Use the Glow to enable drop shadow (EnableDWMDropShadow)

MahApps.Metro/Behaviours/BorderlessWindowBehavior.cs

@@ -17,6 +17,7 @@ public class BorderlessWindowBehavior : Behavior<Window>
         private IntPtr handle;
         private HwndSource hwndSource;
         private WindowChrome windowChrome;
+        private PropertyChangeNotifier borderThicknessChangeNotifier;
         private Thickness? savedBorderThickness;
 
         protected override void OnAttached()
@@ -57,7 +58,10 @@ protected override void OnAttached()
                 }
             }
             AssociatedObject.WindowStyle = WindowStyle.None;
+
             savedBorderThickness = AssociatedObject.BorderThickness;
+            borderThicknessChangeNotifier = new PropertyChangeNotifier(this.AssociatedObject, Window.BorderThicknessProperty);
+            borderThicknessChangeNotifier.ValueChanged += BorderThicknessChangeNotifierOnValueChanged;
 
             AssociatedObject.Loaded += AssociatedObject_Loaded;
             AssociatedObject.Unloaded += AssociatedObject_Unloaded;
@@ -67,6 +71,11 @@ protected override void OnAttached()
             base.OnAttached();
         }
 
+        private void BorderThicknessChangeNotifierOnValueChanged(object sender, EventArgs e)
+        {
+            savedBorderThickness = AssociatedObject.BorderThickness;
+        }
+
         private void UseNoneWindowStylePropertyChangedCallback(object sender, EventArgs e)
         {
             var metroWindow = sender as MetroWindow;
@@ -144,25 +153,8 @@ private void AssociatedObject_Unloaded(object sender, RoutedEventArgs e)
         private IntPtr WindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
         {
             var returnval = IntPtr.Zero;
-            var metroWindow = AssociatedObject as MetroWindow;
-
+
             switch (msg) {
-                case Constants.WM_NCPAINT:
-                    var enableDWMDropShadow = EnableDWMDropShadow;
-
-                    if (metroWindow != null)
-                    {
-                        enableDWMDropShadow = metroWindow.GlowBrush == null && (metroWindow.EnableDWMDropShadow || EnableDWMDropShadow);
-                    }
-                    if (enableDWMDropShadow)
-                    {
-                        var val = 2;
-                        UnsafeNativeMethods.DwmSetWindowAttribute(hwnd, 2, ref val, 4);
-                        var m = new MARGINS { bottomHeight = 1, leftWidth = 1, rightWidth = 1, topHeight = 1 };
-                        UnsafeNativeMethods.DwmExtendFrameIntoClientArea(hwnd, ref m);
-                    }
-                    handled = true;
-                    break;
                 case Constants.WM_NCACTIVATE:
                     /* As per http://msdn.microsoft.com/en-us/library/ms632633(VS.85).aspx , "-1" lParam "does not repaint the nonclient area to reflect the state change." */
                     returnval = UnsafeNativeMethods.DefWindowProc(hwnd, msg, wParam, new IntPtr(-1));
@@ -180,13 +172,21 @@ private void OnAssociatedObjectHandleMaximize(object sender, EventArgs e)
 
         private void HandleMaximize()
         {
+            borderThicknessChangeNotifier.ValueChanged -= BorderThicknessChangeNotifierOnValueChanged;
+
+            var metroWindow = AssociatedObject as MetroWindow;
+            var enableDWMDropShadow = EnableDWMDropShadow;
+            if (metroWindow != null)
+            {
+                enableDWMDropShadow = metroWindow.GlowBrush == null && (metroWindow.EnableDWMDropShadow || EnableDWMDropShadow);
+            }
+
             if (AssociatedObject.WindowState == WindowState.Maximized)
             {
                 // remove resize border and window border, so we can move the window from top monitor position
                 windowChrome.ResizeBorderThickness = new Thickness(0);
                 AssociatedObject.BorderThickness = new Thickness(0);
 
