From 435419588a3702efc1f67eec7a6865c64a03cbb5 Mon Sep 17 00:00:00 2001
From: Eric M <itsjusteza@gmail.com>
Date: Wed, 6 Jul 2022 21:18:40 +1000
Subject: [PATCH] Allow customisation of ProgressBar text format.

---
 .../ControlCatalog/Pages/ProgressBarPage.xaml | 27 ++++++++++++++-----
 .../Converters/StringFormatConverter.cs       | 27 +++++++++++++++++++
 src/Avalonia.Controls/ProgressBar.cs          | 23 ++++++++++++++++
 .../Controls/ProgressBar.xaml                 | 21 ++++++++++++---
 .../Controls/ProgressBar.xaml                 | 16 ++++++++++-
 5 files changed, 104 insertions(+), 10 deletions(-)
 create mode 100644 src/Avalonia.Controls/Converters/StringFormatConverter.cs

diff --git a/samples/ControlCatalog/Pages/ProgressBarPage.xaml b/samples/ControlCatalog/Pages/ProgressBarPage.xaml
index db7d7d3280..8e73f1d0f5 100644
--- a/samples/ControlCatalog/Pages/ProgressBarPage.xaml
+++ b/samples/ControlCatalog/Pages/ProgressBarPage.xaml
@@ -1,22 +1,37 @@
 <UserControl xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="ControlCatalog.Pages.ProgressBarPage">
   <StackPanel Orientation="Vertical" Spacing="4">
     <TextBlock Classes="h2">A progress bar control</TextBlock>
-    <StackPanel>
+    <StackPanel Spacing="5">
+      <StackPanel Orientation="Horizontal" Spacing="5">
+        <TextBlock VerticalAlignment="Center">Maximum</TextBlock>
+        <NumericUpDown x:Name="maximum" Value="100" VerticalAlignment="Center"/>
+      </StackPanel>
+      <StackPanel Orientation="Horizontal" Spacing="5">
+        <TextBlock VerticalAlignment="Center">Minimum</TextBlock>
+        <NumericUpDown x:Name="minimum" Value="0" VerticalAlignment="Center"/>
+      </StackPanel>
+      <StackPanel Orientation="Horizontal" Spacing="5">
+        <TextBlock VerticalAlignment="Center">Progress Text Format</TextBlock>
+        <TextBox x:Name="stringFormat" Text="{}{0:0}%" VerticalAlignment="Center"/>
+      </StackPanel>
       <CheckBox x:Name="showProgress" Margin="10,16,0,0" Content="Show Progress Text" />
       <CheckBox x:Name="isIndeterminate" Margin="10,16,0,0" Content="Toggle Indeterminate" />
       <StackPanel Orientation="Horizontal" Margin="0,16,0,0" HorizontalAlignment="Center" Spacing="16">
         <StackPanel Spacing="16">
-          <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #hprogress.Value}" />
+          <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #hprogress.Value}" 
+                       Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" ProgressTextFormat="{Binding #stringFormat.Text}"/>
         </StackPanel>
-        <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #vprogress.Value}" Orientation="Vertical" />
+        <ProgressBar IsIndeterminate="{Binding #isIndeterminate.IsChecked}" ShowProgressText="{Binding #showProgress.IsChecked}" Value="{Binding #vprogress.Value}" Orientation="Vertical" 
+                     Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" ProgressTextFormat="{Binding #stringFormat.Text}"/>
       </StackPanel>
       <StackPanel Margin="16">
-        <Slider Name="hprogress" Maximum="100" Value="40" />
-        <Slider Name="vprogress" Maximum="100" Value="60" />
+        <Slider Name="hprogress" Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" Value="40" />
+        <Slider Name="vprogress" Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.Value}" Value="60" />
       </StackPanel>
 
