InkCanvasInnerCanvas.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / MS / Internal / Controls / InkCanvasInnerCanvas.cs / 2 / InkCanvasInnerCanvas.cs
                        
                        
                            //---------------------------------------------------------------------------- 
//
// File: InkCanvas.cs
//
// Description: 
//      Defines a Canvas-like class which is used by InkCanvas for the layout.
// 
// Features: 
//
// History: 
//  02/02/2006 [....]:       Ported from the old InnerCanvas.
//
// Copyright (C) 2001 by Microsoft Corporation.  All rights reserved.
// 
//---------------------------------------------------------------------------
 
using System; 
using System.Collections;
using System.ComponentModel; 
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media; 

namespace MS.Internal.Controls 
{ 

    ///  
    /// A subclass of Panel which does layout for InkCanvas.
    /// 
    internal class InkCanvasInnerCanvas : Panel
    { 
        //-----------------------------------------------------
        // 
        //  Cnostructors 
        //
        //----------------------------------------------------- 

        #region Constructors

        internal InkCanvasInnerCanvas(InkCanvas inkCanvas) 
        {
            Debug.Assert(inkCanvas != null); 
            _inkCanvas = inkCanvas; 
        }
 
        // No default constructor
        private InkCanvasInnerCanvas() { }

        #endregion Constructors 

        //------------------------------------------------------ 
        // 
        //  Protected Methods
        // 
        //-----------------------------------------------------

        #region Protected Methods
 
        /// 
        /// Override OnVisualChildrenChanged 
        ///  
        /// 
        ///  
        protected internal override void OnVisualChildrenChanged(DependencyObject visualAdded, DependencyObject visualRemoved)
        {
            base.OnVisualChildrenChanged(visualAdded, visualRemoved);
 
            UIElement removedElement = visualRemoved as UIElement;
 
            // If there is an element being removed, we should make sure to update our selected elements list.. 
            if ( removedElement != null )
            { 
                InkCanvas.InkCanvasSelection.RemoveElement(removedElement);
            }

            //resurface this on the containing InkCanvas 
            InkCanvas.RaiseOnVisualChildrenChanged(visualAdded, visualRemoved);
        } 
 
        /// 
        /// Override of  
        /// The code is similar to Canvas.MeasureOverride. The only difference we have is that
        /// InkCanvasInnerCanvas does report the size based on its children's sizes.
        /// 
        /// Constraint size. 
        /// Computed desired size.
        protected override Size MeasureOverride(Size constraint) 
        { 
            Size childConstraint = new Size(Double.PositiveInfinity, Double.PositiveInfinity);
 
            Size newSize = new Size();
            foreach ( UIElement child in InternalChildren )
            {
                if ( child == null ) { continue; } 
                child.Measure(childConstraint);
 
                // NOTICE-2006/02/03-[....], 
                // We only honor Left and/or Top property for the measure.
                // For Right/Bottom, only the child.Width/Height will be used. Those properties will be used by the arrange 
                // but not the measure.
                double left = (double)InkCanvas.GetLeft(child);
                if ( !DoubleUtil.IsNaN(left) )
                { 
                    newSize.Width = Math.Max(newSize.Width, left + child.DesiredSize.Width);
                } 
                else 
                {
                    newSize.Width = Math.Max(newSize.Width, child.DesiredSize.Width); 
                }

                double top = (double)InkCanvas.GetTop(child);
                if ( !DoubleUtil.IsNaN(top) ) 
                {
                    newSize.Height = Math.Max(newSize.Height, top + child.DesiredSize.Height); 
                } 
                else
                { 
                    newSize.Height = Math.Max(newSize.Height, child.DesiredSize.Height);
                }
            }
 
            return newSize;
        } 
 
        /// 
        /// Canvas computes a position for each of its children taking into account their margin and 
        /// attached Canvas properties: Top, Left.
        ///
        /// Canvas will also arrange each of its children.
        /// This code is same as the Canvas'. 
        /// 
        /// Size that Canvas will assume to position children. 
        protected override Size ArrangeOverride(Size arrangeSize) 
        {
            //Canvas arranges children at their DesiredSize. 
            //This means that Margin on children is actually respected and added
            //to the size of layout partition for a child.
            //Therefore, is Margin is 10 and Left is 20, the child's ink will start at 30.
 
            foreach ( UIElement child in InternalChildren )
            { 
                if ( child == null ) { continue; } 

                double x = 0; 
                double y = 0;