-                var metroWindow = AssociatedObject as MetroWindow;
                 var ignoreTaskBar = metroWindow != null && metroWindow.IgnoreTaskbarOnMaximize;
                 if (ignoreTaskBar)
                 {
@@ -210,7 +210,10 @@ private void HandleMaximize()
             else
             {
                 windowChrome.ResizeBorderThickness = SystemParameters2.Current.WindowResizeBorderThickness;
-                AssociatedObject.BorderThickness = savedBorderThickness.GetValueOrDefault(new Thickness(0));
+                if (!enableDWMDropShadow)
+                {
+                    AssociatedObject.BorderThickness = savedBorderThickness.GetValueOrDefault(new Thickness(0));
+                }
 
                 // fix nasty TopMost bug
                 // - set TopMost="True"
@@ -222,6 +225,8 @@ private void HandleMaximize()
                 AssociatedObject.Topmost = false;
                 AssociatedObject.Topmost = topMost;
             }
+
+            borderThicknessChangeNotifier.ValueChanged += BorderThicknessChangeNotifierOnValueChanged;
         }
 
         private void AssociatedObject_SourceInitialized(object sender, EventArgs e)
@@ -257,8 +262,10 @@ private void AssociatedObject_Loaded(object sender, RoutedEventArgs e)
             window.SetIsHitTestVisibleInChromeProperty<ContentControl>("PART_WindowButtonCommands");
         }
 
+        [Obsolete("This property will be deleted in the next release. Use the MetroWindow EnableDWMDropShadow property instead.")]
         public static readonly DependencyProperty EnableDWMDropShadowProperty = DependencyProperty.Register("EnableDWMDropShadow", typeof(bool), typeof(BorderlessWindowBehavior), new PropertyMetadata(false));
 
+        [Obsolete("This property will be deleted in the next release. Use the MetroWindow EnableDWMDropShadow property instead.")]
         public bool EnableDWMDropShadow
         {
             get { return (bool)GetValue(EnableDWMDropShadowProperty); }

MahApps.Metro/Controls/GlowWindow.xaml.cs

@@ -44,6 +44,10 @@ public GlowWindow(Window owner, GlowDirection direction)
             b.Source = owner;
             glow.SetBinding(Glow.NonActiveGlowBrushProperty, b);
 
+            b = new Binding("BorderThickness");
+            b.Source = owner;
+            glow.SetBinding(Glow.BorderThicknessProperty, b);
+
             switch (direction)
             {
                 case GlowDirection.Left:

MahApps.Metro/Controls/MetroWindow.cs

@@ -86,7 +86,7 @@ public class MetroWindow : Window
         public static readonly DependencyProperty UseNoneWindowStyleProperty = DependencyProperty.Register("UseNoneWindowStyle", typeof(bool), typeof(MetroWindow), new PropertyMetadata(false, OnUseNoneWindowStylePropertyChangedCallback));
         public static readonly DependencyProperty OverrideDefaultWindowCommandsBrushProperty = DependencyProperty.Register("OverrideDefaultWindowCommandsBrush", typeof(SolidColorBrush), typeof(MetroWindow));
 
-        public static readonly DependencyProperty EnableDWMDropShadowProperty = DependencyProperty.Register("EnableDWMDropShadow", typeof(bool), typeof(MetroWindow), new PropertyMetadata(false));
+        public static readonly DependencyProperty EnableDWMDropShadowProperty = DependencyProperty.Register("EnableDWMDropShadow", typeof(bool), typeof(MetroWindow), new PropertyMetadata(false, OnEnableDWMDropShadowPropertyChangedCallback));
         public static readonly DependencyProperty IsWindowDraggableProperty = DependencyProperty.Register("IsWindowDraggable", typeof(bool), typeof(MetroWindow), new PropertyMetadata(true));
 
         UIElement icon;
@@ -132,6 +132,22 @@ public bool EnableDWMDropShadow
             set { SetValue(EnableDWMDropShadowProperty, value); }
         }
 
+        private static void OnEnableDWMDropShadowPropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            if (e.NewValue != e.OldValue && (bool)e.NewValue)
+            {
+                var window = (MetroWindow)d;
+                window.UseDropShadow();
+            }
+        }
+
+        private void UseDropShadow()
+        {
+            this.BorderThickness = new Thickness(0);
+            this.BorderBrush = null;
+            this.GlowBrush = Brushes.Black;
+        }
+
         public bool IsWindowDraggable
         {
             get { return (bool)GetValue(IsWindowDraggableProperty); }
@@ -675,6 +691,11 @@ public MetroWindow()
 
         private void MetroWindow_Loaded(object sender, RoutedEventArgs e)
         {
+            if (EnableDWMDropShadow)
+            {
+                this.UseDropShadow();
+            }
+
             if (this.WindowTransitionsEnabled)
             {
                 VisualStateManager.GoToState(this, "AfterLoaded", true);

