It's a dangerous business using container coordinates. You
internally. Your control's rectangle is stored in m_rcPos.
as the prcBounds supplied in OnDraw. Most likely in the
Thanks for that prompt comment - with which I agree and appreciate.
However, the poly-line is meant to draw under the cursor tip and I think
the
mouse commands WM_LButtonDown etc. give their positions relative to the
window, not the rectangle rc as defined by RECT& rc = *(RECT*)di.prcBounds
on enering OnDraw. I think this is correct?
I am not sure how, in a windowless control, I am able to get hold of the
definitative relationship between the mouse co-ordinates reported when an
event occurs and the areas I write to relative to the rectangle rc.
To me it looks as if my second problem is that the region written to by
polyline has a small clip region and is then tiled into the full region
filled by the rectangle.
Furthet comments appreciated.
Best
Terry
PS: here are "reduced" versions of the code that responds to the mouse
messages:
LRESULT CGestCtl::OnLButtonDown(UINT uMsg, WPARAM wParam, LPARAM lParam,
BOOL& bHandled)
{
ATLTRACE(_T("OnLButtonDownCalled\n"));
m_spInPlaceSite->SetCapture(true);
POINTS ptsBegin = MAKEPOINTS(lParam);
m_startPoint.x = ptsBegin.x; //Convert to long
m_startPoint.y = ptsBegin.y;
m_endPoint=m_startPoint;
m_Path.clear();
// initialise path processing here;
//
// get start position of path
m_Path.push_back(m_startPoint);
return 0;
}
LRESULT CGestCtl::OnMouseMove(UINT uMsg, WPARAM wParam, LPARAM lParam,
BOOL&
bHandled)
{
ATLTRACE(_T("OnMouseMoveCalled\n"));
if (wParam && MK_LBUTTON)
{
POINTS ptsNow = MAKEPOINTS(lParam);
m_endPoint.x = ptsNow.x; //Convert to long
m_endPoint.y = ptsNow.y;
if (m_startPoint.x != -1 )
{
m_Path.push_back(m_endPoint);
if (m_Path.size()>=2)
{
//report the current state of the path here
std::stringstream buff1;
buff1 << "There are " << m_Path.size() << " sample points on the path.";
m_strSignature=(buff1.rdbuf()->str());
}
FireViewChange();
}
}
return 0;
}
LRESULT CGestCtl::OnLButtonUp(UINT uMsg, WPARAM wParam, LPARAM lParam,
BOOL&
bHandled)
{
ATLTRACE(_T("OnLButtonUpCalled\n"));
m_spInPlaceSite->SetCapture(false);//release mouse capture
m_startPoint.x = m_startPoint.y = -1;
return 0;
}
"Alexander Nickolov" <agnickolov@mvps.org> wrote in message
news:uQDvcfUmGHA.4772@TK2MSFTNGP04.phx.gbl...
Your polyline does not shift its points according to the display
rectangle.
--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================
"terry" <news1@lyonstech.net> wrote in message
news:28-dnbKn24vQigLZRVnyrg@eclipse.net.uk...
Hi, I have a simple atl control built using VS 2003 which captures mouse
movements when the left button is depressed and draws the curve on the
screen in real time. The code in the OnDraw is included below. The
drawing works fine in hte test container - but in IE it has two definite
flaws - A) if I draw it to a large region then it seems to clip the line
(but not the rectangle) to a region with a top to bottom distance of
about 200 and then redrarws the line periodically about 4-5 times own
the window against the grey background.
B) The mouse and the line are not properly aligned with each other - the
line appears in the wrong place - offset and slightly to the south of
where it should be. If I resize the IE window it pops back to the
correct position (at least when the object is set to occupy 100% of the
window.
HRESULT OnDraw(ATL_DRAWINFO& di)
{
ATLTRACE(_T("OnDrawCalled\n"));
RECT& rc = *(RECT*)di.prcBounds;
HDC hdc = di.hdcDraw;
HDC & MemDC(hdc);
HBRUSH hOldBrush, hBrush;
HPEN hOldPen, hPen;
// Create and select the colors to draw the circle
hPen = (HPEN)GetStockObject(BLACK_PEN);
hOldPen = (HPEN)SelectObject(MemDC, hPen);
hBrush = (HBRUSH)GetStockObject(LTGRAY_BRUSH);
hOldBrush = (HBRUSH)SelectObject(MemDC, hBrush);
// Create and select the brush that will be used
Rectangle(MemDC, rc.left, rc.top, rc.right, rc.bottom);
if (m_Path.size()>= 2)
Polyline(MemDC, & m_Path[0],m_Path.size());
SetTextAlign(MemDC, TA_LEFT|TA_TOP);
LPCTSTR pszText = _T(/*"ATL 7.0 : GestCtl"*/m_strSignature.c_str());
TextOut(MemDC,
rc.left ,
rc.top + (rc.top + rc.bottom) / 20,
pszText,
lstrlen(pszText));
SelectObject(MemDC, hOldPen);
SelectObject(MemDC, hOldBrush);
DeleteObject(hBrush);
return S_OK;
}
The code is constructed using the standard wizards and is without
attributes. It works fine in the Activex Test Container (VS 2003),
poweropint although it still needs work to avoid flicker
(suggestions?).