Implement Canvas control #144

src/Perspex.Controls/Canvas.cs

@@ -0,0 +1,131 @@
+// Copyright (c) The Perspex Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using System;
+using Perspex.Input;
+
+namespace Perspex.Controls
+{
+    public class Canvas : Panel, INavigableContainer
+    {
+        /// <summary>
+        /// Defines the <see cref="Left"/> property.
+        /// </summary>
+        public static readonly PerspexProperty<double> LeftProperty =
+            PerspexProperty.RegisterAttached<StackPanel, Control, double>("Left");
+
+		/// <summary>
+		/// Defines the <see cref="Top"/> property.
+		/// </summary>
+		public static readonly PerspexProperty<double> TopProperty =
+			PerspexProperty.RegisterAttached<StackPanel, Control, double>("Top");
+
+		/// <summary>
+		/// Initializes static members of the <see cref="Canvas"/> class.
+		/// </summary>
+		static Canvas()
+        {
+            AffectsArrange(LeftProperty);
+			AffectsArrange(TopProperty);
+        }
+
+		/// <summary>
+		/// Gets the value of the Left attached property for a control.
+		/// </summary>
+		/// <param name="element">The control.</param>
+		/// <returns>The control's left coordinate.</returns>
+		public static double GetLeft(PerspexObject element)
+		{
+			return element.GetValue(LeftProperty);
+		}
+
+		/// <summary>
+		/// Sets the value of the Left attached property for a control.
+		/// </summary>
+		/// <param name="element">The control.</param>
+		/// <param name="value">The left value.</param>
+		public static void SetLeft(PerspexObject element, double value)
+		{
+			element.SetValue(LeftProperty, value);
+		}
+
+		/// <summary>
+		/// Gets the value of the Top attached property for a control.
+		/// </summary>
+		/// <param name="element">The control.</param>
+		/// <returns>The control's top coordinate.</returns>
+		public static double GetTop(PerspexObject element)
+		{
+			return element.GetValue(TopProperty);
+		}
+
+		/// <summary>
+		/// Sets the value of the Top attached property for a control.
+		/// </summary>
+		/// <param name="element">The control.</param>
+		/// <param name="value">The top value.</param>
+		public static void SetTop(PerspexObject element, double value)
+		{
+			element.SetValue(TopProperty, value);
+		}
+
+		/// <summary>
+		/// Gets the next control in the specified direction.
+		/// </summary>
+		/// <param name="direction">The movement direction.</param>
+		/// <param name="from">The control from which movement begins.</param>
+		/// <returns>The control.</returns>
+		IInputElement INavigableContainer.GetControl(FocusNavigationDirection direction, IInputElement from)
+        {
+			// TODO: Implement this
+			return null;
+        }
+
+        /// <summary>
+        /// Measures the control.
+        /// </summary>
+        /// <param name="availableSize">The available size.</param>
+        /// <returns>The desired size of the control.</returns>
+        protected override Size MeasureOverride(Size availableSize)
+        {
+			availableSize = new Size(double.PositiveInfinity, double.PositiveInfinity);
+
+            foreach (Control child in Children)
+            {
+                child.Measure(availableSize);
+            }
+
+			return new Size();
+        }
+
+        /// <summary>
+        /// Arranges the control's children.
+        /// </summary>
+        /// <param name="finalSize">The size allocated to the control.</param>
+        /// <returns>The space taken.</returns>
+        protected override Size ArrangeOverride(Size finalSize)
+        {
+            foreach (Control child in Children)
+            {
+				double x = 0.0;
+				double y = 0.0;
+				double elementLeft = GetLeft(child);
+
+				if (double.IsNaN(elementLeft) == false)
+				{
+					x = elementLeft;
+				}
+
+				double elementTop = GetTop(child);
+				if (double.IsNaN(elementTop) == false)
+				{
+					y = elementTop;
+				}
+
+				child.Arrange(new Rect(new Point(x, y), child.DesiredSize));
+			}
+
+			return finalSize;
+        }
+    }
+}

src/Perspex.Controls/Perspex.Controls.csproj

@@ -65,6 +65,7 @@
     <Compile Include="Primitives\IScrollInfo.cs" />
     <Compile Include="Primitives\Popup.cs" />
     <Compile Include="Primitives\ScrollInfoAdapter.cs" />
+    <Compile Include="Canvas.cs" />
     <Compile Include="Templates\ControlTemplate`2.cs" />
     <Compile Include="Templates\DataTemplate`1.cs" />
     <Compile Include="Templates\IControlTemplate.cs" />