bool CAutoPanParameters::DoScroll(CWnd* pParentWnd, int nScrollStepsX, int nScrollStepsY) const
{
int nOriginX, nScrollToX, nMaxX, nSubstepsInAStepX;
int nOriginY, nScrollToY, nMaxY, nSubstepsInAStepY;
nSubstepsInAStepX = GetSubstepsInAStepX(pParentWnd, nScrollStepsX);
nSubstepsInAStepY = GetSubstepsInAStepY(pParentWnd, nScrollStepsY);
// Adjust current positions based on scroll bar constraints.
nOriginX = nScrollToX = pParentWnd->GetScrollPos(SB_HORZ) * nSubstepsInAStepX;
nOriginY = nScrollToY = pParentWnd->GetScrollPos(SB_VERT) * nSubstepsInAStepY;
// Calculate the new positions
if (nScrollStepsX != 0)
{
nMaxX = pParentWnd->GetScrollLimit(SB_HORZ) * nSubstepsInAStepX;
nScrollToX += nScrollStepsX * nSubstepsInAStepX;
//Sanity checks.
if (nScrollToX < 0) nScrollToX = 0;
else if (nScrollToX > nMaxX) nScrollToX = nMaxX;
}
if (nScrollStepsY != 0)
{
nMaxY = pParentWnd->GetScrollLimit(SB_VERT) * nSubstepsInAStepY;
nScrollToY += nScrollStepsY * nSubstepsInAStepY;
//Sanity checks.
if (nScrollToY < 0) nScrollToY = 0;
else if (nScrollToY > nMaxY) nScrollToY = nMaxY;
}
// If nothing changed, just return, no work to do.
if (nScrollToX == nOriginX && nScrollToY == nOriginY)
{
return false;
}
return DoScrollWindow(pParentWnd, nScrollToX, nOriginX, nScrollToY, nOriginY);
}
// update_bars() is called if anything changes that will cause the scroll
// bars to change (move/resize etc). This will happen if total_, page_
// or line_ sizes change, the window is resized, font changed, etc.
// If the parameter 'newpos' is not null_point then the display position
// will be moved to that position. Note that the display may be redrawn.
void CScrView::update_bars(CPointAp newpos)
{
if (in_update_ || m_hWnd == NULL)
return;
in_update_ = TRUE;
// TRACE0("--- update_bars\n");
check_coords(); // Check that mapping mode not changed
caret_hide();
// Get info needed in later calcs
TEXTMETRIC tm;
{
CClientDC dc(this);
OnPrepareDC(&dc);
dc.GetTextMetrics(&tm);
}
// Get display area and convert to logical units (but with +ve values)
CRect cli;
GetDisplayRect(&cli);
//CRectAp doc_rect = ConvertFromDP(cli) - GetScroll();
// If newpos not specified use old pos
if (newpos == null_point)
newpos = scrollpos_;
ASSERT(newpos.x >= 0 && newpos.y >= 0);
if (!page_specified_ || !line_specified_)
{
// Calculate amount of line and page scroll based on size of font
if (!page_specified_)
{
// Recalc page size
int lines = cli.Height()/tm.tmHeight + tm.tmExternalLeading - 1;
if (lines < 1)
lines = 1;
page_.cx = cli.Width() - tm.tmAveCharWidth;
page_.cy = lines * (tm.tmHeight + tm.tmExternalLeading);
}
if (!line_specified_)
{
// Recalc line size
line_.cx = tm.tmAveCharWidth;
line_.cy = tm.tmHeight + tm.tmExternalLeading;
}
}
// Update display and scroll bars.
ASSERT(total_.cx >= 0 && total_.cy >= 0);
// If display position has changed redraw/scroll to it
if (newpos != scrollpos_)
{
scroll_up_ = newpos.y < scrollpos_.y;
// Get scroll & new positions in real logical coords
CPointAp t_scroll = scrollpos_;
if (negx()) t_scroll.x = -t_scroll.x;
if (negy()) t_scroll.y = -t_scroll.y;
CPointAp t_newpos = newpos;
if (negx()) t_newpos.x = -t_newpos.x;
if (negy()) t_newpos.y = -t_newpos.y;
// // For OWNDC window and mapping mode != MM_TEXT ScrollWindow
// // does not move caret properly!?!? - so we do it ourselves!
__int64 tmp = t_scroll.y < t_newpos.y ? t_newpos.y - t_scroll.y : t_scroll.y - t_newpos.y;
if (abs(int(t_scroll.x - t_newpos.x)) > cli.Width() || tmp > __int64(cli.Height()))
DoInvalidate(); // ScrollWindow() can't handle big numbers
else
{
// Work out scroll amount in device coordinates
// LPtoDP can't handle more than 16 bits (signed)
CPoint dev_scroll, dev_newpos;
dev_scroll.x = t_scroll.x;
dev_scroll.y = int(t_scroll.y);
dev_newpos.x = t_newpos.x;
dev_newpos.y = int(t_newpos.y);
{
// Put in compound statement so DC released ASAP
CClientDC dc(this);
OnPrepareDC(&dc);
dc.LPtoDP(&dev_scroll);
dc.LPtoDP(&dev_newpos);
}
DoScrollWindow(dev_scroll.x - dev_newpos.x, dev_scroll.y - dev_newpos.y);
}
}
if (total_.cx <= 0)
DoHScroll(0, 0, 0); // disable scroll bar
else if (newpos.x > total_.cx - cli.Width())
{
// Handle scroll position past right edge
DoHScroll(int(((__int64)(newpos.x + cli.Width()) * maxbar_.cx) / total_.cx),
(cli.Width() * maxbar_.cx) / total_.cx + 1,
int(((__int64)newpos.x * maxbar_.cx) / total_.cx) );
}
else
{
DoHScroll(maxbar_.cx,
(cli.Width() * maxbar_.cx) / total_.cx + 1,
int(((__int64)newpos.x * maxbar_.cx) / total_.cx) );
}
if (total_.cy <= 0)
DoVScroll(0, 0, 0); // disable scroll bar
else if (newpos.y > total_.cy - cli.Height())
{
// Handle scroll position if (somehow) moved past end
DoVScroll(int(((__int64)(newpos.y + cli.Height()) * maxbar_.cy) / total_.cy),
int((cli.Height() * maxbar_.cy) / total_.cy + 1),
int(((__int64)newpos.y * maxbar_.cy) / total_.cy) );
}
else
{
DoVScroll(int(maxbar_.cy),
int((cli.Height() * maxbar_.cy) / total_.cy + 1),
int(((__int64)newpos.y * maxbar_.cy) / total_.cy) );
}
// Store new position and force redraw before restore of scroll_up_
scrollpos_ = newpos; // Keep track of where we moved to
ASSERT(scrollpos_.x >= 0 && scrollpos_.y >= 0);
// if (GetFocus() == this)
caret_show();
DoUpdateWindow(); // Force redraw before changing scroll_up_
scroll_up_ = FALSE; // Make sure redraw defaults to downwards
// Get client window again as changing the scroll bars may have changed it
// (and nested size event was blocked by in_update_ flag)
GetDisplayRect(&cli);
CRectAp doc_rect = ConvertFromDP(cli);
win_height_ = doc_rect.bottom - doc_rect.top;
win_width_ = doc_rect.right - doc_rect.left;
AfterScroll(newpos);
in_update_ = FALSE;
}
