Repositioning Windows on Multiple Monitor Systems

//Wrapping the API to some useful functions
#include "StdAfx.h"
#include ".\monitorinfo.h"
//for Multiple Monitors only inlcude once
//#ifndef COMPILE_MULTIMON_STUBS
	#define COMPILE_MULTIMON_STUBS
	#include <multimon.h>
//#endif

MonitorInfo::MonitorInfo() : m_Count(0), m_Primary(0)
{
	Update();
}

MonitorInfo::~MonitorInfo()
{
}
int MonitorInfo::GetNearestDisplay(CRect rc)
{
	HMONITOR hMonitor = MonitorFromRect( rc, MONITOR_DEFAULTTONEAREST ); ASSERT( hMonitor );

	MONITORINFO mi = {0};//MONITORINFOEX
	mi.cbSize = sizeof(MONITORINFO);

	BOOL b = GetMonitorInfo( hMonitor, &mi ) != 0; ASSERT( b );

	if( b )
	{
		for( int i = 0; i < m_Count; i++ )
		{
			if( m_Array[i] == mi.rcMonitor )
				return i;
		}	
	}
	return m_Primary;
}
int MonitorInfo::GetNearestDisplay(CPoint pt)
{
	HMONITOR hMonitor = MonitorFromPoint( pt, MONITOR_DEFAULTTONEAREST ); ASSERT( hMonitor );

	MONITORINFO mi = {0};//MONITORINFOEX
	mi.cbSize = sizeof(MONITORINFO);

	BOOL b = GetMonitorInfo( hMonitor, &mi ) != 0; ASSERT( b );

	if( b )
	{
		for( int i = 0; i < m_Count; i++ )
		{
			if( m_Array[i] == mi.rcMonitor )
				return i;
		}	
	}
	return m_Primary;
}
//need to call once or by system settings changed
int MonitorInfo::Update()
{
	m_rcVirtualScreen = CRect( GetSystemMetrics( SM_YVIRTUALSCREEN ), GetSystemMetrics( SM_YVIRTUALSCREEN ), GetSystemMetrics( SM_CXVIRTUALSCREEN ), GetSystemMetrics( SM_CYVIRTUALSCREEN ) );
	m_Count = GetSystemMetrics( SM_CMONITORS );
	TRACE( "Virtual Screen: left = %ld, top = %ld, right = %ld, bottom = %ld\n", m_rcVirtualScreen.left, m_rcVirtualScreen.top, m_rcVirtualScreen.right, m_rcVirtualScreen.bottom );
	m_Array.RemoveAll();
	m_Primary = 0;
	m_csDevices.Empty();

	DISPLAY_DEVICE display;
	display.cb = sizeof( DISPLAY_DEVICE );
	DWORD dwNum = 0;
	//get names of all devices
	while( EnumDisplayDevices( NULL, dwNum, &display, 0 ) )
	{
		TRACE( "Device %s\n", display.DeviceString );
		m_csDevices += display.DeviceString;
		m_csDevices += "\n";

		dwNum++;
	}
	//enum all devices
	BOOL b = EnumDisplayMonitors(	0,				// handle to display DC 
									0,			    // clipping rectangle 
									MonitorEnumProc,// callback function
									(LPARAM) &m_Array // data for callback function 
								);
	
	m_Count = (int) m_Array.GetSize();
	//Check for primary
	for( int i = 0; i < m_Count; i++ )
	{
		CPoint pt = m_Array[i].CenterPoint();
		HMONITOR hMonitor = MonitorFromPoint( pt, MONITOR_DEFAULTTONEAREST ); ASSERT( hMonitor );

		MONITORINFO mi = {0};//MONITORINFOEX
		mi.cbSize = sizeof(MONITORINFO);

		b = GetMonitorInfo( hMonitor, &mi ) != 0; ASSERT( b );

		if( mi.dwFlags & MONITORINFOF_PRIMARY )
		{
			m_Primary = i;
			break;
		}

	}
	return 0;
}
//Callback Function
BOOL MonitorInfo::MonitorEnumProc( HMONITOR hMonitor, HDC hdcMonitor, LPRECT lprcMonitor, LPARAM dwData )
{
	TRACE( "MonitorEnumProc\n" );

	MonitorArray* pArray = (MonitorArray*) dwData;

	CRect rc = *lprcMonitor;

	pArray->Add( rc );

	return TRUE;
}
//iDisplay == -1 or not valid index => primary
int MonitorInfo::IsInDisplay(CRect rc, int iDisplay)
{
	if( iDisplay == -1 || m_Count <= iDisplay )
	{
		iDisplay = m_Primary;
	}

	CRect rcDisplay = m_Array[ iDisplay ];

	if( rcDisplay.PtInRect( rc.TopLeft() ) && rcDisplay.PtInRect( rc.BottomRight() ) )
	{
		return TRUE;
	}

	return FALSE;
}
CString MonitorInfo::GetName( int iDisplay )
{
	CString cs;
	AfxExtractSubString( cs, m_csDevices, iDisplay, '\n' );

	return cs;
}
//correct the RC for the display 
//return FALSE if movement is nessesary
int MonitorInfo::EnsureInMonitor(CRect& rc, int iDisplay)
{
	if( iDisplay == -1 || m_Count <= iDisplay )
	{
		iDisplay = m_Primary;
	}

	CRect rcDisplay = m_Array[ iDisplay ];

	BOOL bTL = rcDisplay.PtInRect( rc.TopLeft() );
	BOOL bBR = rcDisplay.PtInRect( rc.BottomRight() );

	if( bTL && bBR )
	{
		return TRUE;
	}
	//Not in Display

	int X = GetSystemMetrics( SM_CXDLGFRAME );
	int Y = GetSystemMetrics( SM_CXDLGFRAME );

	if( !bTL )
	{
		int dx = rc.left - rcDisplay.left;
		int dy = rc.top - rcDisplay.top;

		dx = min( 0, dx - X );
		dy = min( 0, dy - Y );

		rc.OffsetRect( -dx, -dy );
	}

	if( !bBR )
	{
		int dx = rc.right - rcDisplay.right;
		int dy = rc.bottom - rcDisplay.bottom;

		dx = max( 0, dx + X );
		dy = max( 0, dy + Y );

		rc.OffsetRect( -dx, -dy );
	}
	return FALSE;
}
int MonitorInfo::GetPrimary()
{
	return m_Primary;
}