Auto resizing floating window on startup

source/Components/AvalonDock/Controls/LayoutFloatingWindowControl.cs

@@ -45,7 +45,13 @@ public abstract class LayoutFloatingWindowControl : Window, ILayoutControl
 		private DragService _dragService = null;
 		private bool _internalCloseFlag = false;
 		private bool _isClosing = false;
-		#endregion fields
+
+		/// <summary>
+		/// Is false until the margins have been found once.
+		/// </summary>
+		/// <see cref="TotalMargin"/>
+        private bool _isTotalMarginSet = false;
+        #endregion fields
 
 		#region Constructors
 
@@ -181,6 +187,90 @@ protected override void OnStateChanged(EventArgs e)
 
 		#endregion IsMaximized
 
+        #region TotalMargin
+
+        private static readonly DependencyPropertyKey TotalMarginPropertyKey = 
+            DependencyProperty.RegisterReadOnly(nameof(TotalMargin),
+                typeof(Thickness), 
+                typeof(LayoutFloatingWindowControl),
+                new FrameworkPropertyMetadata(default(Thickness)));
+
+        public static readonly DependencyProperty TotalMarginProperty = TotalMarginPropertyKey.DependencyProperty;
+
+        /// <summary>
+        /// The total margin (including window chrome and title bar).
+        /// 
+        /// The margin is queried from the visual tree the first time it is rendered, zero until the first call of FilterMessage(WM_ACTIVATE)
+        /// </summary>
+		public Thickness TotalMargin
+		{
+            get { return (Thickness) GetValue(TotalMarginProperty); }
+            protected set { SetValue(TotalMarginPropertyKey, value); }
+        }
+
+		#endregion
+
+		#region ContentMinHeight
+		public static readonly DependencyPropertyKey ContentMinHeightPropertyKey = DependencyProperty.RegisterReadOnly(
+            nameof(ContentMinHeight), typeof(double), typeof(LayoutFloatingWindowControl), new FrameworkPropertyMetadata(0.0));
+
+        public static readonly DependencyProperty ContentMinHeightProperty =
+            ContentMinHeightPropertyKey.DependencyProperty;
+
+		/// <summary>
+		/// The MinHeight of the content of the window, will be 0 until the window has been rendered, or if the MinHeight is unset for the content
+		/// </summary>
+		public double ContentMinHeight
+        {
+            get { return (double) GetValue(ContentMinHeightProperty); }
+            set { SetValue(ContentMinHeightPropertyKey, value); }
+        }
+		#endregion
+
+		#region ContentMinWidth
+		public static readonly DependencyPropertyKey ContentMinWidthPropertyKey = DependencyProperty.RegisterReadOnly(
+            nameof(ContentMinWidth), typeof(double), typeof(LayoutFloatingWindowControl), new FrameworkPropertyMetadata(0.0));
+
+        public static readonly DependencyProperty ContentMinWidthProperty =
+            ContentMinWidthPropertyKey.DependencyProperty;
+
+		/// <summary>
+		/// The MinWidth ocf the content of the window, will be 0 until the window has been rendered, or if the MinWidth is unset for the content
+		/// </summary>
+		public double ContentMinWidth
+        {
+            get { return (double) GetValue(ContentMinWidthProperty); }
+            set { SetValue(ContentMinWidthPropertyKey, value); }
+        }
+		#endregion
+
+		#region SetWindowSizeWhenOpened
+
+        public static readonly DependencyProperty SetWindowSizeWhenOpenedProperty = DependencyProperty.Register(
+            nameof(SetWindowSizeWhenOpened), typeof(bool), typeof(LayoutFloatingWindowControl), new PropertyMetadata(false,
+                (sender, args) =>
+                {
+                    if (args.OldValue != args.NewValue &&
+                        sender is LayoutFloatingWindowControl control)
+                    {
+						// This will resize the window when this property is set to true and the window is open
+                        control._isTotalMarginSet = false;
+                    }
+                }));
+
+		/// <summary>
+		/// If true the MinHeight and MinWidth of the content will be used together with the margins to determine the initial size of the floating window
+		/// </summary>
+		/// <seealso cref="TotalMargin"/>
+		/// <seealso cref="ContentMinWidth"/>
+		/// <seealso cref="ContentMinHeight"/>
+		public bool SetWindowSizeWhenOpened
+        {
+            get { return (bool) GetValue(SetWindowSizeWhenOpenedProperty); }
+            set { SetValue(SetWindowSizeWhenOpenedProperty, value); }
+        }
+
+        #endregion
 		#endregion Properties
 
 		#region Internal Methods
@@ -248,7 +338,9 @@ protected virtual IntPtr FilterMessage(IntPtr hwnd, int msg, IntPtr wParam, IntP
 							handled = true;
 						}
 					}
-					break;
+                    UpdateWindowsSizeBasedOnMinSize();
+
+                    break;
 				case Win32Helper.WM_EXITSIZEMOVE:
 					UpdatePositionAndSizeOfPanes();
 
@@ -283,7 +375,102 @@ protected virtual IntPtr FilterMessage(IntPtr hwnd, int msg, IntPtr wParam, IntP
 			return IntPtr.Zero;
 		}
 
