void CGroupEditTree::OnBeginDrag(NMHDR* pNMHDR, LRESULT* pResult)
{
NM_TREEVIEW* pNMTreeView = (NM_TREEVIEW*)pNMHDR;
*pResult = 0;
SetFocus(); // Receive WM_KEYDOWN
m_hitemDrag = pNMTreeView->itemNew.hItem;
m_hitemDrop = NULL;
SelectItem(m_hitemDrag);
if (!IsDropSource(m_hitemDrag))
return;
// get the image list for dragging
m_pDragImage = CreateDragImage(m_hitemDrag);
// CreateDragImage() returns NULL if no image list
// associated with the tree view control
if (!m_pDragImage)
return;
m_bDragging = TRUE;
m_pDragImage->BeginDrag(0, CPoint(-15,-15));
m_dropCursor = LoadCursor(NULL, IDC_ARROW);
m_noDropCursor = LoadCursor(NULL, IDC_NO);
POINT pt = pNMTreeView->ptDrag;
ClientToScreen(&pt);
m_pDragImage->DragEnter(NULL, pt);
SetCapture();
*pResult = 0;
}
void CTreeFileCtrl::OnBegindrag(NMHDR* pNMHDR, LRESULT* pResult)
{
NM_TREEVIEW* pNMTreeView = (NM_TREEVIEW*)pNMHDR;
*pResult = 0;
SelectItem(pNMTreeView->itemNew.hItem);
if (!IsDropSource(pNMTreeView->itemNew.hItem) || !m_bAllowDragDrop)
return;
m_pilDrag = CreateDragImage(pNMTreeView->itemNew.hItem);
if (!m_pilDrag)
return;
m_hItemDrag = pNMTreeView->itemNew.hItem;
m_hItemDrop = NULL;
// Calculate the offset to the hotspot
CPoint offsetPt(8,8); // Initialize a default offset
CPoint dragPt = pNMTreeView->ptDrag; // Get the Drag point
UINT nHitFlags = 0;
HTREEITEM htiHit = HitTest(dragPt, &nHitFlags);
if (htiHit != NULL)
{
// The drag point has Hit an item in the tree
CRect itemRect;
if (GetItemRect(htiHit, &itemRect, FALSE))
{
// Count indent levels
HTREEITEM htiParent = htiHit;
int nIndentCnt = 0;
while (htiParent != NULL)
{
htiParent = GetParentItem(htiParent);
nIndentCnt++;
}
if (!(GetStyle() & TVS_LINESATROOT))
nIndentCnt--;
// Calculate the new offset
offsetPt.y = dragPt.y - itemRect.top;
offsetPt.x = dragPt.x - (nIndentCnt * GetIndent()) + GetScrollPos(SB_HORZ);
}
}
//Begin the dragging
m_pilDrag->BeginDrag(0, offsetPt);
POINT pt = pNMTreeView->ptDrag;
ClientToScreen(&pt);
m_pilDrag->DragEnter(NULL, pt);
SetCapture();
m_nTimerID = SetTimer(1, 300, NULL);
}
