FlowDocument rendering not updated when IsHyphenationEnabled changes - wpf

Question

My FlowDocument isn't updated when properties IsHyphenationEnabled and IsOptimalParagraphEnabled are changed as visible in the screenshot and code below:
<Window x:Class="FlowDocumentDemo.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
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:local="clr-namespace:FlowDocumentDemo"
xmlns:sys="clr-namespace:System;assembly=mscorlib"
mc:Ignorable="d"
Title="MainWindow" Height="700" Width="300">
<Window.DataContext>
<local:ViewModel/>
</Window.DataContext>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition/>
</Grid.RowDefinitions>
<StackPanel Grid.Row="0" Orientation="Horizontal" Margin="0,0,0,20">
<CheckBox Margin="8" Content="Hyphenation" IsChecked="{Binding Hyphenation}"/>
<CheckBox Margin="8" Content="Optimal Paragraphs" IsChecked="{Binding OptimalParagraphs}"/>
</StackPanel>
<FlowDocumentReader Grid.Row="1" ViewingMode="Scroll" Document="{Binding Document}"/>
</Grid>
</Window>
C#:
using System;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Media;
namespace FlowDocumentDemo {
public partial class MainWindow : Window { public MainWindow () { InitializeComponent (); } }
class ViewModel : INotifyPropertyChanged {
protected FlowDocument document;
protected bool hyphenation = true;
protected bool optimalParagraphs = true;
public event PropertyChangedEventHandler PropertyChanged;
public FlowDocument Document { get => document; set { document = value; RaisePropertyChanged (); } }
public bool Hyphenation { get => hyphenation; set { hyphenation = value; RaisePropertyChanged (); } }
public bool OptimalParagraphs { get => optimalParagraphs; set { optimalParagraphs = value; RaisePropertyChanged (); } }
public ViewModel () {
Document = new FlowDocument {
ColumnWidth = Double.MaxValue,
TextAlignment = TextAlignment.Justify,
FontFamily = new FontFamily ("Arial"),
IsHyphenationEnabled = Hyphenation,
IsOptimalParagraphEnabled = OptimalParagraphs
};
Paragraph paragraph = new Paragraph ();
paragraph.Inlines.Add (new Run {
FontSize = 35,
FontWeight = FontWeights.Bold,
Text = "NASA announces funding for moon and Mars mission tech"
});
Document.Blocks.Add (paragraph);
paragraph = new Paragraph ();
paragraph.Inlines.Add (new Run {
FontFamily = new FontFamily ("Arial"),
Text = "NASA announced agreements worth a combined $43.2 million with 14 commercial partners " +
"Friday — including Blue Origin and SpaceX — to fund experiments in propellant and power " +
"generation, in-space refueling, efficient propulsion systems, and lunar rover technology."
});
Document.Blocks.Add (paragraph);
}
protected void RaisePropertyChanged ([CallerMemberName] string propertyName = null) {
PropertyChanged?.Invoke (this, new PropertyChangedEventArgs (propertyName));
}
}
}
I don't see in MSDN that the properties are statically defined at document first display. Do I miss something?

Answer 1

Just realizing my properties are not bound using Binding objects. In case someone does the same beginner mistake:
public ViewModel () {
Document = new FlowDocument {
ColumnWidth = Double.MaxValue,
TextAlignment = TextAlignment.Justify,
FontFamily = new FontFamily ("Arial"),
};
Document.SetBinding (FlowDocument.IsHyphenationEnabledProperty, new Binding ("Hyphenation"));
Document.SetBinding (FlowDocument.IsOptimalParagraphEnabledProperty, new Binding ("OptimalParagraphs"));
Maybe this can be simplified / optimized.