/// <summary>
/// Inserts an item in order.
/// </summary>
/// <param name="item">The item to insert.</param>
/// <param name="lowIndex">The index of the lowest item to check.</param>
/// <param name="highIndex">One more than the highest index to check.</param>
/// <returns>The sorted index of the item.</returns>
private int InsertInOrder(ObjectView item, int lowIndex, int highIndex)
{
if (_sorts == null || _sorts.Count == 0 || _sortIndex.Count == 0)
{
_sortIndex.Add(item);
return _sortIndex.Count - 1;
}
if (lowIndex == highIndex)
{
// We have gotten to the end of our test
if (highIndex == _sortIndex.Count)
{
_sortIndex.Add(item);
return _sortIndex.Count - 1;
}
else
{
_sortIndex.Insert(highIndex, item);
return highIndex;
}
}
int testIndex = (lowIndex + highIndex) / 2;
int comparison = CompareObject(item, _sortIndex[testIndex]);
if (comparison == 0)
{
_sortIndex.Insert(testIndex, item);
return testIndex;
}
else if (comparison < 0)
{
return this.InsertInOrder(item, lowIndex, testIndex);
}
else
{
return this.InsertInOrder(item, testIndex + 1, highIndex);
}
}
/// <summary>
/// A helper method that compares items in the list.
/// </summary>
/// <param name="objectA">The first item.</param>
/// <param name="objectB">The second item.</param>
/// <returns>
/// A 32-bit signed integer that indicates the relative order of the objects being compared.
/// The return value has these meanings: Less than zero objectA should be before objectB.
/// Zero the order of objectA and objectB should not be changed.
/// Greater than zero objectA should be after objectB.
/// </returns>
private int CompareObject(ObjectView objectA, ObjectView objectB)
{
if (_sorts == null || (objectA == null && objectB == null))
{
return 0;
}
else if (objectA == null)
{
return -1;
}
else if (objectB == null)
{
return 1;
}
int comparison = 0;
for (int i = 0; i < _sorts.Count; i++)
{
PropertyDescriptor prop = _sorts[i].PropertyDescriptor;
object valueA = objectA[prop.Name];
object valueB = objectB[prop.Name];
if (objectA.Object is IExtendSort)
valueA = ((IExtendSort)objectA.Object).GetSortValue(prop, valueA);
if (objectB.Object is IExtendSort)
valueB = ((IExtendSort)objectB.Object).GetSortValue(prop, valueB);
this.OnExtendSort(prop, valueA);
this.OnExtendSort(prop, valueB);
comparison = this.Compare(valueA, valueB);
if (comparison != 0)
{
if (_sorts[i].SortDirection == ListSortDirection.Descending)
{
comparison *= -1;
}
break;
}
}
return comparison;
}