CListControlComplete auto scroll

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CListControlComplete auto scroll

2023-04-12 08:51:38

It works fine if I get QueryDragDropTypes to return dragDrop_reorder only. Combining with dragDrop_external breaks internal reordering.

If possible, I'd like to get both working. I guess it means overriding some methods myself but I'm stuck.

For completeness, I'm deriving from CListControlComplete and I have the actual reordering / inserting external items working fine, it's just the scroll I'm struggling with.

Code: [Select]

class QueueList : public CListControlComplete
{
public:
	dragDropAccept_t DragDropAccept2(IDataObject* obj) final
	{
		dragDropAccept_t accept;

		metadb_handle_list handles;
		if (get_dd_handles(obj, handles))
		{
			accept.dwEFfect = DROPEFFECT_COPY;
			accept.showDropMark = true;
		}

		return accept;
	}

	uint32_t QueryDragDropTypes() const final
	{
		return dragDrop_reorder | dragDrop_external;
	}

	void OnDrop(IDataObject* obj, CPoint pt) final
	{
		this->ScreenToClient(&pt);
		const size_t idx = InsertIndexFromPoint(pt);
		if (idx == SIZE_MAX) return;

		// do stuff
	}

	void RequestReorder(const size_t* order, size_t count) final
	{
		// do stuff
	}
};

Re: CListControlComplete auto scroll

Reply #1 – 2023-04-13 03:06:02

Well I got there in the end. I had to rip out copies of CDropSourceImpl / CDropTargetImpl and make some minor changes. I then had to override RunDragDrop and wrap the DoDragDrop call with ToggleDDScroll. I also had to bypass the default OnCreatePassthru with my own copy that could make use of ToggleDDScroll as well.

It might be nicer in future if dragDropAccept_t had an additional auto-scroll option then it could have been done without so much copy/pasting.