); });
+    }
+
+    private void OnDisplayModeChanged(AvaloniaPropertyChangedEventArgs<TimelineDisplayMode> e)
+    {
+        if (this.ItemsPanelRoot is TimelinePanel panel)
         {
-            if (this.LogicalChildren[i] is TimelineItem t)
+            panel.Mode = e.NewValue.Value;
+            SetItemMode();
+        }
+    }
+
+    protected override bool NeedsContainerOverride(object? item, int index, out object? recycleKey)
+    {
+        recycleKey = null;
+        return item is not TimelineItem;
+    }
+
+    protected override Control CreateContainerForItemOverride(object? item, int index, object? recycleKey)
+    {
+        if (item is TimelineItem t) return t;
+        return new TimelineItem();
+    }
+
+    protected override void PrepareContainerForItemOverride(Control container, object? item, int index)
+    {
+        base.PrepareContainerForItemOverride(container, item, index);
+        if (container is TimelineItem t)
+        {
+            bool start = index == 0;
+            bool end = index == ItemCount - 1;
+            t.SetEnd(start, end);
+            if (IconMemberBinding is not null)
             {
-                t.SetIndex(i == 0, i == this.LogicalChildren.Count - 1);
+                t.Bind(TimelineItem.IconProperty, IconMemberBinding);
             }
-            else if (this.LogicalChildren[i] is ContentPresenter { Child: TimelineItem t2 })
+            if (HeaderMemberBinding != null)
             {
-                t2.SetIndex(i == 0, i == this.LogicalChildren.Count - 1);
+                t.Bind(HeaderedContentControl.HeaderProperty, HeaderMemberBinding);
+            }
+            if (ContentMemberBinding != null)
+            {
+                t.Bind(ContentControl.ContentProperty, ContentMemberBinding);
+            }
+            if (TimeMemberBinding != null)
+            {
+                t.Bind(TimelineItem.TimeProperty, TimeMemberBinding);
+            }
+
+            t.SetIfUnset(TimelineItem.TimeFormatProperty, TimeFormat);
+            t.SetIfUnset(TimelineItem.IconTemplateProperty, IconTemplate);
+            t.SetIfUnset(HeaderedContentControl.HeaderTemplateProperty, ItemTemplate);
+            t.SetIfUnset(ContentControl.ContentTemplateProperty, DescriptionTemplate);
+        }
+
+    }
+
+    protected override Size ArrangeOverride(Size finalSize)
+    {
+        var panel = this.ItemsPanelRoot as TimelinePanel;
+        panel.Mode = this.Mode;
+        SetItemMode();
+        return base.ArrangeOverride(finalSize);
+    }
+
+    private void SetItemMode()
+    {
+        if (ItemsPanelRoot is TimelinePanel panel)
+        {
+            var items = panel.Children.OfType<TimelineItem>();
+            if (Mode == TimelineDisplayMode.Left)
+            {
+                foreach (var item in items)
+                {
+                    SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Left);
+                }
+            }
+            else if (Mode == TimelineDisplayMode.Right)
+            {
+                foreach (var item in items)
+                {
+                    SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Right);
+                }
+            }
+            else if (Mode == TimelineDisplayMode.Center)
+            {
+                foreach (var item in items)
+                {
+                    SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Separate);
+                }
+            }
+            else if (Mode == TimelineDisplayMode.Alternate)
+            {
+                bool left = false;
+                foreach (var item in items)
+                {
+                    if (left)
+                    {
+                        SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Left);
+                    }
+                    else
+                    {
+                        SetIfUnset(item, TimelineItem.PositionProperty, TimelineItemPosition.Right);
+                    }
+                    left = !left;
+                }
             }
         }
     }
     
+    private void SetIfUnset<T>(AvaloniaObject target, StyledProperty<T> property, T value)
+    {
+        if (!target.IsSet(property))
+            target.SetCurrentValue(property, value);
+    }
 }

src/Ursa/Controls/Timeline/TimelineDisplayMode.cs

@@ -0,0 +1,22 @@
+namespace Ursa.Controls;
+
+public enum TimelineDisplayMode
+{
+    Left,
+    Center,
+    Right,
+    Alternate,
+}
+
+/// <summary>
+/// Placement of timeline.
+/// Left means line is placed left to TimelineItem content.
+/// Right means line is placed right to TimelineItem content.
+/// Separate means line is placed between TimelineItem content and time.
+/// </summary>
+public enum TimelineItemPosition
+{
+    Left,
+    Right,
+    Separate,
+}

src/Ursa/Controls/Timeline/TimelineItem.cs

@@ -1,45 +1,106 @@
-using System.Globalization;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.Metadata;
+using Avalonia.Controls.Presenters;
+using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Templates;
 using Avalonia.Data;
 using Avalonia.Media;
 
 namespace Ursa.Controls;
 
