diagrameditor.cpp

So you wanted to add a forms editor to your application? A dialog editor? Something that allows draw

/* ==========================================================================
	Class :			CDiagramEditor

	Author :		Johan Rosengren, Abstrakt Mekanik AB

	Date :			2004-03-29

	Purpose :		"CDiagramEditor" encapsulates a basic vector editor geared 
					towards diagrams rather than graphics. It supports 
					virtual screens both smaller and larger than the window, 
					snap to grid, copy/paste, unlimited undo, zoom etc. It 
					can be added to both dialogbox- and doc/view apps due to 
					the use of a separate container for data.

					Normally, this class need only to be inherited from when 
					the drawing functionality is insufficient - many of the 
					settings can be modified through member accessors.

	Description :	The class derives from "CWnd", and handles Windows messages 
					relevant to the operations. 

	Usage :			

   ========================================================================
	Changes :		8/4  2004	SendMessageToObjects sets TRUE flag
								sending message only to selected objects.
					9/4  2004	Made some message mapping functions
								virtual to allow enhancements in 
								derived classes.
					9/4  2004	Added accessors for states to allow
								access for derived classes
					28/4 2004	Set interact mode to MODE_NONE after
								ctrl+clicking item (to not move lines)
					28/4 2004	Setting scrollbar positions to zero
								in Clear
					29/4 2004	Sending this window as a parent to the 
								property dialog. This is to be able to 
								redraw the editor properly after changes 
								to the dialog.
					30/4 2004	Changed c-style casts to static_cast
					30/4 2004	Remove ShowProperties-const-ness.
   ========================================================================
					14/5 2004	Added access to m_subMode in 
								SetInteractMode
					14/5 2004	Made OnObjectCommand virtual to allow 
								interception in derived classes.
					15/5 2004	Made GetBackgroundColor const.
					20/5 2004	Made SelectAll virtual.
					24/5 2004	Added virtual size check against the client 
								rect in HScroll and VScroll (Graham).
   ========================================================================
					24/6 2004	Corrected bug in SetZoom, where the minimum
								zoom value was not honoured (pgrohs).
					24/6 2004	Zeroing m_internalData after delete to 
								avoid crash. (pgrohs).
					26/6 2004	Added group handling (Unruled Boy).
   ========================================================================
					26/6 2004	Corrected bug in alignment handling - all 
								objects, not only selected, where modified.
								Also made functions virtual.
					29/6 2004	Added ZoomToFitScreen and 
								mousewheel-handling (John A. Johnson).
					30/6 2004	Added panning (John A. Johnson).
					3/7	 2004	Made AddObject virtual and added the virtual 
								MoveObject function. This is to allow 
								trapping of added or moved objects in the 
								editor in derived classes. Also made 
								clipboard-functions and DeleteAllSelected 
								virtual.
					5/7	2004	Made Clear virtual.
					5/7	2004	Added virtual GetCursor function.
					6/7	2004	Correction in VirtualToScreen, not deducting 
								scrollbar positions any longer (Wolfgang Busch).
					6/7	2004	Coordinate conversion functions made public.
								(Wolfgang Busch).
   ========================================================================
					12/7 2004	Added scroll wheel mode. By calling 
								SetScrollWheelMode( WHEEL_SCROLL/WHEEL_ZOOM), 
								the scroll wheel will either scroll or zoom.
   ========================================================================
					16/7 2004	Added virtual to more message handlers, 
								among them the scrollbar ones.
					16/7 2004	Added virtual to SetZoom.
					16/7 2004	Added virtual functions to set the 
								scrollbar positions to get one single point 
								where this is made.
					25/7 2004	Checking if the cursor is outside of 
								restraint when placing an item in 
								OnLButtonDown.
   ========================================================================
					3/8	 2004	Added ScrollIntoView commands
					4/8	 2004	Fixed bug with selection markers - 
								virtualization of the mouse coordinates was 
								in discord with the selection marker 
								rectangles. (Marc G)
   ========================================================================
					9/8	 2004	Added new ScrollIntoView command taking 
								object as an inparam.
					19/8 2004	Fixed bug in hit testing objects when 
								zooming in OnLButtonDown (Marc G)
   ========================================================================
					28/8 2004	Added check for non-normalized rect when 
								hit-testing in OnLButtonDown, as lines 
								have them.
   ========================================================================
					11/12 2004	Added minimum step size one pixel in 
								OnKeyDown to avoid 0-pixel movement for
								arrow keys (Graham G Pearson)
					11/12 2004	Made UnselectAll virtual (Grisha Vinevich)
  ========================================================================*/

#include "stdafx.h"
#include "DiagramEditor.h"
#include <math.h>

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

#pragma warning( disable : 4706 )

/////////////////////////////////////////////////////////////////////////////
// CDiagramEditor construction/destruction/initialization

CDiagramEditor::CDiagramEditor()
/* ============================================================
	Function :		CDiagramEditor::CDiagramEditor
	Description :	Constructor
	Access :		Public