       <StackPanel Spacing="10">
-        <ProgressBar VerticalAlignment="Center" IsIndeterminate="True" />
+        <ProgressBar VerticalAlignment="Center" IsIndeterminate="True" 
+                     Minimum="{Binding #minimum.Value}" Maximum="{Binding #maximum.value}"/>
         <ProgressBar VerticalAlignment="Center" Value="5" Maximum="10" />
         <ProgressBar VerticalAlignment="Center" Value="50" />
         <ProgressBar VerticalAlignment="Center" Value="50" Minimum="25" Maximum="75" />
diff --git a/src/Avalonia.Controls/Converters/StringFormatConverter.cs b/src/Avalonia.Controls/Converters/StringFormatConverter.cs
new file mode 100644
index 0000000000..ae920dac7e
--- /dev/null
+++ b/src/Avalonia.Controls/Converters/StringFormatConverter.cs
@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using Avalonia.Data;
+using Avalonia.Data.Converters;
+
+namespace Avalonia.Controls.Converters;
+
+/// <summary>
+/// Calls <see cref="string.Format(string, object[])"/> on the passed in values, where the first element in the list
+/// is the string, and everything after it is passed into the object array in order.
+/// </summary>
+public class StringFormatConverter : IMultiValueConverter
+{
+    public object? Convert(IList<object?> values, Type targetType, object? parameter, CultureInfo culture)
+    {
+        try
+        {
+            return string.Format((string)values[0]!, values.Skip(1).ToArray());
+        }
+        catch (Exception e)
+        {
+            return new BindingNotification(e, BindingErrorType.Error);
+        }
+    }
+}
diff --git a/src/Avalonia.Controls/ProgressBar.cs b/src/Avalonia.Controls/ProgressBar.cs
index 1075328c67..70edeadfd9 100644
--- a/src/Avalonia.Controls/ProgressBar.cs
+++ b/src/Avalonia.Controls/ProgressBar.cs
@@ -96,6 +96,7 @@ namespace Avalonia.Controls
             }
         }
 
+        private double _percentage;
         private double _indeterminateStartingOffset;
         private double _indeterminateEndingOffset;
         private Border? _indicator;
@@ -106,9 +107,17 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<bool> ShowProgressTextProperty =
             AvaloniaProperty.Register<ProgressBar, bool>(nameof(ShowProgressText));
 
+        public static readonly StyledProperty<string> ProgressTextFormatProperty =
+            AvaloniaProperty.Register<ProgressBar, string>(nameof(ProgressTextFormat), "{1:0}%");
+        
         public static readonly StyledProperty<Orientation> OrientationProperty =
             AvaloniaProperty.Register<ProgressBar, Orientation>(nameof(Orientation), Orientation.Horizontal);
 
+        public static readonly DirectProperty<ProgressBar, double> PercentageProperty =
+            AvaloniaProperty.RegisterDirect<ProgressBar, double>(
+                nameof(Percentage),
+                o => o.Percentage);
+
         [Obsolete("To be removed when Avalonia.Themes.Default is discontinued.")]
         public static readonly DirectProperty<ProgressBar, double> IndeterminateStartingOffsetProperty =
             AvaloniaProperty.RegisterDirect<ProgressBar, double>(
@@ -123,6 +132,12 @@ namespace Avalonia.Controls
                 p => p.IndeterminateEndingOffset,
                 (p, o) => p.IndeterminateEndingOffset = o);
 
+        public double Percentage
+        {
+            get { return _percentage; }
+            private set { SetAndRaise(PercentageProperty, ref _percentage, value); }
+        }
+        
         [Obsolete("To be removed when Avalonia.Themes.Default is discontinued.")]
         public double IndeterminateStartingOffset
         {
@@ -165,6 +180,12 @@ namespace Avalonia.Controls
             set => SetValue(ShowProgressTextProperty, value);
         }
 
