public void OnSnapPointRequested(SnapPointRequestedEventArgs e)
{
// If there are no restrictions active, don't interfere
if (!activeRestrictions.Any())
{
return;
}
double tolerance = MapConfig.GetProjectedMouseTolerance(_context.Map);
var snapPointChecker = new SnapPointCandidateChecker(new Coordinate(e.PointX, e.PointY), tolerance);
// First try to snap to an intersection of two restrictions (if possible)
bool success = snapPointChecker.ContainsBetterCandidate(c => GetIntersectionBetweenRestrictions(c, tolerance));
// Then try to snap to an intersection of a restriction with layer geometries
if (!success)
{
success = snapPointChecker.ContainsBetterCandidate(c => GetIntersectionsWithLayerFeatures(c, tolerance));
}
// Try a regular snap to the restrictions
if (!success)
{
success = snapPointChecker.ContainsBetterCandidateWithoutTolerance(GetSnapPoints);
}
e.SnappedX = snapPointChecker.BestSnapPoint.X;
e.SnappedY = snapPointChecker.BestSnapPoint.Y;
e.IsFinal = true;
e.IsFound = true;
}
public void SnapSlope(ICoordinate anchor, double slope, ICoordinate offsetAnchor = null, bool needsUserInput = true, int handle = 0)
{
var restriction = new LinearRestriction(anchor, slope, handle);
double offset = 0;
if (offsetAnchor != null)
{
double tolerance = MapConfig.GetProjectedMouseTolerance(_context.Map);
offset = restriction.GetOffsetDistance(offsetAnchor, tolerance);
restriction.OffsetByDistance(offset);
}
AddRestriction(restriction);
if (!needsUserInput)
{
return;
}
void inputAction(double value)
{
restriction.OffsetByDistance(value);
restriction.RefreshGuideline(_context.Map as IMap);
}
// Show input box to end-user to enter the bearing
// live updating the map with the snap line
RequestUserInput(
inputAction,
"Offset:",
offset,
anchor
);
}