	Return :		void
	Parameters :	none

	Usage :			

   ============================================================*/
{

	m_bkgndCol = ::GetSysColor( COLOR_WINDOW );
	m_nonClientBkgndCol = ::GetSysColor( COLOR_3DSHADOW );

	m_gridCol = RGB( 192, 192, 192 );
	m_grid = TRUE;
	m_gridStyle = PS_SOLID;
	m_gridSize = CSize( 8, 8 );

	m_snap = FALSE;
	m_bgResize = FALSE;
	m_bgResizeZone = 10;
	m_bgResizeSelected = FALSE;
	m_markerSize = CSize( 8, 8 );

	m_drawObj = NULL;
	m_objs = NULL;
	m_multiSelObj = NULL;
	m_internalData = NULL;

	m_restraint = RESTRAINT_NONE;

	m_leftMargin = 8;
	m_topMargin = 8;
	m_rightMargin = 8;
	m_bottomMargin = 16;
	m_margin = FALSE;
	m_marginColor = RGB( 128, 128, 255 );

	m_popupMenu = NULL;
	m_multiDraw = FALSE;

	m_zoomFactor = 0.01;
	m_zoomMax = 10.0;
	m_zoomMin = 0.0;

	m_panningTimer = 100;
	m_panning = FALSE;

	m_keyInterface = KEY_ALL;

	m_cursorNorth		= ::LoadCursor( NULL, IDC_SIZENS );
	m_cursorNorthEast	= ::LoadCursor( NULL, IDC_SIZENESW );
	m_cursorEast		= ::LoadCursor( NULL, IDC_SIZEWE );
	m_cursorSouthEast	= ::LoadCursor( NULL, IDC_SIZENWSE );
	m_cursorSouth		= ::LoadCursor( NULL, IDC_SIZENS );
	m_cursorSouthWest	= ::LoadCursor( NULL, IDC_SIZENESW );
	m_cursorWest		= ::LoadCursor( NULL, IDC_SIZEWE );
	m_cursorNorthWest	= ::LoadCursor( NULL, IDC_SIZENWSE );

	SetScrollWheelMode( WHEEL_SCROLL );

	Clear();

}

CDiagramEditor::~CDiagramEditor()
/* ============================================================
	Function :		CDiagramEditor::~CDiagramEditor
	Description :	Destructor
	Access :		Public

	Return :		void
	Parameters :	none

	Usage :			

   ============================================================*/
{

	delete m_drawObj;
	delete m_internalData;
	delete m_popupMenu;

}

void CDiagramEditor::Clear()
/* ============================================================
	Function :		CDiagramEditor::Clear
	Description :	Clears internal run-time variables.
	Access :		Public

	Return :		void
	Parameters :	none

	Usage :			Call to reset internal states.

   ============================================================*/
{

	// Clearing internal states and vars
	m_selectionRect.SetRectEmpty();
	m_interactMode = MODE_NONE;
	m_zoom = 1.0;
	m_bgResizeSelected = FALSE;
	m_deltaPoint = CSize( 0, 0 );
	m_multiSelObj = NULL;
	m_drawing = FALSE;

	SetPanning( FALSE );

	delete m_drawObj;
	m_drawObj = NULL;

	if( m_hWnd )
	{

		SetupScrollbars();
		SetHScroll( 0 );
		SetVScroll( 0 );

		RedrawWindow();

	}

}

BOOL CDiagramEditor::Create( DWORD dwStyle, const RECT &rect, CWnd *pParentWnd, CDiagramEntityContainer* data )
/* ============================================================
	Function :		CDiagramEditor::Create
	Description :	Creates a "CDiagramEditor" window.
	Access :		Public

	Return :		BOOL							-	"TRUE" if success
	Parameters :	DWORD dwStyle					-	Window styles for 
														the editor
					const RECT &rect				-	Window rectangle
					CWnd *pParentWnd				-	Parent of the 
														editor
					CDiagramEntityContainer* data	-	Pointer to data. 
														Might be "NULL".
					
	Usage :			If data is "NULL", a "CDiagramEntityContainer" 
					will be created internally, and the instance 
					of the editor will be responsible for the 
					container deletion.

   ============================================================*/
{
	if( data == NULL )
	{
		m_internalData = new CDiagramEntityContainer;
		SetInternalDiagramEntityContainer( m_internalData );
	}
	else
		SetDiagramEntityContainer( data );

	BOOL res = CWnd::Create( NULL, NULL, dwStyle, rect, pParentWnd, NULL );
	CSize virtualSize;
	if( GetVirtualSize().cx == 0 &&  GetVirtualSize().cy == 0 )
		virtualSize = CSize( rect.right - rect.left, rect.bottom - rect.top );
	else
		virtualSize = GetVirtualSize();

	SetInternalVirtualSize( virtualSize );

	return res;

}

void CDiagramEditor::New()
/* ============================================================
	Function :		CDiagramEditor::New
	Description :	Clears the current 'page' and creates a 
					new one.
	Access :		Public

	Return :		void
	Parameters :	none

	Usage :			Call to start a new drawing.

