/// <summary>
/// Checks whether the current data is enough to construct a direction. If so,
/// draw it. Take care to erase any previously drawn direction.
/// </summary>
void OnChange()
{
Direction dir=null; // Constructed direction.
AngleDirection angle; // Angle from a backsight.
DeflectionDirection deflect; // Deflection angle.
BearingDirection bearing; // Bearing from north.
ParallelDirection par; // Parallel to 2 points.
double srad; // Signed radian value.
// Apply sign to any angle we have.
if (m_IsClockwise)
srad = m_Radians;
else
srad = -m_Radians;
if (m_Backsight!=null)
{
// If we have a backsight, we could either have a regular
// angle or a deflection. To construct either, we need a
// from-point as well.
// Note that an angle of zero (passing through the backsight
// or foresight) is fine.
if (m_From!=null)
{
IAngle obsv = new RadianValue(srad);
if (m_IsDeflection)
{
deflect = new DeflectionDirection(m_Backsight, m_From, obsv);
dir = deflect;
}
else
{
angle = new AngleDirection(m_Backsight, m_From, obsv);
dir = angle;
}
}
}
else if (m_From!=null)
{
// No backsight, so we could have either a bearing,
// or a direction defined using 2 parallel points.
// Since a bearing of zero is quite valid, we check
// the dialog field to see if this is an entered value,
// or just the initial value.
if (m_Par1!=null && m_Par2!=null)
{
par = new ParallelDirection(m_From, m_Par1, m_Par2);
dir = par;
}
else
{
if (m_Radians>Constants.TINY || angleTextBox.Text.Trim().Length==0)
{
bearing = new BearingDirection(m_From, new RadianValue(srad));
dir = bearing;
}
}
}
// If we have formed a direction, apply any offset.
if (dir!=null)
dir.Offset = m_Offset;
// Try to calulate the position of the sideshot.
IPosition to = RadialOperation.Calculate(dir, this.Length);
// Return if we calculated a position that is identical to the old one.
//if (to!=null && to.IsAt(m_To, Double.Epsilon))
// return;
m_Dir = dir;
m_To = to;
m_Cmd.ErasePainting();
}
/// <summary>
/// Uses the currently displayed information to try to construct a
/// direction object.
/// </summary>
/// <returns>The constructed direction (null if a direction cannot be created
/// based on the information that's currently displayed)</returns>
Direction GetCurrentDirection()
{
Direction result = null;
// Get signed direction
double srad = (m_IsClockwise ? m_Radians : -m_Radians);
IAngle dir = new RadianValue(srad);
if (m_Backsight!=null)
{
// If we have a backsight, we could either have a regular
// angle or a deflection. To construct either, we need a
// from-point as well.
// Note that an angle of zero (passing through the backsight
// or foresight) is fine.
if (m_From!=null)
{
if (m_IsDeflection)
result = new DeflectionDirection(m_Backsight, m_From, dir);
else
result = new AngleDirection(m_Backsight, m_From, dir);
}
}
else if (m_From!=null)
{
// No backsight, so we could have either a bearing,
// or a direction defined using 2 parallel points.
// Since a bearing of zero is quite valid, we check
// the dialog field to see if this is an entered value,
// or just the initial value.
if (m_Par1!=null && m_Par2!=null)
result = new ParallelDirection(m_From, m_Par1, m_Par2);
else if (m_Radians > Constants.TINY || directionTextBox.Text.Length>0)
result = new BearingDirection(m_From, dir);
}
// If we haven't formed a direction, ignore any offset
if (result==null)
return null;
// An offset could have been specified by a point, or by
// entering a distance left or right of the direction.
Offset offset = null;
if (m_OffsetPoint!=null)
offset = new OffsetPoint(m_OffsetPoint);
else if (m_OffsetDistance!=null)
offset = new OffsetDistance(m_OffsetDistance, !m_IsRight);
// If we got an offset, include it in the direction.
if (offset!=null)
result.Offset = offset;
return result;
}