+        public string ProgressTextFormat
+        {
+            get => GetValue(ProgressTextFormatProperty);
+            set => SetValue(ProgressTextFormatProperty, value);
+        }
+
         public Orientation Orientation
         {
             get => GetValue(OrientationProperty);
@@ -245,6 +266,8 @@ namespace Avalonia.Controls
                         _indicator.Width = bounds.Width * percent;
                     else
                         _indicator.Height = bounds.Height * percent;
+
+                    Percentage = percent * 100;
                 }
             }
         }
diff --git a/src/Avalonia.Themes.Default/Controls/ProgressBar.xaml b/src/Avalonia.Themes.Default/Controls/ProgressBar.xaml
index fd847b5d65..3f684f3936 100644
--- a/src/Avalonia.Themes.Default/Controls/ProgressBar.xaml
+++ b/src/Avalonia.Themes.Default/Controls/ProgressBar.xaml
@@ -1,4 +1,6 @@
-<Styles xmlns="https://github.com/avaloniaui">
+<Styles xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:converters="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls">
   <Design.PreviewWith>
     <Border Padding="20">
       <StackPanel Spacing="10">
@@ -11,10 +13,13 @@
     </Border>
   </Design.PreviewWith>
   <Style Selector="ProgressBar">
+    <Style.Resources>
+      <converters:StringFormatConverter x:Key="StringFormatConverter"/>
+    </Style.Resources>
     <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush4}"/>
     <Setter Property="Foreground" Value="{DynamicResource ThemeAccentBrush}"/>
     <Setter Property="Template">
-      <ControlTemplate>
+      <ControlTemplate TargetType="ProgressBar">
         <Grid>
           <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding CornerRadius}">
             <Panel>
@@ -23,7 +28,17 @@
             </Panel>
           </Border>
           <LayoutTransformControl HorizontalAlignment="Center" VerticalAlignment="Center" IsVisible="{Binding ShowProgressText, RelativeSource={RelativeSource TemplatedParent}}" Name="PART_LayoutTransformControl">
-            <TextBlock Foreground="{DynamicResource ThemeForegroundBrush}" Text="{Binding Value, RelativeSource={RelativeSource TemplatedParent}, StringFormat={}{0:0}%}" />
+            <TextBlock Foreground="{DynamicResource ThemeForegroundBrush}">
+              <TextBlock.Text>
+                <MultiBinding Converter="{StaticResource StringFormatConverter}">
+                  <TemplateBinding Property="ProgressTextFormat"/>
+                  <Binding Path="Value" RelativeSource="{RelativeSource TemplatedParent}"/>
+                  <TemplateBinding Property="Percentage"/>
+                  <TemplateBinding Property="Minimum"/>
+                  <TemplateBinding Property="Maximum"/>
+                </MultiBinding>
+              </TextBlock.Text>
+            </TextBlock>
           </LayoutTransformControl>
         </Grid>
       </ControlTemplate>
diff --git a/src/Avalonia.Themes.Fluent/Controls/ProgressBar.xaml b/src/Avalonia.Themes.Fluent/Controls/ProgressBar.xaml
index 482b219589..5c0edf19c2 100644
--- a/src/Avalonia.Themes.Fluent/Controls/ProgressBar.xaml
+++ b/src/Avalonia.Themes.Fluent/Controls/ProgressBar.xaml
@@ -1,5 +1,6 @@
 <Styles xmlns="https://github.com/avaloniaui" 
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:converters="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls"
         x:CompileBindings="True">
   <Design.PreviewWith>
     <Border Padding="20">
@@ -13,6 +14,9 @@
     </Border>
   </Design.PreviewWith>
   <Style Selector="ProgressBar">
+    <Style.Resources>
+      <converters:StringFormatConverter x:Key="StringFormatConverter"/>
+    </Style.Resources>
     <Setter Property="Foreground" Value="{DynamicResource SystemControlHighlightAccentBrush}" />
     <Setter Property="Background" Value="{DynamicResource SystemControlBackgroundBaseLowBrush}" />
     <Setter Property="BorderThickness" Value="{DynamicResource ProgressBarBorderThemeThickness}" />
@@ -32,7 +36,17 @@
                 <Border x:Name="IndeterminateProgressBarIndicator2" CornerRadius="{TemplateBinding CornerRadius}" Margin="{TemplateBinding Padding}" Background="{TemplateBinding Foreground}" />
               </Panel>
               <LayoutTransformControl x:Name="PART_LayoutTransformControl" HorizontalAlignment="Center" VerticalAlignment="Center" IsVisible="{TemplateBinding ShowProgressText}">
-                <TextBlock Foreground="{DynamicResource SystemControlForegroundBaseHighBrush}" Text="{Binding Value, RelativeSource={RelativeSource TemplatedParent}, StringFormat={}{0:0}%}" />
+                <TextBlock Foreground="{DynamicResource SystemControlForegroundBaseHighBrush}">
+                  <TextBlock.Text>
+                    <MultiBinding Converter="{StaticResource StringFormatConverter}">
+                      <TemplateBinding Property="ProgressTextFormat"/>
+                      <Binding Path="Value" RelativeSource="{RelativeSource TemplatedParent}"/>
+                      <TemplateBinding Property="Percentage"/>
+                      <TemplateBinding Property="Minimum"/>
+                      <TemplateBinding Property="Maximum"/>
+                    </MultiBinding>
+                  </TextBlock.Text>
+                </TextBlock>
               </LayoutTransformControl>
             </Panel>
         </Border>