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Remove unused dead code in ElementUtil, make class static #10680

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Remove unused dead code in ElementUtil, make class static #10680

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327 changes: 43 additions & 284 deletions src/Microsoft.DotNet.Wpf/src/PresentationCore/MS/internal/Automation/ElementUtil.cs
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Original file line number Diff line number Diff line change
@@ -1,316 +1,75 @@
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Windows.Threading;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Automation;
using System.Windows.Automation.Peers;
using MS.Win32;
using MS.Internal.Media;
using System.Runtime.InteropServices;
using System.Windows.Automation;
using System.Windows.Threading;

using MS.Internal.PresentationCore;
namespace MS.Internal.Automation;

namespace MS.Internal.Automation
/// <summary>
/// Utility class for working with <see cref="AutomationPeer"/>.
/// </summary>
internal static class ElementUtil
{
// static class providing utility information for working with WCP elements
internal class ElementUtil
/// <summary>
/// Provides a helper to invoke work on the UI thread, re-throwing all exceptions on the thread that invoked this execution.
/// </summary>
internal static object Invoke(AutomationPeer peer, DispatcherOperationCallback work, object arg)
{
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------

#region Constructors

// static class, so use private ctor
private ElementUtil() { }

#endregion Constructors


//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------

#region Internal Methods

internal static Visual GetParent( Visual el )
{
return VisualTreeHelper.GetParent(el) as Visual;
}

internal static Visual GetFirstChild( Visual el )
{
if (el == null)
{
return null;
}

return FindVisibleSibling ( el, 0, true );
}

internal static Visual GetLastChild( Visual el )
{
if (el == null)
{
return null;
}

return FindVisibleSibling ( el, el.InternalVisualChildrenCount - 1, false );
}

// Warning: Method is O(N). See FindVisibleSibling function for more information.
internal static Visual GetNextSibling( Visual el )
{
// To get next/previous sibling, have to find out where we
// are in our parent's children collection (ie. our siblings)
Visual parent = VisualTreeHelper.GetParent(el) as Visual;
// If parent is null, we're at root, so have no siblings
if (parent == null)
{
return null;
}
return FindVisibleSibling ( parent, el, searchForwards: true);
}

// Warning: Method is O(N). See FindVisibleSibling function for more information.
internal static Visual GetPreviousSibling( Visual el )
{
// To get next/previous sibling, have to find out where we
// are in our parent's children collection (ie. our siblings)
Visual parent = VisualTreeHelper.GetParent(el) as Visual;
// If parent is null, we're at root, so have no siblings
if (parent == null)
{
return null;
}

return FindVisibleSibling ( parent, el, searchForwards: false);
}

internal static Visual GetRoot( Visual el )
{
// Keep moving up parent chain till we reach the top...
Visual scan = el;
for( ; ; )
{
Visual test = VisualTreeHelper.GetParent(scan) as Visual;
if( test == null )
break;
scan = test;
}
return scan;
}

// Get bounding rectangle, in coords relative to root (not screen)
internal static Rect GetLocalRect( UIElement element )
{
// Get top-most visual.
Visual parent = GetRoot( element );

// Get the points for the rectangle and transform them.
double height = element.RenderSize.Height;
double width = element.RenderSize.Width;
Rect rect = new Rect(0, 0, width, height);

GeneralTransform g = element.TransformToAncestor(parent);
return g.TransformBounds(rect);
}

// Get bounding rectangle, relative to screen
internal static Rect GetScreenRect( IntPtr hwnd, UIElement el )
{
Rect rc = GetLocalRect( el );

// Map from local to screen coords...
NativeMethods.RECT rcWin32 = new NativeMethods.RECT( (int) rc.Left, (int) rc.Top, (int) rc.Right, (int) rc.Bottom );
try
{
SafeSecurityHelper.TransformLocalRectToScreen(new HandleRef(null, hwnd), ref rcWin32);
}
catch (System.ComponentModel.Win32Exception)
{
return Rect.Empty;
}

rc = new Rect( rcWin32.left, rcWin32.top, rcWin32.right - rcWin32.left, rcWin32.bottom - rcWin32.top );

return rc;
}
// Null dispatcher likely means the visual is in bad shape
Dispatcher dispatcher = peer.Dispatcher ?? throw new ElementNotAvailableException();

// Get element at given point (screen coords)
internal static Visual GetElementFromPoint( IntPtr hwnd, Visual root, Point pointScreen )
{
HwndSource hwndSource = HwndSource.CriticalFromHwnd(hwnd);

if(hwndSource == null)
return null;

