MainWindow.xaml

<Window x:Name="Win_Main" x:Class="DesktopNote.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        xmlns:local="clr-namespace:DesktopNote"
        Title="Desktop Note" Height="350" Width="300" ShowInTaskbar="False" AllowsTransparency="True" WindowStyle="None" Background="{x:Null}"
        ResizeMode="CanResizeWithGrip" UseLayoutRounding="True"
        MouseEnter="Win_Main_MouseEnter" Loaded="Win_Main_Loaded">
    <!--<Window.CacheMode>
        <BitmapCache/>
    </Window.CacheMode>-->
    <Window.Resources>
        <ContextMenu x:Key="TrayMenu">
            <MenuItem Header="{StaticResource menu_newnote}" Click="TM_NewNote_Click"/>
            <MenuItem Header="{StaticResource menu_opennote}" Click="TM_OpenNote_Click"/>
            <MenuItem Header="{StaticResource menu_reset_positions}" Click="TM_ResetPos_Click"/>
            <MenuItem Header="{StaticResource menu_exit}" Click="TM_Exit_Click"/>
        </ContextMenu>
        <local:ThicknessConverter x:Key="ThicknessConverter"/>
    </Window.Resources>
    <Grid>
        <Rectangle x:Name="Rec_BG" Fill="#FFFFF7C5" Margin="10" RadiusX="12" RadiusY="12"
                   MouseLeftButtonDown="Rec_BG_MouseLeftButtonDown" MouseLeftButtonUp="Rec_BG_MouseLeftButtonUp" MouseMove="Rec_BG_MouseMove" Cursor="SizeAll">
            <Rectangle.Effect>
                <DropShadowEffect ShadowDepth="0" BlurRadius="8"/>
            </Rectangle.Effect>
        </Rectangle>
        <RichTextBox x:Name="RTB_Main" Margin="20" Background="{x:Null}" BorderBrush="{x:Null}" AcceptsTab="True" BorderThickness="0" IsInactiveSelectionHighlightEnabled="True"
                     TextChanged="RTB_Main_TextChanged" PreviewKeyDown="RTB_Main_PreviewKeyDown" PreviewMouseWheel="RTB_Main_PreviewMouseWheel"
                     GotKeyboardFocus="RTB_Main_GotKeyboardFocus"
                     ContextMenuOpening="RTB_Main_ContextMenuOpening" PreviewMouseDown="RTB_Main_PreviewMouseDown">
            <!--<wtk:RichTextBoxFormatBarManager.FormatBar>
                <wtk:RichTextBoxFormatBar/>
            </wtk:RichTextBoxFormatBarManager.FormatBar>-->
            <RichTextBox.Resources>
                <SolidColorBrush x:Key="{x:Static SystemColors.InactiveSelectionHighlightBrushKey}" Color="{StaticResource {x:Static SystemColors.HighlightColorKey}}"/>
                <Style TargetType="{x:Type List}">
                    <Setter Property="Margin" Value="0"/>
                    <Setter Property="Padding" Value="{Binding
                        RelativeSource={RelativeSource AncestorType=RichTextBox}, Path=FontSize, Mode=OneWay,
                        Converter={StaticResource ThicknessConverter}, ConverterParameter='1.5 0 0 0'}"/>
                    <!--marker padding according to the type of the marker. if the marker is not a fixed length character, give more space to the marker-->
                    <Style.Triggers>
                        <Trigger Property="MarkerStyle" Value="Decimal">
                            <Setter Property="Padding" Value="{Binding
                                RelativeSource={RelativeSource AncestorType=RichTextBox}, Path=FontSize, Mode=OneWay,
                                Converter={StaticResource ThicknessConverter}, ConverterParameter='2.5 0 0 0'}"/>
                        </Trigger>
                    </Style.Triggers>
                </Style>
                <Style TargetType="{x:Type Paragraph}">
                    <Setter Property="Margin" Value="0"/>
                </Style>
            </RichTextBox.Resources>
            <RichTextBox.ContextMenu>
                <!--this is necessary for not showing the default menu.-->
                <ContextMenu/>
            </RichTextBox.ContextMenu>

            <FlowDocument>
                <List>
                    <ListItem>
                        <Paragraph>
                            <Run Text="{StaticResource default_note_text}"/>
                        </Paragraph>
                    </ListItem>
                </List>
            </FlowDocument>
        </RichTextBox>
        <TextBlock x:Name="TB_Status" Text="{StaticResource status_saved}" Margin="18" VerticalAlignment="Bottom" HorizontalAlignment="Right" Opacity="0.5" FontStyle="Italic" FontSize="10" Visibility="Hidden"/>
    </Grid>
</Window>