private void OnMouseWheel(object sender, MouseWheelEventArgs e)
{
if (ElementContainer != null)
{
ElementContainer.ScrollToVerticalOffset(ElementContainer.VerticalOffset + -e.Delta);
e.Handled = true;
}
}
private void ElementContent_MouseMove(object sender, MouseEventArgs e)
{
Point p;
if (IsEnabled && _leftButtonDown)
{
p = e.GetPosition(ElementRoot);
ElementContainer.ScrollToHorizontalOffset(ElementContainer.HorizontalOffset - ((p.X - _lastMouseDownPosition.X) * Zoom * DragSpeed));
ElementContainer.ScrollToVerticalOffset(ElementContainer.VerticalOffset - ((p.Y - _lastMouseDownPosition.Y) * Zoom * DragSpeed));
_lastMouseDownPosition = p;
}
}
/// <summary>
/// Scrolls the area control into position
/// </summary>
/// <param name="x">X position</param>
/// <param name="y">Y position</param>
/// <param name="width">Width of the area that must be in view</param>
/// <param name="height">Height of the area that must be in view</param>
private void ScrollIntoPosition(double x, double y, double width, double height)
{
if (y + height >= ElementContainer.VerticalOffset + ElementContainer.ViewportHeight)
{
ElementContainer.ScrollToVerticalOffset((y + height) - ElementContainer.ViewportHeight);
}
else if (y < ElementContainer.VerticalOffset)
{
ElementContainer.ScrollToVerticalOffset(y);
}
if (x + width >= ElementContainer.HorizontalOffset + ElementContainer.ViewportWidth)
{
ElementContainer.ScrollToHorizontalOffset((x + width) - ElementContainer.ViewportWidth);
}
else if (x < ElementContainer.HorizontalOffset)
{
ElementContainer.ScrollToHorizontalOffset(x);
}
}
/// <summary>
/// Scrolls into position
/// </summary>
/// <param name="position">Position to be in view</param>
/// <param name="size">Size that should be in view</param>
private void ScrollIntoPosition(Point position, Size size)
{
if ((position.Y + size.Height) * Zoom >= ElementContainer.VerticalOffset + ElementContainer.ViewportHeight)
{
ElementContainer.ScrollToVerticalOffset(((position.Y + size.Height) * Zoom) - ElementContainer.ViewportHeight);
}
else if (position.Y * Zoom < ElementContainer.VerticalOffset)
{
ElementContainer.ScrollToVerticalOffset(position.Y * Zoom);
}
if ((position.X + size.Width * Zoom) >= ElementContainer.HorizontalOffset + ElementContainer.ViewportWidth)
{
ElementContainer.ScrollToHorizontalOffset(((position.X + size.Width) * Zoom) - ElementContainer.ViewportWidth);
}
else if (position.X * Zoom < ElementContainer.HorizontalOffset)
{
ElementContainer.ScrollToHorizontalOffset(position.X * Zoom);
}
}
protected override void Tick(object sender, System.EventArgs e)
{
double nodeMoveStep;
double temp;
base.Tick(sender, e);
if (ElementChildren != null)
{
if (_mouseDown)
{
nodeMoveStep = 10;
if (LastMousePosition.Y * _zoom < ElementContainer.VerticalOffset)
{
temp = ElementContainer.VerticalOffset - nodeMoveStep;
LastMousePosition = new Point(LastMousePosition.X, LastMousePosition.Y - nodeMoveStep);
if (temp < 0)
{
temp = 0;
}
ElementContainer.ScrollToVerticalOffset(temp);
}
else if (LastMousePosition.Y * _zoom > ElementContainer.VerticalOffset + ElementContainer.ViewportHeight)
{
temp = ElementContainer.VerticalOffset + nodeMoveStep;
LastMousePosition = new Point(LastMousePosition.X, LastMousePosition.Y + nodeMoveStep);
if (temp > ElementContainer.ScrollableHeight)
{
temp = ElementContainer.ScrollableHeight;
}
ElementContainer.ScrollToVerticalOffset(temp);
}
}
}
}