A Better Bitmap Button Class

// ToggleButton.cpp : implementation file
//
// Originally by Joseph M. Newcomer.
// Modified in Aug 01 by Jeff Mallett to display highlight color when pressed.

#include "stdafx.h"
#include "button.h"
#include "ToggleButton.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CToggleButton

CToggleButton::CToggleButton()
{
 depressed = FALSE;
}

CToggleButton::~CToggleButton()
{
}


BEGIN_MESSAGE_MAP(CToggleButton, CButton)
	//{{AFX_MSG_MAP(CToggleButton)
	ON_WM_LBUTTONDOWN()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CToggleButton message handlers

/****************************************************************************
*                            CToggleButton::SetVPos
* Inputs:
*       DWORD newstyle: Vertical style, one of BS_TOP, BS_BOTTOM, BS_VCENTER
* Result: DWORD
*       Previous style
* Effect: 
*       Sets the style
****************************************************************************/

DWORD CToggleButton::SetVPos(DWORD newstyle)
   {
    DWORD style = GetStyle();
    DWORD result = style;
    style &= ~ (BS_TOP | BS_BOTTOM | BS_VCENTER);
    style |= newstyle;
    ::SetWindowLong(m_hWnd, GWL_STYLE, (long)style);
    InvalidateRect(NULL);
    return result & (BS_TOP | BS_BOTTOM | BS_VCENTER);
   } // CToggleButton::SetVPos

/****************************************************************************
*                            CToggleButton::SetHPos
* Inputs:
*       DWORD newstyle: Horizontal style, one of BS_LEFT, BS_RIGHT, BS_CENTER
* Result: DWORD
*       Previous style
* Effect: 
*       Sets the style
****************************************************************************/

DWORD CToggleButton::SetHPos(DWORD newstyle)
   {
    DWORD style = GetStyle();
    DWORD result = style;
    style &= ~ (BS_LEFT | BS_RIGHT | BS_CENTER);
    style |= newstyle;
    ::SetWindowLong(m_hWnd, GWL_STYLE, (long)style);
    InvalidateRect(NULL);
    return result & (BS_LEFT | BS_RIGHT | BS_CENTER);
   } // CToggleButton::SetHPos


void CToggleButton::DrawItem(LPDRAWITEMSTRUCT dis) 
{
     CDC * dc = CDC::FromHandle(dis->hDC); // Get a CDC we can use
     CRect r(dis->rcItem);		   // Copy the button rectangle
     int saved = dc->SaveDC();		   // Save the DC for later restoration
     CPoint pt;                            // left point of text
     CSize sz;                             // size of text
     CSize border(::GetSystemMetrics(SM_CXBORDER), ::GetSystemMetrics(SM_CYBORDER));
					   // Dimensions of a border line
					   // We use ::GetSystemMetrics so we work on
					   // hi-res displays
     CPoint baseOffset(border.cx, border.cy); // Offset amount if button-down

     // The three states are
     //  ODS_SELECTED  ODS_DISABLED 
     //       1		n/a		Button is pressed
     //	      0		0		Button is up
     //	      0		1		Button is disabled
     //

     dc->SetTextColor(::GetSysColor(COLOR_BTNTEXT));
     //dc->SetBkMode(TRANSPARENT);
     if(dis->itemState & (ODS_DISABLED | ODS_GRAYED))
	{ /* grayed */
	 dc->SetTextColor(::GetSysColor(COLOR_GRAYTEXT));
	} /* grayed */

     DWORD style = GetStyle();
     style &= (BS_LEFT | BS_RIGHT | BS_CENTER);

#define MARGIN 4
     CString s;
     GetWindowText(s);
     sz = dc->GetTextExtent(s);

     UINT flags = (GetStyle() & BS_MULTILINE ? 0 : DT_SINGLELINE);
     switch(style)
	{ /* hstyle */
	 case BS_LEFT:
	    pt.x = MARGIN * border.cx;
	    flags |= DT_LEFT;
	    break;
	 case BS_RIGHT:
	    pt.x = r.Width() - MARGIN * border.cx - sz.cx;
	    flags |= DT_RIGHT;
	    break;
	 case 0:
	 case BS_CENTER:
	    pt.x = (r.Width() - sz.cx) / 2;
	    flags |= DT_CENTER;
	    break;
	} /* hstyle */

     style = GetStyle();
     style &= (BS_TOP | BS_BOTTOM | BS_VCENTER);

     switch(style)
	{ /* vstyle */
	 case BS_TOP:
	    pt.y = 3 * border.cy;
	    flags |= DT_TOP;
	    break;
	 case BS_BOTTOM:
	    pt.y = r.Height() - MARGIN * border.cy - sz.cy;
	    flags |= DT_BOTTOM;
	    break;
	 case 0:
	 case BS_VCENTER:
	    pt.y = (r.Height() - sz.cy) / 2;
	    flags |= DT_VCENTER;
	    break;
	} /* vstyle */

     // Compute the focus rectangle area
     CRect focus(pt.x, pt.y, pt.x + sz.cx, pt.y + sz.cy);

     // For visual effect, if the button is down, shift the text over and
     // down to make it look "pushed".
     CPoint useOffset(0, 0);
     if(depressed)
	{ /* down */
	 useOffset = baseOffset;
	} /* down */

     // Draw the traditional pushbutton edge using DrawEdge
     if(depressed)
	{ /* down */
	 dc->DrawEdge(&dis->rcItem, EDGE_SUNKEN, BF_RECT | BF_MIDDLE | BF_SOFT);
	} /* down */
     else
	{ /* up */
	 dc->DrawEdge(&dis->rcItem, EDGE_RAISED, BF_RECT | BF_MIDDLE | BF_SOFT);
	} /* up */

	// Fill background with highlight color
	if (depressed)
	{
		UINT x = 3 * border.cx; 
		UINT y = 3 * border.cy;
		CRect rect(x, y,
					x + r.Width() - baseOffset.x - 4,
					y + r.Height() - baseOffset.y - 4);
		dc->FillSolidRect( &rect, ::GetSysColor(COLOR_BTNHIGHLIGHT));
		dc->SetBkColor(::GetSysColor(COLOR_BTNHIGHLIGHT));
	}

     // Adjust the focus position and text position by shifting them
     // right-and-down by the desired offset
     focus += useOffset;
     pt += useOffset;

     focus.InflateRect(border.cx, border.cy);

     r.InflateRect(-MARGIN * border.cx, -MARGIN * border.cy);
     r += useOffset;

     dc->DrawText(s, r, flags);

     if(dis->itemState & ODS_FOCUS)
	::DrawFocusRect(dis->hDC, &focus);

     dc->RestoreDC(saved);
}

void CToggleButton::OnLButtonDown(UINT nFlags, CPoint point) 
{
    depressed = !depressed;
    InvalidateRect(NULL);
    CButton::OnLButtonDown(nFlags, point);
}