Setting Children Nodes of Tree View Based on Parent Node [modified]

[Mark Salsbery]

There is a lot of notifications sent by a tree control. Do you really want your code to execute on every one of them? Also, what are you doing with the item check state, and how does that apply to the selected item? Tree View Controls[^] Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Stuck At Zero]

I am using a tree view with 16,384 nodes (2048 nodes per root node). I'm trying to allow a user to select or deselect a node anywhere on the tree view such that when a node is selected or deselected, all of its children nodes would mirror that selection.

[Stuck At Zero]

I originally tried doing a message map of the OnNotify that I saw elsewhere through googling, but there does not seem to be a notification appropriate for what I want to do. I was using item check state to see if the node which has the user's focus was checked or not. The idea was that once a user clicks on a node within the tree view, OnNotify would fire off and it would check to see if the node was selected or not. Depending on its state, I would either select or deselect all decedent nodes from the node the user selected.

[Mark Salsbery]

What about something like this:

BOOL CViewFilter::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{
if (wParam == IDC_TREE1)
{
NMHDR *pHdr = (NMHDR *)lParam;

if (pHdr->code == TVN\_SELCHANGED)
{
  LPNMTREEVIEW pNMTreeView = (LPNMTREEVIEW)lParam;

  // pNMTreeView->itemNew is the new selected item (TVITEM)
  // pNMTreeView->itemNew.hItem is the new selected item's HTREEITEM

  if (pNMTreeView->itemNew.hItem)
  {
    if (m\_filterTreeCtrl.GetCheck(pNMTreeView->itemNew.hItem))
    {
      // Select All Subsequent Children Nodes
      SetDecendentNodesOn(pNMTreeView->itemNew.hItem);
    }
    else
    {
      // Deselect All Subsequent Children Nodes
      SetDecendentNodesOff(pNMTreeView->itemNew.hItem);
    }
  }

  return TRUE;
}

}

return CDialog::OnNotify(wParam, lParam, pResult);
}

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Stuck At Zero]

It only works on the very first mouse click for the first root node only. Decendent nodes nor any of the other root nodes have any effect on the OnNotify. After the first mouse click to either select / deselect the 1st root node, that root node then behaves like the other root nodes.

[Mark Salsbery]

Do you call SetCheck anywhere? How do the items get their check state set? What's happening in your SetDecendentNodes functions? Have you put a breakpoint in the OnNotify? Are you getting notifications for all item selections?

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Stuck At Zero]

I do not call SetCheck. The nodes get their check state set whenever the user clicks on the node's box to check or uncheck the node.

[Mark Salsbery]

Ohhh.... Maybe you want the TVN_ITEMCHANGED notification instead of TVN_SELCHANGED

BOOL CViewFilter::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{
if (wParam == IDC_TREE1)
{
NMHDR *pHdr = (NMHDR *)lParam;

if (pHdr->code == TVN\_ITEMCHANGED)
{
  NMTVITEMCHANGE \*pNMTVItemChange = (NMTVITEMCHANGE \*)lParam;

  if (pNMTVItemChange->hItem)
  {
    if (m\_filterTreeCtrl.GetCheck(pNMTreeView->itemNew.hItem))
    {
      // Select All Subsequent Children Nodes
      SetDecendentNodesOn(pNMTVItemChange->hItem);
    }
    else
    {
      // Deselect All Subsequent Children Nodes
      SetDecendentNodesOff(pNMTVItemChange->hItem);
    }
  }

  return TRUE;
}

}

return CDialog::OnNotify(wParam, lParam, pResult);
}

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Stuck At Zero]

Yeah, that was one I had tried using before but the problem is you need Windows Vista to use it. I'm running on XP Pro.

[Mark Salsbery]

Stuck At Zero wrote:

the problem is you need Windows Vista to use it

There's other OSs? Do you get any notification in XP when you check/uncheck an item? If so, what is the code? Mark

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Stuck At Zero]

I do not know how to find any other notification in XP other than what's listed in MSDN.... but the one you just recommended is here: http://msdn.microsoft.com/en-us/library/bb773526(VS.85).aspx It says the minimum operating system is Windows Vista.

[Mark Salsbery]

I really thought it was available on XP. The macro is wrapped in "#if (_WIN32_IE >= 0x0600)" which seems to indicate a common controls version 6 or better feature. If you define _WIN32_IE to something >= 0x0600 does it work on XP? I don't have a handy XP machine to test on. Also, have you tried (in the debugger)to see if there's any notification sent when you change the check state? I'm interested in what notification code it is if there is one.

Mark Salsbery Microsoft MVP - Visual C++ :java:

[Stuck At Zero]

I couldn't figure out how to filter out the other things OnNotify would trigger, but I believe part of my problem seems to be that the hItem is what the TreeView has as a keyboard highlighted region rather than the actual node clicked on by mouse. Do you have any ideas as to change hItem to reflect what is actually clicked on by the mouse and thus ignore the keyboard rectangular region that highlights the 1st root node or changes if I use my keyboard to move it around? In other words,

HTREEITEM hItem = m_filterTreeCtrl.GetSelectedItem(); // Keyboard Highlighted Region

Is not with respect to the node I click on with my mouse.