/// <summary>
/// Attempts to find a scope cursor's lines at the the specified position.
/// Cursors at the end of the cursor list have the highest priority.
/// </summary>
/// <param name="searchPosition">The position to search at.</param>
/// <param name="selectableOnly">
/// A value indicating whether to restrict the search to selectable cursor lines.
/// </param>
/// <returns>A scope cursor selection at the position or <c>null</c>.</returns>
public ScopeCursorSelection FindScopeCursorLines(PointD searchPosition, bool selectableOnly)
{
var extents = _currentScopeGraphicsRangeExtents;
var userRange = extents != null
? CreateScopeGraphicsRange(extents,
_xMinimumGraticuleUnits, _yMinimumGraticuleUnits, _userOriginOffset)
: null;
if (userRange == null)
{
return(null);
}
return(Cursors
.Select(cursor =>
{
var deviceCursorPosition = userRange.Matrix.TransformPoint(cursor.Position.CairoPoint);
// Select each axis we are nearby and which a visible line exists for.
return new ScopeCursorSelection(cursor,
// X axis
((cursor.Lines & ScopeCursorLines.X) != ScopeCursorLines.None &&
((cursor.SelectableLines & ScopeCursorLines.X) != ScopeCursorLines.None || !selectableOnly) &&
Math.Abs(searchPosition.X - deviceCursorPosition.X) < _maxSnapDistance
? ScopeCursorLines.X : ScopeCursorLines.None)
|
// Y axis
((cursor.Lines & ScopeCursorLines.Y) != ScopeCursorLines.None &&
((cursor.SelectableLines & ScopeCursorLines.Y) != ScopeCursorLines.None || !selectableOnly) &&
Math.Abs(searchPosition.Y - deviceCursorPosition.Y) < _maxSnapDistance
? ScopeCursorLines.Y : ScopeCursorLines.None));
})
.LastOrDefault(cursorSelection => cursorSelection.SelectedLines != ScopeCursorLines.None));
}