// Update list based on selection.
// Return true if there's an exact match, or false if not.
static bool SelectListItem(ListBox list, object value)
{
ItemCollection itemList = list.Items;
// Perform a binary search for the item.
int first = 0;
int limit = itemList.Count;
while (first < limit)
{
int i = first + (limit - first) / 2;
var item = (IComparable)(itemList[i]);
int comparison = item.CompareTo(value);
if (comparison < 0)
{
// Value must be after i
first = i + 1;
}
else if (comparison > 0)
{
// Value must be before i
limit = i;
}
else
{
// Exact match; select the item.
list.SelectedIndex = i;
itemList.MoveCurrentToPosition(i);
list.ScrollIntoView(itemList[i]);
return true;
}
}
// Not an exact match; move current position to the nearest item but don't select it.
if (itemList.Count > 0)
{
int i = Math.Min(first, itemList.Count - 1);
itemList.MoveCurrentToPosition(i);
list.ScrollIntoView(itemList[i]);
}
return false;
}
void MoveListPosition(ListBox listBox, int distance)
{
int i = listBox.Items.CurrentPosition + distance;
if (i >= 0 && i < listBox.Items.Count)
{
listBox.Items.MoveCurrentToPosition(i);
listBox.SelectedIndex = i;
listBox.ScrollIntoView(listBox.Items[i]);
}
}
public void OnPositionChanged(ListBox listBox, TimeSpan position)
{
var lyrics = LyricModel;
if (lyrics != null && lyrics.Lyrics != null)
{
var selected = lyrics.BeforeOrAt(position);
if (selected != null)
{
listBox.SelectedItem = selected;
var display = lyrics.Lyrics.SkipWhile(o => o != selected).Skip(3).FirstOrDefault();
if (display != null)
listBox.ScrollIntoView(display);
else
listBox.ScrollIntoView(selected);
}
}
}
