ChartCtrl源码剖析之——CChartAxisLabel类

CChartAxisLabel类用来绘制轴标签，上、下、左、右都可以根据实际需要设置对应的轴标签。它处于该控件的区域，如下图所示：

CChartAxisLabel类的头文件。

#if !defined(AFX_CHARTAXISLABEL_H__0E5519C8_A2F4_4CED_9681_32A56B25D0C5__INCLUDED_)

#define AFX_CHARTAXISLABEL_H__0E5519C8_A2F4_4CED_9681_32A56B25D0C5__INCLUDED_

#if _MSC_VER > 1000

#pragma once

#endif // _MSC_VER > 1000

#include "ChartObject.h"

#include "ChartString.h"

class CChartAxis;

class CChartAxisLabel : public CChartObject

{

    friend CChartAxis;

public:

    void SetText(const TChartString& NewText);

    TChartString GetText() const        { return m_strLabelText;    }

    void SetFont(int nPointSize, const TChartString& strFaceName);

    CChartAxisLabel(CChartCtrl* pParent, bool bHorizontal);

    virtual ~CChartAxisLabel();

private:

    void SetPosition(int LeftBorder, int TopBorder, CDC *pDC);

    void Draw(CDC* pDC);

    CSize GetSize(CDC* pDC) const;

    bool m_bIsHorizontal;      // Specifies if the axis is horizontal or not

    int  m_iFontSize;

    TChartString m_strFontName;

    TChartString m_strLabelText;

};

#endif // !defined(AFX_CHARTAXISLABEL_H__0E5519C8_A2F4_4CED_9681_32A56B25D0C5__INCLUDED_)

CChartAxisLabel类的源文件。

#include "stdafx.h"

#include "ChartAxisLabel.h"

#include "ChartCtrl.h"

#ifdef _DEBUG

#undef THIS_FILE

static char THIS_FILE[]=__FILE__;

#define new DEBUG_NEW

#endif

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

// Construction/Destruction

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

CChartAxisLabel::CChartAxisLabel(CChartCtrl* pParent, bool bHorizontal):CChartObject(pParent)

{

    m_bIsHorizontal = bHorizontal;

    m_iFontSize = ;

    m_strFontName = _T("Microsoft Sans Serif");

    m_strLabelText = _T("");

}

CChartAxisLabel::~CChartAxisLabel()

{

}

void CChartAxisLabel::SetText(const TChartString& NewText)

{

    m_strLabelText = NewText;

    m_pParent->RefreshCtrl();

}

void CChartAxisLabel::SetFont(int nPointSize, const TChartString& strFaceName)

{

    m_iFontSize = nPointSize;

    m_strFontName = strFaceName;

    m_pParent->RefreshCtrl();

}

CSize CChartAxisLabel::GetSize(CDC *pDC) const

{

    CSize LabelSize;

    LabelSize.cx = ;

    LabelSize.cy = ;

    if (!m_bIsVisible)

        return LabelSize;

    if (!pDC->GetSafeHdc())

        return LabelSize;

    if (m_strLabelText == _T(""))

        return LabelSize;

    CFont NewFont;

    CFont* pOldFont;

    NewFont.CreatePointFont(m_iFontSize,m_strFontName.c_str(),pDC);

    pOldFont = pDC->SelectObject(&NewFont);

    LabelSize = pDC->GetTextExtent(m_strLabelText.c_str());

    LabelSize.cx += ;

    LabelSize.cy += ;

    if (!m_bIsHorizontal)

    {

        int Width = LabelSize.cy;

        int Height = LabelSize.cx;

        LabelSize.cx = Width;

        LabelSize.cy = Height;

    }

    pDC->SelectObject(pOldFont);

    DeleteObject(NewFont);

    return LabelSize;

}

void CChartAxisLabel::Draw(CDC *pDC)

{

    if (!m_bIsVisible)

        return;

    if (!pDC->GetSafeHdc())

        return;

    if (m_strLabelText == _T(""))

        return;

    int iPrevMode = pDC->SetBkMode(TRANSPARENT);

    COLORREF OldColor = pDC->SetTextColor(m_ObjectColor);

    CFont NewFont;

    NewFont.CreatePointFont(m_iFontSize,m_strFontName.c_str(),pDC);

    CFont* pOldFont;

    if (!m_bIsHorizontal)

    {

        LOGFONT LogFont;

        NewFont.GetLogFont(&LogFont);

        LogFont.lfOrientation = ;

        LogFont.lfEscapement = ;

        CFont VertFont;

        VertFont.CreateFontIndirect(&LogFont);

        pOldFont = pDC->SelectObject(&VertFont);

        pDC->ExtTextOut(m_ObjectRect.left + ,m_ObjectRect.top,

                    ETO_CLIPPED,NULL,m_strLabelText.c_str(),NULL);

        pDC->SelectObject(pOldFont);

        DeleteObject(VertFont);

        DeleteObject(NewFont);

    }

    else

    {

        pOldFont = pDC->SelectObject(&NewFont);

        pDC->ExtTextOut(m_ObjectRect.left,m_ObjectRect.top + ,

                    ETO_CLIPPED,NULL,m_strLabelText.c_str(),NULL);

        pDC->SelectObject(pOldFont);

        DeleteObject(NewFont);

    }

    pDC->SetBkMode(iPrevMode);

    pDC->SetTextColor(OldColor);

}

void CChartAxisLabel::SetPosition(int LeftBorder, int TopBorder, CDC *pDC)

{

    CSize NewSize = GetSize(pDC);

    CRect NewRect;

    NewRect.top = TopBorder;

    NewRect.bottom = TopBorder + NewSize.cy;

    NewRect.left = LeftBorder;

    NewRect.right = LeftBorder + NewSize.cx;

    CChartObject::SetRect(NewRect);

}

CChartAxisLabel类在CChartAxis类中设定最终绘制的位置。