Scrollbar move with mouse ?

[mesajflaviu]

If I have an CScrollView with few lines , rectangles and other , can I move scrollbar with mouse due the mouse is within client area ? Something like acrobat reader sheets , when the mouse cursor is hand , on OnLButtonDown mouse pointer change to 'MoveHand' cursor and OnMouseMove move scrollbars ?

[Sauro Viti]

Yes, you could, but you have to write all the required code: provide an "hand" mode and change the cursor when that mode is active, then handle the WM_LBUTTONDOWN, WM_MOUSEMOVE and WM_LBUTTONUP to do it. Basically, in the WM_LBUTTONDOWN message handler you have to set a flag that mean dragging and save the cursor location and the scrollbars position; in the WM_LBUTTONUP you have to reset the dragging flag. Finally, in the WM_MOUSEMOVE you have to test the dragging flag, and if it is set, set the scrollbars position to obtain a shift of your view that correspond to one that the mouse has been moved.

[mesajflaviu]

Thank you Viti . I develop this [^] project , that have implement all things that you said ... but I don't know how effectively move scrollbars considering mouse position on client area ... do you know some sample code ?

[Sauro Viti]

Try this article[^] from Microsoft, and refer to the IntelliMouse panning implementation.

[mesajflaviu]

Thanks again Viti , is not like what I want but from this sample I learn very much !!!!

[mesajflaviu]

I did it :

void CDragSheetView::OnLButtonDown(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default

m\_point = point;
m\_bMouseCapture = TRUE;
SetCursor(AfxGetApp()->LoadCursor(IDC\_CURSOR\_HANDMOVE));
SetCapture();

CScrollView::OnLButtonDown(nFlags, point);

}

void CDragSheetView::OnMouseMove(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default

if(m\_bMouseCapture)
{
	CPoint ptScroll = GetScrollPosition();
	if(m\_point.x < point.x)ptScroll.x -= (point.x - m\_point.x);
	if(m\_point.x > point.x)ptScroll.x += (m\_point.x - point.x);
	if(m\_point.y < point.y)ptScroll.y -= (point.y - m\_point.y);
	if(m\_point.y > point.y)ptScroll.y += (m\_point.y - point.y);
	ScrollToPosition(ptScroll);
	m\_point = point;
}

CScrollView::OnMouseMove(nFlags, point);

}