/// <summary>
/// Private helper that takes an element and transforms it's 4 points
/// into the InkCanvas's space
/// </summary>
private static ElementCornerPoints GetTransformedElementCornerPoints(InkCanvasInnerCanvas canvas, UIElement childElement)
{
Debug.Assert(canvas != null);
Debug.Assert(childElement != null);
Debug.Assert(canvas.CheckAccess());
ElementCornerPoints elementPoints = new ElementCornerPoints();
elementPoints.Set = false;
if (childElement.Visibility != Visibility.Visible)
{
//
// this little one's not worth it...
//
return(elementPoints);
}
//
// get the transform from us to our parent InkCavas
//
GeneralTransform parentTransform = childElement.TransformToAncestor(canvas);
//
parentTransform.TryTransform(new Point(0, 0), out elementPoints.UpperLeft);
parentTransform.TryTransform(new Point(childElement.RenderSize.Width, 0), out elementPoints.UpperRight);
parentTransform.TryTransform(new Point(0, childElement.RenderSize.Height), out elementPoints.LowerLeft);
parentTransform.TryTransform(new Point(childElement.RenderSize.Width, childElement.RenderSize.Height), out elementPoints.LowerRight);
elementPoints.Set = true;
return(elementPoints);
}
/// <summary>
/// Private helper that will generate a grid of points 5 px apart given the elements bounding points
/// this works with any affline transformed points
/// </summary>
private Point[] GeneratePointGrid(ElementCornerPoints elementPoints)
{
if (!elementPoints.Set)
{
return(new Point[] {});
}
ArrayList pointArray = new ArrayList();
UpdatePointDistances(elementPoints);
//
// add our original points
//
pointArray.Add(elementPoints.UpperLeft);
pointArray.Add(elementPoints.UpperRight);
FillInPoints(pointArray, elementPoints.UpperLeft, elementPoints.UpperRight);
pointArray.Add(elementPoints.LowerLeft);
pointArray.Add(elementPoints.LowerRight);
FillInPoints(pointArray, elementPoints.LowerLeft, elementPoints.LowerRight);
FillInGrid(pointArray,
elementPoints.UpperLeft,
elementPoints.UpperRight,
elementPoints.LowerRight,
elementPoints.LowerLeft);
Point[] retPointArray = new Point[pointArray.Count];
pointArray.CopyTo(retPointArray);
return(retPointArray);
}
/// <summary>
/// Private helper that takes an element and transforms it's 4 points
/// into the InkCanvas's space
/// </summary>
private static ElementCornerPoints GetTransformedElementCornerPoints(InkCanvasInnerCanvas canvas, UIElement childElement)
{
Debug.Assert(canvas != null);
Debug.Assert(childElement != null);
Debug.Assert(canvas.CheckAccess());
ElementCornerPoints elementPoints = new ElementCornerPoints();
elementPoints.Set = false;
if (childElement.Visibility != Visibility.Visible)
{
//
// this little one's not worth it...
//
return(elementPoints);
}
//
// get the transform from us to our parent InkCavas
//
GeneralTransform parentTransform = childElement.TransformToAncestor(canvas);
// REVIEW: any of the methods below may not actually perform the transformation
// Do we need to do anything special in that scenario?
