// Returns the previous sibling element in the raw hierarchy.
// Peripheral controls have always negative values.
// Returns null is no previous
internal override ProxySimple GetPreviousSibling(ProxySimple child)
{
GroupManager.GroupInfo groupInfo = GetGroupInfo(_hwnd, ID);
if (groupInfo)
{
int [] items = groupInfo._items;
int current = child._item;
// The subset link has an index that is one past the list items
// If we are on that then the previous is the last item in the items array.
if (_isComctrlV6OnOsVerV6orHigher && current == groupInfo._count)
{
int index = items [groupInfo._count - 1];
return(CreateListViewItem(index));
}
// find the index of the current lvitem
int prevLocation = groupInfo.IndexOf(current) - 1;
if (prevLocation <= -2)
{
throw new InvalidOperationException(SR.Get(SRID.OperationCannotBePerformed));
}
if (prevLocation >= 0)
{
return(CreateListViewItem(items [prevLocation]));
}
}
return(null);
}
// retrieve lvitem column position in the Grid
// To be called only when Group is enabled
private int GetItemColumnPositionInGroup()
{
// get id of the group to which this item belongs
int groupID = GetGroupID(_hwnd, _item);
if (groupID != -1)
{
// get position of this lvitem within the array of all items in the group
GroupManager.GroupInfo groupInfo = WindowsListViewGroup.GetGroupInfo(_hwnd, groupID);
if (groupInfo)
{
int position = groupInfo.IndexOf(_item); //Array.IndexOf(groupInfo._items, _item);
if (position != -1)
{
// number of columns in the grid
int columnCount = WindowsListViewGroup.GetColumnCountExternal(_hwnd, groupID);
// item's row position
int itemRowPosition = position / columnCount;
// item's column position
return(position - (itemRowPosition * columnCount));
}
}
}
return(-1);
}
// Returns the next sibling element in the raw hierarchy.
// Peripheral controls have always negative values.
// Returns null if no next child
internal override ProxySimple GetNextSibling(ProxySimple child)
{
GroupManager.GroupInfo groupInfo = GetGroupInfo(_hwnd, ID);
if (groupInfo)
{
int [] items = groupInfo._items;
int current = child._item;
// find the index of the current lvitem
int nextLocation = groupInfo.IndexOf(current) + 1; //Array.IndexOf(items, current) + 1;
if (nextLocation <= 0)
{
// No more siblings
return(null);
}
if (nextLocation < groupInfo._count)
{
return(CreateListViewItem(items [nextLocation]));
}
// List view groups in vista can have an extra link at the end that says
// somthing like "show all 11 items..."
if (_isComctrlV6OnOsVerV6orHigher && nextLocation == groupInfo._count)
{
NativeMethods.LVGROUP_V6 group = new NativeMethods.LVGROUP_V6();
group.Init(Marshal.SizeOf(typeof(NativeMethods.LVGROUP_V6)));
group.iGroupID = _groupID;
group.mask = NativeMethods.LVGF_STATE;
group.stateMask = NativeMethods.LVGS_SUBSETED;
// Note: return code of GetGroupInfo() is not reliable.
XSendMessage.GetGroupInfo(_hwnd, ref group); // ignore return code.
// The items array holds the list items in this group. If we have a subset link we
// don't store it with the list items because it isn't really a list item. Instead we just
// create the subset link proxy with an item index one more than the last index.
if ((group.state & NativeMethods.LVGS_SUBSETED) != 0)
{
return(CreateGroupSubsetLink(items [groupInfo._count - 1] + 1));
}
}
}
return(null);
}