SDragWnd.cpp

#include "souistd.h"
#include "helper/SDragWnd.h"
#include "helper/SMemDC.h"
SNSBEGIN
 
SDragWnd *SDragWnd::s_pCurDragWnd = NULL;
 
SDragWnd::SDragWnd(void)
    : m_bmp(NULL)
{
}
 
SDragWnd::~SDragWnd(void)
{
}
 
void SDragWnd::OnPaint(HDC dc)
{
    PAINTSTRUCT ps;
    dc = ::BeginPaint(m_hWnd, &ps);
    if (m_bmp)
    {
        CRect rc;
        GetClientRect(rc);
        HDC hMemDC = CreateCompatibleDC(dc);
        HGDIOBJ hOldBmp = SelectObject(hMemDC, m_bmp);
        BitBlt(dc, 0, 0, rc.Width(), rc.Height(), hMemDC, 0, 0, SRCCOPY);
        ::SelectObject(hMemDC, hOldBmp);
        ::DeleteDC(hMemDC);
    }
    ::EndPaint(m_hWnd, &ps);
}
 
BOOL SDragWnd::BeginDrag(HBITMAP hBmp, POINT ptHot, COLORREF crKey, BYTE byAlpha, DWORD dwFlags)
{
    if (s_pCurDragWnd)
        return FALSE;
    s_pCurDragWnd = new SDragWnd;
    BITMAP bm;
    GetObject(hBmp, sizeof(bm), &bm);
 
#ifdef _WIN32
    if (!s_pCurDragWnd->CreateNative(NULL, WS_POPUP, WS_EX_TRANSPARENT | WS_EX_TOOLWINDOW | WS_EX_TOPMOST, 0, 0, bm.bmWidth, bm.bmHeight, 0, 0, NULL))
    {
        delete s_pCurDragWnd;
        s_pCurDragWnd = NULL;
        return FALSE;
    }
 
    s_pCurDragWnd->ModifyStyleEx(0, WS_EX_LAYERED);
 
    if (bm.bmBitsPixel == 32)
    {
        HDC dc = s_pCurDragWnd->GetDC();
        SMemDC memdc(dc, hBmp);
        BLENDFUNCTION bf = { AC_SRC_OVER, 0, byAlpha, AC_SRC_ALPHA };
        CPoint pt(0, 0);
        CSize sz(bm.bmWidth, bm.bmHeight);
        CPoint pt1(0, 0);
        s_pCurDragWnd->UpdateLayeredWindow(dc, &pt, &sz, memdc, &pt1, crKey, &bf, LWA_ALPHA);
        s_pCurDragWnd->ReleaseDC(dc);
    }
    else
    {
        s_pCurDragWnd->SetLayeredWindowAttributes(crKey, byAlpha, dwFlags);
        s_pCurDragWnd->m_bmp = hBmp;
        s_pCurDragWnd->Invalidate();
    }
#else  //_WIN32
 
    DWORD dwExStyle = WS_EX_TRANSPARENT | WS_EX_TOOLWINDOW | WS_EX_TOPMOST | WS_EX_LAYERED;
    if (bm.bmBitsPixel == 32)
        dwExStyle |= WS_EX_COMPOSITED;
    if (!s_pCurDragWnd->CreateNative(NULL, WS_POPUP, dwExStyle, 0, 0, bm.bmWidth, bm.bmHeight, 0, 0, NULL))
    {
        delete s_pCurDragWnd;
        s_pCurDragWnd = NULL;
        return FALSE;
    }
    s_pCurDragWnd->m_bmp = hBmp;
    s_pCurDragWnd->SetLayeredWindowAttributes(crKey, byAlpha, dwFlags);
    s_pCurDragWnd->Invalidate();
#endif //_WIN32
    s_pCurDragWnd->m_ptHot = ptHot;
    return TRUE;
}
 
void SDragWnd::DragMove(POINT pt)
{
    SASSERT(s_pCurDragWnd);
    s_pCurDragWnd->SetWindowPos(HWND_TOPMOST, pt.x - s_pCurDragWnd->m_ptHot.x, pt.y - s_pCurDragWnd->m_ptHot.y, 0, 0, SWP_NOSIZE | SWP_NOSENDCHANGING | SWP_NOOWNERZORDER | SWP_SHOWWINDOW | SWP_NOACTIVATE);
}
 
void SDragWnd::EndDrag()
{
    SASSERT(s_pCurDragWnd);
    s_pCurDragWnd->DestroyWindow();
    delete s_pCurDragWnd;
    s_pCurDragWnd = NULL;
}
 
SNSEND