unit sCalcUnit;
{$I sDefs.inc}

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  sCustomButton, ExtCtrls, sPanel, ActnList, sStyleUtil, Menus, StdCtrls, sUtils,
  Clipbrd, mask, sButtonControl, sEditorsManager, sControlsManager;

type
  TsCalcState = (csFirst, csValid, csError);

  TsCalcForm = class(TForm)
    OK1: TMenuItem;
    Cancel1: TMenuItem;
    FMainPanel: TsPanel;
    PopupMenu1: TPopupMenu;
    N1: TMenuItem;
    N2: TMenuItem;
    FCalculatorPanel: TsPanel;
    FCalcPanel: TsPanel;
    sSpeedButton1: TsSpeedButton;
    sSpeedButton2: TsSpeedButton;
    sSpeedButton3: TsSpeedButton;
    sSpeedButton4: TsSpeedButton;
    sSpeedButton5: TsSpeedButton;
    sSpeedButton6: TsSpeedButton;
    sSpeedButton7: TsSpeedButton;
    sSpeedButton8: TsSpeedButton;
    sSpeedButton9: TsSpeedButton;
    sSpeedButton10: TsSpeedButton;
    sSpeedButton11: TsSpeedButton;
    sSpeedButton12: TsSpeedButton;
    sSpeedButton13: TsSpeedButton;
    sSpeedButton14: TsSpeedButton;
    sSpeedButton15: TsSpeedButton;
    sSpeedButton16: TsSpeedButton;
    sSpeedButton17: TsSpeedButton;
    sSpeedButton18: TsSpeedButton;
    sSpeedButton19: TsSpeedButton;
    sSpeedButton20: TsSpeedButton;
    sSpeedButton21: TsSpeedButton;
    sSpeedButton22: TsSpeedButton;
    sSpeedButton23: TsSpeedButton;
    sSpeedButton24: TsSpeedButton;
    sSpeedButton25: TsSpeedButton;
    sSpeedButton26: TsSpeedButton;
    FDisplayPanel: TsPanel;
    sDragBar1: TsDragBar;
    sToolButton3: TsSpeedButton;
    sToolButton1: TsSpeedButton;
    sControlsManager1: TsControlsManager;
    procedure sSpeedButton22Click(Sender: TObject);
    procedure FormKeyPress(Sender: TObject; var Key: Char);
    procedure N1Click(Sender: TObject);
    procedure N2Click(Sender: TObject);
    procedure PopupMenu1Popup(Sender: TObject);
    procedure sSpeedButton24Click(Sender: TObject);
    procedure sSpeedButton23Click(Sender: TObject);
    procedure sSpeedButton25Click(Sender: TObject);
    procedure sSpeedButton26Click(Sender: TObject);
    procedure sSpeedButton19Click(Sender: TObject);
    procedure sSpeedButton13Click(Sender: TObject);
    procedure sSpeedButton7Click(Sender: TObject);
    procedure sSpeedButton21Click(Sender: TObject);
    procedure sSpeedButton15Click(Sender: TObject);
    procedure sSpeedButton9Click(Sender: TObject);
    procedure sSpeedButton3Click(Sender: TObject);
    procedure OK1Click(Sender: TObject);
    procedure Cancel1Click(Sender: TObject);
    procedure sSpeedButton2Click(Sender: TObject);
    procedure sSpeedButton14Click(Sender: TObject);
    procedure sSpeedButton8Click(Sender: TObject);
    procedure sSpeedButton20Click(Sender: TObject);
    procedure sSpeedButton1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure sToolButton3Click(Sender: TObject);
    procedure sToolButton1Click(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FormDeactivate(Sender: TObject);
  protected
    FOperand: Double;

    FOnError: TNotifyEvent;
    FOnOk: TNotifyEvent;
    FOnCancel: TNotifyEvent;
    FOnResult: TNotifyEvent;
    FOnTextChange: TNotifyEvent;
    FOnCalcKey: TKeyPressEvent;
    FOnDisplayChange: TNotifyEvent;

  private
    procedure TextChanged; virtual;
  public
    FText: string;
    FMemory: Double;
    FPrecision: Byte;
    FBeepOnError: Boolean;
    FStatus: TsCalcState;
    FOperator: Char;
    FEditor: TCustomMaskEdit;
    function GetValue: Variant;
    procedure SetValue(const Value: Variant);

    procedure SetText(const Value: string);
    procedure CheckFirst;
    procedure CalcKey(Key: Char);
    procedure Clear;
    procedure Error;
    procedure SetDisplay(R: Double);
    function GetDisplay: Double;
    procedure UpdateMemoryLabel;
    procedure Copy;
    procedure Paste;
    property DisplayValue: Double read GetDisplay write SetDisplay;
    property Text: string read FText;

    property OnResultClick: TNotifyEvent read FOnResult write FOnResult;
    property OnError: TNotifyEvent read FOnError write FOnError;
    property OnTextChange: TNotifyEvent read FOnTextChange write FOnTextChange;
    property OnCalcKey: TKeyPressEvent read FOnCalcKey write FOnCalcKey;
    property OnDisplayChange: TNotifyEvent read FOnDisplayChange write FOnDisplayChange;
  end;

const
  ResultKeys = [#13, '=', '%'];

implementation

uses sCurrEdit, sCustomComboEdit;

