protected SpatialComparison _InvertSpatialComparison(SpatialComparison comparison)
{
SpatialComparison result = comparison;
switch (comparison)
{
case SpatialComparison.Before:
result = SpatialComparison.After;
break;
case SpatialComparison.After:
result = SpatialComparison.Before;
break;
case SpatialComparison.OverlapBefore:
result = SpatialComparison.OverlapAfter;
break;
case SpatialComparison.OverlapAfter:
result = SpatialComparison.OverlapBefore;
break;
default:
break;
}
return(result);
}
protected int _SpatialToAbsoluteComparison(SpatialComparison comparison)
{
int result = 0;
switch (comparison)
{
case SpatialComparison.Before:
case SpatialComparison.OverlapBefore:
result = -1;
break;
case SpatialComparison.After:
case SpatialComparison.OverlapAfter:
result = 1;
break;
case SpatialComparison.Equal:
result = 0;
break;
default:
Debug.Assert(false);
break;
}
return(result);
}
//Method that compares horizontally according to specific reading order
//In the future we should take into account the document language and plug it into this algorithm
protected SpatialComparison _CompareVertical(FixedSOMSemanticBox otherBox)
{
SpatialComparison result = SpatialComparison.None;
Rect thisRect = this.BoundingRect;
Rect otherRect = otherBox.BoundingRect;
if (thisRect.Top == otherRect.Top)
{
result = SpatialComparison.Equal;
}
else if (thisRect.Bottom <= otherRect.Top)
{
//Clearly before the other object
result = SpatialComparison.Before;
}
else if (otherRect.Bottom <= thisRect.Top)
{
//Clearly after the other object
result = SpatialComparison.After;
}
else
{
//Objects overlap
if (thisRect.Top < otherRect.Top)
{
result = SpatialComparison.OverlapBefore;
}
else
{
result = SpatialComparison.OverlapAfter;
}
}
return(result);
}
//--------------------------------------------------------------------
//
// Protected Methods
//
//---------------------------------------------------------------------
#region Private Methods
//Method that compares horizontally according to specific reading order
protected SpatialComparison _CompareHorizontal(FixedSOMSemanticBox otherBox, bool RTL)
{
SpatialComparison result = SpatialComparison.None;
Rect thisRect = this.BoundingRect;
Rect otherRect = otherBox.BoundingRect;
double thisRectRefX = RTL ? thisRect.Right : thisRect.Left;
double otherRectRefX = RTL ? otherRect.Right : otherRect.Left;
if (thisRectRefX == otherRectRefX)
{
result = SpatialComparison.Equal;
}
//Easiest way: calculate as if it's LTR and invert the result if RTL
else if (thisRect.Right < otherRect.Left)
{
//Clearly before the other object
result = SpatialComparison.Before;
}
else if (otherRect.Right < thisRect.Left)
{
//Clearly after the other object
result = SpatialComparison.After;
}
else
{
double overlap = Math.Abs(thisRectRefX - otherRectRefX);
double longerWidth = thisRect.Width > otherRect.Width ? thisRect.Width : otherRect.Width;
if (overlap / longerWidth < 0.1)
{
//If less than 10% overlap then assume these are equal in horizontal comparison
result = SpatialComparison.Equal;
}
//Objects overlap
else if (thisRect.Left < otherRect.Left)
{
result = SpatialComparison.OverlapBefore;
}
else
{
result = SpatialComparison.OverlapAfter;
}
}
if (RTL && result != SpatialComparison.Equal)
{
result = _InvertSpatialComparison(result);
}
return(result);
}
int IComparable.CompareTo(object comparedObj)
{
int result = Int32.MinValue;
FixedSOMPageElement compared = comparedObj as FixedSOMPageElement;
FixedSOMPageElement This = this as FixedSOMPageElement;
Debug.Assert(compared != null);
Debug.Assert(This != null);
if (compared == null)
{
throw new ArgumentException(SR.Get(SRID.UnexpectedParameterType, comparedObj.GetType(), typeof(FixedSOMContainer)), "comparedObj");
}
SpatialComparison compareHor = base._CompareHorizontal(compared, false);
SpatialComparison compareVer = base._CompareVertical(compared);
Debug.Assert(compareHor != SpatialComparison.None);
Debug.Assert(compareVer != SpatialComparison.None);
switch (compareHor)
{
case SpatialComparison.Before:
if (compareVer != SpatialComparison.After)
{
result = -1;
}
break;
case SpatialComparison.After:
if (compareVer != SpatialComparison.Before)
{
result = 1;
}
break;
case SpatialComparison.OverlapBefore:
if (compareVer == SpatialComparison.Before)
{
result = -1;
}
else if (compareVer == SpatialComparison.After)
{
result = 1;
}
break;
case SpatialComparison.OverlapAfter:
if (compareVer == SpatialComparison.After)
{
result = 1;
}
else if (compareVer == SpatialComparison.Before)
{
result = -1;
}
break;
case SpatialComparison.Equal:
switch (compareVer)
{
case SpatialComparison.After:
case SpatialComparison.OverlapAfter:
result = 1;
break;
case SpatialComparison.Before:
case SpatialComparison.OverlapBefore:
result = -1;
break;
case SpatialComparison.Equal:
result = 0;
break;
default:
Debug.Assert(false);
break;
}
break;
default:
//Shouldn't happen
Debug.Assert(false);
break;
}
if (result == Int32.MinValue)
{
//Indecisive. Does markup order help?
