/// <summary>
/// Walks up the visual tree from the specified visual and returns the nearest instance of <see cref="AdornerLayer"/>.
/// </summary>
/// <param name="visual">The visual at which to begin searching for adorner layers.</param>
/// <returns>The nearest <see cref="AdornerLayer"/> which is above <paramref name="visual"/> in the visual tree.</returns>
public static AdornerLayer GetAdornerLayer(Visual visual)
{
Contract.Require(visual, "visual");
var current = (DependencyObject)visual;
while (current != null)
{
if (current is AdornerDecorator)
return ((AdornerDecorator)current).AdornerLayer;
current = VisualTreeHelper.GetParent(current);
}
return null;
}
/// <summary>
/// Returns a transformation matrix which can be used to transform coordinates from this visual to
/// the specified ancestor of this visual.
/// </summary>
/// <param name="ancestor">The ancestor to which coordinates will be transformed.</param>
/// <param name="inDevicePixels">A value indicating whether the transform is scaled to device pixels (<c>true</c>) or device-independent pixels (<c>false</c>).</param>
/// <returns>A <see cref="Matrix"/> which represents the specified transformation.</returns>
public Matrix GetTransformToAncestorMatrix(Visual ancestor, Boolean inDevicePixels = false)
{
Contract.Require(ancestor, "ancestor");
return this.MatrixTransformToAncestorInternal(ancestor, false, inDevicePixels);
}
/// <summary>
/// Returns a transformation matrix which can be used to transform coordinates from this visual to
/// the specified ancestor of this visual.
/// </summary>
/// <param name="ancestor">The ancestor to which coordinates will be transformed.</param>
/// <param name="invert">A value indicating whether to invert the resulting matrix.</param>
/// <param name="inDevicePixels">A value indicating whether the transform is scaled to device pixels (<c>true</c>) or device-independent pixels (<c>false</c>).</param>
/// <returns>A <see cref="Matrix"/> which represents the specified transformation.</returns>
private Matrix MatrixTransformToAncestorInternal(Visual ancestor, Boolean invert, Boolean inDevicePixels = false)
{
var mtxFinal = Matrix.Identity;
DependencyObject current;
for (current = this; current != null && current != ancestor; current = VisualTreeHelper.GetParent(current))
{
var uiElement = current as UIElement;
if (uiElement != null)
{
var bounds = uiElement.UntransformedRelativeBounds.Location;
if (inDevicePixels)
{
bounds = uiElement.View.Display.DipsToPixels(bounds);
}
var mtxTransform = uiElement.GetTransformMatrix(inDevicePixels);
var mtxTranslateToClientSpace = Matrix.CreateTranslation(
(Single)bounds.X,
(Single)bounds.Y, 0f);
Matrix mtxResult;
Matrix.Concat(ref mtxFinal, ref mtxTransform, out mtxResult);
Matrix.Concat(ref mtxResult, ref mtxTranslateToClientSpace, out mtxFinal);
}
}
if (current != ancestor)
{
var paramName = invert ? "descendant" : "ancestor";
var message = invert ? PresentationStrings.ElementIsNotADescendant : PresentationStrings.ElementIsNotAnAncestor;
throw new ArgumentException(message, paramName);
}
if (invert)
{
if (Matrix.TryInvert(mtxFinal, out mtxFinal))
{
return mtxFinal;
}
return Matrix.Identity;
}
return mtxFinal;
}
/// <summary>
/// Occurs when the object's visual parent is changed.
/// </summary>
/// <param name="oldParent">The visual's old visual parent.</param>
/// <param name="newParent">The visual's new visual parent.</param>
protected virtual void OnVisualParentChanged(Visual oldParent, Visual newParent)
{
}
/// <summary>
/// Removes a visual child from this object.
/// </summary>
/// <param name="child">The child object to remove from this object.</param>
protected internal void RemoveVisualChild(Visual child)
{
if (child == null || child.visualParent == null)
return;
if (child.visualParent == this)
{
child.visualParent = null;
child.OnVisualParentChangedInternal(this, null);
}
}
/// <summary>
/// Adds a visual as a child of this object.
/// </summary>
/// <param name="child">The child object to add to this object.</param>
protected internal void AddVisualChild(Visual child)
{
if (child == null)
return;
if (child.visualParent != null)
throw new InvalidOperationException(PresentationStrings.VisualAlreadyHasAParent);
if (child.visualParent != this)
{
var oldParent = child.visualParent;
var newParent = this;
child.visualParent = newParent;
child.OnVisualParentChangedInternal(oldParent, newParent);
}
}
/// <summary>
/// Invokes the <see cref="OnVisualParentChanged(Visual, Visual)"/> method.
