public double?GetOffset(ConnectedPosition position, string axis)
{
if (axis == "x")
{
// We don't do something like `position['offset' + axis]` in
// order to avoid breking minifiers that rename properties.
return(position.OffsetX ?? _offsetX);
}
return(position.OffsetY ?? _offsetY);
}
/*
* Adds new preferred positions.
* @param positions List of positions options for this overlay.
*/
public FlexibleConnectedPositionStrategyBuilder WithPositions(List <ConnectedPosition> connectedPositions)
{
_preferredPositions = connectedPositions;
var isOnPositions = connectedPositions.Contains(_lastPosition);
if (!isOnPositions)
{
_lastPosition = null;
}
ValidatePositions();
return(this);
}
/* Gets how well an overlay at the given point will fit within the viewport. */
public OverlayFit GetOverlayFit(Point point, ClientRect overlay, ClientRect viewport, ConnectedPosition position)
{
var x = point.X;
var y = point.Y;
var offsetX = GetOffset(position, "x");
var offsetY = GetOffset(position, "y");
// Account for the offsets since they could push the overlay out of the viewport.
if (offsetX != null)
{
x += (double)offsetX;
}
if (offsetY != null)
{
y += (double)offsetY;
}
// How much the overlay would overflow at this position, on each side.
var leftOverflow = 0 - x;
var rightOverflow = (x + overlay.Width) - viewport.Width;
var topOverflow = 0 - y;
var bottomOverflow = (y + overlay.Height) - viewport.Height;
// Visible parts of the element on each axis.
var visibleWidth = this.SubtractOverflows(overlay.Width, new List <double> {
leftOverflow, rightOverflow
});
var visibleHeight = this.SubtractOverflows(overlay.Height, new List <double> {
topOverflow, bottomOverflow
});
var visibleArea = visibleWidth * visibleHeight;
return(new OverlayFit()
{
VisibleArea = visibleArea,
IsCompletelyWithinViewport = (overlay.Width * overlay.Height) == visibleArea,
FitsInViewportVertically = visibleHeight == overlay.Height,
FitsInViewportHorizontally = visibleWidth == overlay.Width,
});
}