   ============================================================*/
{

	SetRedraw( FALSE );
	Clear();
	m_objs->Clear();
	SetRedraw( TRUE );
	RedrawWindow();

}

void CDiagramEditor::SetDiagramEntityContainer( CDiagramEntityContainer* objs )
/* ============================================================
	Function :		CDiagramEditor::SetDiagramEntityContainer
	Description :	Sets the data container for the editor.
	Access :		Public
					
	Return :		void
	Parameters :	CDiagramEntityContainer* objs	-	the data 
														container
					
	Usage :			If this function is used, the caller is 
					responsible for deleting the container. Can 
					be called before or after "Create".

   ============================================================*/
{

	if( m_internalData )
		delete m_internalData;

	m_internalData = NULL;

	SetInternalDiagramEntityContainer ( objs );

}

void CDiagramEditor::SetInternalDiagramEntityContainer( CDiagramEntityContainer* objs )
/* ============================================================
	Function :		CDiagramEditor::SetInternalDiagramEntityContainer
	Description :	Sets the internal data container pointer.
	Access :		Protected

	Return :		void
	Parameters :	CDiagramEntityContainer* objs	-	A pointer to the 
														container to set.
					
	Usage :			Internal function.

   ============================================================*/
{

	m_objs = objs;

}

CDiagramEntityContainer* CDiagramEditor::GetDiagramEntityContainer() const
/* ============================================================
	Function :		CDiagramEditor::GetDiagramEntityContainer
	Description :	Returns a pointer to the data container.
	Access :		Public

	Return :		CDiagramEntityContainer*	-	The current data 
													container (might 
													be "NULL").
	Parameters :	none

	Usage :			If modifications are made to the contents of 
					the container, "SetModified" must be called as 
					appropriate. If visual changes are expected, 
					"RedrawWindow" must be called for the editor.

   ============================================================*/
{

	return m_objs;

}

BEGIN_MESSAGE_MAP( CDiagramEditor, CWnd )
	//{{AFX_MSG_MAP( CDiagramEditor )
	ON_WM_PAINT()
	ON_WM_ERASEBKGND()
	ON_WM_SETCURSOR()
	ON_WM_SIZE()
	ON_WM_HSCROLL()
	ON_WM_VSCROLL()
	ON_WM_LBUTTONDOWN()
	ON_WM_LBUTTONUP()
	ON_WM_RBUTTONUP()
	ON_WM_RBUTTONDOWN()
	ON_WM_MOUSEMOVE()
	ON_WM_GETDLGCODE()
	ON_WM_KEYDOWN()
	ON_WM_LBUTTONDBLCLK()
	ON_WM_MBUTTONDOWN()
	//}}AFX_MSG_MAP

	ON_WM_KILLFOCUS()
	ON_WM_TIMER()
	ON_WM_MOUSEWHEEL()
	ON_COMMAND_RANGE( CMD_START, CMD_END, OnObjectCommand )

	ON_COMMAND( ID_EDIT_CUT, OnEditCut )
	ON_COMMAND( ID_EDIT_COPY, OnEditCopy )
	ON_COMMAND( ID_EDIT_PASTE, OnEditPaste )
	ON_COMMAND( ID_EDIT_GROUP, OnEditGroup )
	ON_COMMAND( ID_EDIT_UNGROUP, OnEditUngroup )

END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CDiagramEditor painting

void CDiagramEditor::OnPaint() 
/* ============================================================
	Function :		CDiagramEditor::OnPaint
	Description :	Draws the screen. A memory "CDC" is created 
					and drawn to.
	Access :		Protected

	Return :		void
	Parameters :	none

	Usage :			Called from MFC. Do not call from code.

   ============================================================*/
{

	CPaintDC outputdc( this );

	// Getting coordinate data
	CRect rect;
	GetClientRect( &rect );

	SCROLLINFO sih;
	sih.cbSize = sizeof( SCROLLINFO );
	sih.fMask = SIF_POS;
	SCROLLINFO siv;
	siv.cbSize = sizeof( SCROLLINFO );
	siv.fMask = SIF_POS;
	if( !GetScrollInfo( SB_HORZ, &sih ) )
		sih.nPos = 0;
	if( !GetScrollInfo( SB_VERT, &siv ) )
		siv.nPos = 0;

	CRect totalRect;
	int virtwidth = round( static_cast< double >( GetVirtualSize().cx ) * GetZoom() ) + 1;
	int virtheight = round( static_cast< double >( GetVirtualSize().cy ) * GetZoom() ) + 1;
	totalRect.SetRect( 0, 0, virtwidth, virtheight );

	// Creating memory CDC
	CDC dc;
	dc.CreateCompatibleDC( &outputdc );
	CBitmap bmp;