                //Compute offset of the child: 
                //If Left is specified, then Right is ignored
                //If Left is not specified, then Right is used 
                //If both are not there, then 0 
                double left = (double)InkCanvas.GetLeft(child);
                if ( !DoubleUtil.IsNaN(left) ) 
                {
                    x = left;
                }
                else 
                {
                    double right = (double)InkCanvas.GetRight(child); 
 
                    if ( !DoubleUtil.IsNaN(right) )
                    { 
                        x = arrangeSize.Width - child.DesiredSize.Width - right;
                    }
                }
 
                double top = (double)InkCanvas.GetTop(child);
                if ( !DoubleUtil.IsNaN(top) ) 
                { 
                    y = top;
                } 
                else
                {
                    double bottom = (double)InkCanvas.GetBottom(child);
 
                    if ( !DoubleUtil.IsNaN(bottom) )
                    { 
                        y = arrangeSize.Height - child.DesiredSize.Height - bottom; 
                    }
                } 

                child.Arrange(new Rect(new Point(x, y), child.DesiredSize));
            }
 
            return arrangeSize;
        } 
 
        /// 
        /// OnChildDesiredSizeChanged 
        /// 
        /// 
        protected override void OnChildDesiredSizeChanged(UIElement child)
        { 
            base.OnChildDesiredSizeChanged(child);
 
            // Invalid InkCanvasInnerCanvas' measure. 
            InvalidateMeasure();
        } 

        /// 
        /// Override CreateUIElementCollection method.
        /// The logical parent of InnerCanvas will be set to InkCanvas instead. 
        /// 
        ///  
        ///  
        protected override UIElementCollection CreateUIElementCollection(FrameworkElement logicalParent)
        { 
            // Replace the logical parent of the InnerCanvas children with our InkCanvas.
            return base.CreateUIElementCollection(_inkCanvas);
        }
 
        /// 
        /// Returns LogicalChildren 
        ///  
        protected internal override IEnumerator LogicalChildren
        { 
            get
            {
                // InnerCanvas won't have any logical children publicly.
                return EmptyEnumerator.Instance; 
            }
        } 
 
        /// 
        /// The overridden GetLayoutClip method 
        /// 
        /// Geometry to use as additional clip if ClipToBounds=true
        protected override Geometry GetLayoutClip(Size layoutSlotSize)
        { 
            //
 
 

 
            if ( ClipToBounds )
            {
                return base.GetLayoutClip(layoutSlotSize);
            } 
            else
                return null; 
        } 

        #endregion Protected Methods 

        //------------------------------------------------------
        //
        //  Internal Methods 
        //
        //------------------------------------------------------ 
 
        #region Internal Methods
 
        /// 
        /// Hit test on the children
        /// 
        ///  
        /// 
        internal UIElement HitTestOnElements(Point point) 
        { 
            UIElement hitElement = null;
 
            // Do hittest.
            HitTestResult hitTestResult = VisualTreeHelper.HitTest(this, point);

            // Now find out which element is hit if there is a result. 
            if ( hitTestResult != null )
            { 
                Visual visual = hitTestResult.VisualHit as Visual; 
                System.Windows.Media.Media3D.Visual3D visual3D = hitTestResult.VisualHit as System.Windows.Media.Media3D.Visual3D;
 
                DependencyObject currentObject = null;
                if ( visual != null )
                {
                    currentObject = visual; 
                }
                else if ( visual3D != null ) 
                { 
                    currentObject = visual3D;
                } 

                while ( currentObject != null )
                {
                    DependencyObject parent = VisualTreeHelper.GetParent(currentObject); 
                    if ( parent == InkCanvas.InnerCanvas )
                    { 
                        // Break when we hit the inner canvas in the visual tree. 
                        hitElement = currentObject as UIElement;
                        Debug.Assert(Children.Contains(hitElement), "The hit element should be a child of InnerCanvas."); 
                        break;
                    }
                    else
                    { 
                        currentObject = parent;
                    } 
                } 
            }
 
            return hitElement;
        }

        ///  
        /// Returns the private logical children
        ///  
        internal IEnumerator PrivateLogicalChildren 
        {
            get 
            {
                // Return the logical children of the base - Canvas
                return base.LogicalChildren;
            } 
        }
 
        ///  
        /// Returns the associated InkCanvas
        ///  
        internal InkCanvas InkCanvas
        {
            get
            { 
                return _inkCanvas;
            } 
        } 

        #endregion Internal Methods 

        //-----------------------------------------------------
        //
        //  Private Methods 
        //
        //------------------------------------------------------ 
 
        #region Private Methods
 

        #endregion Private Methods

        //----------------------------------------------------- 
        //
        //  Private Fields 
        // 
        //-----------------------------------------------------
 
        #region Private Fields

        // The host InkCanvas
        private InkCanvas   _inkCanvas; 

        #endregion Private Fields 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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InkCanvasInnerCanvas.cs source code in C# .NET

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