feat: improve layer calculation

src/Ursa.Themes.Semi/Controls/Dialog.axaml

@@ -53,10 +53,26 @@
         <Style Selector="^:not(:modal) /template/ Panel#PART_TitleArea">
             <Setter Property="ContextFlyout">
                 <MenuFlyout>
-                    <MenuItem Header="Bring Forward" Command="{Binding $parent[u:DialogControl].BringForward}"></MenuItem>
+                    <MenuItem Header="Bring Forward" Command="{Binding $parent[u:DialogControl].BringForward}">
-                    <MenuItem Header="Send Backward" Command="{Binding $parent[u:DialogControl].SendBackward}" ></MenuItem>
+                        <MenuItem.Icon>
-                    <MenuItem Header="Bring To Front" Command="{Binding $parent[u:DialogControl].BringToFront}"></MenuItem>
+                            <PathIcon Width="12" Height="12" Data="{DynamicResource DialogArrangeBringForwardGlyph}"></PathIcon>
-                    <MenuItem Header="Send To Back" Command="{Binding $parent[u:DialogControl].SendToBack}"></MenuItem>
+                        </MenuItem.Icon>
+                    </MenuItem>
+                    <MenuItem Header="Bring To Front" Command="{Binding $parent[u:DialogControl].BringToFront}">
+                        <MenuItem.Icon>
+                            <PathIcon Width="12" Height="12" Data="{DynamicResource DialogArrangeBringToFrontGlyph}"></PathIcon>
+                        </MenuItem.Icon>
+                    </MenuItem>
+                    <MenuItem Header="Send Backward" Command="{Binding $parent[u:DialogControl].SendBackward}" >
+                        <MenuItem.Icon>
+                            <PathIcon Width="12" Height="12" Data="{DynamicResource DialogArrangeSendBackwardGlyph}"></PathIcon>
+                        </MenuItem.Icon>
+                    </MenuItem>
+                    <MenuItem Header="Send To Back" Command="{Binding $parent[u:DialogControl].SendToBack}">
+                        <MenuItem.Icon>
+                            <PathIcon Width="12" Height="12" Data="{DynamicResource DialogArrangeSendToBackGlyph}"></PathIcon>
+                        </MenuItem.Icon>
+                    </MenuItem>
                 </MenuFlyout>
             </Setter>
         </Style>

src/Ursa.Themes.Semi/Themes/Shared/Dialog.axaml

@@ -0,0 +1,8 @@
+<ResourceDictionary xmlns="https://github.com/avaloniaui"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
+    <!-- Add Resources Here -->
+    <StreamGeometry x:Key="DialogArrangeBringForwardGlyph">M2,2H16V16H2V2M22,8V22H8V18H10V20H20V10H18V8H22Z</StreamGeometry>
+    <StreamGeometry x:Key="DialogArrangeBringToFrontGlyph">M2,2H11V6H9V4H4V9H6V11H2V2M22,13V22H13V18H15V20H20V15H18V13H22M8,8H16V16H8V8Z</StreamGeometry>
+    <StreamGeometry x:Key="DialogArrangeSendBackwardGlyph">M2,2H16V16H2V2M22,8V22H8V18H18V8H22M4,4V14H14V4H4Z</StreamGeometry>
+    <StreamGeometry x:Key="DialogArrangeSendToBackGlyph">M2,2H11V11H2V2M9,4H4V9H9V4M22,13V22H13V13H22M15,20H20V15H15V20M16,8V11H13V8H16M11,16H8V13H11V16Z</StreamGeometry>
+</ResourceDictionary>

src/Ursa.Themes.Semi/Themes/Shared/_index.axaml

@@ -4,6 +4,7 @@
         <MergeResourceInclude Source="Badge.axaml" />
         <MergeResourceInclude Source="Banner.axaml" />
         <MergeResourceInclude Source="ButtonGroup.axaml" />
+        <MergeResourceInclude Source="Dialog.axaml" />
         <MergeResourceInclude Source="Divider.axaml" />
         <MergeResourceInclude Source="DualBadge.axaml" />
         <MergeResourceInclude Source="IPv4Box.axaml" />

src/Ursa/Controls/Dialog/OverlayDialogHost.cs

@@ -41,13 +41,13 @@ public class OverlayDialogHost : Canvas
         IsVisible = true,
     };
 
-    protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
+    protected sealed override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
     {
         base.OnAttachedToVisualTree(e);
         OverlayDialogManager.RegisterOverlayDialogHost(this, HostId);
     }
 
-    protected override void OnSizeChanged(SizeChangedEventArgs e)
+    protected sealed override void OnSizeChanged(SizeChangedEventArgs e)
     {
         base.OnSizeChanged(e);
         for (int i = 0; i < _masks.Count; i++)
@@ -90,7 +90,7 @@ public class OverlayDialogHost : Canvas
         }
     }
 
-    public void AddDialog(DialogControl control)
+    internal void AddDialog(DialogControl control)
     {
         this.Children.Add(control);
         _dialogs.Add(control);
@@ -127,18 +127,25 @@ public class OverlayDialogHost : Canvas
         }
     }
 
-    public void AddModalDialog(DialogControl control)
+    internal void AddModalDialog(DialogControl control)
     {
         var mask = CreateOverlayMask();
-        this.Children.Add(mask);
+        _masks.Add(mask);
-        this.Children.Add(control);
         _modalDialogs.Add(control);
-        for (int i = 0; i < _masks.Count; i++)
+        int start = _dialogs.LastOrDefault()?.ZIndex ?? 1;
+        for (int i = 0; i < _masks.Count; i += 1)
         {
-            _masks[i].IsVisible = false;
+            _masks[i].ZIndex = start + 2 * i;
+            _modalDialogs[i].ZIndex = start + 2 * i + 1;
+        }
+        
+        for (int i = 0; i < _masks.Count-1; i++)
+        {
+            _masks[i].Opacity = 0.5;
         }
 
-        _masks.Add(mask);
+        this.Children.Add(mask);
+        this.Children.Add(control);
         control.OnClose += OnDialogClose;
         control.OnLayerChange += OnDialogLayerChange;
     }
@@ -173,5 +180,12 @@ public class OverlayDialogHost : Canvas
         {
             _dialogs[i].ZIndex = i;
         }
+
+        for (int i = 0; i < _masks.Count * 2; i += 2) 
+        {
+            _masks[i].ZIndex = _dialogs.Count + i;
+            _modalDialogs[i].ZIndex = _dialogs.Count + i + 1;
+        }
+        
     }
 }