Point pointClient = PointUtil.ScreenToClient( pointScreen, hwndSource );
Point pointRoot = PointUtil.ClientToRoot(pointClient, hwndSource);
PointHitTestResult result = VisualTreeUtils.AsNearestPointHitTestResult(VisualTreeHelper.HitTest(root, pointRoot));
Visual visual = result?.VisualHit;


return visual;
}
Exception remoteException = null;
bool completed = false;

// Ensures that an element is enabled; throws exception otherwise
internal static void CheckEnabled(Visual visual)
{
UIElement el = visual as UIElement;

if( el != null && ! el.IsEnabled )
object retVal = dispatcher.Invoke(
DispatcherPriority.Send,
TimeSpan.FromMinutes(3),
(DispatcherOperationCallback)delegate (object unused)
{
throw new ElementNotEnabledException();
}
}

internal static object Invoke(AutomationPeer peer, DispatcherOperationCallback work, object arg)
{
Dispatcher dispatcher = peer.Dispatcher;

// Null dispatcher likely means the visual is in bad shape!
if( dispatcher == null )
{
throw new ElementNotAvailableException();
}

Exception remoteException = null;
bool completed = false;

object retVal = dispatcher.Invoke(
DispatcherPriority.Send,
TimeSpan.FromMinutes(3),
(DispatcherOperationCallback) delegate(object unused)
try
{
try
{
return work(arg);
}
catch(Exception e)
{
remoteException = e;
return null;
}
catch //for non-CLS Compliant exceptions
{
remoteException = null;
return null;
}
finally
{
completed = true;
}
},
null);

if(completed)
{
if(remoteException != null)
return work(arg);
}
catch (Exception e)
{
throw remoteException;
remoteException = e;
return null;
}
}
else
{
bool dispatcherInShutdown = dispatcher.HasShutdownStarted;

if(dispatcherInShutdown)
catch //for non-CLS Compliant exceptions
{
throw new InvalidOperationException(SR.AutomationDispatcherShutdown);
remoteException = null;
return null;
}
else
finally
{
throw new TimeoutException(SR.AutomationTimeout);
completed = true;
}
}

return retVal;
}

#endregion Internal Methods

//------------------------------------------------------
//
// Private Methods
//
//------------------------------------------------------
},
null);

// Potential enhancement: Consider Visual3Ds in this walk?
// Does this walk need to continue through the Visual3D tree once
// we have UIElement3D?
private static Visual FindVisibleSibling ( Visual parent, int start, bool searchForwards)
if (completed)
{
int index = start;
int childrenCount = parent.InternalVisualChildrenCount;

while ( index >= 0 && index < childrenCount )
if (remoteException is not null)
{
Visual sibling = parent.InternalGetVisualChild(index);

// if its visible or something other than a UIElement keep it
if ( !(sibling is UIElement) || (((UIElement)sibling).Visibility == Visibility.Visible ) )
return sibling;

index += searchForwards ? 1 : -1;
throw remoteException;
}

return null;
}

// Potential enhancement - Consider Visual3Ds in this walk?
// Does this walk need to continue through the Visual3D tree once
// we have UIElement3D?
//
// WARNING: This method is O(N) and can therefore lead to O(N^2) algorithms.
private static Visual FindVisibleSibling(Visual parent, Visual child, bool searchForwards)
else
{
//
// First we figure out the index of the specified child Visual. This is why the runtime
// of this method is O(n).

int childrenCount = parent.InternalVisualChildrenCount;
int childIndex;
bool dispatcherInShutdown = dispatcher.HasShutdownStarted;

for (childIndex = 0; childIndex < childrenCount; childIndex++)
if (dispatcherInShutdown)
{
Visual current = parent.InternalGetVisualChild(childIndex);
if (current == child)
{
// Found the child.
break;
}
throw new InvalidOperationException(SR.AutomationDispatcherShutdown);
}

//
// Now that we have the child index, we can go and lookup the sibling.
if(searchForwards)
return FindVisibleSibling(parent, childIndex+1, searchForwards); // (FindVisibleSibling can deal with out of range indices).
else
return FindVisibleSibling(parent, childIndex-1, searchForwards); // (FindVisibleSibling can deal with out of range indices).
{
throw new TimeoutException(SR.AutomationTimeout);
}
}

//------------------------------------------------------
//
// Private Fields
//
//------------------------------------------------------

#region Private Fields

// static class, so no private fields

#endregion Private Fields
return retVal;
}
}