-		internal void InternalClose(bool closeInitiatedByUser = false)
+		/// <summary>
+		/// Set the margins of the window control (including the borders of the floating window and the title bar).
+		/// The result will be stored in <code>_totalMargin</code>.
+		/// </summary>
+		/// <remarks>If the control is not loaded <code>_totalMargin</code> will not be set.</remarks>
+		private void UpdateMargins()
+        {
+			// The grid with window bar and content
+            var grid = this.GetChildrenRecursive()
+                .OfType<Grid>()
+                .FirstOrDefault(g => g.RowDefinitions.Count > 0);
+            ContentPresenter contentControl = this.GetChildrenRecursive()
+                .OfType<ContentPresenter>()
+                .FirstOrDefault(c => c.Content is LayoutContent);
+            if (contentControl == null)
+                return;
+            // The content control in the grid, this has a different tree to walk up
+			var layoutContent = (LayoutContent)contentControl.Content;	
+    		if (grid != null && layoutContent.Content is FrameworkElement content)
+            {
+                var parents = content.GetParents().ToArray();
+                var children = this.GetChildrenRecursive()
+                    .TakeWhile(c => c != grid)
+                    .ToArray();
+				var borders = children
+					.OfType<Border>()
+                    .Concat(parents
+                        .OfType<Border>())
+                    .ToArray();
+                var controls = children
+                    .OfType<Control>()
+                    .Concat(parents
+                        .OfType<Control>())
+                    .ToArray();
+                var frameworkElements = children
+                    .OfType<FrameworkElement>()
+                    .Concat(parents
+                        .OfType<FrameworkElement>())
+                    .ToArray();
+				var padding = controls.Sum(b => b.Padding);
+                var border = borders.Sum(b => b.BorderThickness);
+                var margin = frameworkElements.Sum(f => f.Margin);
+                margin = margin.Add(padding).Add(border).Add(grid.Margin);
+                margin.Top = grid.RowDefinitions[0].MinHeight;
+                TotalMargin = margin;
+                _isTotalMarginSet = true;
+            }
+        }
+
+		/// <summary>
+		/// Update the floating window size based on the <code>MinHeight</code> and <code>MinWidth</code> of the content of the control.
+		/// </summary>
+		/// <remarks>This will only be run once, when the window is rendered the first time and <code>_totalMargin</code> is identified.</remarks>
+		private void UpdateWindowsSizeBasedOnMinSize()
+        {
+            if (!_isTotalMarginSet)
+            {
+                UpdateMargins();
+                if(_isTotalMarginSet)
+                {
+					// The LayoutAnchorableControl is bound via the ContentPresenter, hence it is best to do below in code and not in a style
+					// See https://github.com/Dirkster99/AvalonDock/pull/146#issuecomment-609974424
+					var layoutContents = this.GetChildrenRecursive()
+                        .OfType<ContentPresenter>()
+                        .Select(c => c.Content)
+                        .OfType<LayoutContent>()
+                        .Select(lc => lc.Content);
+					var contents = layoutContents.OfType<FrameworkElement>();
+                    foreach (var content in contents)
+                    {
+                        ContentMinHeight = Math.Max(content.MinHeight, ContentMinHeight);
+                        ContentMinWidth = Math.Max(content.MinWidth, ContentMinWidth);
+                        if (SetWindowSizeWhenOpened)
+                        {
+                            var parent = content.GetParents()
+                                .OfType<FrameworkElement>()
+                                .FirstOrDefault();
+                            // StackPanels among others have an ActualHeight larger than visible, hence we check the parent control as well
+                            if (content.ActualHeight < content.MinHeight ||
+                                parent != null && parent.ActualHeight < content.MinHeight)
+                            {
+                                Height = content.MinHeight + TotalMargin.Top + TotalMargin.Bottom;
+                            }
+
+                            if (content.ActualWidth < content.MinWidth ||
+                                parent != null && parent.ActualWidth < content.MinWidth)
+                            {
+                                Width = content.MinWidth + TotalMargin.Left + TotalMargin.Right;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        internal void InternalClose(bool closeInitiatedByUser = false)
 		{
 			_internalCloseFlag = !closeInitiatedByUser;
 			if (_isClosing) return;

source/Components/AvalonDock/Extensions.cs

@@ -8,37 +8,124 @@ This program is provided to you under the terms of the Microsoft Public
  ************************************************************************/
 
 using System;
-using System.Collections.Generic;
 using System.Collections;
+using System.Collections.Generic;
+using System.Windows;
+using System.Windows.Media;
 
