{
    $Id$
    This file is part of the Free Pascal Integrated Development Environment
    Copyright (c) 1998 by Berczi Gabor

    Calculator object for the IDE

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 **********************************************************************}
{$I globdir.inc}
unit FPCalc;

interface

uses
  Drivers,Objects,Commands,Views,Dialogs,App,
  WViews,
  FPViews;

const
      MaxDecimals = 10;
      MaxDigits   = 30;

type

  TCalcState = (csFirst, csValid, csError);

  PCalcButton = ^TCalcButton;
  TCalcButton = object(TButton)
    procedure HandleEvent(var Event: TEvent); virtual;
  end;

  PCalcDisplay = ^TCalcDisplay;
  TCalcDisplay = object(TView)
    Status: TCalcState;
    Number: string[MaxDigits];
    Sign: Char;
    _Operator: Char;
    Operand: extended;
    Memory: extended;
    DispNumber: extended;
    constructor Init(var Bounds: TRect);
    constructor Load(var S: TStream);
    function  CalcKey(Key: string): boolean;
    procedure Clear;
    procedure Draw; virtual;
    function  GetPalette: PPalette; virtual;
    procedure HandleEvent(var Event: TEvent); virtual;
    procedure Store(var S: TStream);
  private
    procedure GetDisplay(var R: extended);
    procedure SetDisplay(R: extended;ShouldKeepZeroes : boolean);
    procedure Error;
  end;

  PCalculator = ^TCalculator;
  TCalculator = object(TCenterDialog)
    CD : PCalcDisplay;
    constructor Init;
    procedure   HandleEvent(var Event: TEvent); virtual;
    procedure   Show; virtual;
    procedure   Close; virtual;
    constructor Load(var S: TStream);
    procedure   Store(var S: TStream);
  end;

{$ifndef NOOBJREG}
const
  RCalcButton: TStreamRec = (
     ObjType: 10139;
     VmtLink: Ofs(TypeOf(TCalcButton)^);
     Load:    @TCalcButton.Load;
     Store:   @TCalcButton.Store
  );
  RCalcDisplay: TStreamRec = (
     ObjType: 10140;
     VmtLink: Ofs(TypeOf(TCalcDisplay)^);
     Load:    @TCalcDisplay.Load;
     Store:   @TCalcDisplay.Store
  );
  RCalculator: TStreamRec = (
     ObjType: 10141;
     VmtLink: Ofs(TypeOf(TCalculator)^);
     Load:    @TCalculator.Load;
     Store:   @TCalculator.Store
  );
{$endif}

procedure RegisterFPCalc;

implementation

uses FPUtils,FPConst;

const
  cmCalcButton  = 100;
  cmPressButton = 101;

procedure TCalcButton.HandleEvent(var Event: TEvent);
var
  Call : boolean;
  i : Sw_Word;
begin
  Call:=true;
  case Event.What of
    evKeyDown :
     case Event.KeyCode of
       kbEnter   : Call:=false;
     end;
    evBroadcast :
     case Event.Command of
       cmDefault     : Call:=false;
       cmPressButton :
         begin
           if (PString(Event.InfoPtr)^=Title^) or
              ((PString(Event.InfoPtr)^='^') and (Title^='x^y')) then
              begin
                Select;
                DrawState(true);
                i:=GetDosTicks+2;
                repeat
                until GetDosTicks>i;
                DrawState(false);
                ClearEvent(Event);
              end;
         end;
     end;
  end;
  if Call then
  inherited HandleEvent(Event);
end;

constructor TCalcDisplay.Init(var Bounds: TRect);
begin
  inherited Init(Bounds);
  Options := Options or ofSelectable;
  EventMask := evKeyDown + evBroadcast;
  Clear;
  HelpCtx:={hcCalculatorLine}0;
end;

constructor TCalcDisplay.Load(var S: TStream);
begin
  inherited Load(S);
  S.Read(Status, SizeOf(Status) + SizeOf(Number) + SizeOf(Sign) +
    SizeOf(_Operator) + SizeOf(Operand));
end;

procedure TCalcDisplay.GetDisplay(var R: extended);
begin
{  Val(Sign + Number, R, E);}
  R:=DispNumber;
end;

procedure TCalcDisplay.SetDisplay(R: extended;ShouldKeepZeroes : boolean);
var
  S: string[MaxDigits];
  i,KeepZeroes : byte;
begin
  DispNumber:=R;
  KeepZeroes:=0;
  if ShouldKeepZeroes and (pos('.',Number)>0) then
    for i:=length(Number) downto pos('.',Number)+1 do
      if Number[i]='0' then
        inc(KeepZeroes)
      else
        break;

