/// <summary>
/// Compute the offset to use in determining the position of a label.
/// </summary>
/// <param name="elt">the label being positioned, either a child element of the <see cref="LinkPanel"/>
/// or the <see cref="Part.VisualElement"/> of a label <see cref="Node"/></param>
/// <param name="index">the segment of the link, or a negative value if the label should be at the <see cref="Route.MidPoint"/></param>
/// <param name="segangle">the angle of the <paramref name="index"/>th segment, or the <see cref="Route.MidAngle"/></param>
/// <param name="sz">the size of the label</param>
/// <param name="labelangle">the angle at which the label is rotated, from calling <see cref="ComputeAngle"/></param>
/// <returns>an offset that is rotated according to the angle of the segment;
/// this will be added to the midpoint of the link or to the fractional point along the segment</returns>
protected virtual Point ComputeOffset(UIElement elt, int index, double segangle, Size sz, double labelangle)
{
Point off = GetOffset(elt);
Spot align = GetAlignment(elt);
if (align.IsNoSpot)
{
align = Spot.Center;
}
Point p = align.PointInRect(new Rect(0, 0, sz.Width, sz.Height));
if (Double.IsNaN(off.X))
{
if (index >= 0)
{
off.X = p.X + 3;
}
else
{
off.X = -(p.X + 3);
}
}
if (Double.IsNaN(off.Y))
{
//?? make this smarter to handle short end segments, especially if Orthogonal
off.Y = -(p.Y + 3);
}
//?? make this better for larger non-square/circular labels that are not rotated
return(Geo.RotatePoint(off, segangle));
}
private Size actualSize; // remember between MeasureAuto and ArrangeAuto
/// <summary>
/// Arranges the children according to the rules defined by NodePanelSizing.Auto.
/// Resizes the first shape to fit around the other children and wraps text appropriately if requested.
/// </summary>
/// <param name="finalSize"></param>
/// <returns></returns>
private Size ArrangeAuto(Size finalSize)
{
finalSize = actualSize;
Rect outer = new Rect(0, 0, finalSize.Width, finalSize.Height);
Rect inner = outer;
bool first = true;
foreach (UIElement child in this.Children)
{
Part.ClearCachedValues(child);
if (first) // first child is the background
{
first = false;
child.Arrange(outer);
Spot spot1 = ComputeSpot1(child);
Spot spot2 = ComputeSpot2(child);
inner = new Rect(spot1.PointInRect(outer), spot2.PointInRect(outer));
//Diagram.Debug("NodePanel arrange1: " + Diagram.Str(outer) + Diagram.Str(inner));
}
else
{
child.Arrange(inner);
}
}
return(finalSize);
}
/// <summary>
/// Measures the children according to the rules defined by NodePanelSizing.Fixed.
/// </summary>
/// <param name="finalSize"></param>
/// <returns></returns>
private Size ArrangeFixed(Size finalSize)
{
bool first = true;
Rect outer = new Rect(0, 0, finalSize.Width, finalSize.Height);
Rect inner = outer;
foreach (UIElement child in this.Children)
{
Part.ClearCachedValues(child);
if (finalSize == new Size(0, 0))
{
child.Arrange(outer); continue;
} //???
if (first)
{
first = false;
Spot spot1 = ComputeSpot1(child);
Spot spot2 = ComputeSpot2(child);
inner = new Rect(spot1.PointInRect(outer), spot2.PointInRect(outer));
child.Arrange(outer);
}
else // Alignments are auto-accounted for, so just arrange in whatever rect is given
{
Rect r = inner;
// adjust R according to each child's HorizontalAlignment and VerticalAlignment
FrameworkElement elt = child as FrameworkElement;
if (elt != null)
{
Size sz = EffectiveDesiredSize(child);
if (sz.Width < inner.Width)
{
switch (elt.HorizontalAlignment)
{
case HorizontalAlignment.Left:
r.Width = sz.Width;
r.X = inner.X;
break;
case HorizontalAlignment.Center:
r.Width = sz.Width;
r.X = inner.X + inner.Width / 2 - sz.Width / 2;
break;
case HorizontalAlignment.Right:
r.Width = sz.Width;
r.X = inner.X + inner.Width - sz.Width;
break;
default: // Stretch means use full inner.Width
break;
}
}
if (sz.Height < inner.Height)
{
switch (elt.VerticalAlignment)
{
case VerticalAlignment.Top:
r.Height = sz.Height;
r.Y = inner.Y;
break;
case VerticalAlignment.Center:
r.Height = sz.Height;
r.Y = inner.Y + inner.Height / 2 - sz.Height / 2;
break;
case VerticalAlignment.Bottom:
r.Height = sz.Height;
r.Y = inner.Y + inner.Height - sz.Height;
break;
default: // Stretch means use full inner.Height
break;
}
}
}
child.Arrange(r);
}
}
return(finalSize);
}