/// </summary>
/// <param name="oldParent">The visual's old visual parent.</param>
/// <param name="newParent">The visual's new visual parent.</param>
internal virtual void OnVisualParentChangedInternal(Visual oldParent, Visual newParent)
{
OnVisualParentChanged(oldParent, newParent);
}
/// <summary>
/// Transforms a point from the coordinate space of this visual to the coordinate space
/// of the specified descendant visual.
/// </summary>
/// <param name="descendant">The descendant to which coordinates will be transformed.</param>
/// <param name="point">The point to transform.</param>
/// <returns>The transformed point.</returns>
public Point2D TransformToDescendant(Visual descendant, Point2D point)
{
var matrix = GetTransformToDescendantMatrix(descendant);
Point2D result;
Point2D.Transform(ref point, ref matrix, out result);
return result;
}
/// <summary>
/// Transforms a vector from the coordinate space of this visual to the coordinate space
/// of the specified descendant visual.
/// </summary>
/// <param name="descendant">The descendant to which coordinates will be transformed.</param>
/// <param name="vector">The vector to transform.</param>
/// <returns>The transformed vector.</returns>
public Vector2 TransformToDescendant(Visual descendant, Vector2 vector)
{
var matrix = GetTransformToDescendantMatrix(descendant);
Vector2 result;
Vector2.Transform(ref vector, ref matrix, out result);
return result;
}
/// <summary>
/// Transforms a point from the coordinate space of this visual to the coordinate space
/// of the specified ancestor visual.
/// </summary>
/// <param name="ancestor">The ancestor to which coordinates will be transformed.</param>
/// <param name="point">The point to transform.</param>
/// <returns>The transformed point.</returns>
public Point2D TransformToAncestor(Visual ancestor, Point2D point)
{
var matrix = GetTransformToAncestorMatrix(ancestor);
Point2D result;
Point2D.Transform(ref point, ref matrix, out result);
return result;
}
/// <summary>
/// Transforms a vector from the coordinate space of this visual to the coordinate space
/// of the specified ancestor visual.
/// </summary>
/// <param name="ancestor">The ancestor to which coordinates will be transformed.</param>
/// <param name="vector">The vector to transform.</param>
/// <returns>The transformed vector.</returns>
public Vector2 TransformToAncestor(Visual ancestor, Vector2 vector)
{
var matrix = GetTransformToAncestorMatrix(ancestor);
Vector2 result;
Vector2.Transform(ref vector, ref matrix, out result);
return result;
}
/// <summary>
/// Retrieves a transform which can be used to transform coordinates from this visual
/// to the specified descendant visual.
/// </summary>
/// <param name="descendant">The descendant to which coordinates will be transformed.</param>
/// <returns>A <see cref="Transform"/> which represents the specified transformation.</returns>
public Transform TranformToDescendant(Visual descendant)
{
return new MatrixTransform(GetTransformToDescendantMatrix(descendant));
}
/// <summary>
/// Retrieves a transform which can be used to transform coordinates from this visual
/// to the specified ancestor visual.
/// </summary>
/// <param name="ancestor">The ancestor to which coordinates will be transformed.</param>
/// <returns>A <see cref="Transform"/> which represents the specified transformation.</returns>
public Transform TransformToAncestor(Visual ancestor)
{
return new MatrixTransform(GetTransformToAncestorMatrix(ancestor));
}
/// <summary>
/// Returns a transformation matrix which can be used to transform coordinates from this visual to
/// the specified descendant of this visual.
/// </summary>
/// <param name="descendant">The descendnat to which coordinates will be transformed.</param>
/// <param name="inDevicePixels">A value indicating whether the transform is scaled to device pixels (<c>true</c>) or device-independent pixels (<c>false</c>).</param>
/// <returns>A <see cref="Matrix"/> which represents the specified transformation.</returns>
public Matrix GetTransformToDescendantMatrix(Visual descendant, Boolean inDevicePixels = false)
{
Contract.Require(descendant, "descendant");
return descendant.MatrixTransformToAncestorInternal(this, true, inDevicePixels);
}
/// <inheritdoc/>
protected override void OnVisualParentChanged(Visual oldParent, Visual newParent)
{
base.OnVisualParentChanged(oldParent, newParent);
EnsureIsInitialized();
}
/// <inheritdoc/>
internal override void OnVisualParentChangedInternal(Visual oldParent, Visual newParent)
{
var parent = VisualParent as FrameworkElement;
if (parent != null)
{
if (parent.IsLoaded != IsLoaded)
{
if (parent.IsLoaded)
{
EnsureIsLoaded(true);
}
else
{
EnsureIsLoaded(false);
}
}
}
else
{
if (IsLoaded)
{
EnsureIsLoaded(false);
}
}
base.OnVisualParentChangedInternal(oldParent, newParent);
}