  Str(R: 0: MaxDecimals, S);
  if Pos('.',S)<>0 then
     while (length(S)>1) and (S[length(S)]='0') do Dec(S[0]);
  if KeepZeroes>0 then
    for i:=1 to KeepZeroes do
      S:=S+'0';
  if S[1] <> '-' then Sign := ' ' else
  begin
    Delete(S, 1, 1);
    Sign := '-';
  end;
  if Length(S) > MaxDigits + 1 + MaxDecimals then Error
  else
  begin
    if S[Length(S)] = '.' then Dec(S[0]);
    Number := S;
  end;
end;

procedure TCalcDisplay.Error;
begin
  Status := csError;
  Number := 'Error';
  Sign := ' ';
  DrawView;
end;

function TCalcDisplay.CalcKey(Key: string): boolean;
var
  R,D: extended;
procedure CheckFirst;
begin
  if Status = csFirst then
  begin
    Status := csValid;
    SetDisplay(0,false);
  end;
end;
begin
  CalcKey:=true;
  Key := UpCaseStr(Key);
  if (Status = csError) and (Key <> 'C') then Key := ' ';
  if Key='X^Y' then Key:='^';
  if length(Key)>1 then
     begin
{        if Status = csFirst then}
        begin
{          Status := csValid;}
          GetDisplay(R);
          if Key='1/X' then begin if R=0 then Error else SetDisplay(1/R,false) end else
          if Key='SQR' then begin if R<0 then Error else SetDisplay(sqrt(R),false) end else
          if Key='LOG' then begin if R<=0 then Error else SetDisplay(ln(R),false) end else
          if Key='X^2' then SetDisplay(R*R,false) else
          if Key='M+' then Memory:=Memory+R else
          if Key='M-' then Memory:=Memory-R else
          if Key='M'#26 then SetDisplay(Memory,false) else
          if Key='M'#27 then Memory:=R else
          if Key='M'#29 then begin D:=Memory; Memory:=R; SetDisplay(D,false); end;
        end;
     end
  else
  case Key[1] of
    '0'..'9':
    if Length(Number)<MaxDigits then
      begin
        CheckFirst;
        if Number = '0' then Number := '';
        Number := Number + Key;
        SetDisplay(StrToExtended(Number),true);
      end;
    '.':
      begin
        CheckFirst;
        if Pos('.', Number) = 0 then Number := Number + '.';
      end;
    #8, #27:
      begin
        CheckFirst;
        if Length(Number) = 1 then Number := '0' else Dec(Number[0]);
        SetDisplay(StrToExtended(Number),true); { !!! }
      end;
    '_', #241:
      if Sign = ' ' then Sign := '-' else Sign := ' ';
    '+', '-', '*', '/', '=', '%', #13, '^':
      begin
        if Status = csValid then
        begin
          Status := csFirst;
          GetDisplay(R);
          if Key = '%' then
            case _Operator of
              '+', '-': R := Operand * R / 100;
              '*', '/': R := R / 100;
            end;
          case _Operator of
            '^': SetDisplay(Power(Operand,R),false);
            '+': SetDisplay(Operand + R,false);
            '-': SetDisplay(Operand - R,false);
            '*': SetDisplay(Operand * R,false);
            '/': if R = 0 then Error else SetDisplay(Operand / R,false);
          end;
        end;
        _Operator := Key[1];
        GetDisplay(Operand);
      end;
    'C':
      Clear;
    else CalcKey:=false;
  end;
  DrawView;
end;

procedure TCalcDisplay.Clear;
begin
  Status := csFirst;
  Number := '0';
  Sign := ' ';
  _Operator := '=';
end;

procedure TCalcDisplay.Draw;
var
  Color: Byte;
  I: Integer;
  B: TDrawBuffer;
begin
  Color := GetColor(1);
  I := Size.X - Length(Number) - 2;
  MoveChar(B, ' ', Color, Size.X);
  MoveChar(B[I], Sign, Color, 1);
  MoveStr(B[I + 1], Number, Color);
  WriteBuf(0, 0, Size.X, 1, B);
end;

function TCalcDisplay.GetPalette: PPalette;
const
  P: string[1] = #19;
begin
  GetPalette := @P;
end;

procedure TCalcDisplay.HandleEvent(var Event: TEvent);
var S: string[3];
begin
  inherited HandleEvent(Event);
  case Event.What of
    evKeyDown:
      if Owner<>nil then
      if (Owner^.State and sfSelected)<>0 then
      begin
        S:=Event.CharCode;
        Message(Owner,evBroadcast,cmPressButton,@S);
        if CalcKey(Event.CharCode) then
        ClearEvent(Event);
      end;
    evBroadcast:
      if Event.Command = cmCalcButton then
      begin
        CalcKey(PButton(Event.InfoPtr)^.Title^);
        ClearEvent(Event);
      end;
  end;
end;

procedure TCalcDisplay.Store(var S: TStream);
begin
  TView.Store(S);
  S.Write(Status, SizeOf(Status) + SizeOf(Number) + SizeOf(Sign) +
    SizeOf(_Operator) + SizeOf(Operand));
end;

