CChartLegend类用来绘制每一个波形的描述信息，它处于该控件的区域，如下图所示：
CChartLegend类的头文件。
#if !defined(AFX_CHARTLEGEND_H__CD72E5A0_8F52_472A_A611_C588F642080B__INCLUDED_)
#define AFX_CHARTLEGEND_H__CD72E5A0_8F52_472A_A611_C588F642080B__INCLUDED_
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "ChartObject.h"
#include "ChartCtrl.h"
#include "ChartString.h"
class CChartSerie;
class CChartLegend : public CChartObject
{
friend CChartCtrl;
public:
void SetFont(int iPointSize, const TChartString& strFaceName);
CChartLegend(CChartCtrl* pParent);
virtual ~CChartLegend();
enum DockSide
{
dsDockRight,
dsDockLeft,
dsDockTop,
dsDockBottom
};
void DockLegend(DockSide dsSide);
void UndockLegend(int iLeftPos, int iTopPos);
void SetTransparent(bool bTransparent);
void SetHorizontalMode(bool bHorizontal);
private:
void Draw(CDC* pDC);
void ClipArea(CRect& rcControl, CDC* pDC);
void UpdatePosition(CDC* pDC, const CRect& rcControl);
TChartString m_strFontName;
int m_iFontSize;
bool m_bDocked; // true if the legend is docked
DockSide m_DockSide;
// If the legend is not docked:
int m_iLeftPos;
int m_iTopPos;
bool m_bIsTransparent;
bool m_bIsHorizontal;
CSize m_BitmapSize;
};
#endif // !defined(AFX_CHARTLEGEND_H__CD72E5A0_8F52_472A_A611_C588F642080B__INCLUDED_)
CChartLegend类的源文件。
#include "stdafx.h"
#include "ChartLegend.h"
#include "ChartSerie.h"
#include "ChartCtrl.h"
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CChartLegend::CChartLegend(CChartCtrl* pParent):CChartObject(pParent)
{
m_ObjectColor = RGB(,,);
m_iFontSize = ;
m_strFontName = _T("Times New Roman");
m_bIsVisible = false;
m_bDocked = true;
m_DockSide = dsDockRight;
m_iLeftPos = m_iTopPos = ;
m_bIsTransparent = false;
m_bIsHorizontal = false;
m_bShadow = true;
m_iShadowDepth = ;
m_BitmapSize.cx = ;
m_BitmapSize.cy = ;
}
CChartLegend::~CChartLegend()
{
}
void CChartLegend::SetFont(int iPointSize, const TChartString& strFaceName)
{
m_iFontSize = iPointSize;
m_strFontName = strFaceName;
m_pParent->RefreshCtrl();
}
void CChartLegend::SetTransparent(bool bTransparent)
{
m_bIsTransparent = bTransparent;
m_pParent->RefreshCtrl();
}
void CChartLegend::SetHorizontalMode(bool bHorizontal)
{
m_bIsHorizontal = bHorizontal;
m_pParent->RefreshCtrl();
}
void CChartLegend::DockLegend(DockSide dsSide)
{
m_bDocked = true;
m_DockSide = dsSide;
m_pParent->RefreshCtrl();
}
void CChartLegend::UndockLegend(int iLeftPos, int iTopPos)
{
m_bDocked = false;
m_iLeftPos = iLeftPos;
m_iTopPos = iTopPos;
m_pParent->RefreshCtrl();
}
void CChartLegend::ClipArea(CRect& rcControl, CDC* pDC)
{
UpdatePosition(pDC,rcControl);
if (m_ObjectRect.IsRectEmpty())
return;
if (m_bDocked)
{
switch (m_DockSide)
{
case dsDockRight:
rcControl.right = m_ObjectRect.left + ;
break;
case dsDockLeft:
rcControl.left = m_ObjectRect.right - ;
break;
case dsDockTop:
rcControl.top = m_ObjectRect.bottom + ;
break;
case dsDockBottom:
rcControl.bottom = m_ObjectRect.top - ;
break;
}
}
}
void CChartLegend::UpdatePosition(CDC* pDC, const CRect& rcControl)
{
CRect NewPosition;
NewPosition.SetRectEmpty();
if (!m_bIsVisible)
{
SetRect(NewPosition);
return;
}
CFont* pOldFont;
CFont NewFont;
NewFont.CreatePointFont(m_iFontSize,m_strFontName.c_str(),pDC);
pOldFont = pDC->SelectObject(&NewFont);
int Height = ;
int Width = ;
int MaxText = ;
CSize TextSize;
size_t SeriesCount = m_pParent->GetSeriesCount();
int Drawn = ;
for (size_t i=;i<SeriesCount;i++)
{
CChartSerie* pSerie = m_pParent->GetSerie(i);
if ( (pSerie->GetName() == _T("")) || !pSerie->IsVisible() )
continue;
Drawn++;
TextSize = pDC->GetTextExtent(pSerie->GetName().c_str());
if (!m_bIsHorizontal)
{
if (TextSize.cy>m_BitmapSize.cy)
Height += TextSize.cy + ;
else
Height += m_BitmapSize.cy + ;
if (TextSize.cx > MaxText)
MaxText = TextSize.cx;
}
else
{
Width += TextSize.cx + + m_BitmapSize.cx + ;
if (TextSize.cy > MaxText)
MaxText = TextSize.cy;
}
}
pDC->SelectObject(pOldFont);
DeleteObject(NewFont);
if (!Drawn)
{
SetRect(NewPosition);
return;
}
if (!m_bIsHorizontal)
{
