unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Imaging.jpeg,
  Vcl.ExtCtrls, Vcl.Menus;

type
  TStatkevich_Angelina_851001_Lab1_1 = class(TForm)
    LbEnterSide1: TLabel;
    LbEnterSide2: TLabel;
    LbEnterSide3: TLabel;
    EdSide1: TEdit;
    EdSide2: TEdit;
    EdSide3: TEdit;
    BtDefiner: TButton;
    LbRes: TLabel;
    MainMenu: TMainMenu;
    OpenFile: TOpenDialog;
    FileMenuItem: TMenuItem;
    OpenMenuItem: TMenuItem;
    SaveAsMenuItem: TMenuItem;
    SaveFile: TSaveDialog;
    HelpMenuItem: TMenuItem;
    Aboutprogram1: TMenuItem;
    Aboutprogrammer1: TMenuItem;
    LineMenuItem: TMenuItem;
    ExitMenuItem: TMenuItem;
    PopupMenu: TPopupMenu;
    procedure BtDefinerClick(Sender: TObject);
    procedure EdSide2Change(Sender: TObject);
    procedure EdSide3Change(Sender: TObject);
    procedure EdSide1Change(Sender: TObject);
    procedure OpenMenuItemClick(Sender: TObject);
    procedure SaveAsMenuItemClick(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure AboutProgramClick(Sender: TObject);
    procedure AboutProgrammerClick(Sender: TObject);
    procedure ExitMenuItemClick(Sender: TObject);
    procedure CheckInput(Sender: TObject);
    procedure EdSideKeyPress(Sender: TObject; var Key: Char);
    function CheckFileName(MyFile: string): string;
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Statkevich_Angelina_851001_Lab1_1: TStatkevich_Angelina_851001_Lab1_1;

implementation

{$R *.dfm}

procedure TStatkevich_Angelina_851001_Lab1_1.AboutProgramClick(Sender: TObject);
const
   sms = 'Программа определяет, является ли треугольник равносторонним';
begin
   MessageDlg(sms, mtInformation, [mbOk], 0);
end;

procedure TStatkevich_Angelina_851001_Lab1_1.AboutProgrammerClick(Sender: TObject);
begin
   MessageDlg('Программа разработана Статкевич Ангелиной' + #13 +
   'студенткой группы 851001, ФКСиС, ПОИТ' , mtInformation, [mbOk], 0);
end;



procedure TStatkevich_Angelina_851001_Lab1_1.BtDefinerClick(Sender: TObject);
var
   FirstSide, SecondSide, ThirdSide: Real;
begin
   FirstSide := StrToFloat(EdSide1.Text);
   SecondSide := StrToFloat(EdSide2.Text);
   ThirdSide := StrToFloat(EdSide3.Text);
   if (FirstSide < SecondSide + ThirdSide) and (SecondSide < FirstSide + ThirdSide) and (ThirdSide < FirstSide + SecondSide) then
   begin
      if (FirstSide = SecondSide) and (SecondSide = ThirdSide) then
         LbRes.Caption := 'Треугольник равносторонний'
      else
         LbRes.Caption := 'Треугольник неравносторонний';
    end
    else
       LbRes.Caption := 'Треугольника с такими сторонами не существует';
    SaveAsMenuItem.Enabled := True;
end;

procedure TStatkevich_Angelina_851001_Lab1_1.CheckInput(Sender: TObject);
begin
   with Sender as TEdit do
   begin
      if (length(Text) > 15) then
      begin
         color := clMaroon;
         ShowMessage('Ошибка ввода. Вы ввели слишком большое число');
         BtDefiner.Enabled := false;
         Clear;
      end
      else
         color := clWhite;
   end;
end;

function GetIsRepeated(Text: string): Boolean;
var
   i: Integer;
   IsRepeated: Boolean;
begin
   i := 1;
   IsRepeated := False;
   while (i <= Length(Text)) and not (IsRepeated) do
   begin
      if (Text[i] = ',') or (Text[i] = '.') then
         IsRepeated := True;
      inc(i);
   end;
   GetIsRepeated := IsRepeated;
end;

