Folder as Workspace: Change folder images after "Expand/Collapse All"

Folder images are changed in FileBrowser::notified() when TVN_ITEMEXPANDED
is recieved. This works fine when e.g. expand/collapse using "+" button.
However, when foldAll() or expandAll() are called on a TreeView,
the TVN_ITEMEXPANDED is not sent. The reason is that TVIS_EXPANDEDONCE flag
is set. To reset that flag, it would be needed to pass TVE_COLLAPSERESET
to TreeView_Expand that also removes all child items which is unwanted.

Resolve the problem by notifying TreeView parent manually when recieve
TVM_EXPAND and TVIS_EXPANDEDONCE is set.

Fix #8912
This commit is contained in:
mere-human 2020-11-25 21:16:01 +02:00 committed by Don HO
parent 814e6591b5
commit ecf44bd085
No known key found for this signature in database
GPG Key ID: 6C429F1D8D84F46E

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@ -66,6 +66,36 @@ void TreeView::destroy()
LRESULT TreeView::runProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam)
{
if (Message == TVM_EXPAND)
{
if (wParam & (TVE_COLLAPSE | TVE_EXPAND))
{
// If TVIS_EXPANDEDONCE flag is set, TVM_EXPAND messages do not generate
// TVN_ITEMEXPANDING or TVN_ITEMEXPANDED notifications.
// To reset the flag, you must send a TVM_EXPAND message
// with the TVE_COLLAPSE and TVE_COLLAPSERESET flags set.
// That in turn removes child items which is unwanted.
// Below is a workaround for that.
TVITEM tvItem = {};
tvItem.hItem = reinterpret_cast<HTREEITEM>(lParam);
tvItem.mask = TVIF_STATE | TVIF_HANDLE | TVIF_PARAM;
tvItem.stateMask = TVIS_EXPANDEDONCE;
TreeView_GetItem(_hSelf, &tvItem);
// Check if a flag is set.
if (tvItem.state & TVIS_EXPANDEDONCE)
{
// If the flag is set, then manually notify parent that an item is collapsed/expanded
// so that it can change icon, etc.
NMTREEVIEW nmtv = {};
nmtv.hdr.code = TVN_ITEMEXPANDED;
nmtv.hdr.hwndFrom = _hSelf;
nmtv.hdr.idFrom = 0;
nmtv.action = wParam & TVE_COLLAPSE ? TVE_COLLAPSE : TVE_EXPAND;
nmtv.itemNew.hItem = tvItem.hItem;
::SendMessage(_hParent, WM_NOTIFY, nmtv.hdr.idFrom, reinterpret_cast<LPARAM>(&nmtv));
}
}
}
return ::CallWindowProc(_defaultProc, hwnd, Message, wParam, lParam);
}