protected void AddFocusedElementRange(IList <FrameworkElement> availableElements, RectangleF?startingRect,
int firstElementIndex, int lastElementIndex, int elementsBefore, int elementsAfter, ICollection <FrameworkElement> outElements)
{
int numItems = availableElements.Count;
if (numItems == 0)
{
return;
}
CalcHelper.Bound(ref firstElementIndex, 0, numItems - 1);
CalcHelper.Bound(ref lastElementIndex, 0, numItems - 1);
if (elementsBefore > 0)
{
// Find children before the first index which have focusable elements.
int formerNumElements = outElements.Count;
for (int i = firstElementIndex - 1; i >= 0; i--)
{
FrameworkElement fe = availableElements[i];
fe.AddPotentialFocusableElements(startingRect, outElements);
if (formerNumElements == outElements.Count)
{
continue;
}
// Found focusable elements
elementsBefore--;
if (elementsBefore == 0)
{
break;
}
formerNumElements = outElements.Count;
}
}
for (int i = firstElementIndex; i <= lastElementIndex; i++)
{
FrameworkElement fe = availableElements[i];
fe.AddPotentialFocusableElements(startingRect, outElements);
}
if (elementsAfter > 0)
{
// Find children after the last index which have focusable elements.
int formerNumElements = outElements.Count;
for (int i = lastElementIndex + 1; i < availableElements.Count; i++)
{
FrameworkElement fe = availableElements[i];
fe.AddPotentialFocusableElements(startingRect, outElements);
if (formerNumElements == outElements.Count)
{
continue;
}
// Found focusable elements
elementsAfter--;
if (elementsAfter == 0)
{
break;
}
formerNumElements = outElements.Count;
}
}
}
protected void AddFocusedElementRange(IList <FrameworkElement> availableElements, RectangleF?startingRect,
int firstLineIndex, int lastLineIndex, int linesBefore, int linesAfter, ICollection <FrameworkElement> outElements)
{
IList <LineMeasurement> lines = new List <LineMeasurement>(_arrangedLines);
int numLines = lines.Count;
if (numLines == 0)
{
return;
}
CalcHelper.Bound(ref firstLineIndex, 0, numLines - 1);
CalcHelper.Bound(ref lastLineIndex, 0, numLines - 1);
if (linesBefore > 0)
{
// Find children before the first index which have focusable elements.
int formerNumElements = outElements.Count;
for (int lineIndex = firstLineIndex - 1; lineIndex >= 0; lineIndex--)
{
LineMeasurement line = lines[lineIndex];
for (int childIndex = line.StartIndex; childIndex <= line.EndIndex; childIndex++)
{
FrameworkElement fe = availableElements[childIndex];
fe.AddPotentialFocusableElements(startingRect, outElements);
}
if (formerNumElements == outElements.Count)
{
continue;
}
// Found focusable elements
linesBefore--;
if (linesBefore == 0)
{
break;
}
formerNumElements = outElements.Count;
}
}
for (int lineIndex = firstLineIndex; lineIndex <= lastLineIndex; lineIndex++)
{
LineMeasurement line = lines[lineIndex];
for (int childIndex = line.StartIndex; childIndex <= line.EndIndex; childIndex++)
{
FrameworkElement fe = availableElements[childIndex];
fe.AddPotentialFocusableElements(startingRect, outElements);
}
}
if (linesAfter > 0)
{
// Find children after the last index which have focusable elements.
int formerNumElements = outElements.Count;
for (int lineIndex = lastLineIndex + 1; lineIndex < lines.Count; lineIndex++)
{
LineMeasurement line = lines[lineIndex];
for (int childIndex = line.StartIndex; childIndex <= line.EndIndex; childIndex++)
{
FrameworkElement fe = availableElements[childIndex];
fe.AddPotentialFocusableElements(startingRect, outElements);
}
if (formerNumElements == outElements.Count)
{
continue;
}
// Found focusable elements
linesAfter--;
if (linesAfter == 0)
{
break;
}
formerNumElements = outElements.Count;
}
}
}