if (This.FixedNodes.Count == 0 || compared.FixedNodes.Count == 0)
{
result = 0;
}
else
{
FixedNode thisObjFirstNode = This.FixedNodes[0];
FixedNode thisObjLastNode = This.FixedNodes[This.FixedNodes.Count - 1];
FixedNode otherObjFirstNode = compared.FixedNodes[0];
FixedNode otherObjLastNode = compared.FixedNodes[compared.FixedNodes.Count - 1];
if (This.FixedSOMPage.MarkupOrder.IndexOf(otherObjFirstNode) - This.FixedSOMPage.MarkupOrder.IndexOf(thisObjLastNode) == 1)
{
result = -1;
}
else if (This.FixedSOMPage.MarkupOrder.IndexOf(otherObjLastNode) - This.FixedSOMPage.MarkupOrder.IndexOf(thisObjFirstNode) == 1)
{
result = 1;
}
else
{
//Indecisive. Whichever is below comes after; if same whichever is on the right comes after
int absVerComparison = _SpatialToAbsoluteComparison(compareVer);
result = absVerComparison != 0 ? absVerComparison : _SpatialToAbsoluteComparison(compareHor);
}
}
}
return(result);
}
protected SpatialComparison _InvertSpatialComparison(SpatialComparison comparison)
{
SpatialComparison result = comparison;
switch (comparison)
{
case SpatialComparison.Before:
result = SpatialComparison.After;
break;
case SpatialComparison.After:
result = SpatialComparison.Before;
break;
case SpatialComparison.OverlapBefore:
result = SpatialComparison.OverlapAfter;
break;
case SpatialComparison.OverlapAfter:
result = SpatialComparison.OverlapBefore;
break;
default:
break;
}
return result;
}
protected int _SpatialToAbsoluteComparison(SpatialComparison comparison)
{
int result=0;
switch (comparison)
{
case SpatialComparison.Before:
case SpatialComparison.OverlapBefore:
result = -1;
break;
case SpatialComparison.After:
case SpatialComparison.OverlapAfter:
result = 1;
break;
case SpatialComparison.Equal:
result = 0;
break;
default:
Debug.Assert(false);
break;
}
return result;
}
public int CompareTo(object o)
{
Debug.Assert(o != null);
if (!(o is FixedSOMSemanticBox))
{
throw new ArgumentException(SR.Get(SRID.UnexpectedParameterType, o.GetType(), typeof(FixedSOMSemanticBox)), "o");
}
SpatialComparison compareHor = _CompareHorizontal(o as FixedSOMSemanticBox, false);
SpatialComparison compareVer = _CompareVertical(o as FixedSOMSemanticBox);
Debug.Assert(compareHor != SpatialComparison.None && compareVer != SpatialComparison.None);
int result;
if (compareHor == SpatialComparison.Equal && compareVer == SpatialComparison.Equal)
{
result = 0;
}
else if (compareHor == SpatialComparison.Equal)
{
if (compareVer == SpatialComparison.Before || compareVer == SpatialComparison.OverlapBefore)
{
result = -1;
}
else
{
result = 1;
}
}
else if (compareVer == SpatialComparison.Equal)
{
if (compareHor == SpatialComparison.Before || compareHor == SpatialComparison.OverlapBefore)
{
result = -1;
}
else
{
result = 1;
}
}
else if (compareHor == SpatialComparison.Before)
{
result = -1;
}
else if (compareHor == SpatialComparison.After)
{
result = 1;
}
else
{
//Objects overlap
if (compareVer == SpatialComparison.Before)
{
result = -1;
}
else if (compareVer == SpatialComparison.After)
{
result = 1;
}
//These objects intersect.
else if (compareHor == SpatialComparison.OverlapBefore)
{
result = -1;
}
else
{
result = 1;
}
}
return(result);
}
int IComparable.CompareTo(object comparedObj)
{
int result = Int32.MinValue;
FixedSOMGroup compared = comparedObj as FixedSOMGroup;
Debug.Assert(compared != null);
if (compared == null)
{
throw new ArgumentException(SR.Get(SRID.UnexpectedParameterType, comparedObj.GetType(), typeof(FixedSOMGroup)), "comparedObj");
}
bool RTL = this.IsRTL && compared.IsRTL;
SpatialComparison compareHor = base._CompareHorizontal(compared, RTL);
SpatialComparison compareVer = base._CompareVertical(compared);
Debug.Assert(compareHor != SpatialComparison.None);
Debug.Assert(compareVer != SpatialComparison.None);
switch (compareVer)
{
case SpatialComparison.Before:
result = -1;
break;
case SpatialComparison.After:
result = 1;
break;
case SpatialComparison.OverlapBefore:
if ((int)compareHor <= (int)SpatialComparison.Equal)
{
result = -1;
}
else
{
result = 1;
}
break;
case SpatialComparison.OverlapAfter:
if ((int)compareHor >= (int)SpatialComparison.Equal)
{
result = 1;
}
else
{
result = -1;
}
break;
case SpatialComparison.Equal:
switch (compareHor)
{
case SpatialComparison.After:
case SpatialComparison.OverlapAfter:
result = 1;
break;
case SpatialComparison.Before:
case SpatialComparison.OverlapBefore:
result = -1;
break;
case SpatialComparison.Equal:
result = 0;
break;
default:
Debug.Assert(false);
break;
}
break;
default:
//Shouldn't happen
Debug.Assert(false);
break;
}
return(result);
}
