ch23.htm

好书《C++ Builder高级编程技术》

{

  Close();

}



void __fastcall 
TForm1::DataPallet10MouseDown(TObject *Sender,

  TMouseButton Button, TShiftState Shift, int X, int Y)

{

  if (Shift.Contains(ssLeft))

  {

    if (dynamic_cast<TDataPallet *>(Sender))

    {

      TDataPallet *D = (TDataPallet *)(Sender);

      
D->QueryPallet(DMod->WidgetsQuery);

      QueryForm->Panel1->Caption =

        "List of Items on Pallet: " + AnsiString(D->PalletNumber);

      QueryForm->ShowModal();

    }

  }

}



void __fastcall 
TForm1::ItemsOnPallet1Click(TObject *Sender)

{

  TDataPallet *D = (TDataPallet *)PopupMenu1->PopupComponent;

  DataPallet10MouseDown(D, TMouseButton(), TShiftState() << ssLeft, 0, 0);

}



void __fastcall 
TForm1::ValueofItems1Click(TObject *Sender)

{

  TDataPallet *D = (TDataPallet *)PopupMenu1->PopupComponent;

  D->QueryPalletSum(DMod->WidgetsQuery);

  QueryForm->Panel1->Caption =

    "Value of Items on Pallet: " + 
AnsiString(D->PalletNumber);

  QueryForm->ShowModal();

}



void __fastcall TForm1::GetHierarchy1Click(TObject *Sender)

{

  TDataPallet *D = (TDataPallet *)PopupMenu1->PopupComponent;

  HierarchyDlg->ListBox1->Items = 
D->GetHierarchy();

  HierarchyDlg->ShowModal();

}



void __fastcall TForm1::ListClick(TObject *Sender)

{

  DMod->SumByProduct();

  QueryForm->Panel1->Caption = "Sum By Product of Entire Warehouse";

  
QueryForm->ShowModal();

}



void __fastcall TForm1::ListbyPallet1Click(TObject *Sender)

{

  DMod->ReportByPallet();

  QueryForm->Panel1->Caption = "Report By Pallet";

  QueryForm->ShowModal();

}



</FONT></PRE>
<P><A 
NAME="Heading16"></A><FONT COLOR="#000077"><B>Listing 23.4. The header file
for the Widgets unit.</B></FONT></P>
<PRE><FONT COLOR="#0066FF">///////////////////////////////////////

// Widgets.h

// Learning how to use objects

// Copyright (c) 1997 by 
Charlie Calvert

//



#ifndef WidgetsH

#define WidgetsH

#include &lt;vcl\dbtables.hpp&gt;

#include &quot;myobject.h&quot;





TCustomControl *ReadWidgetFromStream(AnsiString StreamName);

void WriteWidgetToStream(AnsiString StreamName, 
TCustomControl *Widget);



class __declspec(delphiclass) TWidget;



namespace Widgets

{

  void __fastcall RegisterShort();

  void __fastcall Register();

}



class TWidget: public TCustomControl

{

private:

  TListHierarchy *Hierarchy;

  
Currency FCost;

  TDateTime FTimeCreated;

  AnsiString FDescription;

  void __fastcall SetTimeCreated(AnsiString S);

  AnsiString __fastcall GetTimeCreated();

protected:

  virtual void __fastcall Paint(void);

public:

  __fastcall virtual 
TWidget(TComponent *AOwner): TCustomControl(AOwner)

    { Hierarchy = new TListHierarchy(); Width = 25; Height = 25; }

  __fastcall virtual TWidget(TComponent *AOwner, int ACol, int ARow);

  __fastcall virtual ~TWidget() { delete Hierarchy; }

  
TStringList *GetHierarchy() { return Hierarchy-&gt;GetHierarchy(this); }

  void __fastcall WidgetMouseDown(TObject *Sender, TMouseButton Button,

                                 TShiftState Shift, int X, int Y);

__published:

  __property Currency 
Cost={read=FCost, write=FCost};

  __property AnsiString TimeCreated={read=GetTimeCreated, write=SetTimeCreated};

  __property AnsiString Description={read=FDescription, write=FDescription};

  __property OnDragDrop;

  __property OnMouseDown;

};




class TChip: public TWidget

{

public:

  virtual __fastcall TChip(TComponent *AOwner): TWidget(AOwner) {}

  virtual __fastcall TChip(TComponent *AOwner, int ACol, int ARow)

    : TWidget(AOwner, ACol, ARow) {}

};



class TPentium: public TChip


{

protected:

  virtual void __fastcall Paint(void);

public:

  virtual __fastcall TPentium(TComponent *AOwner): TChip(AOwner) {}

  virtual __fastcall TPentium(TComponent *AOwner, int ACol, int ARow)

    : TChip(AOwner, ACol, ARow) {}

};



class 
TPentiumPro: public TChip

{

protected:

  virtual void __fastcall Paint(void);

public:

  virtual __fastcall TPentiumPro(TComponent *AOwner): TChip(AOwner) {}

  virtual __fastcall TPentiumPro(TComponent *AOwner, int ACol, int ARow)

