Delphi design mode: "Headfirst design mode" DELPHI7 Code---Command mode simpleremotecontroltest [GO]

The recipient of the order

Unit ureceiveobject;

Interface

Type
Tlight = Class (TObject)
Public
Procedure Open;
Procedure Off;
End

Tgaragedoor = Class (TObject)
Public
Procedure up;
Procedure down;
Procedure Stop;
Procedure Lighton;
Procedure Lightoff;
End

Implementation

{Tlight}

Procedure Tlight.off;
Begin
Writeln (");
End

Procedure Tlight.open;
Begin
Writeln (' light was on. ');
End

{Tgaragedoor}

Procedure Tgaragedoor.down;
Begin
Writeln (");
End

Procedure Tgaragedoor.lightoff;
Begin
Writeln (");
End

Procedure Tgaragedoor.lighton;
Begin
Writeln (");
End

Procedure Tgaragedoor.stop;
Begin
Writeln (");
End

Procedure Tgaragedoor.up;
Begin
Writeln (' Garagedoor is Open. ');
End

End.

Command object

Unit ucommandobject;

Interface

Uses
Ureceiveobject;

Type
TCommand = Class (TObject)
Public
Procedure Execute; Virtual Abstract
End

Tlightoncommand = Class (TCommand)
Private
Flight:tlight;
Public
Constructor Create (alight:tlight);
Procedure Execute; Override
End

Tgaragedooropencommand = Class (TCommand)
Private
Fgaragedoor:tgaragedoor;
Public
Constructor Create (Agaragedoor:tgaragedoor);
Procedure Execute; Override
End

Implementation

{Tlightoncommand}

Constructor Tlightoncommand.create (alight:tlight);
Begin
FLight: = alight;
End

Procedure Tlightoncommand.execute;
Begin
Flight.open;
End

{Tgaragedooropencommand}

Constructor Tgaragedooropencommand.create (Agaragedoor:tgaragedoor);
Begin
Fgaragedoor: = Agaragedoor;
End

Procedure Tgaragedooropencommand.execute;
Begin
Fgaragedoor.up;
End

End.

The requestor of the command is the issuer

Unit Usimpleremotecontrol;

Interface

Uses
Ucommandobject;

Type
Tsimpleremotecontrol = Class (TObject)
Private
Fslot:tcommand;
Public
Procedure SetCommand (Acommand:tcommand);
Procedure buttonwaspressed;
End

Implementation

{Tsimpleremotecontrol}

Procedure tsimpleremotecontrol.buttonwaspressed;
Begin
Fslot.execute;
End

Procedure Tsimpleremotecontrol.setcommand (Acommand:tcommand);
Begin
Fslot: = Acommand;
End

End.

Client code

Program Psimpleremotecontroltest;

{$APPTYPE CONSOLE}

Uses
Usimpleremotecontrol in ' Usimpleremotecontrol.pas ',
Ucommandobject in ' Ucommandobject.pas ',
Ureceiveobject in ' Ureceiveobject.pas ';

Var
Remote:tsimpleremotecontrol;
Light:tlight;
Garagedoor:tgaragedoor;
Lightoncommand:tcommand;
Garagedooropencommand:tcommand;

Begin
{Create the issuer of the command}
Remote: = tsimpleremotecontrol.create;

{The recipient of the Create command}
Light: = Tlight.create;
Garagedoor: = tgaragedoor.create;

{Create a specific command object}
Lightoncommand: = Tlightoncommand.create (light);
Garagedooropencommand: = Tgaragedooropencommand.create (Garagedoor);

{Load command and execute}
Remote.setcommand (Lightoncommand);
remote.buttonwaspressed;
Remote.setcommand (Garagedooropencommand);
remote.buttonwaspressed;

Remote.free;
Light.free;
Garagedoor.free;
Lightoncommand.free;
Garagedooropencommand.free;

READLN;
End.

Run results

Delphi design mode: "Headfirst design mode" DELPHI7 Code---Command mode simpleremotecontroltest [GO]