-[PseudoClasses(PC_First, PC_Last, PC_Default, PC_Ongoing, PC_Success, PC_Warning, PC_Error, PC_None)]
+[PseudoClasses(PC_First, PC_Last, PC_EmptyIcon, PC_AllLeft, PC_AllRight, PC_Separate)]
-public class TimelineItem: ContentControl
+[TemplatePart(PART_Header, typeof(ContentPresenter))]
+[TemplatePart(PART_Icon, typeof(Panel))]
+[TemplatePart(PART_Content, typeof(ContentPresenter))]
+[TemplatePart(PART_Time, typeof(TextBlock))]
+[TemplatePart(PART_RootGrid, typeof(Grid))]
+public class TimelineItem: HeaderedContentControl
 {
-    private const string PC_First = ":first";
+    public const string PC_First = ":first";
-    private const string PC_Last = ":last";
+    public const string PC_Last = ":last";
-    private const string PC_Default = ":default";
+    public const string PC_EmptyIcon = ":empty-icon";
-    private const string PC_Ongoing = ":ongoing";
+    public const string PC_AllLeft=":all-left"; 
-    private const string PC_Success = ":success";
+    public const string PC_AllRight=":all-right";
-    private const string PC_Warning = ":warning";
+    public const string PC_Separate = ":separate";
-    private const string PC_Error = ":error";
+    public const string PART_Header = "PART_Header";
-    private const string PC_None = ":none";
+    public const string PART_Icon = "PART_Icon";
+    public const string PART_Content = "PART_Content";
+    public const string PART_Time = "PART_Time";
+    public const string PART_RootGrid = "PART_RootGrid";
     
-    private static readonly IReadOnlyDictionary<TimelineItemType, string> _itemTypeMapping = new Dictionary<TimelineItemType, string>
+    private ContentPresenter? _headerPresenter;
+    private Panel? _iconPresenter;
+    private ContentPresenter? _contentPresenter;
+    private TextBlock? _timePresenter;
+    private Grid? _rootGrid;
+    
+    public static readonly StyledProperty<object?> IconProperty = AvaloniaProperty.Register<TimelineItem, object?>(
+        nameof(Icon));
+
+    public object? Icon
     {
-        {TimelineItemType.Default, PC_Default},
+        get => GetValue(IconProperty);
-        {TimelineItemType.Ongoing, PC_Ongoing},
+        set => SetValue(IconProperty, value);
-        {TimelineItemType.Success, PC_Success},
+    }
-        {TimelineItemType.Warning, PC_Warning},
-        {TimelineItemType.Error, PC_Error},
-    };
 
-    public static readonly StyledProperty<IBrush> IconForegroundProperty =
+    public static readonly StyledProperty<IDataTemplate?> IconTemplateProperty = AvaloniaProperty.Register<TimelineItem, IDataTemplate?>(
-        AvaloniaProperty.Register<TimelineItem, IBrush>(nameof(IconForeground));
+        nameof(IconTemplate));
 
-    public IBrush IconForeground
+    public IDataTemplate? IconTemplate
     {
-        get => GetValue(IconForegroundProperty);
+        get => GetValue(IconTemplateProperty);
-        set => SetValue(IconForegroundProperty, value);
+        set => SetValue(IconTemplateProperty, value);
+    }
+
+    public static readonly StyledProperty<TimelineItemType> TypeProperty = AvaloniaProperty.Register<TimelineItem, TimelineItemType>(
+        nameof(Type));
+
+    public TimelineItemType Type
+    {
+        get => GetValue(TypeProperty);
+        set => SetValue(TypeProperty, value);
+    }
+
+    public static readonly StyledProperty<TimelineItemPosition> PositionProperty = AvaloniaProperty.Register<TimelineItem, TimelineItemPosition>(
+        nameof(Position), defaultValue: TimelineItemPosition.Right);
+
+    public TimelineItemPosition Position
+    {
+        get => GetValue(PositionProperty);
+        set => SetValue(PositionProperty, value);
+    }
+    
+    public static readonly DirectProperty<TimelineItem, double> LeftWidthProperty = AvaloniaProperty.RegisterDirect<TimelineItem, double>(
+        nameof(LeftWidth), o => o.LeftWidth, (o, v) => o.LeftWidth = v);
+    private double _leftWidth;
+    public double LeftWidth
+    {
+        get => _leftWidth;
+        set => SetAndRaise(LeftWidthProperty, ref _leftWidth, value);
+    }
+    
+    public static readonly DirectProperty<TimelineItem, double> IconWidthProperty = AvaloniaProperty.RegisterDirect<TimelineItem, double>(
+        nameof(IconWidth), o => o.IconWidth, (o, v) => o.IconWidth = v);
+    private double _iconWidth;
+    public double IconWidth
+    {
+        get => _iconWidth;
+        set => SetAndRaise(IconWidthProperty, ref _iconWidth, value);
+    }
+    
+    public static readonly DirectProperty<TimelineItem, double> RightWidthProperty = AvaloniaProperty.RegisterDirect<TimelineItem, double>(
+        nameof(RightWidth), o => o.RightWidth, (o, v) => o.RightWidth = v);
+    private double _rightWidth;
+    public double RightWidth
+    {
+        get => _rightWidth;
+        set => SetAndRaise(RightWidthProperty, ref _rightWidth, value);
     }
 
