/**********************************************************************************************
MFC screen dim test
:: oystein :: November 2010
Creates a simple window - click it to toggle whether a translucent black "dimmer" window
is shown. The dimmer-window covers the entire screen, but the taskbar ("superbar" in
Windows 7) will jump on top of it if clicked - it seems. Simple suggestions to fix that
are welcome.
Should work on Windows 2000 and later.
Disclaimer: This is my first MFC program ever, so if anything seems wrong, it probably is.
I have previously only coded with pure Win32 API, and hacked this together using online
tutorials. Code provided "as-is" with no guarantees - I can not be held responsible for
anything bad that happens if you run this program.
***********************************************************************************************/
#include "stdafx.h"
#undef WINVER
#define WINVER 0x500 // Windows 2000 & above, because of layered windows
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
//
// Black window used to dim everything else
//
class CDimWnd : public CFrameWnd
{
public:
CDimWnd()
{
// Get screen res into rect
RECT rc;
GetDesktopWindow()->GetWindowRect(&rc);
CreateEx(WS_EX_LAYERED | // Layered window for translucency
WS_EX_TRANSPARENT | // Click through
WS_EX_TOPMOST | // Always on top
WS_EX_TOOLWINDOW, // Do not appear in taskbar & similar
NULL, TEXT(""),
WS_POPUP, // No frame/borders - though there is
// still some border left - we'll remove
// it with regions
0, 0, rc.right + 10, rc.bottom + 10, // Make the window 10px larger
// than screen resolution in both
// directions - it is still positioned
// at 0,0
NULL, NULL);
// Grab a part of the window the size of the desktop - but 5px into it
// Because the window is larger than the desktop res, the borders are removed
CRgn rgn;
rgn.CreateRectRgn(rc.left + 5, rc.top + 5, rc.right + 5, rc.bottom + 5);
SetWindowRgn((HRGN)rgn, FALSE);
rgn.Detach();
// We have to reposition window - (0,0) of window has not changed
SetWindowPos(NULL, -5, -5, 0, 0, SWP_NOSIZE | SWP_NOZORDER);
// This is where we set the opacity of the window: 0-255
SetLayeredWindowAttributes(RGB(0,0,0), 150, LWA_ALPHA);
}
void Close()
{
CFrameWnd::OnClose();
}
BOOL CDimWnd::OnEraseBkgnd(CDC* pDC); // Set BKG color
DECLARE_MESSAGE_MAP()
};
BOOL CDimWnd::OnEraseBkgnd(CDC* pDC)
{
// Set brush to desired background color
CBrush backBrush(RGB(0, 0, 0));
// Save old brush
CBrush* pOldBrush = pDC->SelectObject(&backBrush);
CRect rect;
pDC->GetClipBox(&rect); // Erase the area needed
pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(), PATCOPY);
pDC->SelectObject(pOldBrush);
return TRUE;
}
BEGIN_MESSAGE_MAP(CDimWnd, CFrameWnd)
ON_WM_ERASEBKGND()
END_MESSAGE_MAP()
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// Global variable - is screen dimmed?
bool g_bIsDimmed = false;
// The main window
class CMainWnd : public CFrameWnd
{
// Contains a CDimWnd - I'm not sure if this is the "MFC way" of doing things
CDimWnd dimmer;
public:
CMainWnd()
{
Create(NULL, TEXT("Screen dimmer - Press left mouse button on window to toggle"),
WS_OVERLAPPEDWINDOW, CRect(50, 50, 400, 250));
}
// Left mouse button toggles dimming
afx_msg void OnLButtonDown(UINT Flags, CPoint Point)
{
if(!g_bIsDimmed)
{
dimmer.ShowWindow(SW_SHOW);
dimmer.BringWindowToTop();
g_bIsDimmed = true;
}
else
{
dimmer.ShowWindow(SW_HIDE);
g_bIsDimmed = false;
}
}
DECLARE_MESSAGE_MAP()
};
BEGIN_MESSAGE_MAP(CMainWnd, CFrameWnd)
ON_WM_LBUTTONDOWN()
END_MESSAGE_MAP()
// The app
class CApp : public CWinApp
{
public:
virtual BOOL InitInstance();
};
BOOL CApp::InitInstance()
{
m_pMainWnd = new CMainWnd();
m_pMainWnd->ShowWindow(m_nCmdShow);
m_pMainWnd->UpdateWindow();
return TRUE;
}
CApp HelloApp;