{$R *.dfm}

procedure TsCalcForm.CalcKey(Key: Char);
var
  R: Double;
begin
  Key := UpCase(Key);
  if (FStatus = csError) and (Key <> 'C') then Key := #0;

  if Assigned(FOnCalcKey) then FOnCalcKey(Self, Key);

  case Key of
    '.', ',': begin
      CheckFirst;
      if Pos(DecimalSeparator, FText) = 0 then SetText(FText + DecimalSeparator);
      Exit;
    end;
    'R': if FStatus in [csValid, csFirst] then begin
      FStatus := csFirst;
      if GetDisplay = 0 then Error else SetDisplay(1.0 / GetDisplay);
    end;
    'Q': if FStatus in [csValid, csFirst] then begin
      FStatus := csFirst;
      if GetDisplay < 0 then Error else SetDisplay(Sqrt(GetDisplay));
    end;
    '0'..'9': begin
      CheckFirst;
      if FText = '0' then SetText('');
      if Pos('E', FText) = 0 then begin
        if Length(FText) < Maxi(2, FPrecision) + Ord(Boolean(Pos('-', FText)))
          then SetText(FText + Key)
          else if FBeepOnError then MessageBeep(0);
      end;
    end;
    #8: begin
      CheckFirst;
      if (Length(FText) = 1) or ((Length(FText) = 2) and (FText[1] = '-'))
        then SetText('0')
        else SetText(System.Copy(FText, 1, Length(FText) - 1));
    end;
    '_': SetDisplay(-GetDisplay);
    '+', '-', '*', '/', '=', '%', #13: begin
      if (Key = #13) and (FStatus = csFirst) then begin
        if FEditor <> nil then begin
          TsCalcEdit(FEditor).Value := StrToFloat(FText);
          FEditor.SetFocus;
          if TsCustomComboEdit(FEditor).AutoSelect then TsCustomComboEdit(FEditor).SelectAll;
          Close;
        end;
      end
      else begin
        if FStatus = csValid then begin
          FStatus := csFirst;
          R := GetDisplay;
          if Key = '%' then
            case FOperator of
              '+', '-': R := FOperand * R / 100.0;
              '*', '/': R := R / 100.0;
            end;
          case FOperator of
            '+': SetDisplay(FOperand + R);
            '-': SetDisplay(FOperand - R);
            '*': SetDisplay(FOperand * R);
            '/': if R = 0 then Error else SetDisplay(FOperand / R);
          end;
        end;
        FOperator := Key;
        FOperand := GetDisplay;
        if Key in ResultKeys then if Assigned(FOnResult) then FOnResult(Self);
      end;
    end;
    #27: if FText = '0' then begin
      if Assigned(FEditor) then FEditor.SetFocus;
      Close;
    end
    else CLear;
    'C': Clear;
    ^C: Clipboard.AsText := FText;
    ^V: Paste;
  end;
end;

procedure TsCalcForm.CheckFirst;
begin
  if FStatus = csFirst then begin
    FStatus := csValid;
    SetText('0');
  end;
end;

procedure TsCalcForm.Clear;
begin
  FStatus := csFirst;
  SetDisplay(0.0);
  FOperator := '=';
end;

procedure TsCalcForm.Error;
begin
  FStatus := csError;
  SetText('Error');
  if FBeepOnError then MessageBeep(0);
  if Assigned(FOnError) then FOnError(Self);
end;

procedure TsCalcForm.FormKeyPress(Sender: TObject; var Key: Char);
begin
  CalcKey(Key);
end;

function TsCalcForm.GetDisplay: Double;
begin
  if FStatus = csError
    then Result := 0.0
    else Result := StrToFloat(Trim(FText));
end;

procedure TsCalcForm.N1Click(Sender: TObject);
begin
  Copy;
end;

procedure TsCalcForm.N2Click(Sender: TObject);
begin
  Paste;
end;

procedure TsCalcForm.PopupMenu1Popup(Sender: TObject);
begin
  N2.Enabled := Clipboard.HasFormat(CF_TEXT);
end;

procedure TsCalcForm.SetDisplay(R: Double);
var
  S: string;
begin
  S := FloatToStrF(R, ffGeneral, Maxi(2, FPrecision), 0);
  if FText <> S then begin
    SetText(S);
    if Assigned(FOnDisplayChange) then FOnDisplayChange(Self);
  end;
end;

procedure TsCalcForm.SetText(const Value: string);
begin
  if FText <> Value then begin
    FText := Value;
    TextChanged;
  end;
end;