     public static readonly StyledProperty<DateTime> TimeProperty = AvaloniaProperty.Register<TimelineItem, DateTime>(
         nameof(Time));
+
     public DateTime Time
     {
         get => GetValue(TimeProperty);
@@ -47,7 +108,7 @@ public class TimelineItem: ContentControl
     }
 
     public static readonly StyledProperty<string?> TimeFormatProperty = AvaloniaProperty.Register<TimelineItem, string?>(
-        nameof(TimeFormat), defaultValue:CultureInfo.CurrentUICulture.DateTimeFormat.ShortDatePattern);
+        nameof(TimeFormat));
 
     public string? TimeFormat
     {
@@ -55,47 +116,86 @@ public class TimelineItem: ContentControl
         set => SetValue(TimeFormatProperty, value);
     }
 
-    public static readonly StyledProperty<IDataTemplate> DescriptionTemplateProperty = AvaloniaProperty.Register<TimelineItem, IDataTemplate>(
-        nameof(DescriptionTemplate));
-
-    public IDataTemplate DescriptionTemplate
-    {
-        get => GetValue(DescriptionTemplateProperty);
-        set => SetValue(DescriptionTemplateProperty, value);
-    }
-
-    public static readonly StyledProperty<TimelineItemType> ItemTypeProperty = AvaloniaProperty.Register<TimelineItem, TimelineItemType>(
-        nameof(ItemType));
-
-    public TimelineItemType ItemType
-    {
-        get => GetValue(ItemTypeProperty);
-        set => SetValue(ItemTypeProperty, value);
-    }
-
-    internal void SetIndex(bool isFirst, bool isLast)
-    {
-        PseudoClasses.Set(PC_First, isFirst);
-        PseudoClasses.Set(PC_Last, isLast);
-    }
-
     static TimelineItem()
     {
-        ItemTypeProperty.Changed.AddClassHandler<TimelineItem>((o, e) => { o.OnItemTypeChanged(e); });
+        IconProperty.Changed.AddClassHandler<TimelineItem, object?>((item, args) => { item.OnIconChanged(args); });
-        IconForegroundProperty.Changed.AddClassHandler<TimelineItem>((o, e) => { o.OnIconForegroundChanged(e); });
+        PositionProperty.Changed.AddClassHandler<TimelineItem, TimelineItemPosition>((item, args) => { item.OnModeChanged(args); });
+        AffectsMeasure<TimelineItem>(LeftWidthProperty, RightWidthProperty, IconWidthProperty);
     }
 
-    private void OnItemTypeChanged(AvaloniaPropertyChangedEventArgs args)
+    private void OnModeChanged(AvaloniaPropertyChangedEventArgs<TimelineItemPosition> args)
     {
-        var oldValue = args.GetOldValue<TimelineItemType>();
+        SetMode(args.NewValue.Value);
-        var newValue = args.GetNewValue<TimelineItemType>();
-        PseudoClasses.Set(_itemTypeMapping[oldValue], false);
-        PseudoClasses.Set(_itemTypeMapping[newValue], true);
     }
 