procedure TStatkevich_Angelina_851001_Lab1_1.EdSideKeyPress(Sender: TObject; var Key: Char);
const
   Numerals = ['0'..'9', #8, '.'];
begin
   with Sender as TEdit do
   begin
      if not (Key in Numerals) then
         Key := #0;
      if (Key = '.') and GetIsRepeated(Text) then
         Key := #0;
      if (Key = '.') and (Length(Text) = 0) then
         Key := #0;
      if (Key = '0') and (Length(Text) = 1) then
         Key := #0;
   end;
end;

procedure TStatkevich_Angelina_851001_Lab1_1.EdSide1Change(Sender: TObject);
begin
   CheckInput(EdSide1);
   EdSide2.Enabled := True;
   LbRes.Caption := '';
end;

procedure TStatkevich_Angelina_851001_Lab1_1.EdSide2Change(Sender: TObject);
begin
   CheckInput(EdSide2);
   EdSide3.Enabled := True;
   LbRes.Caption := '';
end;

procedure TStatkevich_Angelina_851001_Lab1_1.EdSide3Change(Sender: TObject);
begin
   CheckInput(EdSide3);
   BtDefiner.Enabled := True;
   SaveAsMenuItem.Enabled := False;
   LbRes.Caption := '';
end;

procedure TStatkevich_Angelina_851001_Lab1_1.ExitMenuItemClick(Sender: TObject);
begin
    Close;
end;

procedure TStatkevich_Angelina_851001_Lab1_1.FormClose(Sender: TObject; var Action: TCloseAction);
var
   Choice: Integer;
begin
   Choice := MessageDlg('Are you sure you want to exit?', mtConfirmation, [mbYes, mbNo], 0);
   case Choice  of
      1: ;
      2: Action := caNone;
   end;
end;

procedure TStatkevich_Angelina_851001_Lab1_1.OpenMenuItemClick(Sender: TObject);
var
   inputFile: TextFile;
   temp: Real;
begin
   if OpenFile.Execute then
   begin
       try
          AssignFile(inputFile, OpenFile.FileName);
          Reset(inputFile);
          if SeekEof(inputFile) then
          begin
             MessageDlg('Похоже, файл пустой. Повторите попытку', mtError, [mbRetry], 0);
             EdSide1.Clear;
             EdSide2.Clear;
             EdSide3.Clear;
          end
          else
          begin
             ReadLn(inputFile,temp);
             EdSide1.Text := FloatToStr(temp);
             ReadLn(inputFile,temp);
             EdSide2.Text := FloatToStr(temp);
             ReadLn(inputFile,temp);
             EdSide3.Text := FloatToStr(temp);
             CloseFile(inputFile);
          end;
       except
          MessageDlg('Ошибка ввода данных. Повторите попытку.', mtError, [mbRetry], 0);
          EdSide1.Clear;
          EdSide2.Clear;
          EdSide3.Clear;
       end;
   end;

end;

function TStatkevich_Angelina_851001_Lab1_1.CheckFileName(MyFile: string): string;
var
   i: byte;
   isCorrect: boolean;
begin
   isCorrect := false;
   i := 1;
   while  not isCorrect and (i <= length(MyFile)) do
   begin
      if MyFile[i] = '.' then
         isCorrect := true;
      inc(i);
   end;
   if (not isCorrect) then
      MyFile := MyFile + '.txt';
   CheckFileName := MyFile;
end;

procedure TStatkevich_Angelina_851001_Lab1_1.SaveAsMenuItemClick(Sender: TObject);
var
   outputFile: TextFile;
   MyFile: string;
   ButtonSelected: byte;
begin
   if SaveFile.Execute then
   begin
      MyFile := SaveFile.FileName;
      MyFile := CheckFileName(MyFile);
      if FileExists(MyFile) then
      begin
         ButtonSelected := MessageDlg('Сохранить результаты в файл?', mtConfirmation, [mbYes, mbNo], 0);
         if ButtonSelected = mrYes then
         begin
            AssignFile(outputFile, MyFile);
            Rewrite(outputFile);
            writeln(outputFile, LbRes.Caption);
            CloseFile(outputFile);
         end
         else
            SaveAsMenuItemClick(Sender);
      end
      else
      begin
         AssignFile(outputFile, MyFile);
         Rewrite(outputFile);
         writeln(outputFile, LbRes.Caption);
         CloseFile(outputFile);
      end;
   end;
end;

end.