    : 
TChip(AOwner, ACol, ARow) {}

};



class TCustomPallet: public TCustomControl

{

private:

  int FPalletNumber;

  TListHierarchy *FHierarchy;

protected:

  virtual void __fastcall Paint(void);

public:

  virtual __fastcall 
TCustomPallet(TComponent *AOwner);

  virtual __fastcall ~TCustomPallet(void)

    { delete FHierarchy; }

  TStringList *GetHierarchy() { return FHierarchy-&gt;GetHierarchy(this); }

  __property int PalletNumber={read=FPalletNumber, 
write=FPalletNumber};

};



class TPallet: public TCustomPallet

{

public:

  virtual __fastcall TPallet(TComponent *AOwner): TCustomPallet(AOwner)

    { Width = 25; Height = 25; }

__published:

  __property PalletNumber;

  __property OnDragDrop;

  
__property OnDragOver;

  __property Color;

};



class TDataPallet: public TCustomPallet

{

private:

  TTable *FWidgetsTable;

  TQuery *FWidgetsQuery;

protected:

  void __fastcall PalletDragDrop(TObject *Sender,

    TObject *Source, int X, int 
Y);

  void __fastcall PalletDragOver(TObject *Sender, TObject *Source,

    int X, int Y, TDragState State, bool &amp;Accept);

  void virtual EnterWidgets(int Total, TWidget *W);

public:

  virtual __fastcall TDataPallet(TComponent *AOwner);

  
void __fastcall QueryPallet(TQuery *Query);

  float __fastcall QueryPalletSum(TQuery *Query);

__published:

  __property TTable *WidgetsTable={read=FWidgetsTable, write=FWidgetsTable};

  __property TQuery *WidgetsQuery={read=FWidgetsQuery, 
write=FWidgetsQuery};

  __property PalletNumber;

  __property Hint;

  __property Color;

  __property TabOrder;

  __property OnMouseDown;

  __property PopupMenu;

};



#endif



</FONT></PRE>
<P><A NAME="Heading17"></A><FONT 
COLOR="#000077"><B>Listing 23.5. The main source
file for the Widgets unit.</B></FONT></P>
<PRE><FONT COLOR="#0066FF">///////////////////////////////////////

// Widgets.cpp

// Learning how to use objects

// Copyright (c) 1997 by Charlie Calvert

//


#include &lt;vcl\vcl.h&gt;

#include &lt;conio.h&gt;

#pragma hdrstop

#include &quot;widgets.h&quot;



#pragma link &quot;MyObject.obj&quot;



void WriteWidgetToStream(AnsiString StreamName, TCustomControl *Widget)

{

  TFileStream *Stream = new 
TFileStream(StreamName, fmCreate | fmOpenWrite);

  Stream-&gt;WriteComponent(Widget);

  delete Stream;

}



TCustomControl *ReadWidgetFromStream(AnsiString StreamName)

{

  Widgets::RegisterShort();

  TFileStream *Stream = new 
TFileStream(StreamName, fmOpenRead);

  TWidget *Widget = (TWidget *)Stream-&gt;ReadComponent(NULL);

  delete Stream;

  return Widget;

}



__fastcall TWidget::TWidget(TComponent *AOwner, int ACol, int ARow)

  : TCustomControl(AOwner)

{

  
Hierarchy = new TListHierarchy();

  Left = ACol;

  Top = ARow;

  Width = 25;

  Height = 25;

  OnMouseDown = WidgetMouseDown;

}



AnsiString __fastcall TWidget::GetTimeCreated()

{

  return FTimeCreated.DateTimeString();

}



void __fastcall 
TWidget::SetTimeCreated(AnsiString S)

{

  FTimeCreated = TDateTime(S);

}



void __fastcall TWidget::Paint()

{                     

  Canvas-&gt;Brush-&gt;Color = clBlue;

  Canvas-&gt;Rectangle(0, 0, ClientWidth, ClientHeight);

  
Canvas-&gt;Brush-&gt;Color = clYellow;

  Canvas-&gt;Ellipse(0, 0, ClientWidth, ClientHeight);

}



void __fastcall TWidget::WidgetMouseDown(TObject *Sender, TMouseButton Button,

                                        TShiftState Shift, int X, int 
Y)

{

  ShowMessage(Format(&quot;%m&quot;, OPENARRAY(TVarRec, (FCost))));

}



void __fastcall TPentium::Paint()

{

  Canvas-&gt;Brush-&gt;Color = clPurple;

  Canvas-&gt;Rectangle(0, 0, ClientWidth, ClientHeight);

  Canvas-&gt;Brush-&gt;Color = 
clRed;

  Canvas-&gt;Ellipse(0, 0, ClientWidth, ClientHeight);

}



void __fastcall TPentiumPro::Paint()

{                     

  Canvas-&gt;Brush-&gt;Color = clGreen;

  Canvas-&gt;Rectangle(0, 0, ClientWidth, ClientHeight);

  
Canvas-&gt;Brush-&gt;Color = clBlue;

  Canvas-&gt;Ellipse(0, 0, ClientWidth, ClientHeight);

}





__fastcall TCustomPallet::TCustomPallet(TComponent *AOwner)

  : TCustomControl(AOwner)