Streaming IPicture to Compound Document file

• Download source files - 7 Kb
• Download demo project - 150 Kb

Introduction

I really like the IPicture object. This COM object works very well. However, I met some problems when I was trying to use this object in the Document-View architecture. The main problem is implementation of serialization. I built two classes to resolve those problems. The first class called CPictureObj. This class is responsible for drawing picture. The second one is collection of picture objects. By using both of them it is easy to implement the following functionality:

• Load one or more images into document (*.bmp, *.jpeg, *.ico,...)
• Scaling images (Zoom In, Zoom Out)
• Move images by cursor
• Alignment
• Save/Load images to/from compound document file.

Classes

class <code>CPictureObj  :	public CPictureHolder, public CObject
{
	DECLARE_SERIAL(CPictureObj);
public:
	CPictureObj();
	CPictureObj(const CRect position);
	virtual  ~CPictureObj();
	void RemoveAndDestroy();

	virtual  void Copy( CPictureObj &right);
	virtual  HRESULT WriteToStream(IStream* pStream);
	virtual  HRESULT ReadFromStream(IStream* pStream);
	
// Attributes
public:
	HorzAlign	GetHorzAlign( void ) const;
	void		SetHorzAlign( HorzAlign eHorzAlign );
	VertAlign	GetVertAlign( void ) const;
	void		SetVertAlign( VertAlign eVertAlign );
	BOOL		GetSelected( void ) const;
	void		SetSelected( BOOL bValue );
	void		SetVisible(BOOL bValue);
	BOOL		GetVisible();
	CRect		GetPosition();
	void		SetPosition(const CRect pos);
	CRect		GetStartRect();
	void		SetStartRect(const CRect pos);
	CString		GetPathName();
	void		SetPathName(const CString pathname);

	OLE_HANDLE	GetHandle();
	CSize		GetSize();			// in himetric
	CSize		GetSize(CDC*pDC);	// in pixel
	CSize		GetSize(CWnd*pWnd);	// in pixel
	BOOL		IsValidPicture();

// Operations
public:

	BOOL Load(LPCTSTR szFile);
	BOOL CreateFromFile(const CPoint pt);
	void ReleasePicture();
	void MoveTo(const CRect& position, CWnd* pView);

	// Drawing picture
	void Draw(CDC* pDC);
	void Draw(CDC* pDC, CRect& rcBounds);
	void Draw(CDC* pDC, const CRect& rcPosition, const CRect& rcBounds);
	void DrawTracker(CDC* pDC);
	void DrawTracker(CDC* pDC, const CRect& rect);
	void ZoomIn();
	void ZoomOut();

protected:

	void CalcZoom();
	void SetZoomToPosition();

protected:

	HorzAlign	m_eHorizAlign;
	VertAlign	m_eVertAlign;
	BOOL		m_bSelected;
	BOOL		m_bVisible;
	CRect		m_rcPosition;		// in pixels
	CRect		m_startRect;		// in pixels
	int		m_trackerStyle;
	int		m_zoomX,m_zoomY;

	// Not serialized
	CString		m_strPathName;

};

class  CPictureObjList : public CTypedPtrList {CObList, CPictureObj*}
{
public :
	~CPictureObjList();

	void RemoveAndDestroy();
	void DeselectAll();
	
	CSize ComputeMaxSize();			// in himetric
	CSize ComputeMaxSize(CDC* pDC);		// in pixel
	CSize ComputeMaxSize(CWnd* pWnd);	// in pixel
	CRect GetRect();			// in pixel

	CPictureObj* FindSelected();
	CPictureObj* ObjectAt(const CPoint& pt);
	bool Remove(CPictureObj* pObj);
	void Draw(CDC* pDC);

	// Streaming
	HRESULT WriteToStream(IStream* pStream);
	HRESULT ReadFromStream(IStream* pStream);
	BOOL	WriteToStorage(LPSTORAGE lpRootStg);
	BOOL	ReadFromStorage(LPSTORAGE lpRootStg);

};

Using the classes

For use streaming picture create your document object derived from COleDocument.

class CYourDoc : public COleDocument

Inside of the document object define a picture collection like here:

CPictureObjList	m_objects;

Now, you can insert picture by this simple method:

CPictureObj* pObj =  new CPictureObj;
pObj->CreateFromFile(CPoint(10,10));
m_objects.AddHead(pObj);

Also, you can load picture directly from the file:

CPictureObj* pObj =  new CPictureObj;
pObj->Load("MyFile.jpg");
m_objects.AddHead(pObj);

For scaling pictures you can use the ZoomIn, ZoomOut member functions:

CPictureObj* pObj = m_objects.FindSelected();
if(pObj)
{
    pObj->ZoomIn();
}

Moving the selected picture is easy:

   CPoint delta = point - c_last;
   CPictureObj* pSel = m_objects.FindSelected();
   if(pSel)
   {
	CRect position = pSel->GetPosition();
	position += delta;
	pSel->MoveTo(position, this);
   }

Drawing a collection of pictures is also easy:

GetDocument()->m_objects.Draw(pDC);

Implementation of picture serialization you can get from here:

void CYourDoc::Serialize(CArchive& ar)
{
	CWaitCursor wait;
	COleDocument::Serialize(ar);
	if (ar.IsStoring())
	{
		m_objects.WriteToStorage(m_lpRootStg); 
	}
	else
	{
		m_objects.ReadFromStorage(m_lpRootStg); 
		m_objects.DeselectAll();
	}
}

Good luck!