-    private void OnIconForegroundChanged(AvaloniaPropertyChangedEventArgs args)
+    private void SetMode(TimelineItemPosition mode)
     {
-        IBrush? newValue = args.GetOldValue<IBrush?>();
+        PseudoClasses.Set(PC_AllLeft, mode == TimelineItemPosition.Left);
-        PseudoClasses.Set(PC_None, newValue is null);
+        PseudoClasses.Set(PC_AllRight, mode == TimelineItemPosition.Right);
+        PseudoClasses.Set(PC_Separate, mode == TimelineItemPosition.Separate);
+    }
+
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+    {
+        base.OnApplyTemplate(e);
+        _rootGrid = e.NameScope.Find<Grid>(PART_RootGrid);
+        _headerPresenter = e.NameScope.Find<ContentPresenter>(PART_Header);
+        _iconPresenter = e.NameScope.Find<Panel>(PART_Icon);
+        _contentPresenter = e.NameScope.Find<ContentPresenter>(PART_Content);
+        _timePresenter = e.NameScope.Find<TextBlock>(PART_Time);
+        PseudoClasses.Set(PC_EmptyIcon, Icon is null);
+        SetMode(Position);
+    }
+
+    private void OnIconChanged(AvaloniaPropertyChangedEventArgs<object?> args)
+    {
+        PseudoClasses.Set(PC_EmptyIcon, args.NewValue.Value is null);
+    }
+
+    internal void SetEnd(bool start, bool end)
+    {
+        PseudoClasses.Set(PC_First, start);
+        PseudoClasses.Set(PC_Last, end);
+    }
+
+    internal (double left, double mid, double right) GetWidth()
+    {
+        if (_headerPresenter is null) return new ValueTuple<double, double, double>(0, 0, 0);
+        double header = _headerPresenter?.DesiredSize.Width ?? 0;
+        double icon = _iconPresenter?.DesiredSize.Width ?? 0;
+        double content = _contentPresenter?.DesiredSize.Width ?? 0;
+        double time = _timePresenter?.DesiredSize.Width ?? 0;
+        double max = Math.Max(header, content);
+        if (Position == TimelineItemPosition.Left)
+        {
+            max = Math.Max(max, time);
+            return (0, icon, max);
+        }
+        if (Position == TimelineItemPosition.Right)
+        {
+            max = Math.Max(max, time);
+            return (max    , icon, 0);
+        }
+        if (Position == TimelineItemPosition.Separate)
+        {
+            return (time, icon, max);
+        }
+        return new ValueTuple<double, double, double>(0, 0, 0);
+    }
+
+    internal void SetWidth(double? left, double? mid, double? right)
+    {
+        if (_rootGrid is null) return;
+        _rootGrid.ColumnDefinitions[0].Width = new GridLength(left??0);
+        _rootGrid.ColumnDefinitions[1].Width = new GridLength(mid??0);
+        _rootGrid.ColumnDefinitions[2].Width = new GridLength(right??0);
+    }
+
+    internal void SetIfUnset<T>(AvaloniaProperty<T> property, T value)
+    {
+        if (!IsSet(property))
+        {
+            SetCurrentValue(property, value);
+        }
     }
 }

src/Ursa/Controls/Timeline/TimelinePanel.cs

@@ -0,0 +1,75 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Layout;
+
+namespace Ursa.Controls;
+
+public class TimelinePanel: Panel
+{
+    public static readonly StyledProperty<TimelineDisplayMode> ModeProperty =
+        Timeline.ModeProperty.AddOwner<TimelinePanel>();
+
+    public TimelineDisplayMode Mode
+    {
+        get => GetValue(ModeProperty);
+        set => SetValue(ModeProperty, value);
+    }
+
+    static TimelinePanel()
+    {
+        AffectsMeasure<TimelinePanel>(ModeProperty);
+    }
+    
+    protected override Size MeasureOverride(Size availableSize)
+    {
+        double left = 0;
+        double right = 0;
+        double icon = 0;
+        double height = 0;
+        foreach (var child in Children)
+        {
+            child.Measure(availableSize);
+            if (child is TimelineItem t)
+            {
+                var doubles = t.GetWidth();
+                left = Math.Max(left, doubles.left);
+                icon = Math.Max(icon, doubles.mid);
+                right = Math.Max(right, doubles.right);
+            }
+            height+=child.DesiredSize.Height;
+        }
+        return new Size(left+icon+right, height);
+    }
+
+    protected override Size ArrangeOverride(Size finalSize)
+    {
+        
+        double left = 0, mid = 0, right = 0;
+        double height = 0;
+        foreach (var child in Children)
+        {
+            if (child is TimelineItem t)
+            {
+                var doubles = t.GetWidth();
+                left = Math.Max(left, doubles.left);
+                mid = Math.Max(mid, doubles.mid);
+                right = Math.Max(right, doubles.right);
+            }
+        }
+
+        Rect rect = new Rect(0, 0, left + mid + right, 0);
+        foreach (var child in Children)
+        {
+            if (child is TimelineItem t)
+            {
+                t.SetWidth(left, mid, right);
+                t.InvalidateArrange();
+                rect = rect.WithHeight(t.DesiredSize.Height);
+                child.Arrange(rect);
+                rect = rect.WithY(rect.Y + t.DesiredSize.Height);
+                height+=t.DesiredSize.Height;
+            }
+        }
+        return new Size(left + mid + right, height);
+    }
+}