Pascal Super Library/Pascal Super Library (CW International)(1997).bin/BORL_TIP/TI100/TI675.ASC

Text File | 1992-09-03 | 6KB | 331 lines

  PRODUCT  :  Turbo Pascal                           NUMBER  :  675
  VERSION  :  6.0
       OS  :  MS/PC DOS
     DATE  :  September 3, 1992                        PAGE  :  1/5

    TITLE  :  Simple Pick List Example




  {

  The following example is to demonstrate the use of a Pick List.
  This Pick List will read a line of data and validate the field
  as well as keep a history of valid commands.

  }
  {$X+}
  Program PickListExample;

  uses Objects, App, Menus, Drivers, Views, Dialogs, MsgBox;

  type
    YourKeySet = set of char;

  const
     cmMakeDialog = 101;
     ValidSet  : YourKeySet = [#0..#31,'0'..'9'];

  type

    PFInputLine = ^TFInputLine;
    TFInputLine = object(TInputLine)
      ValidKeys : YourKeySet;
      constructor Init(var Bounds: TRect; AMaxLen: integer;
                       ChrSet: YourKeySet);
      procedure HandleEvent(var Event: TEvent); virtual;
      procedure GetData(var Rec); virtual;
      procedure SetData(var Rec); virtual;
      function DataSize: word; virtual;
    end;

  PMyApp = ^TMyApp;
  TMyApp = object(TApplication)
    procedure InitMenuBar;virtual;
    procedure InitStatusLine;virtual;
    procedure MakeDialog;
    procedure HandleEvent(var Event: TEvent);virtual;
   end;

  constructor TFInputLine.Init(var Bounds: TRect; AMaxLen: integer;
                               ChrSet: YourKeySet);
  begin













  PRODUCT  :  Turbo Pascal                           NUMBER  :  675
  VERSION  :  6.0
       OS  :  MS/PC DOS
     DATE  :  September 3, 1992                        PAGE  :  2/5

    TITLE  :  Simple Pick List Example




    TInputLine.Init(Bounds,AMaxLen);
    ValidKeys:= ChrSet;
  end;

  procedure TFInputLine.HandleEvent(var Event: TEvent);
  {
    Data validation handle event:
    Please note that validation happens BEFORE the parent
    is called. This ensures that the key is not trapped by
    the parent method.
  }

  var
    Number : longint;
    Code : integer;
  begin
    case Event.What of
      evKeyDown :
        begin
          if not(Event.CharCode in ValidKeys) then
            ClearEvent(Event)
           else
             if Data^ <> '' then
               begin
                 val(Data^, Number, Code);
                 if (Code <> 0) or (Number < 0) or (Number > 65535)
  then
                   begin
                     Data^ := '';
                     MessageBox('Valid number is 0 to
  65536.',nil,mfOkButton);
                     ClearEvent(Event);
                   end;
               end;
        end;
    end;
    TInputLine.HandleEvent(Event);
  end;

  procedure TFInputLine.GetData(var Rec);
  var
    Code : integer;
  begin













  PRODUCT  :  Turbo Pascal                           NUMBER  :  675
  VERSION  :  6.0
       OS  :  MS/PC DOS
     DATE  :  September 3, 1992                        PAGE  :  3/5

    TITLE  :  Simple Pick List Example




    Val(Data^,word(Rec), Code);
  end;

  procedure TFInputLine.SetData(var Rec);
  begin
    Str(word(Rec),Data^);
  end;

  function TFInputLine.DataSize: word;
  begin
    DataSize := SizeOf(word);
  end;

  procedure TMyApp.InitMenuBar;
    var R: TRect;
  begin
    GetExtent(R);
    R.B.Y := R.A.Y + 1;
    MenuBar := New(PMenuBar, Init(R, NewMenu(
      NewSubMenu('~T~est', hcNoContext, NewMenu(
        NewItem('~D~ialog','F2',kbF2,cmMakeDialog,hcNoContext,
        NewLine(
        NewItem('E~x~it', 'Alt-X', kbAltX, cmQuit, hcNoContext,
        nil)))),nil))));
  end;

  procedure TMyApp.MakeDialog;
  var
   R : TRect;
   Dialog : PDialog;
   InputLine : PInputLine;
   Lable,Hist : PView;
  begin
   GetExtent(R);
   R.Assign(10,5,60,15);
   Dialog := New(PDialog,Init(R,'Demo Dialog'));
   With Dialog^ do
     begin
       R.Assign(5,4,20,5);
       InputLine := New(PFInputLine,Init(R,15,ValidSet));
       Insert(InputLine);
       R.Assign(5,3,20,4);
       Lable := New(PLabel,Init(R,'InputLine',Inputline));













  PRODUCT  :  Turbo Pascal                           NUMBER  :  675
  VERSION  :  6.0
       OS  :  MS/PC DOS
     DATE  :  September 3, 1992                        PAGE  :  4/5

    TITLE  :  Simple Pick List Example




       Insert(Lable);
       R.Assign(21,4,23,5);
       Hist := New(PHistory,Init(R,InputLine,0));
       Insert(Hist);
     end;
   Desktop^.ExecView(Dialog);
   Dispose(Dialog,Done);
  end;

  procedure TMyApp.InitStatusLine;
  var
   R : TRect;
  begin
   GetExtent(R);
   R.A.Y := R.B.Y - 1;
   StatusLine :=  New(PStatusLine,Init(R,
                    NewStatusDef(0,$FFFF,
                      NewStatusKey('~A~lt-X',kbAltX,cmQuit,
                  nil),nil)));
  end;

  procedure TMyApp.HandleEvent(var Event: TEvent);
  begin
    TApplication.HandleEvent(Event);
    if Event.What = evCommand then
    begin
      case Event.Command of
        cmMakeDialog: MakeDialog;
      else
        Exit;
      end;
      ClearEvent(Event);
    end;
  end;

  var
   MyApp: TMyApp;

  begin
   MyApp.Init;
   MyApp.Run;
   MyApp.Done;
  end.













  PRODUCT  :  Turbo Pascal                           NUMBER  :  675
  VERSION  :  6.0
       OS  :  MS/PC DOS
     DATE  :  September 3, 1992                        PAGE  :  5/5

    TITLE  :  Simple Pick List Example




  DISCLAIMER: You have the right to use this technical information
  subject to the terms of the No-Nonsense License Statement that
  you received with the Borland product to which this information
  pertains.