scrollbitmapdlg.cpp

Displaying a large bitmap file on a dialog box, in its original size, is quite difficult in the VC++

// ScrollBitmapDlg.cpp : implementation file
//

#include "stdafx.h"
#include "ScrollBitmap.h"
#include "ScrollBitmapDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
/////////////////////////////////////////////////////////////////////////////
// ScrollBitmapDlg.cpp: Implementation File.
// Written by Shibu K.V ([e-mail])
// Sr.Research Associate
// ASIC Hardware Design Group
// Electronics Research & Development Centre of India
// Trivandrum, Kerala, India.
// Copyright (c) 2002
//
// Warning: this code hasn't been subject to a heavy testing, so
// use it on your own risk. The author accepts no liability for the 
// possible damage caused by this code.
//
// Version 1.0  22 Oct 2002.

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CScrollBitmapDlg dialog

CScrollBitmapDlg::CScrollBitmapDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CScrollBitmapDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CScrollBitmapDlg)
	m_hBmpNew = NULL;
	flag=true;
	erase=false;
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CScrollBitmapDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CScrollBitmapDlg)
	DDX_Control(pDX, IDC_STATIC1, m_st1);
	DDX_Control(pDX, IDC_SCROLLBAR2, m_vbar);
	DDX_Control(pDX, IDC_SCROLLBAR1, m_hbar);
	DDX_Control(pDX, IDC_COMMONDIALOG1, m_com);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CScrollBitmapDlg, CDialog)
	//{{AFX_MSG_MAP(CScrollBitmapDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_SHOW, OnShow)
	ON_WM_VSCROLL()
	ON_WM_HSCROLL()
	ON_WM_ERASEBKGND()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CScrollBitmapDlg message handlers

BOOL CScrollBitmapDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	CClientDC dc(this);
	 m_dcMem.CreateCompatibleDC( &dc );
		m_vbar.ShowWindow(false);
			m_hbar.ShowWindow(false);
		
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CScrollBitmapDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CScrollBitmapDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{	
		CPaintDC dc(this);
	  dc.BitBlt(offsetx,offsety,m_size.cx,m_size.cy, 
                   &m_dcMem, sourcex, sourcey,SRCCOPY);
	  erase=false;
			CDialog::OnPaint();
		
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CScrollBitmapDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CScrollBitmapDlg::OnShow() 
{
	// TODO: Add your control notification handler code here
	CString	file;
	file.Empty();
	m_com.ShowOpen();
	file=m_com.GetFileName();
	file.TrimRight();
	if(m_hBmpNew != NULL )
		DeleteObject(m_hBmpNew);
	sourcex=sourcey=0;//
	if(file.IsEmpty())
AfxMessageBox("Please Select a picture file");
		else{
			if(file.Right(3)!="bmp")
				AfxMessageBox("Please Select a .bmp file");
			else
			{
	m_hBmpNew =	 (HBITMAP) LoadImage(
	AfxGetInstanceHandle(),   // handle to instance
	file,  // name or identifier of the image (root is where project is)
	IMAGE_BITMAP,        // image types
	0,     // desired width
	0,     // desired height
	LR_LOADFROMFILE); 
	if( m_hBmpNew == NULL ){
	AfxMessageBox("Load Image Failed");}
	
   // put the HBITMAP info into the CBitmap (but not the bitmap itself)
   else{
	 m_st1.GetClientRect( &rectStaticClient );
	rectStaticClient.NormalizeRect();
	m_size.cx=rectStaticClient.Size().cx;
	m_size.cy=rectStaticClient.Size().cy;
   m_size.cx = rectStaticClient.Width();    // zero based
    m_size.cy = rectStaticClient.Height();    // zero based

    // Convert to screen coordinates using static as base,
    // then to DIALOG (instead of static) client coords 
    // using dialog as base
  m_st1.ClientToScreen( &rectStaticClient );
  ScreenToClient( &rectStaticClient);
        
    m_pt.x = rectStaticClient.left;
    m_pt.y = rectStaticClient.top;
  GetObject( m_hBmpNew , sizeof(BITMAP), &m_bmInfo );
 VERIFY(m_hBmpOld = (HBITMAP)SelectObject(m_dcMem, m_hBmpNew )  );

  offsetx= m_pt.x;
  offsety=m_pt.y;
m_vbar.MoveWindow(offsetx+m_size.cx,offsety,18,m_size.cy);
m_hbar.MoveWindow(offsetx,offsety+m_size.cy,m_size.cx,18);
horz.cbSize = sizeof(SCROLLINFO);
horz.fMask = SIF_ALL;
horz.nMin = 0;
horz.nMax = m_bmInfo.bmWidth-m_size.cx;
horz.nPage =0;
horz.nPos = 0;
horz.nTrackPos=0;
if(m_bmInfo.bmWidth<=m_size.cx)
{
	if((m_size.cx-m_bmInfo.bmWidth)==0)
		offsetx= m_pt.x;
	else
		offsetx= m_pt.x+((m_size.cx-m_bmInfo.bmWidth)/2);
	m_vbar.MoveWindow(offsetx+m_bmInfo.bmWidth,offsety,18,m_size.cy);
	m_hbar.ShowWindow(false);
}
else
m_hbar.ShowWindow(true);
m_hbar.SetScrollInfo(&horz);
vert.cbSize = sizeof(SCROLLINFO);
vert.fMask = SIF_ALL;
vert.nMin = 0;
vert.nMax = m_bmInfo.bmHeight-(m_size.cy);
vert.nPage = 0;
vert.nTrackPos=0;
if(m_bmInfo.bmHeight<=m_size.cy)
{
	if((m_size.cy-m_bmInfo.bmHeight)==0)
		offsety= m_pt.y;
	else
		offsety= m_pt.y+((m_size.cy-m_bmInfo.bmHeight)/2);
	m_hbar.MoveWindow(offsetx,offsety+m_bmInfo.bmHeight,m_size.cx,18);
	m_vbar.ShowWindow(false);
}
else
m_vbar.ShowWindow(true);
m_vbar.SetScrollInfo(&vert);

  InvalidateRect(&rectStaticClient);
		}
			}
		}

}

void CScrollBitmapDlg::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar) 
{
	// TODO: Add your message handler code here and/or call default
	switch (nSBCode)
{
case SB_TOP:
sourcey = 0;
break;
case SB_BOTTOM:
sourcey = INT_MAX;
break;
case SB_THUMBTRACK:
sourcey = nPos;
break;
}

//ScrollWindow(0,-(x-xOrig));
m_vbar.SetScrollPos(sourcey);
erase=true;
InvalidateRect(&rectStaticClient);
	CDialog::OnVScroll(nSBCode, nPos, pScrollBar);
}

void CScrollBitmapDlg::OnHScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar) 
{
	// TODO: Add your message handler code here and/or call default
switch (nSBCode)
{
case SB_TOP:
sourcex = 0;
break;
case SB_BOTTOM:
sourcex = INT_MAX;
break;
case SB_THUMBTRACK:
sourcex= nPos;
break;
}	
m_hbar.SetScrollPos(sourcex);
//Invalidate();
erase=true;
InvalidateRect(&rectStaticClient);
	CDialog::OnHScroll(nSBCode, nPos, pScrollBar);
}


BOOL CScrollBitmapDlg::OnEraseBkgnd(CDC* pDC) 
{
	// TODO: Add your message handler code here and/or call default
	if(erase)
		return false;
	else
	return CDialog::OnEraseBkgnd(pDC);
}


void CScrollBitmapDlg::OnOK() 
{
	// TODO: Add extra validation here
	
	CDialog::OnOK();
}