procedure TsCalcForm.TextChanged;
begin
  FDisplayPanel.Caption := FText;
  FDisplayPanel.sStyle.BGChanged := True;
  if Assigned(FOnTextChange) then FOnTextChange(Self);
end;

procedure TsCalcForm.UpdateMemoryLabel;
begin
  if FMemory <> 0.0
    then FCalcPanel.Caption := 'M'
    else FCalcPanel.Caption := '';
end;

procedure TsCalcForm.sSpeedButton22Click(Sender: TObject);
begin
  CalcKey(Char(TComponent(Sender).Tag + Ord('0'))); // Digits
end;

procedure TsCalcForm.sSpeedButton24Click(Sender: TObject);
begin
  CalcKey('.');
end;

procedure TsCalcForm.sSpeedButton23Click(Sender: TObject);
begin
  CalcKey('_');
end;

procedure TsCalcForm.sSpeedButton25Click(Sender: TObject);
begin
  CalcKey('+');
end;

procedure TsCalcForm.sSpeedButton26Click(Sender: TObject);
begin
  CalcKey('=');
end;

procedure TsCalcForm.sSpeedButton19Click(Sender: TObject);
begin
  CalcKey('-');
end;

procedure TsCalcForm.sSpeedButton13Click(Sender: TObject);
begin
  CalcKey('*');
end;

procedure TsCalcForm.sSpeedButton7Click(Sender: TObject);
begin
  CalcKey('/');
end;

procedure TsCalcForm.sSpeedButton21Click(Sender: TObject);
begin
  if FStatus in [csValid, csFirst] then begin
    FStatus := csFirst;
    FMemory := FMemory + GetDisplay;
    UpdateMemoryLabel;
  end;
end;

procedure TsCalcForm.sSpeedButton15Click(Sender: TObject);
begin
  if FStatus in [csValid, csFirst] then begin
    FStatus := csFirst;
    FMemory := GetDisplay;
    UpdateMemoryLabel;
  end;
end;

procedure TsCalcForm.sSpeedButton9Click(Sender: TObject);
begin
  if FStatus in [csValid, csFirst] then begin
    FStatus := csFirst;
    CheckFirst;
    SetDisplay(FMemory);
  end;
end;

procedure TsCalcForm.sSpeedButton3Click(Sender: TObject);
begin
  FMemory := 0.0;
  UpdateMemoryLabel;
end;

procedure TsCalcForm.OK1Click(Sender: TObject);
begin
  if FStatus <> csError then begin
    DisplayValue := DisplayValue;
    if Assigned(FOnOk) then FOnOk(Self);
  end
  else if FBeepOnError then MessageBeep(0);
end;

procedure TsCalcForm.Cancel1Click(Sender: TObject);
begin
  if Assigned(FOnCancel) then FOnCancel(Self);
end;

procedure TsCalcForm.sSpeedButton2Click(Sender: TObject);
begin
  CalcKey('C');
end;

procedure TsCalcForm.Paste;
begin
  if Clipboard.HasFormat(CF_TEXT) then begin
    try
      SetDisplay(StrToFloat(Trim(ReplaceStr(Clipboard.AsText, CurrencyString, ''))));
    except
      SetText('0');
    end;
  end;
end;

procedure TsCalcForm.sSpeedButton14Click(Sender: TObject);
begin
  CalcKey('%');
end;

procedure TsCalcForm.sSpeedButton8Click(Sender: TObject);
begin
  CalcKey('Q');
end;

procedure TsCalcForm.sSpeedButton20Click(Sender: TObject);
begin
  CalcKey('R');
end;

procedure TsCalcForm.sSpeedButton1Click(Sender: TObject);
begin
  CalcKey(#8);
end;

procedure TsCalcForm.Copy;
begin
  Clipboard.AsText := FText;
end;

procedure TsCalcForm.FormCreate(Sender: TObject);
begin
  FText := '0';
end;

procedure TsCalcForm.sToolButton3Click(Sender: TObject);
begin
  Application.Minimize;
end;

procedure TsCalcForm.sToolButton1Click(Sender: TObject);
begin
  Close;
end;

function TsCalcForm.GetValue: Variant;
begin
  Result := 0;
end;

procedure TsCalcForm.SetValue(const Value: Variant);
begin
  DisplayValue := 0;
end;

procedure TsCalcForm.FormShow(Sender: TObject);
begin
  if FEditor <> nil then SetDisplay(TsCustomNumEdit(FEditor).Value);
  if (FEditor <> nil) and (TsCustomNumEdit(FEditor).sStyle.sC <> nil) then begin
//    sEditorsManager.Assign(TsCustomNumEdit(FEditor).sStyle.sC)!
  end;
end;

procedure TsCalcForm.FormDeactivate(Sender: TObject);
begin
  if FEditor <> nil then Close;
end;

end.