MahApps.Metro/Styles/Clean/CleanWindow.xaml

@@ -203,11 +203,22 @@
         </ControlTemplate.Resources>
         <ControlTemplate.Triggers>
             <!-- handle active/inactive state -->
-            <Trigger Property="IsActive"
-                     Value="False">
+            <MultiTrigger>
+                <MultiTrigger.Conditions>
+                    <Condition Property="IsActive"
+                               Value="False" />
+                    <Condition Property="GlowBrush"
+                               Value="{x:Null}" />
+                </MultiTrigger.Conditions>
                 <Setter TargetName="PART_Border"
                         Property="BorderBrush"
                         Value="{Binding Path=NonActiveBorderBrush, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Controls:MetroWindow}}}" />
+            </MultiTrigger>
+            <Trigger Property="BorderBrush"
+                     Value="{x:Null}">
+                <Setter TargetName="PART_Border"
+                        Property="Visibility"
+                        Value="Collapsed" />
             </Trigger>
             <!-- no icon and no icon content template -> collapse the icon content control -->
             <MultiTrigger>

MahApps.Metro/Themes/Glow.xaml

@@ -6,12 +6,8 @@
                      TargetType="{x:Type Controls:Glow}">
         <Grid Margin="{TemplateBinding Padding}"
               Background="Transparent">
-            <Border Grid.Row="1"
-                    Grid.Column="1"
-                    Background="{TemplateBinding Background}" />
+            <Border Background="{TemplateBinding Background}" />
             <Border x:Name="glowSource"
-                    Grid.Row="1"
-                    Grid.Column="1"
                     Margin="-1,0"
                     Opacity="0.6"
                     Background="{TemplateBinding Background}">
@@ -27,14 +23,21 @@
                         Property="Margin"
                         Value="0,-1" />
             </Trigger>
+            <Trigger Property="BorderThickness" Value="0">
+                <Setter TargetName="glowSource"
+                        Property="Opacity"
+                        Value="1" />
+            </Trigger>
         </ControlTemplate.Triggers>
     </ControlTemplate>
 
     <Style TargetType="{x:Type Controls:Glow}">
+        <Setter Property="BorderThickness"
+                Value="1" />
         <Setter Property="Background"
                 Value="{Binding RelativeSource={RelativeSource Self}, Path=GlowBrush}" />
         <Setter Property="Width"
-                Value="1" />
+                Value="{Binding RelativeSource={RelativeSource Self}, Path=BorderThickness.Left, Mode=OneWay}" />
         <Setter Property="Padding"
                 Value="0,8" />
         <Setter Property="Template"
@@ -50,7 +53,7 @@
                 <Setter Property="Width"
                         Value="Auto" />
                 <Setter Property="Height"
-                        Value="1" />
+                        Value="{Binding RelativeSource={RelativeSource Self}, Path=BorderThickness.Top, Mode=OneWay}" />
                 <Setter Property="Padding"
                         Value="0" />
             </Trigger>

MahApps.Metro/Themes/MetroWindow.xaml

@@ -199,14 +199,28 @@
         </ControlTemplate.Resources>
         <ControlTemplate.Triggers>
             <!-- handle active/inactive state -->
+            <MultiTrigger>
+                <MultiTrigger.Conditions>
+                    <Condition Property="IsActive"
+                               Value="False" />
+                    <Condition Property="GlowBrush"
+                               Value="{x:Null}" />
+                </MultiTrigger.Conditions>
+                <Setter TargetName="PART_Border"
+                        Property="BorderBrush"
+                        Value="{Binding Path=NonActiveBorderBrush, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Controls:MetroWindow}}}" />
+            </MultiTrigger>
             <Trigger Property="IsActive"
                      Value="False">
                 <Setter TargetName="PART_WindowTitleBackground"
                         Property="Fill"
                         Value="{Binding Path=NonActiveWindowTitleBrush, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Controls:MetroWindow}}}" />
+            </Trigger>
+            <Trigger Property="BorderBrush"
+                     Value="{x:Null}">
                 <Setter TargetName="PART_Border"
-                        Property="BorderBrush"
-                        Value="{Binding Path=NonActiveBorderBrush, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Controls:MetroWindow}}}" />
+                        Property="Visibility"
+                        Value="Collapsed" />
             </Trigger>
             <!-- no icon and no icon content template -> collapse the icon content control -->
             <MultiTrigger>
@@ -238,6 +252,8 @@
     </ControlTemplate>
 