 namespace AvalonDock
 {
-	internal static class Extensions
-	{
-		public static bool Contains(this IEnumerable collection, object item)
-		{
-			foreach (var o in collection)
-				if (o == item) return true;
-			return false;
-		}
-
-
-		public static void ForEach<T>(this IEnumerable<T> collection, Action<T> action)
-		{
-			foreach (var v in collection) action(v);
-		}
-
-
-		public static int IndexOf<T>(this T[] array, T value) where T : class
-		{
-			for (var i = 0; i < array.Length; i++)
-				if (array[i] == value) return i;
-			return -1;
-		}
-
-		public static V GetValueOrDefault<V>(this WeakReference wr)
-		{
-			return wr == null || !wr.IsAlive ? default : (V) wr.Target;
-		}
-	}
+    internal static class Extensions
+    {
+        public static bool Contains(this IEnumerable collection, object item)
+        {
+            foreach (var o in collection)
+                if (o == item) return true;
+            return false;
+        }
+
+
+        public static void ForEach<T>(this IEnumerable<T> collection, Action<T> action)
+        {
+            foreach (var v in collection) action(v);
+        }
+
+
+        public static int IndexOf<T>(this T[] array, T value) where T : class
+        {
+            for (var i = 0; i < array.Length; i++)
+                if (array[i] == value) return i;
+            return -1;
+        }
+
+        public static V GetValueOrDefault<V>(this WeakReference wr)
+        {
+            return wr == null || !wr.IsAlive ? default : (V)wr.Target;
+        }
+
+        /// <summary>
+        /// Recursively get the visual tree children of a dependency object.
+        /// </summary>
+        /// <remarks>This function is recursive and will return all children.</remarks>
+        /// <param name="dependencyObject">The object to find the children of</param>
+        /// <returns>An enumerable with all the children of the dependency object</returns>
+        public static IEnumerable<DependencyObject> GetChildrenRecursive(this DependencyObject dependencyObject)
+        {
+            var children = dependencyObject.GetChildren();
+            foreach (var child in children)
+            {
+                yield return child;
+                foreach (var c in GetChildrenRecursive(child))
+                {
+                    yield return c;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Get the visual tree children of a dependency object.
+        /// </summary>
+        /// <remarks>This function is not recursive and will only return the first level of children.</remarks>
+        /// <param name="dependencyObject">The object to find the children of</param>
+        /// <returns>An enumerable with all the first level children of the dependency object</returns>
+        public static IEnumerable<DependencyObject> GetChildren(this DependencyObject dependencyObject)
+        {
+            int n = VisualTreeHelper.GetChildrenCount(dependencyObject);
+            for (int i = 0; i < n; i++)
+            {
+                yield return VisualTreeHelper.GetChild(dependencyObject, i);
+            }
+        }
+
+        /// <summary>
+        /// Get the visual tree parents of a dependency object, 
+        /// </summary>
+        /// <param name="dependencyObject">The object to find the parents of</param>
+        /// <returns>An enumerable with the parents of the  <code>dependencyObject</code>, the first parent returned will be
+        /// the direct parent of <code>dependencyObject</code></returns>
+        public static IEnumerable<DependencyObject> GetParents(this DependencyObject dependencyObject)
+        {
+            while (dependencyObject != null)
+            {
+                dependencyObject = VisualTreeHelper.GetParent(dependencyObject);
+                if (dependencyObject != null)
+                    yield return dependencyObject;
+            }
+        }
+
+        /// <summary>
+        /// Calculate the sum multiple thicknesses in an enumerable
+        /// </summary>
+        /// <typeparam name="T">The type in the enumerable</typeparam>
+        /// <param name="enumerable">The enumerable with thicknesses</param>
+        /// <param name="func">A function returning the thickness from <code>T</code></param>
+        /// <returns>The total thickness</returns>
+        public static Thickness Sum<T>(this IEnumerable<T> enumerable, Func<T, Thickness> func)
+        {
+            double top = 0, bottom = 0, left = 0, right = 0;
+            foreach (var e in enumerable)
+            {
+                var t = func(e);
+                left = t.Left;
+                top += t.Top;
+                right = t.Right;
+                bottom += t.Bottom;
+            }
+            return new Thickness(left, top, right, bottom);
+        }
+
+        /// <summary>
+        /// Add two thicknesses, each individual component will be added independently of the others.
+        /// </summary>
+        /// <param name="thickness">The first thickness</param>
+        /// <param name="other">The second thickness</param>
+        /// <returns>The total thickness</returns>
+        public static Thickness Add(this Thickness thickness, Thickness other)
+        {
+            return new Thickness(thickness.Left + other.Left,
+                thickness.Top + other.Top,
+                thickness.Right + other.Right,
+                thickness.Bottom + other.Bottom);
+        }
+    }
 }

source/TestApp/MainWindow.xaml

@@ -54,6 +54,7 @@
 			<MenuItem Header="Tools">
 				<MenuItem Click="OnShowWinformsWindow" Header="WinForms Window" />
 				<MenuItem Click="OnShowToolWindow1" Header="Tool Window1" />
+				<MenuItem Click="OnNewFloatingWindow" Header="New floating window"/>
 			</MenuItem>
 		</Menu>
 
@@ -108,7 +109,7 @@
 								Title="Tool Window 1"
 								ContentId="toolWindow1"
 								Hiding="OnToolWindow1Hiding">
-								<StackPanel>
+								<StackPanel MinHeight="1500">
 									<local:TestUserControl />
 									<TextBox Text="{Binding TestTimer, Mode=OneWay, StringFormat='Tool Window 1 Attached to Timer ->\{0\}'}" />
 								</StackPanel>