From a5f43c7ee1b07d852f275f61500bf3dd7862a7ec Mon Sep 17 00:00:00 2001
From: Mihai Stan <stanmihai17cs@gmail.com>
Date: Thu, 2 Jul 2020 14:49:20 +0200
Subject: [PATCH 1/3] Add ticks property on Slider

This property will allow setting custom ticks on the slider without having to create a custom template for the TickBar.
---
 samples/ControlCatalog/Pages/SliderPage.xaml  | 20 ++++++++++++++-----
 .../ControlCatalog/Pages/SliderPage.xaml.cs   | 11 ++++++++++
 src/Avalonia.Controls/Slider.cs               | 19 +++++++++++++++++-
 src/Avalonia.Themes.Default/Slider.xaml       |  9 ++++++---
 src/Avalonia.Themes.Fluent/Slider.xaml        |  1 +
 5 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/samples/ControlCatalog/Pages/SliderPage.xaml b/samples/ControlCatalog/Pages/SliderPage.xaml
index c6f5521e60..ca289e21fd 100644
--- a/samples/ControlCatalog/Pages/SliderPage.xaml
+++ b/samples/ControlCatalog/Pages/SliderPage.xaml
@@ -6,11 +6,21 @@
     <TextBlock Classes="h2">A control that lets the user select from a range of values by moving a Thumb control along a Track.</TextBlock>
 
     <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0 16 0 0" Spacing="16">
-      <Slider Value="0"
-              Minimum="0"
-              Maximum="100"
-              TickFrequency="10"
-              Width="300"/>
+      <StackPanel Orientation="Vertical"
+                  HorizontalAlignment="Center">
+        <Slider Value="0"
+                Minimum="0"
+                Maximum="100"
+                TickFrequency="10"
+                Width="300" />
+        <Slider Name="CustomTickedSlider"
+                Value="0"
+                Minimum="0"
+                Maximum="100"
+                TickPlacement="BottomRight"
+                IsSnapToTickEnabled="True"
+                Width="300" />
+      </StackPanel>
       <Slider Value="0"
               Minimum="0"
               Maximum="100"
diff --git a/samples/ControlCatalog/Pages/SliderPage.xaml.cs b/samples/ControlCatalog/Pages/SliderPage.xaml.cs
index 2f4a5fabc9..22c2d6735b 100644
--- a/samples/ControlCatalog/Pages/SliderPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/SliderPage.xaml.cs
@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
@@ -13,6 +14,16 @@ namespace ControlCatalog.Pages
         private void InitializeComponent()
         {
             AvaloniaXamlLoader.Load(this);
+
+            var slider = this.FindControl<Slider>("CustomTickedSlider");
+            slider.Ticks = new List<double>
+            {
+                0d,
+                5d,
+                20d,
+                50d,
+                100d
+            };
         }
     }
 }
diff --git a/src/Avalonia.Controls/Slider.cs b/src/Avalonia.Controls/Slider.cs
index fe1a4f5ac1..00a26a4c91 100644
--- a/src/Avalonia.Controls/Slider.cs
+++ b/src/Avalonia.Controls/Slider.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
@@ -64,6 +65,12 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<TickPlacement> TickPlacementProperty =
             AvaloniaProperty.Register<TickBar, TickPlacement>(nameof(TickPlacement), 0d);
 
+        /// <summary>
+        /// Defines the <see cref="TicksProperty"/> property.
+        /// </summary>
+        public static readonly StyledProperty<List<double>> TicksProperty =
+            TickBar.TicksProperty.AddOwner<Slider>();
+
         // Slider required parts
         private bool _isDragging = false;
         private Track _track;
@@ -83,7 +90,8 @@ namespace Avalonia.Controls
             PressedMixin.Attach<Slider>();
             OrientationProperty.OverrideDefaultValue(typeof(Slider), Orientation.Horizontal);
             Thumb.DragStartedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragStarted(e), RoutingStrategies.Bubble);
-            Thumb.DragCompletedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragCompleted(e), RoutingStrategies.Bubble);
+            Thumb.DragCompletedEvent.AddClassHandler<Slider>((x, e) => x.OnThumbDragCompleted(e),
+                RoutingStrategies.Bubble);
         }
 
         /// <summary>
@@ -94,6 +102,15 @@ namespace Avalonia.Controls
             UpdatePseudoClasses(Orientation);
         }
 
