Double Buffered Canvas

Introduction

I wrote this code a while ago to learn the basics of drawing in windows. I am more a Java guy than an MFC guy, so I wanted a control that was as easy to manipulate as the Java component Canvas.
The control extends CStatic and handles the mouse events. I guess it is an easy demo for a starter. I also included in the demo files some useful code for bitmap manipulation.

Here is the header file:

#if !defined(AFX_CANVAS_H__9AFA14C2_2DA3_48F1_9CC9_33B220B96494__INCLUDED_)
#define AFX_CANVAS_H__9AFA14C2_2DA3_48F1_9CC9_33B220B96494__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

// Canvas.h : header file

//


/////////////////////////////////////////////////////////////////////////////

// CCanvas window


class CCanvas : public CStatic
{
// Construction

public:
    CCanvas();

// Attributes

public:
    // Border style

    enum BORDER
    {
        SUNKEN,             // Sunken (CLIENT_EDGE)

        LOW,                // Low sunken (STATIC_EDGE)

        UP,                 // Up (not too high)

        HIGH,               // High (MODAL_FRAME)

        FLAT,               // Flat (2 pixels large Border DKSHADOW)

        FRAME,              // Raised frame

        LIGHT_FRAME,        // Light raised frame

        THIN_FRAME,         // Thin raised frame

        THIN_LIGHT_FRAME,   // Thin light raised frame

        ETCHED,             // Etched

        ETCHED2,            // Etched 2

        SIMPLE              // Simple rectangle DKSHADOW

    };

private:
    // Buffer

    CDC* m_buffer;
    // Bitmap associated to m_buffer

    CBitmap* m_bitmap;

    // Double buffer / simple buffer

    bool m_double_buffered;
    // Auto focus

    bool m_auto_focus;
    // Mouse In

    bool m_mouse_in;
    // Draw the background

    bool m_draw_background;
    // Draw the border

    bool m_draw_border;

    // Background color

    COLORREF m_back_color;

    // Border Style

    BORDER m_border_style;

    // Cursor

    HCURSOR m_cursor;

    // Width and Height

    int m_width, m_height;

// Overrides

    // ClassWizard generated virtual function overrides

    //{{AFX_VIRTUAL(CCanvas)

    protected:
    virtual void PreSubclassWindow();
    //}}AFX_VIRTUAL


// Operations

public:
    // Return true if the mouse is in the client area

    bool IsMouseIn() { return m_mouse_in; }

    // Set double buffer

    void SetDoubleBuffer(bool flag) { m_double_buffered = flag; } 
    // Check if double buffered

    bool IsDoubleBuffered() { return m_double_buffered; }

    // Set auto focus

    void SetAutoFocus(bool flag) { m_auto_focus = flag; } 
    // Check if auto focus

    bool IsAutoFocus() { return m_auto_focus; }

    // Set the background color

    void SetBackgroundColor(COLORREF back) { m_back_color = back; }
    // Get the background color

    COLORREF GetBackgroundColor() { return m_back_color; }

    // Set background to be displayed

    void DrawBackground(bool flag) { m_draw_background = flag; }
    // Check if the background is displayed

    bool DrawBackground() { return m_draw_background; }

    // Set the border style

    void SetBorder(BORDER border_style) { m_border_style = border_style; }
    // Get the border Style

    BORDER GetBorder() { return m_border_style; }

    // Draw the border

    void DrawBorder(bool flag) { m_draw_border = flag; }
    // Check if the border is displayed

    bool DrawBorder() { return m_draw_border; }

    // Set the cursor (Win32 cursor)

    void SetWinCursor(LPCTSTR cursor);
    // Set application cursor from ID resource

    void SetAppCursor(UINT nIDResource);
    // Set custom cursor

    void SetCursor(HCURSOR hCursor) { m_cursor = hCursor; }

    // Get the width

    int GetWidth() { return m_width; }
    // Get the height

    int GetHeight() { return m_height; }

private:

// Implementation

public:
    virtual ~CCanvas();

    // Main Paint method

    virtual void Paint(CDC* dc) {}
    
    // Draw border

    virtual void DrawBorder(CDC* dc);

    // Repaint

    void Repaint();
    
    // OnMouseExit: Called each time the mouse exit the client area

    virtual void OnMouseExit() {}

// Helpers

public:
    // Draw a rectangle

    void DrawRect(CDC *dc, RECT rect);
    void DrawRect(CDC *dc, int x, int y, int w, int h);
    void DrawRect(CDC *dc, RECT rect, COLORREF color);
    void DrawRect(CDC *dc, int x, int y, int w, int h, COLORREF color);

    // Draw a circle

    void DrawCircle(CDC *dc, int x, int y, int radius);
    void DrawCircle(CDC *dc, int x, int y, int radius, COLORREF color);

    // Draw a line

    void DrawLine(CDC *dc, CPoint& start, CPoint& end);
    void DrawLine(CDC *dc, int xStart, int yStart, int xEnd, int yEnd);
    void DrawLine(CDC *dc, CPoint& start, CPoint& end, 
                                                        COLORREF color);
    void DrawLine(CDC *dc, int xStart, int yStart, int xEnd, int yEnd, 
                                                        COLORREF color);

private:
    // Initialize the buffer

    void Init();

    // Clean the buffer

    void Clean();

protected:
    // Generated message map functions

    //{{AFX_MSG(CCanvas)

    afx_msg UINT OnNcHitTest(CPoint point);
    afx_msg void OnPaint();
    afx_msg void OnMouseMove(UINT nFlags, CPoint point);
    afx_msg BOOL OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message);
    afx_msg void OnTimer(UINT nIDEvent);
    afx_msg BOOL OnEraseBkgnd(CDC* pDC);
    //}}AFX_MSG


    DECLARE_MESSAGE_MAP()
};

/////////////////////////////////////////////////////////////////////////////


//{{AFX_INSERT_LOCATION}}


#endif // !defined(AFX_CANVAS_H__9AFA14C2_2DA3_48F1_9CC9_33B220B96494__INCLUDED_)