     <Style TargetType="{x:Type Controls:MetroWindow}">
+        <Setter Property="BorderThickness"
+                Value="1" />
         <Setter Property="UseLayoutRounding"
                 Value="True" />
         <Setter Property="WindowTitleBrush"

samples/MetroDemo/MainWindow.xaml

@@ -166,6 +166,10 @@
                               IsChecked="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Controls:MetroWindow}}, Path=IgnoreTaskbarOnMaximize}" />
                     <MenuItem IsCheckable="True" Header="Toggle FullScreen (no taskbar, window style = none)"
                               IsChecked="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Controls:MetroWindow}}, Path=ToggleFullScreen}" />
+                    <Separator />
+                    <MenuItem Header="Window with a Border" Click="MenuWindowWithBorderOnClick" />
+                    <MenuItem Header="Window with a Glow" Click="MenuWindowWithGlowOnClick" />
+                    <MenuItem Header="Window with drop shadow" Click="MenuWindowWithShadowOnClick" />
                 </MenuItem>
             </Menu>
 

samples/MetroDemo/MainWindow.xaml.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Threading.Tasks;
 using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
 using MahApps.Metro.Controls;
 using MahApps.Metro.Controls.Dialogs;
 using MetroDemo.ExampleWindows;
@@ -288,5 +290,45 @@ private async void MetroWindow_Closing(object sender, System.ComponentModel.Canc
             if (_shutdown)
                 Application.Current.Shutdown();
         }
+
+        private MetroWindow testWindow;
+
+        private MetroWindow GetTestWindow()
+        {
+            if (testWindow != null) {
+                testWindow.Close();
+            }
+            testWindow = new MetroWindow() { Owner = this, WindowStartupLocation = WindowStartupLocation.CenterOwner, Title = "Another Test...", Width = 500, Height = 300 };
+            testWindow.Closed += (o, args) => testWindow = null;
+            return testWindow;
+        }
+
+        private void MenuWindowWithBorderOnClick(object sender, RoutedEventArgs e)
+        {
+            var w = this.GetTestWindow();
+            w.Content = new TextBlock() { Text = "MetroWindow with a Border", FontSize = 28, FontWeight = FontWeights.Light, VerticalAlignment = VerticalAlignment.Center, HorizontalAlignment = HorizontalAlignment.Center };
+            w.BorderThickness = new Thickness(1);
+            w.GlowBrush = null;
+            w.BorderBrush = this.FindResource("AccentColorBrush") as Brush;
+            w.Show();
+        }
+
+        private void MenuWindowWithGlowOnClick(object sender, RoutedEventArgs e)
+        {
+            var w = this.GetTestWindow();
+            w.Content = new TextBlock() { Text = "MetroWindow with a Glow", FontSize = 28, FontWeight = FontWeights.Light, VerticalAlignment = VerticalAlignment.Center, HorizontalAlignment = HorizontalAlignment.Center };
+            w.BorderThickness = new Thickness(1);
+            w.BorderBrush = null;
+            w.GlowBrush = this.FindResource("AccentColorBrush") as SolidColorBrush;
+            w.Show();
+        }
+
+        private void MenuWindowWithShadowOnClick(object sender, RoutedEventArgs e)
+        {
+            var w = this.GetTestWindow();
+            w.Content = new TextBlock() { Text = "MetroWindow with a Glow", FontSize = 28, FontWeight = FontWeights.Light, VerticalAlignment = VerticalAlignment.Center, HorizontalAlignment = HorizontalAlignment.Center };
+            w.EnableDWMDropShadow = true;
+            w.Show();
+        }
     }
 }