newshape.cpp

C++Builder程序员编程手记《配书光盘》

//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop

#include "NewShape.h"
#pragma package(smart_init)
//---------------------------------------------------------------------------
// ValidCtrCheck is used to assure that the components created do not have
// any pure virtual functions.
//

static inline void ValidCtrCheck(TNewShape *)
{
    new TNewShape(NULL);
}
//---------------------------------------------------------------------------
__fastcall TNewShape::TNewShape(TComponent* Owner)
    : TGraphicControl(Owner)
{
  Width = 65;
  Height = 65;
  FBrush = new TBrush();
  FBrush->OnChange = StyleChanged;		//修改刷子的OnChange事件              //增加的代码，构造刷子
  FPen = new TPen();
  FPen->OnChange = StyleChanged;
}
//---------------------------------------------------------------------------
namespace Newshape
{
    void __fastcall PACKAGE Register()
    {
         TComponentClass classes[1] = {__classid(TNewShape)};
         RegisterComponents("Samples", classes, 0);
    }
}
//---------------------------------------------------------------------------
void __fastcall TNewShape::SetShape(TNewShapeType Value)
{
  if (FShape != Value)               // 属性值如果被修改
  {
     FShape = Value;               // 保存新的值
     Invalidate();                 // 强制重新画一个新的图形
  }
}
//------------------------------------------------------------------------------------------
void __fastcall TNewShape::SetBrush( TBrush* Value)
{
  FBrush->Assign(Value); //用参数值代替已有的刷子模式
}
//---------------------------------------------------------------------------
void __fastcall TNewShape::SetPen( TPen* Value)

{
  FPen->Assign(Value);	 //用参数值代替已有的画笔模式
}
//---------------------------------------------------------------------------
__fastcall TNewShape::~TNewShape()
{
  delete FPen;              // 删除画笔对象
  delete FBrush;            // 删除刷子对象
}
//---------------------------------------------------------------------------
void __fastcall TNewShape::StyleChanged( TObject* Sender)

{
  Invalidate();         // 控件的重画
}
//------------------------------------------------------------------------------------------
void __fastcall TNewShape::Paint()
{
  int X,Y,W,H,S;
  Canvas->Pen = FPen;              // 将画布的画笔指定为控件的画笔
  Canvas->Brush = FBrush;          // 将画布的刷子指定为控件的刷子
  W=Width;                      // 调用控件的宽度属性值
  H=Height;                      // 调用控件的高度属性值
  X=Y=0;                       //  圆和正方形左上角坐标
  if( W<H ) S=W;			   //如果宽度小于高度，那么圆角半径变量等于宽度
  else
  S=H;						//否则圆角半径变量等于高度
    switch(FShape)                         // 调整高度、宽度和坐标值
  {
    case sstRectangle:						//如果画矩形、圆角矩形和椭圆
    case sstRoundRect:
    case sstEllipse:
      Y=X=0;                           // 坐标原点为图形的左上角
      break;
    case sstSquare:							//如果画正方形、圆角正方形和圆
    case sstRoundSquare:
    case sstCircle:
      X= (W-S)/2;                        // 坐标原点在图形的中心
      Y= (H-S)/2;                            
      break;
    default:
    break;
  }
  switch(FShape)				//检查要画的图形
  {
    case sstSquare:
    case sstRoundSquare:
      W=H=S;                 //使用宽度和高度中的最小值
    case sstRectangle:         // 如果是画矩形或正方形
      Canvas->Rectangle(X,Y,X+W,Y+H);		//画矩形
      break;
    case sstRoundRect:                     // 如果是画圆角矩形或圆角正方形
//画圆角矩形
      Canvas->RoundRect(X,Y,X+W,Y+H,S/4,S/4);
      break;
    case sstCircle:
      W=H=S;                      // 如果是画圆或椭圆
    case sstEllipse:
      Canvas->Ellipse(X,Y,X+W,Y+H);	//椭圆包含和前面所画的矩形一样的范围内
      break;
    default:
      break;
  }
}
//------------------------------------------------------------------------------------------