Click here to Skip to main content
12,757,627 members (35,711 online)
Click here to Skip to main content


74 bookmarked
Posted 21 Jan 2001

Enhanced Progress Bar Control

, 11 Jun 2002 CPOL
An enhanced progress control that supports gradient shading, formatted text, animation, tooltips, shape, 'snake' and reverse modes, and vertical modes
#if !defined(AFX_MEMDC_H__CA1D3541_7235_11D1_ABBA_00A0243D1382__INCLUDED_)
#define AFX_MEMDC_H__CA1D3541_7235_11D1_ABBA_00A0243D1382__INCLUDED_

#if _MSC_VER >= 1000
#pragma once
#endif // _MSC_VER >= 1000
// MemDC.h : header file

// CMemDC - memory DC
// Author: Keith Rule
// Email:
// Copyright 1996-1997, Keith Rule
// You may freely use or modify this code provided this
// Copyright is included in all derived versions.
// History - 10/3/97 Fixed scrolling bug.
//					 Added print support.
//			 25 feb 98 - fixed minor assertion bug
// This class implements a memory Device Context

// Modified by:  Yury Goltsman
// email:
// page:
// Modifications provided without warranty of any kind.
// version : 1.0
// Added optional parameter : rectangle of dc area
// Added preliminary copying image from orig. dc to bitmap
// (somewhy without this it doesn't work in some places)

class CMemDC : public CDC

	// constructor sets up the memory DC
	CMemDC(CDC* pDC, LPRECT pRect = NULL, BOOL fCopyOld = FALSE, BOOL fUsePalette = FALSE) : CDC()

		m_pDC = pDC;
		m_pOldBitmap = NULL;
		m_bMemDC = !pDC->IsPrinting();
		m_fUsePalette = fUsePalette;

		if (m_bMemDC) // Create a Memory DC
				m_rect = *pRect;
			m_bitmap.CreateCompatibleBitmap(pDC, m_rect.Width(), m_rect.Height());
			m_pOldBitmap = SelectObject(&m_bitmap);
				BitBlt(m_rect.left,, m_rect.Width(), m_rect.Height(),
				       m_pDC, m_rect.left,, SRCCOPY);
		else  // Make a copy of the relevent parts of the current DC for printing
			m_bPrinting = pDC->m_bPrinting;
			m_hDC = pDC->m_hDC;
			m_hAttribDC = pDC->m_hAttribDC;
	// Destructor copies the contents of the mem DC to the original DC
		if (m_bMemDC) 
			CPalette pal, *pOldPal=NULL;
			if(m_fUsePalette && CreatePalette(pal))
				pOldPal = m_pDC->SelectPalette(&pal, FALSE);
			// Copy the offscreen bitmap onto the screen.
			m_pDC->BitBlt(m_rect.left,, m_rect.Width(), m_rect.Height(),
			              this, m_rect.left,, SRCCOPY);

				m_pDC->SelectPalette(pOldPal, TRUE);
			//Swap back the original bitmap.
			// All we need to do is replace the DC with an illegal value,
			// this keeps us from accidently deleting the handles associated with
			// the CDC that was passed to the constructor.
			m_hDC = m_hAttribDC = NULL;

	BOOL CreatePalette(CPalette& pal, CDC* pDC = NULL)
		if(!pDC) pDC = this;
		if(!(pDC->GetDeviceCaps(RASTERCAPS) & RC_PALETTE))
			return FALSE;

		//Get the DIBSection's color table
		const int nColors = 236;
		RGBQUAD rgb[nColors];
		::GetDIBColorTable(pDC->m_hDC, 0, nColors, rgb);

		//Create a palette from the color table
		lpPal->palVersion = 0x300;       
		lpPal->palNumEntries = nColors;

		for (int i = 0; i < nColors; i++)       
			lpPal->palPalEntry[i].peRed = rgb[i].rgbRed;
			lpPal->palPalEntry[i].peGreen = rgb[i].rgbGreen;
			lpPal->palPalEntry[i].peBlue = rgb[i].rgbBlue;
			lpPal->palPalEntry[i].peFlags = 0;
		//Clean up
		delete lpPal;
		return TRUE;

	// Allow usage as a pointer
	CMemDC* operator->() {return this;}
	// Allow usage as a pointer
	operator CMemDC*() {return this;}

	CBitmap  m_bitmap;      // Offscreen bitmap
	CBitmap* m_pOldBitmap;  // bitmap originally found in CMemDC
	CDC*     m_pDC;         // Saves CDC passed in constructor
	CRect    m_rect;        // Rectangle of drawing area.
	BOOL     m_bMemDC;      // TRUE if CDC really is a Memory DC.
	BOOL     m_fUsePalette; // if necessary create and select palette


// Microsoft Developer Studio will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_MEMDC_H__CA1D3541_7235_11D1_ABBA_00A0243D1382__INCLUDED_)

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Yury Goltsman
Software Developer (Senior)
Israel Israel
Yury is Software Engineer since 1988.
His programming experience includes C#/VB.NET, WPF, C/C++(MFC/STL), Borland Delphi & C++ (VCL), JavaScript, HTML, CSS, XML, SQL, VB6, DirectX, Flash.
He has worked on PCs (DOS/Win3.1-Vista) and PocketPCs (WinCE).

Yury was born in Ukraine, but currently based in Jerusalem.

You may also be interested in...

Permalink | Advertise | Privacy | Terms of Use | Mobile
Web02 | 2.8.170217.1 | Last Updated 12 Jun 2002
Article Copyright 2001 by Yury Goltsman
Everything else Copyright © CodeProject, 1999-2017
Layout: fixed | fluid