public Columns CalculateColumns()
{
Columns columns = new Columns();
Column lastColumn = null;
Offset lastOffset = Offset.Zero;
int count = _members.Count;
for (int i = 0; i < count; i++)
{
Offset thisOffset = this[i].TopOffset;
if (thisOffset.IsLessThanOrEqualTo(lastOffset))
{
if (lastColumn != null)
{
lastColumn.SetEnd(i);
}
Column col = new Column(this, i);
columns.Add(col);
lastColumn = col;
}
lastOffset = thisOffset;
}
lastColumn.SetEnd(count);
return columns;
}
public void Adjoin(Column column, out Column resetted)
{
if (_stack.Count == 0)
{
_stack.Push(column);
resetted = null;
return;
}
Column newColumn = column;
Column curColumn;
for (; ; )
{
// 在找到被重置的列之前，堆栈不可能被挖空
// 最糟糕的情况，就是被重置的列正好是最底一列
curColumn = _stack.Peek();
if (curColumn.IsAbove(newColumn))
{
resetted = curColumn;
_stack.Push(newColumn);
return;
}
if (curColumn.IsParallelTo(newColumn))
{
resetted = curColumn;
_stack.Pop();
_stack.Push(newColumn);
return;
}
_stack.Pop();
}
}
public bool IsParallelTo(Column o)
{
return this.TopOffset.IsEqualTo(o.TopOffset);
}
public void PushResetter(Column resetter)
{
_resetters.Add(resetter);
}
public bool IsAbove(Column o)
{
return this.TopOffset.IsLessThan(o.TopOffset);
}
