private static unsafe GroupManager InitializeManager(IntPtr hwnd)
{
bool isComctrlV6OnOsVerV6orHigher = Misc.IsComctrlV6OnOsVerV6orHigher(hwnd);
int itemCount = WindowsListView.GetItemCount(hwnd);
NativeMethods.LVITEM_V6 item = new NativeMethods.LVITEM_V6();
item.mask = NativeMethods.LVIF_GROUPID;
// The only place where the GroupManager gets constructed
GroupManager manager = new GroupManager(itemCount, hwnd, isComctrlV6OnOsVerV6orHigher);
if (isComctrlV6OnOsVerV6orHigher)
{
NativeMethods.LVITEMINDEX ii = new NativeMethods.LVITEMINDEX(-1, -1);
int flags = NativeMethods.LVNI_VISIBLEONLY | NativeMethods.LVNI_VISIBLEORDER;
// When a listview is being "grouped by" an item may be in more than one group. The itemCount
// is the number of unique items. This loop may iterate for more than the unique items in the group.
// We are taking advantage of that fact the the array list will expand if there are alot of duplicates.
while (XSendMessage.XSend(hwnd, NativeMethods.LVM_GETNEXTITEMINDEX, new IntPtr(&ii), flags, Marshal.SizeOf(ii.GetType())))
{
// need to convert the item id to a group id
NativeMethods.LVGROUP_V6 groupInfo = new NativeMethods.LVGROUP_V6();
groupInfo.Init(Marshal.SizeOf(typeof(NativeMethods.LVGROUP_V6)));
groupInfo.mask = NativeMethods.LVGF_GROUPID;
bool lresult = XSendMessage.XSend(hwnd, NativeMethods.LVM_GETGROUPINFOBYINDEX, new IntPtr(ii.iGroup), new IntPtr(&groupInfo), Marshal.SizeOf(typeof(NativeMethods.LVGROUP_V6)));
if (!lresult)
{
if (groupInfo.iGroupID == -1)
{
// A -1 here means that there are no duplicates in this grouped listview so
// we have to get the group the old way. This is done for performance reasons.
break;
}
// no group for this item should never happen.
// If it ever does the other items might ok so just keep going.
continue;
}
if (!manager.Add(groupInfo.iGroupID, ii.iItem))
{
// we had problem adding item to the needed group at this point it makes no
// sense to continue
System.Diagnostics.Debug.Assert(false, "Cannot add item to the needed group");
return(null);
}
}
}
bool sortNeeded = false;
// If the code above did not yield anything try this way. This will work for
// listviews pre Vista and grouped listviews in vista that don't have duplicate items.
if (manager.GroupCount() == 0)
{
// if we get the groups this way they need to be sorted. The code above brings them in sorted.
sortNeeded = true;
int current = 0;
while (current < itemCount)
{
item.iItem = current;
if (XSendMessage.GetItem(hwnd, ref item) && manager.Add(item.iGroupID, item.iItem))
{
current++;
}
else
{
// we had problem adding item to the needed group at this point it makes no
// sense to continue
System.Diagnostics.Debug.Assert(false, "Cannot add item to the needed group");
return(null);
}
}
}
// Sort items within the group
int groupsCount = manager.GroupCount();
for (int i = 0; i < groupsCount; i++)
{
Group group = (Group)manager._groups[i];
Array.Sort(group.Items, 0, group.Count, new SortGroupItems(hwnd));
}
// Depending on how we got the group info we may need to sort it.
// In vista the the listview can put the list items in the correct order.
// Pre vista or old ui (v5) will always need to be sorted.
if (sortNeeded)
{
// Sort groups
manager._groups.Sort(new SortGroups(hwnd));
}
return(manager);
}
public void OnCacheHint(NativeMethods.LVITEMINDEX from, NativeMethods.LVITEMINDEX to)
{
//System.Diagnostics.Debug.WriteLine(String.Format("OnCacheHint({0}, {1}, {2}, {3})", from.iGroup, from.iItem, to.iGroup, to.iItem));
this.olv.GroupingStrategy.CacheHint(from.iGroup, from.iItem, to.iGroup, to.iItem);
}
