/// <summary>
/// Initializes a new instance of the <see cref="XInkPresenter"/> class
/// </summary>
/// <param name="inkCanvasView">the <see cref="InkCanvasView"/></param>
internal XInkPresenter(IInkCanvasView inkCanvasView)
{
InkCanvasView = inkCanvasView ?? throw new ArgumentNullException(nameof(inkCanvasView));
UnprocessedInput = new XInkUnprocessedInput(this);
StrokeContainer = new XInkStrokeContainer();
}
private void UpdateApex(IInkCanvasView inkCanvasView, EquirectangularStencil stencil)
{
if (Point1 == Point2)
{
return;
}
stencil.Apex = GetApex(inkCanvasView.CanvasHeight);
inkCanvasView.InvalidateCanvas(false, true);
}
/// <summary>
/// Handle touch events to move the stencil points
/// </summary>
/// <param name="inkCanvasView">the ink canvas view</param>
/// <param name="stencil">the equirectangular stencil</param>
/// <param name="e">the touch event arguments</param>
internal void Touch(IInkCanvasView inkCanvasView, EquirectangularStencil stencil, SKTouchEventArgs e)
{
if (inkCanvasView == null)
{
throw new ArgumentNullException(nameof(inkCanvasView));
}
if (stencil == null || stencil.Mode != EquirectangularStencilMode.TwoPoint)
{
return;
}
if (e == null)
{
throw new ArgumentNullException(nameof(e));
}
var location = inkCanvasView.GetCanvasPosition(e.Location);
var deltaX = location.X - _startPoint.X;
var deltaY = location.Y - _startPoint.Y;
if (e.InContact)
{
switch (e.ActionType)
{
case SKTouchAction.Pressed:
if (Distance(location, Point1) < Radius / inkCanvasView.ZoomFactor)
{
_touchingPoint = 1;
_startPoint = location;
e.Handled = true;
}
else if (Distance(location, Point2) < Radius / inkCanvasView.ZoomFactor)
{
_touchingPoint = 2;
_startPoint = location;
e.Handled = true;
}
else
{
_touchingPoint = 0;
}
break;
case SKTouchAction.Moved:
switch (_touchingPoint)
{
case 1:
Point1 = Point1.Offset(deltaX, deltaY);
e.Handled = true;
UpdateApex(inkCanvasView, stencil);
break;
case 2:
Point2 = Point2.Offset(deltaX, deltaY);
e.Handled = true;
UpdateApex(inkCanvasView, stencil);
break;
}
_startPoint = location;
break;
}
}
else if (e.ActionType == SKTouchAction.Released)
{
switch (_touchingPoint)
{
case 1:
Point1 = Point1.Offset(deltaX, deltaY);
e.Handled = true;
UpdateApex(inkCanvasView, stencil);
break;
case 2:
Point2 = Point2.Offset(deltaX, deltaY);
e.Handled = true;
UpdateApex(inkCanvasView, stencil);
break;
}
_touchingPoint = 0;
}
}