Width += MaxText + m_BitmapSize.cx + ;
Height += + - ; // Top and bottom margins. -2 because space counted once too much
}
else
{
Width += + - ;
Height = + max(m_BitmapSize.cy,MaxText) + ;
} if (!m_bDocked)
{
NewPosition.top = m_iTopPos;
NewPosition.left = m_iLeftPos;
NewPosition.bottom = m_iTopPos + Height + ;
NewPosition.right = m_iLeftPos + Width;
}
else
{
switch (m_DockSide)
{
case dsDockRight:
NewPosition.top = ((rcControl.bottom-rcControl.top)/) - ((Height + )/);
NewPosition.left = rcControl.right - (Width + );
NewPosition.bottom = NewPosition.top + Height;
NewPosition.right = NewPosition.left + Width;
break;
case dsDockLeft:
NewPosition.top = ((rcControl.bottom-rcControl.top)/) - ((Height + )/);
NewPosition.left = rcControl.left + ;
NewPosition.bottom = NewPosition.top + Height;
NewPosition.right = NewPosition.left + Width;
break;
case dsDockTop:
NewPosition.top = rcControl.top + ; //((rcControl.bottom-rcControl.top)/2) - ((Height + 2)/2);
NewPosition.left = ((rcControl.right-rcControl.left)/) - (Width/); // rcControl.left + 3;
NewPosition.bottom = NewPosition.top + Height;
NewPosition.right = NewPosition.left + Width;
break;
case dsDockBottom:
NewPosition.top = rcControl.bottom - (Height + ); //((rcControl.bottom-rcControl.top)/2) - ((Height + 2)/2);
NewPosition.left = ((rcControl.right-rcControl.left)/) - (Width/); // rcControl.left + 3;
NewPosition.bottom = NewPosition.top + Height;
NewPosition.right = NewPosition.left + Width;
break;
}
}
SetRect(NewPosition);
}
void CChartLegend::Draw(CDC *pDC)
{
if (!pDC->GetSafeHdc())
return;
if (!m_bIsVisible)
return;
if (m_ObjectRect.IsRectEmpty())
return;
CPen SolidPen(PS_SOLID,,RGB(,,));
CPen* pOldPen;
CFont* pOldFont;
CFont NewFont;
NewFont.CreatePointFont(m_iFontSize,m_strFontName.c_str(),pDC);
// Draw the shadow
if (m_bShadow)
{
CRect ShadowRect = m_ObjectRect;
ShadowRect.OffsetRect(m_iShadowDepth,m_iShadowDepth);
CBrush BrushShadow;
BrushShadow.CreateSolidBrush(m_ShadowColor) ;
pDC->FillRect(ShadowRect,&BrushShadow);
}
if (!m_bIsTransparent)
{
//Fill back color
CBrush BrushBack;
BrushBack.CreateSolidBrush(m_ObjectColor) ;
pDC->FillRect(m_ObjectRect,&BrushBack);
}
pOldFont = pDC->SelectObject(&NewFont);
pOldPen = pDC->SelectObject(&SolidPen);
//Draw rectangle:
pDC->MoveTo(m_ObjectRect.left,m_ObjectRect.top);
pDC->LineTo(m_ObjectRect.right,m_ObjectRect.top);
pDC->LineTo(m_ObjectRect.right,m_ObjectRect.bottom);
pDC->LineTo(m_ObjectRect.left,m_ObjectRect.bottom);
pDC->LineTo(m_ObjectRect.left,m_ObjectRect.top);
int iPrevMode = pDC->SetBkMode(TRANSPARENT);
CRect rectBitmap(m_ObjectRect.left+,m_ObjectRect.top+,
m_ObjectRect.left++m_BitmapSize.cx,
m_ObjectRect.top++m_BitmapSize.cy);
int SeriesCount = m_pParent->GetSeriesCount();
for (int i=;i<SeriesCount;i++)
{
CChartSerie* pSerie = m_pParent->GetSerie(i);
if ( (pSerie->GetName() == _T("")) || !pSerie->IsVisible() )
continue;
int MaxHeight = ;
CSize TextSize = pDC->GetTextExtent(pSerie->GetName().c_str());
if (TextSize.cy > m_BitmapSize.cy)
{
pDC->ExtTextOut(rectBitmap.right+,rectBitmap.top,ETO_CLIPPED,NULL,pSerie->GetName().c_str(),NULL);
CRect rectTemp(rectBitmap);
int YOffset = TextSize.cy/ - rectBitmap.Height()/;
rectTemp.OffsetRect(,YOffset);
pSerie->DrawLegend(pDC,rectTemp);
MaxHeight = TextSize.cy;
}
else
{
int YOffset = rectBitmap.CenterPoint().y - TextSize.cy/;
pDC->ExtTextOut(rectBitmap.right+,YOffset,ETO_CLIPPED,NULL,pSerie->GetName().c_str(),NULL);
MaxHeight = m_BitmapSize.cy;
pSerie->DrawLegend(pDC,rectBitmap);
} if (!m_bIsHorizontal)
rectBitmap.OffsetRect(,MaxHeight+);
else
rectBitmap.OffsetRect(m_BitmapSize.cx++TextSize.cx+,);
}
pDC->SetBkMode(iPrevMode);
pDC->SelectObject(pOldFont);
DeleteObject(NewFont);
pDC->SelectObject(pOldPen);
DeleteObject(SolidPen);
}
ClipArea函数的作用是将ChartLegend与波形绘制区域分离开，其中rcControl表示的是绘制波形的区域，m_ObjectRect表示的是绘制ChartLegend的区域。UpdatePosition函数用来在当前绘制区域里面计算ChartLegend所处的位置并记录下该位置。Draw函数用来绘制ChartLegend控件，调用CChartSeries类的DrawLegend用来绘制ChartLegend里面的波形图像信息。