private static object CoerceRectInterior(DependencyObject d, object value)
{
PuncturedRect pr = (PuncturedRect)d;
Rect rcExterior = pr.RectExterior;
Rect rcProposed = (Rect)value;
double left = Math.Max(rcProposed.Left, rcExterior.Left);
double top = Math.Max(rcProposed.Top, rcExterior.Top);
double width = Math.Min(rcProposed.Right, rcExterior.Right) - left;
double height = Math.Min(rcProposed.Bottom, rcExterior.Bottom) - top;
if (width < 0 || height < 0)
{
return(pr.RectInterior);
}
rcProposed = new Rect(left, top, width, height);
return(rcProposed);
}
public CroppingAdorner(UIElement adornedElement)
: base(adornedElement)
{
CropEnabled = false;
_visualChildren = new VisualCollection(this);
_drawingSelection = false;
_adornedElement = adornedElement;
_selectRect = new Rect();
_geometry = new RectangleGeometry();
var dashes = new DoubleCollection(new double[] { 6, 1 });
Rubberband = new Path
{
Data = _geometry,
StrokeThickness = 2,
Stroke = Brushes.White,
StrokeDashArray = dashes,
Opacity = 0.6,
Visibility = Visibility.Hidden
};
_visualChildren.Add(Rubberband);
// A transparent black background to show outside the crop area over the rest
// of the image
Fill = new SolidColorBrush(Color.FromArgb(110, 0, 0, 0));
_cropMask = new PuncturedRect();
_cropMask.IsHitTestVisible = false;
_cropMask.RectInterior = _selectRect;
_cropMask.Fill = Fill;
_cropMask.Visibility = Visibility.Hidden;
_visualChildren.Add(_cropMask);
// We're going to put the thumbs in a canvas, since the events and placement
// actually work correctly in a canvas.
_thumbsCanvas = new Canvas();
_thumbsCanvas.HorizontalAlignment = HorizontalAlignment.Stretch;
_thumbsCanvas.VerticalAlignment = VerticalAlignment.Stretch;
_visualChildren.Add(_thumbsCanvas);
// Call a helper method to initialize the Thumbs
// with a customized cursors.
_thumbSize = new Size(10, 10);
BuildAdornerCorner(ref _topLeft, Cursors.SizeNWSE);
BuildAdornerCorner(ref _topRight, Cursors.SizeNESW);
BuildAdornerCorner(ref _bottomLeft, Cursors.SizeNESW);
BuildAdornerCorner(ref _bottomRight, Cursors.SizeNWSE);
// Add handlers for resizing.
_bottomLeft.DragDelta += HandleBottomLeft;
_bottomRight.DragDelta += HandleBottomRight;
_topLeft.DragDelta += HandleTopLeft;
_topRight.DragDelta += HandleTopRight;
MouseMove += DrawSelection;
MouseUp += EndSelection;
SetElementVisibility(Visibility.Hidden);
}