+        /// <summary>
+        /// Defines the ticks to be drawn on the tick bar.
+        /// </summary>
+        public List<double> Ticks
+        {
+            get => GetValue(TicksProperty);
+            set => SetValue(TicksProperty, value);
+        }
+
         /// <summary>
         /// Gets or sets the orientation of a <see cref="Slider"/>.
         /// </summary>
diff --git a/src/Avalonia.Themes.Default/Slider.xaml b/src/Avalonia.Themes.Default/Slider.xaml
index 1d48a946fc..ba4b1ee998 100644
--- a/src/Avalonia.Themes.Default/Slider.xaml
+++ b/src/Avalonia.Themes.Default/Slider.xaml
@@ -87,7 +87,10 @@
         </ControlTemplate>
     </Setter>
   </Style>
-    <Style Selector="Slider:disabled /template/ Grid#grid">
-        <Setter Property="Opacity" Value="{DynamicResource ThemeDisabledOpacity}" />
-    </Style>
+  <Style Selector="Slider /template/ TickBar">
+    <Setter Property="Ticks" Value="{TemplateBinding Ticks}" />
+  </Style>
+  <Style Selector="Slider:disabled /template/ Grid#grid">
+    <Setter Property="Opacity" Value="{DynamicResource ThemeDisabledOpacity}" />
+  </Style>
 </Styles>
diff --git a/src/Avalonia.Themes.Fluent/Slider.xaml b/src/Avalonia.Themes.Fluent/Slider.xaml
index 539c448e0f..099c2000b8 100644
--- a/src/Avalonia.Themes.Fluent/Slider.xaml
+++ b/src/Avalonia.Themes.Fluent/Slider.xaml
@@ -182,6 +182,7 @@
 
   <Style Selector="Slider /template/ TickBar">
     <Setter Property="IsVisible" Value="False" />
+    <Setter Property="Ticks" Value="{TemplateBinding Ticks}" />
   </Style>
 
   <!-- TickBar Placement States -->

From 6561cb739ad0ea3ae5292e3e17d84e75a01e0e94 Mon Sep 17 00:00:00 2001
From: Mihai Stan <stanmihai17cs@gmail.com>
Date: Thu, 2 Jul 2020 14:50:17 +0200
Subject: [PATCH 2/3] Snap thumb on custom ticks when they are set

---
 src/Avalonia.Controls/Slider.cs | 47 +++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 8 deletions(-)

diff --git a/src/Avalonia.Controls/Slider.cs b/src/Avalonia.Controls/Slider.cs
index 00a26a4c91..b94f9bb7c9 100644
--- a/src/Avalonia.Controls/Slider.cs
+++ b/src/Avalonia.Controls/Slider.cs
@@ -257,19 +257,50 @@ namespace Avalonia.Controls
         /// <param name="value">Value that want to snap to closest Tick.</param>
         private double SnapToTick(double value)
         {
-            var previous = Minimum;
-            var next = Maximum;
-
-            if (TickFrequency > 0.0)
+            if (IsSnapToTickEnabled)
             {
-                previous = Minimum + (Math.Round((value - Minimum) / TickFrequency) * TickFrequency);
-                next = Math.Min(Maximum, previous + TickFrequency);
+                double previous = Minimum;
+                double next = Maximum;
+
+                // This property is rarely set so let's try to avoid the GetValue
+                List<double> ticks = Ticks;
+
+                // If ticks collection is available, use it.
+                // Note that ticks may be unsorted.
+                if ((ticks != null) && (ticks.Count > 0))
+                {
+                    for (int i = 0; i < ticks.Count; i++)
+                    {
+                        double tick = ticks[i];
+                        if (MathUtilities.AreClose(tick, value))
+                        {
+                            return value;
+                        }
+
+                        if (MathUtilities.LessThan(tick, value) && MathUtilities.GreaterThan(tick, previous))
+                        {
+                            previous = tick;
+                        }
+                        else if (MathUtilities.GreaterThan(tick, value) && MathUtilities.LessThan(tick, next))
+                        {
+                            next = tick;
+                        }
+                    }
+                }
+                else if (MathUtilities.GreaterThan(TickFrequency, 0.0))
+                {
+                    previous = Minimum + (Math.Round(((value - Minimum) / TickFrequency)) * TickFrequency);
+                    next = Math.Min(Maximum, previous + TickFrequency);
+                }
+
+                // Choose the closest value between previous and next. If tie, snap to 'next'.
+                value = MathUtilities.GreaterThanOrClose(value, (previous + next) * 0.5) ? next : previous;
             }
 
-            // Choose the closest value between previous and next. If tie, snap to 'next'.
-            return MathUtilities.GreaterThanOrClose(value, (previous + next) * 0.5) ? next : previous;
+            return value;
         }
 
+
         private void UpdatePseudoClasses(Orientation o)
         {
             PseudoClasses.Set(":vertical", o == Orientation.Vertical);