{ TCalculator }

constructor TCalculator.Init;
const
  Keys: array[0..29] of string[3] =
   ('M+',  'x^y','C'  ,#27  ,'%'  ,#241 ,
    'M-',  'x^2','7'  ,'8'  ,'9'  ,'/'  ,
    'M'#26,'1/x','4'  ,'5'  ,'6'  ,'*'  ,
    'M'#27,'sqr','1'  ,'2'  ,'3'  ,'-'  ,
    'M'#29,'log','0'  ,'.'  ,'='  ,'+'  );
var
  I: Integer;
  P: PView;
  R: TRect;
begin
  R.Assign(5, 3, 43, 18);
  inherited Init(R, 'Calculator');
  Options := Options or ofFirstClick or ofTopSelect;
  HelpCtx:=hcCalcWindow;

  for I := 0 to 29 do
  begin
    R.A.X := (I mod 6) * 5 + 2;
    R.A.Y := (I div 6) * 2 + 4;
    R.B.X := R.A.X + 5;
    R.B.Y := R.A.Y + 2;
    if (I mod 6)=0 then Inc(R.B.X,1) else
    if (I mod 6)=1 then begin R.Move(1,0); Inc(R.B.X,2) end else
    R.Move(3,0);
    P := New(PCalcButton, Init(R, Keys[I], cmCalcButton,
      bfNormal + bfBroadcast+bfGrabFocus));
    P^.Options := P^.Options {and not ofSelectable};
    Insert(P);
  end;
  R.Assign(3, 2, 35, 3);
  New(CD, Init(R));
  CD^.Options:=CD^.Options or ofSelectable;
  Insert(CD);
end;

procedure TCalculator.HandleEvent(var Event: TEvent);
var R: extended;
    Re: real;
begin
  if (State and sfSelected)<>0 then
  case Event.What of
    evCommand :
     case Event.Command of
       cmCalculatorPaste :
         Message(@Self,evKeyDown,kbCtrlEnter,nil);
     end;
    evKeyDown :
     case Event.KeyCode of
       kbEnter :
         begin
           Event.KeyCode:=0;
           Event.CharCode:='=';
         end;
       kbCtrlEnter :
         begin
           ClearEvent(Event);
           CD^.GetDisplay(R); Re:=R;
           Close;
           CalcClipboard:=R;
           Message(Application,evBroadcast,cmCalculatorPaste,nil);
         end;
       kbEsc :
         begin
           CD^.GetDisplay(R);
           if R<>0 then begin
                          CD^.SetDisplay(0,false);
                          CD^.DrawView;
                        end
                   else Close;
           ClearEvent(Event);
         end;
     end;
  end;
  { lets CD try to handle this }
  if Event.What=evKeyDown then
     Message(CD,Event.What,Event.KeyCode,Event.InfoPtr);
  inherited HandleEvent(Event);
end;

procedure TCalculator.Show;
begin
{  if GetState(sfVisible)=false then CD^.Clear;}
  inherited Show;
end;

procedure TCalculator.Close;
begin
  Hide;
end;

constructor TCalculator.Load(var S: TStream);
begin
  inherited Load(S);
  GetSubViewPtr(S,CD);
end;

procedure TCalculator.Store(var S: TStream);
begin
  inherited Store(S);
  PutSubViewPtr(S,CD);
end;


procedure RegisterFPCalc;
begin
{$ifndef NOOBJREG}
  RegisterType(RCalcButton);
  RegisterType(RCalcDisplay);
  RegisterType(RCalculator);
{$endif}
end;

end.
{
  $Log$
  Revision 1.7  1999-09-13 16:24:42  peter
    + clock
    * backspace unident like tp7

  Revision 1.6  1999/09/07 09:20:52  pierre
    * traling zero after . could not be inserted
    * load/store was missing => CD not set on loading.
    * log function was not implemented : ln is used,
      should it rather be decimal logarithm ?

  Revision 1.5  1999/06/28 19:25:35  peter
    * fixes from gabor

  Revision 1.4  1999/04/07 21:55:41  peter
    + object support for browser
    * html help fixes
    * more desktop saving things
    * NODEBUG directive to exclude debugger

  Revision 1.3  1999/03/01 15:41:49  peter
    + Added dummy entries for functions not yet implemented
    * MenuBar didn't update itself automatically on command-set changes
    * Fixed Debugging/Profiling options dialog
    * TCodeEditor converts spaces to tabs at save only if efUseTabChars is
 set
    * efBackSpaceUnindents works correctly
    + 'Messages' window implemented
    + Added '$CAP MSG()' and '$CAP EDIT' to available tool-macros
    + Added TP message-filter support (for ex. you can call GREP thru
      GREP2MSG and view the result in the messages window - just like in TP)
    * A 'var' was missing from the param-list of THelpFacility.TopicSearch,
      so topic search didn't work...
    * In FPHELP.PAS there were still context-variables defined as word instead
      of THelpCtx
    * StdStatusKeys() was missing from the statusdef for help windows
    + Topic-title for index-table can be specified when adding a HTML-files

  Revision 1.1  1998/12/22 14:27:54  peter
    * moved

  Revision 1.2  1998/12/22 10:39:39  peter
    + options are now written/read
    + find and replace routines

}