/// <summary>
/// Invoked when the mouse is moved around after the left button has been pressed on the NavigatorCanvas. Moves the DisplayArea around.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void NavigatorPointerMoved(object sender, PointerEventArgs e)
{
if (IsMouseDown)
{
PDFRenderer renderer = this.FindControl <PDFRenderer>("MuPDFRenderer");
Avalonia.Controls.Shapes.Rectangle displayRect = this.FindControl <Avalonia.Controls.Shapes.Rectangle>("DisplayAreaRectangle");
Point point = e.GetPosition(this.FindControl <Canvas>("NavigatorCanvas"));
double deltaX = -(-point.X + MouseDownPoint.X) / displayRect.Width * MouseDownDisplayArea.Width;
double deltaY = -(-point.Y + MouseDownPoint.Y) / displayRect.Height * MouseDownDisplayArea.Height;
renderer.SetDisplayAreaNow(new Rect(new Point(this.MouseDownDisplayArea.X + deltaX, this.MouseDownDisplayArea.Y + deltaY), new Point(this.MouseDownDisplayArea.Right + deltaX, this.MouseDownDisplayArea.Bottom + deltaY)));
}
}
