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// 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.Media;
using MS.Internal;
using System.Windows.Interop;
using System.Windows.Media.Media3D;
namespace System.Windows.Input
{
// Helper class for working with IInputElement objects.
internal static class InputElement
{
// Return whether the InputElement is one of our types.
internal static bool IsValid(IInputElement e)
{
DependencyObject o = e as DependencyObject;
return IsValid(o);
}
internal static bool IsValid(DependencyObject o)
{
return o is UIElement or ContentElement or UIElement3D;
}
// Returns the containing input element of the given DynamicObject.
// If onlyTraverse2D is set to true, then we stop once we see a 3D object and return null
internal static DependencyObject GetContainingUIElement(DependencyObject o, bool onlyTraverse2D)
{
DependencyObject container = null;
if(o != null)
{
if(o is UIElement)
{
container = o;
}
else if (o is UIElement3D && !onlyTraverse2D)
{
container = o;
}
else if(o is ContentElement contentElement)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if(parent != null)
{
container = GetContainingUIElement(parent, onlyTraverse2D);
}
else
{
parent = contentElement.GetUIParentCore();
if(parent != null)
{
container = GetContainingUIElement(parent, onlyTraverse2D);
}
}
}
else if (o is Visual v)
{
DependencyObject parent = VisualTreeHelper.GetParent(v);
if(parent != null)
{
container = GetContainingUIElement(parent, onlyTraverse2D);
}
}
else if (!onlyTraverse2D && o is Visual3D v3D)
{
DependencyObject parent = VisualTreeHelper.GetParent(v3D);
if (parent != null)
{
container = GetContainingUIElement(parent, onlyTraverse2D);
}
}
}
return container;
}
// Returns the containing input element of the given DynamicObject.
internal static DependencyObject GetContainingUIElement(DependencyObject o)
{
return GetContainingUIElement(o, false);
}
// Returns the containing input element of the given DynamicObject.
// If onlyTraverse2D is set to true, then we stop once we see a 3D object and return null
internal static IInputElement GetContainingInputElement(DependencyObject o, bool onlyTraverse2D)
{
IInputElement container = null;
if(o != null)
{
if(o is UIElement uiElement)
{
container = uiElement;
}
else if(o is ContentElement contentElement)
{
container = contentElement;
}
else if (o is UIElement3D uIElement3D && !onlyTraverse2D)
{
container = uIElement3D;
}
else if(o is Visual v)
{
DependencyObject parent = VisualTreeHelper.GetParent(v);
if(parent != null)
{
container = GetContainingInputElement(parent, onlyTraverse2D);
}
}
else if (!onlyTraverse2D && o is Visual3D v3D)
{
DependencyObject parent = VisualTreeHelper.GetParent(v3D);
if (parent != null)
{
container = GetContainingInputElement(parent, onlyTraverse2D);
}
}
}
return container;
}
// Returns the containing input element of the given DynamicObject.
//
internal static IInputElement GetContainingInputElement(DependencyObject o)
{
return GetContainingInputElement(o, false);
}
// Returns the containing visual of the given DynamicObject.
internal static DependencyObject GetContainingVisual(DependencyObject o)
{
DependencyObject v = null;
if(o != null)
{
if(o is UIElement uiElement)
{
v = uiElement;
}
else if (o is Visual3D visual3D)
{
v = visual3D;
}
else if(o is ContentElement contentElement)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if(parent != null)
{
v = GetContainingVisual(parent);
}
else
{
parent = contentElement.GetUIParentCore();
if(parent != null)
{
v = GetContainingVisual(parent);
}
}
}
else
{
v = o as Visual;
if (v == null)
{
v = o as Visual3D;
}
}
}
return v;
}
// Returns the root visual of the containing element.
internal static DependencyObject GetRootVisual(DependencyObject o)
{
return GetRootVisual(o, true /* enable2DTo3DTransition */);
}
internal static DependencyObject GetRootVisual(DependencyObject o, bool enable2DTo3DTransition)
{
DependencyObject rootVisual = GetContainingVisual(o);
DependencyObject parentVisual;
while(rootVisual != null && ((parentVisual = VisualTreeHelper.GetParent(rootVisual)) != null))
{
// if we are not supposed to transition from 2D to 3D and the root
// is a Visual and the parent is a Visual3D break
if (!enable2DTo3DTransition &&
rootVisual is Visual && parentVisual is Visual3D)
{
break;
}
rootVisual = parentVisual;
}
return rootVisual;
}
internal static Point TranslatePoint(Point pt, DependencyObject from, DependencyObject to)
{
bool unused = false;
return TranslatePoint(pt, from, to, out unused);
}
internal static Point TranslatePoint(Point pt, DependencyObject from, DependencyObject to, out bool translated)
{
translated = false;
Point ptTranslated = pt;
// Get the containing and root visuals we are coming from.
