scrollerctrl.cpp

现在USB设备却很多

      if ( m_pbmpPattern->GetBitmap(&bitmap) && bitmap.bmWidth > 0 && bitmap.bmHeight > 0 )
      {
         if ( m_bTilePattern )
         {
            for (int y=0; y<rectClient.bottom+bitmap.bmHeight; y += bitmap.bmHeight)
            {
               for (int x=0; x<rectClient.right+bitmap.bmWidth; x += bitmap.bmWidth)
               {
                  pDC->BitBlt(x,y, bitmap.bmWidth, bitmap.bmHeight, &dcPat, 0,0, SRCCOPY);
               }
            }
         }
         else
         {
      	   pDC->FillSolidRect(rectClient, m_crBackground);
            pDC->BitBlt((m_sizeBuffer.cx-bitmap.bmWidth)/2,(m_sizeBuffer.cy-bitmap.bmHeight)/2, bitmap.bmWidth, bitmap.bmHeight, &dcPat, 0,0, SRCCOPY);
         }
      }
      dcPat.SelectObject(pbmpOld);
   }
}

// Draws the logo (if specified) at the given offset.
// If bDraw is false, calculates height, but does not draw.
// Returns height of logo.
int CScrollerCtrl::DrawLogo(CDC* pDC, int nOffset, BOOL bDraw)
{
   if ( NULL == m_pbmpLogo )
      return 0;

   BITMAP bitmap;
   memset(&bitmap,0,sizeof(bitmap));
   if ( m_pbmpLogo->GetBitmap(&bitmap) && bDraw && bitmap.bmWidth > 0 && bitmap.bmHeight > 0 )
   {
      CDC dcLogo;
      dcLogo.CreateCompatibleDC(pDC);
      CBitmap* pbmpOld = dcLogo.SelectObject(m_pbmpLogo);
      pDC->BitBlt((m_sizeBuffer.cx-bitmap.bmWidth)/2,nOffset, bitmap.bmWidth, bitmap.bmHeight, &dcLogo, 0,0, SRCCOPY);
      dcLogo.SelectObject(pbmpOld);
   }
   return bitmap.bmHeight;
}

// Draws the text at the specified offset.
// If bDraw is false, will calculate text height, but not draw.
// Returns height of text.
int CScrollerCtrl::DrawBodyText(CDC* pDC, int nOffset, BOOL bDraw)
{
	CRect rect(nMARGIN,nOffset,m_sizeBuffer.cx-nMARGIN,m_sizeBuffer.cy);
	UINT uFlags = bDraw ? DT_EXPANDTABS|DT_NOPREFIX|DT_WORDBREAK : DT_EXPANDTABS|DT_NOCLIP|DT_CALCRECT|DT_NOPREFIX|DT_WORDBREAK;

   CFont* pOldFont = pDC->SelectObject(&m_font);
   pDC->SetBkMode(TRANSPARENT);
   // draw shadow if displayed over pattern
   if ( bDraw && NULL != m_pbmpPattern )
   {
      // offset 1/10 of font size
      LOGFONT logFont;
      m_font.GetLogFont(&logFont);
      int nShadowOffset = MulDiv(-logFont.lfHeight, 72, pDC->GetDeviceCaps(LOGPIXELSY)*10);
      // get color between forground and background for shadow (not correct i'm sure)
      int red = (GetRValue(m_crForeground) + GetRValue(m_crBackground)*2)/3;
      int green = (GetGValue(m_crForeground) + GetGValue(m_crBackground)*2)/3;
      int blue = (GetBValue(m_crForeground) + GetBValue(m_crBackground)*2)/3;
      COLORREF crDarker = RGB(red, green, blue);

      pDC->SetTextColor(crDarker);
      rect.OffsetRect(nShadowOffset,nShadowOffset);
      pDC->DrawText(m_strText, &rect, uFlags);
      rect.OffsetRect(-nShadowOffset,-nShadowOffset);
   }
   if(m_eState == PAUSED)
   pDC->SetTextColor(m_crForeground);
   else
   {
	   pDC->SetTextColor(RGB((int)160,0,0));
   }
	int nHeight = pDC->DrawText(m_strText, &rect, uFlags);
   pDC->SelectObject(pOldFont);
	return nHeight;
}

// indicate that this control will process arrow keystrokes.
UINT CScrollerCtrl::OnGetDlgCode()
{
   if ( GetStyle()&WS_TABSTOP )
      return DLGC_WANTARROWS;
   return 0;
}

// Grab focus if required.
void CScrollerCtrl::OnLButtonDown(UINT nFlags, CPoint point)
{
   if ( GetStyle()&WS_TABSTOP )
      SetFocus();
}

// Handle keyboard scrolling.
void CScrollerCtrl::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
   switch ( nChar )
   {
   case VK_UP:
      PostMessage(WM_VSCROLL, SB_LINEUP);
      break;
   case VK_DOWN:
      PostMessage(WM_VSCROLL, SB_LINEDOWN);
      break;
   case VK_PRIOR:    // why not VK_PAGEUP?
      PostMessage(WM_VSCROLL, SB_PAGEUP);
      break;
   case VK_NEXT:     // why not VK_PAGEDOWN?
      PostMessage(WM_VSCROLL, SB_PAGEDOWN);
      break;
   }
}