parentTransform.TryTransform(new Point(0, 0), out elementPoints.UpperLeft);
parentTransform.TryTransform(new Point(childElement.RenderSize.Width, 0), out elementPoints.UpperRight);
parentTransform.TryTransform(new Point(0, childElement.RenderSize.Height), out elementPoints.LowerLeft);
parentTransform.TryTransform(new Point(childElement.RenderSize.Width, childElement.RenderSize.Height), out elementPoints.LowerRight);
elementPoints.Set = true;
return(elementPoints);
}
/// <summary>
/// Private helper that will turn an element in any nesting level into a stroke
/// in the InkCanvas's coordinate space. This method calls itself recursively
/// </summary>
private void HitTestElement(InkCanvasInnerCanvas parent, UIElement uiElement, List <UIElement> elementsToSelect)
{
ElementCornerPoints elementPoints = LassoSelectionBehavior.GetTransformedElementCornerPoints(parent, uiElement);
if (elementPoints.Set != false)
{
Point[] points = GeneratePointGrid(elementPoints);
//
// perform hit testing against our lasso
//
System.Diagnostics.Debug.Assert(null != _lassoHelper);
if (_lassoHelper.ArePointsInLasso(points, _percentIntersectForElements))
{
elementsToSelect.Add(uiElement);
}
}
//
// we used to recurse into the childrens children. That is no longer necessary
//
}
/// <summary>
/// Used to calc the diff between points on the x and y axis
/// </summary>
private void UpdatePointDistances(ElementCornerPoints elementPoints)
{
//
// calc the x and y diffs
//
double width = elementPoints.UpperLeft.X - elementPoints.UpperRight.X;
if (width < 0)
{
width = -width;
}
double height = elementPoints.UpperLeft.Y - elementPoints.LowerLeft.Y;
if (height < 0)
{
height = -height;
}
_xDiff = width * 0.25f;
if (_xDiff > _maxThreshold)
{
_xDiff = _maxThreshold;
}
else if (_xDiff < _minThreshold)
{
_xDiff = _minThreshold;
}
_yDiff = height * 0.25f;
if (_yDiff > _maxThreshold)
{
_yDiff = _maxThreshold;
}
else if (_yDiff < _minThreshold)
{
_yDiff = _minThreshold;
}
}
/// <summary>
/// Used to calc the diff between points on the x and y axis
/// </summary>
private void UpdatePointDistances(ElementCornerPoints elementPoints)
{
//
// calc the x and y diffs
//
double width = elementPoints.UpperLeft.X - elementPoints.UpperRight.X;
if (width < 0)
{
width = -width;
}
double height = elementPoints.UpperLeft.Y - elementPoints.LowerLeft.Y;
if (height < 0)
{
height = -height;
}
_xDiff = width * 0.25f;
if (_xDiff > _maxThreshold)
{
_xDiff = _maxThreshold;
}
else if (_xDiff < _minThreshold)
{
_xDiff = _minThreshold;
}
_yDiff = height * 0.25f;
if (_yDiff > _maxThreshold)
{
_yDiff = _maxThreshold;
}
else if (_yDiff < _minThreshold)
{
_yDiff = _minThreshold;
}
}
/// <summary>
/// Private helper that will generate a grid of points 5 px apart given the elements bounding points
/// this works with any affline transformed points
/// </summary>
private Point[] GeneratePointGrid(ElementCornerPoints elementPoints)
{
if (!elementPoints.Set)
{
return new Point[]{};
}
ArrayList pointArray = new ArrayList();
UpdatePointDistances(elementPoints);
//
// add our original points
//
pointArray.Add(elementPoints.UpperLeft);
pointArray.Add(elementPoints.UpperRight);
FillInPoints(pointArray, elementPoints.UpperLeft, elementPoints.UpperRight);
pointArray.Add(elementPoints.LowerLeft);
pointArray.Add(elementPoints.LowerRight);
FillInPoints(pointArray, elementPoints.LowerLeft, elementPoints.LowerRight);
FillInGrid( pointArray,
elementPoints.UpperLeft,
elementPoints.UpperRight,
elementPoints.LowerRight,
elementPoints.LowerLeft);
Point[] retPointArray = new Point[pointArray.Count];
pointArray.CopyTo(retPointArray);
return retPointArray;
}
/// <summary>
/// Private helper that takes an element and transforms it's 4 points
/// into the InkCanvas's space
/// </summary>
private static ElementCornerPoints GetTransformedElementCornerPoints(InkCanvasInnerCanvas canvas, UIElement childElement)
{
Debug.Assert(canvas != null);
Debug.Assert(childElement != null);
Debug.Assert(canvas.CheckAccess());
ElementCornerPoints elementPoints = new ElementCornerPoints();
elementPoints.Set = false;
if (childElement.Visibility != Visibility.Visible)
{
//
// this little one's not worth it...
//
return elementPoints;
}
//
// get the transform from us to our parent InkCavas
//
GeneralTransform parentTransform = childElement.TransformToAncestor(canvas);
//
parentTransform.TryTransform(new Point(0, 0), out elementPoints.UpperLeft);
parentTransform.TryTransform(new Point(childElement.RenderSize.Width, 0), out elementPoints.UpperRight);
parentTransform.TryTransform(new Point(0, childElement.RenderSize.Height), out elementPoints.LowerLeft);
parentTransform.TryTransform(new Point(childElement.RenderSize.Width, childElement.RenderSize.Height), out elementPoints.LowerRight);
elementPoints.Set = true;
return elementPoints;
}