DependencyObject vFromAsDO = InputElement.GetContainingVisual(from);
Visual rootFrom = InputElement.GetRootVisual(from) as Visual;
Visual vFrom = vFromAsDO as Visual;
if (vFromAsDO != null && vFrom == null)
{
// must be a Visual3D - get it's 2D visual parent
vFrom = VisualTreeHelper.GetContainingVisual2D(vFromAsDO);
}
if(vFrom != null && rootFrom != null)
{
GeneralTransform gUp;
Matrix mUp;
bool isUpSimple = false;
isUpSimple = vFrom.TrySimpleTransformToAncestor(rootFrom,
false, /* do not apply inverse */
out gUp,
out mUp);
if (isUpSimple)
{
ptTranslated = mUp.Transform(ptTranslated);
}
else if (gUp.TryTransform(ptTranslated, out ptTranslated) == false)
{
// Error. Out parameter has been set false.
return new Point();
}
// If no element was specified to translate to, we leave the coordinates
// translated to the root.
if(to != null)
{
// Get the containing and root visuals we are going to.
DependencyObject vTo = InputElement.GetContainingVisual(to);
Visual rootTo = InputElement.GetRootVisual(to) as Visual;
if(vTo != null && rootTo != null)
{
// If both are under the same root visual, we can easily translate the point
// between them by translating up to the root, and then back down.
//
// However, if both are under different roots, we can only translate
// between them if we know how to relate the two root visuals. Currently
// we only know how to do that if both roots are sourced in HwndSources.
if(rootFrom != rootTo)
{
HwndSource sourceFrom = PresentationSource.CriticalFromVisual(rootFrom) as HwndSource;
HwndSource sourceTo = PresentationSource.CriticalFromVisual(rootTo) as HwndSource;
if(sourceFrom != null && sourceFrom.Handle != IntPtr.Zero && sourceFrom.CompositionTarget != null &&
sourceTo != null && sourceTo.Handle != IntPtr.Zero && sourceTo.CompositionTarget != null)
{
// Translate the point into client coordinates.
ptTranslated = PointUtil.RootToClient(ptTranslated, sourceFrom);
// Translate the point into screen coordinates.
Point ptScreen = PointUtil.ClientToScreen(ptTranslated, sourceFrom);
// Translate the point back the the client coordinates of the To window.
ptTranslated = PointUtil.ScreenToClient(ptScreen, sourceTo);
// Translate the point back to the root element.
ptTranslated = PointUtil.ClientToRoot(ptTranslated, sourceTo);
}
else
{
// Error. Out parameter has been set false.
return new Point();
}
}
// Translate the point from the root to the visual.
GeneralTransform gDown;
Matrix mDown;
Visual vToAsVisual = vTo as Visual;
if (vToAsVisual == null)
{
// must be a Visual3D
vToAsVisual = VisualTreeHelper.GetContainingVisual2D(vTo);
}
bool isDownSimple = vToAsVisual.TrySimpleTransformToAncestor(rootTo,
true, /* apply inverse */
out gDown,
out mDown);
if (isDownSimple)
{
ptTranslated = mDown.Transform(ptTranslated);
}
else if (gDown != null)
{
if (gDown.TryTransform(ptTranslated, out ptTranslated) == false)
{
// Error. Out parameter has been set false.
return new Point();
}
}
else
{
// Error. Out parameter has been set false.
return new Point();
}
}
else
{
// Error. Out parameter has been set false.
return new Point();
}
}
}
else
{
// Error. Out parameter has been set false.
return new Point();
}
translated = true;
return ptTranslated;
}
// Caches the ContentElement's DependencyObjectType
private static DependencyObjectType ContentElementType = DependencyObjectType.FromSystemTypeInternal(typeof(ContentElement));
// Caches the UIElement's DependencyObjectType
private static DependencyObjectType UIElementType = DependencyObjectType.FromSystemTypeInternal(typeof(UIElement));
// Caches the UIElement3D's DependencyObjectType
private static DependencyObjectType UIElement3DType = DependencyObjectType.FromSystemTypeInternal(typeof(UIElement3D));
}
}
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