// Handle scrolling.
// This can be triggered by mouse wheel and keyboard, 
// as well as the scrollbar.
void CScrollerCtrl::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
   if ( !(GetStyle()&WS_TABSTOP) )
      return;

   // delay autoscroll after manual scroll
   if ( m_nScrollPause > m_nScrollDelay )
   {
      m_eState = PAUSED;
      m_unTimerPause = SetTimer(m_unTimerPause, m_nScrollPause, NULL);
   }

   switch (nSBCode)
   {
   case SB_BOTTOM:      // Scroll to bottom. 
      m_nScrollOffset = m_sizeBuffer.cy-m_nContentHeight;
      break;
   case SB_TOP:         // Scroll to top. 
      m_nScrollOffset = 0;
      break;
   case SB_LINEDOWN:    // Scroll one line down. 
      m_nScrollOffset -= 8;
      break;
   case SB_LINEUP:      // Scroll one line up. 
      m_nScrollOffset += 8;
      break;
   case SB_PAGEDOWN:    // Scroll one page down. 
      m_nScrollOffset -= m_sizeBuffer.cy;
      break;
   case SB_PAGEUP:      // Scroll one page up. 
      m_nScrollOffset += m_sizeBuffer.cy;
      break;
   case SB_THUMBPOSITION:
   case SB_THUMBTRACK:
      m_nScrollOffset = -((int)nPos);
      break;
   default:
      return;
   }

   // constrain
	if ( m_nScrollOffset < m_sizeBuffer.cy-m_nContentHeight )
		m_nScrollOffset = m_sizeBuffer.cy-m_nContentHeight;
   else if ( m_nScrollOffset > 0 )
      m_nScrollOffset = 0;

   // scroll
   SetScrollPos(SB_VERT, -m_nScrollOffset);
   Invalidate(FALSE);
}

// Handle mouse wheel scrolling.
// I'll put actual effort into handling non-WHEEL_DELTA increments
// when i actually get a mouse that sends them. ;~)
BOOL CScrollerCtrl::OnMouseWheel(UINT nFlags, short zDelta, CPoint pt)
{
   int nDist = abs(zDelta)/WHEEL_DELTA+1;

   while ( nDist-- )
   {
      PostMessage(WM_VSCROLL, zDelta > 0 ? SB_LINEUP : SB_LINEDOWN);
   }
   return TRUE;
}

// Timers are used for three purposes:
//    + Periodic checking to show/hide the scrollbar
//    + Automatic scrolling (when m_eState == SCROLLING)
//    + Ending automatic scrolling pauses (when m_eState == PAUSED)
// This is accomplished via two timers:
//    The first does double duty, handling both the scrollbar and
//    automatic scrolling; it is active for the life of the window.
//    The second is used for ending autoscroll pauses.
void CScrollerCtrl::OnTimer(UINT nIDEvent)
{
   // don't autoscroll or hide scrollbar when user is dragging the scroll button.
   if ( this == GetCapture() )
      return;

   // the scrollbar can be shown if the following are true:
   //    + The content size is larger than the window
   //    + The mouse cursor is over the window
   //    + The top-level parent containing this control is active
   if ( m_bShowScroll )
   {
	   CRect rectWindow;
	   GetWindowRect(&rectWindow);
      CPoint pntCursor;
      ::GetCursorPos(&pntCursor);
      if ( m_sizeBuffer.cy < m_nContentHeight && GetTopLevelParent() == GetActiveWindow() && rectWindow.PtInRect(pntCursor) )
      {
         SetScrollRange(SB_VERT, 0, m_nContentHeight-m_sizeBuffer.cy, FALSE);
         SetScrollPos(SB_VERT, -m_nScrollOffset, TRUE);
         ShowScrollBar(SB_VERT, TRUE);
      }
      else if ( this != GetCapture() )
      {
         ShowScrollBar(SB_VERT, FALSE);
      }
   }

   if ( nIDEvent == m_unTimerPause )
   {
      m_eState = SCROLLING;
      KillTimer(m_unTimerPause);
   }

   if ( m_eState == SCROLLING )
   {
	   --m_nScrollOffset;
	   if ( m_nContentHeight+m_nScrollOffset < 0 )
      {
         // scrolling is complete; restart
         m_nScrollOffset = m_bWrap ? 0 : m_sizeBuffer.cy;
         CWnd* pwndParent = GetParent();
         if ( NULL != pwndParent )
            pwndParent->SendMessage(WM_COMMAND, MAKELPARAM(GetDlgCtrlID(), SC_SCROLL_COMPLETE), (LPARAM)GetSafeHwnd());
      }

      // pause at top and bottom
      if ( 0 == m_nScrollOffset || (m_nScrollOffset+m_nContentHeight == m_sizeBuffer.cy && m_sizeBuffer.cy < m_nContentHeight) )
      {
         if ( m_nScrollPause > m_nScrollDelay )
         {
            m_eState = PAUSED;
            m_unTimerPause = SetTimer(m_unTimerPause, m_nScrollPause, NULL);
         }
      }
	   Invalidate(FALSE);
   }
}