From d8d9a1865dc4abe7466a43f14edbab7262222f7a Mon Sep 17 00:00:00 2001
From: Mihai Stan <stanmihai17cs@gmail.com>
Date: Thu, 2 Jul 2020 16:34:28 +0200
Subject: [PATCH 3/3] Use AvaloniaList instead of List

---
 samples/ControlCatalog/Pages/SliderPage.xaml    |  1 +
 samples/ControlCatalog/Pages/SliderPage.xaml.cs | 11 -----------
 src/Avalonia.Controls/Slider.cs                 |  8 ++++----
 src/Avalonia.Controls/TickBar.cs                | 12 ++++--------
 4 files changed, 9 insertions(+), 23 deletions(-)

diff --git a/samples/ControlCatalog/Pages/SliderPage.xaml b/samples/ControlCatalog/Pages/SliderPage.xaml
index ca289e21fd..ea31ed0050 100644
--- a/samples/ControlCatalog/Pages/SliderPage.xaml
+++ b/samples/ControlCatalog/Pages/SliderPage.xaml
@@ -19,6 +19,7 @@
                 Maximum="100"
                 TickPlacement="BottomRight"
                 IsSnapToTickEnabled="True"
+                Ticks="0,20,25,40,75,100"
                 Width="300" />
       </StackPanel>
       <Slider Value="0"
diff --git a/samples/ControlCatalog/Pages/SliderPage.xaml.cs b/samples/ControlCatalog/Pages/SliderPage.xaml.cs
index 22c2d6735b..2f4a5fabc9 100644
--- a/samples/ControlCatalog/Pages/SliderPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/SliderPage.xaml.cs
@@ -1,4 +1,3 @@
-using System.Collections.Generic;
 using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 
@@ -14,16 +13,6 @@ namespace ControlCatalog.Pages
         private void InitializeComponent()
         {
             AvaloniaXamlLoader.Load(this);
-
-            var slider = this.FindControl<Slider>("CustomTickedSlider");
-            slider.Ticks = new List<double>
-            {
-                0d,
-                5d,
-                20d,
-                50d,
-                100d
-            };
         }
     }
 }
diff --git a/src/Avalonia.Controls/Slider.cs b/src/Avalonia.Controls/Slider.cs
index b94f9bb7c9..293cbac82f 100644
--- a/src/Avalonia.Controls/Slider.cs
+++ b/src/Avalonia.Controls/Slider.cs
@@ -1,5 +1,5 @@
 using System;
-using System.Collections.Generic;
+using Avalonia.Collections;
 using Avalonia.Controls.Mixins;
 using Avalonia.Controls.Primitives;
 using Avalonia.Input;
@@ -68,7 +68,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="TicksProperty"/> property.
         /// </summary>
-        public static readonly StyledProperty<List<double>> TicksProperty =
+        public static readonly StyledProperty<AvaloniaList<double>> TicksProperty =
             TickBar.TicksProperty.AddOwner<Slider>();
 
         // Slider required parts
@@ -105,7 +105,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the ticks to be drawn on the tick bar.
         /// </summary>
-        public List<double> Ticks
+        public AvaloniaList<double> Ticks
         {
             get => GetValue(TicksProperty);
             set => SetValue(TicksProperty, value);
@@ -263,7 +263,7 @@ namespace Avalonia.Controls
                 double next = Maximum;
 
                 // This property is rarely set so let's try to avoid the GetValue
-                List<double> ticks = Ticks;
+                var ticks = Ticks;
 
                 // If ticks collection is available, use it.
                 // Note that ticks may be unsorted.
diff --git a/src/Avalonia.Controls/TickBar.cs b/src/Avalonia.Controls/TickBar.cs
index 16e063beb3..22145d8742 100644
--- a/src/Avalonia.Controls/TickBar.cs
+++ b/src/Avalonia.Controls/TickBar.cs
@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using Avalonia.Controls.Primitives;
-using Avalonia.Data;
-using Avalonia.Data.Converters;
+using Avalonia.Collections;
 using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Utilities;
@@ -135,15 +131,15 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Ticks"/> property.
         /// </summary>
-        public static readonly StyledProperty<List<double>> TicksProperty =
-            AvaloniaProperty.Register<TickBar, List<double>>(nameof(Ticks));
+        public static readonly StyledProperty<AvaloniaList<double>> TicksProperty =
+            AvaloniaProperty.Register<TickBar, AvaloniaList<double>>(nameof(Ticks));
 
         /// <summary>
         /// The Ticks property contains collection of value of type Double which
         /// are the logical positions use to draw the ticks.
         /// The property value is a <see cref="DoubleCollection" />.
         /// </summary>
-        public List<double> Ticks
+        public AvaloniaList<double> Ticks
         {
             get { return GetValue(TicksProperty); }
             set { SetValue(TicksProperty, value); }