Merge pull request #80 from AvaloniaUtils/replaceGrid

Replaces PART_DialogHostRoot Grid with Panel to simplify calculations

Author: SKProCH

DialogHost.Avalonia/DialogHost.axaml

@@ -31,13 +31,13 @@
     <Setter Property="dialogHostAvalonia:DialogHostStyle.CornerRadius" Value="2" />
     <Setter Property="Template">
       <ControlTemplate>
-        <Grid Name="PART_DialogHostRoot" Focusable="False">
+        <Panel Name="PART_DialogHostRoot" Focusable="False">
           <ContentPresenter Name="PART_ContentPresenter"
                             Content="{TemplateBinding Content}"
                             ContentTemplate="{TemplateBinding ContentTemplate}"
                             HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                             VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
-                            Tag="{TemplateBinding BlurBackgroundRadius}"/>
+                            Tag="{TemplateBinding BlurBackgroundRadius}" />
           <Rectangle Name="PART_ContentCover"
                      Fill="{TemplateBinding OverlayBackground}"
                      Focusable="False">
@@ -47,7 +47,7 @@
               </Style>
             </Rectangle.Styles>
           </Rectangle>
-        </Grid>
+        </Panel>
       </ControlTemplate>
     </Setter>
     <Setter Property="PopupTemplate">
@@ -85,7 +85,6 @@
       </Style>
     </Style>
 
-
     <Style Selector="^[IsOpen=True] /template/ Rectangle#PART_ContentCover">
       <Setter Property="IsHitTestVisible" Value="True" />
       <Setter Property="Opacity" Value="0.56" />

DialogHost.Avalonia/DialogHost.axaml.cs

@@ -5,6 +5,7 @@
 using System.Windows.Input;
 using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 using Avalonia.Controls.Shapes;
 using Avalonia.Controls.Templates;
@@ -215,7 +216,7 @@ public static readonly StyledProperty<double> BlurBackgroundRadiusProperty
     private IDialogPopupPositioner? _popupPositioner;
     private IInputElement? _restoreFocusDialogClose;
 
-    private Grid? _root;
+    private Panel _root;
 
     private IDisposable? _templateDisposables;
 
@@ -627,7 +628,9 @@ protected void RaiseCommandsCanExecuteChanged() {
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e) {
         _templateDisposables?.Dispose();
 
-        _root = e.NameScope.Find<Grid>(DialogHostRoot) ?? throw new InvalidOperationException($"No Grid with name {DialogHostRoot} found");
+        _root = e.NameScope.Find<Panel>(DialogHostRoot) 
+                ?? throw new InvalidOperationException($"No Panel with name {DialogHostRoot} found. " +
+                                                       $"Did you add the styles as stated in getting started?");
         _overlayPopupHost = new DialogOverlayPopupHost(_root) {
             Content = DialogContent, ContentTemplate = DialogContentTemplate, Template = PopupTemplate,
             Padding = DialogMargin, ClipToBounds = false, DisableOpeningAnimation = DisableOpeningAnimation,

DialogHost.Avalonia/DialogOverlayPopupHost.axaml.cs

@@ -8,7 +8,7 @@
 
 namespace DialogHostAvalonia;
 
-public class DialogOverlayPopupHost : ContentControl, ICustomKeyboardNavigation {
+public class DialogOverlayPopupHost(Panel root) : ContentControl, ICustomKeyboardNavigation {
     public static readonly DirectProperty<DialogOverlayPopupHost, bool> IsOpenProperty =
         AvaloniaProperty.RegisterDirect<DialogOverlayPopupHost, bool>(
             nameof(IsOpen),
@@ -28,17 +28,10 @@ public class DialogOverlayPopupHost : ContentControl, ICustomKeyboardNavigation
             o => o.PopupPositioner,
             (o, v) => o.PopupPositioner = v);
 
-    private readonly Grid _root;
-
     private bool _disableOpeningAnimation;
     private bool _isOpen;
     private IDialogPopupPositioner? _popupPositioner;
 
-    public DialogOverlayPopupHost(Grid root)
-    {
-        this._root = root;
-    }
-
     public bool IsOpen {
         get => _isOpen;
         set {
@@ -71,52 +64,49 @@ public IDialogPopupPositioner? PopupPositioner {
         }
     }
 
-    public void Show()
-    {
+    public void Show() {
         if (Parent == null) {
-            _root.Children.Add(this);
+            root.Children.Add(this);
         }
+
         // Set the minimum priority to allow overriding it everywhere
         ClearValue(IsActuallyOpenProperty);
         Focus();
         UpdatePosition();
     }
 
-    public void Hide()
-    {
-        _root.Children.Remove(this);
+    public void Hide() {
+        root.Children.Remove(this);
     }
 
-    protected override Size MeasureOverride(Size availableSize)
-    {
-        if (PopupPositioner is IDialogPopupPositionerConstrainable constrainable)
-        {
+    protected override Size MeasureOverride(Size availableSize) {
+        if (PopupPositioner is IDialogPopupPositionerConstrainable constrainable) {
             return base.MeasureOverride(constrainable.Constrain(availableSize));
         }
+
         return base.MeasureOverride(availableSize);
     }
 
     /// <inheritdoc />
     protected override void ArrangeCore(Rect finalRect) {
         var margin = Margin;
-        
+
         var size = new Size(
             Math.Max(0, finalRect.Width - margin.Left - margin.Right),
             Math.Max(0, finalRect.Height - margin.Top - margin.Bottom));
-            
+
         var contentSize = new Size(
-            Math.Min(size.Width, DesiredSize.Width - margin.Left - margin.Right), 
+            Math.Min(size.Width, DesiredSize.Width - margin.Left - margin.Right),
             Math.Min(size.Height, DesiredSize.Height - margin.Top - margin.Bottom));
         var positioner = PopupPositioner ?? CenteredDialogPopupPositioner.Instance;
         var bounds = positioner.Update(size, contentSize);
-            
+
         var (finalWidth, finalHeight) = ArrangeOverride(bounds.Size).Constrain(size);
         Bounds = new Rect(bounds.X + margin.Left, bounds.Y + margin.Top, finalWidth, finalHeight);
     }
 
 
-    private void UpdatePosition()
-    {
+    private void UpdatePosition() {
         // Don't bother the positioner with layout system artifacts
         // if (_positionerParameters.Size.Width == 0 || _positionerParameters.Size.Height == 0)
         // return;
@@ -131,7 +121,7 @@ private void UpdatePosition()
         if (!element.Equals(this)) {
             return (false, null);
         }
-            
+
         // Finding the focusable descendant
         var focusable = this.GetVisualDescendants()
             .OfType<IInputElement>()
@@ -146,6 +136,7 @@ protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs chang
         if (change.Property == IsActuallyOpenProperty && !change.GetNewValue<bool>()) {
             Hide();
         }
+
         base.OnPropertyChanged(change);
     }
 }