Lab.5.1

implementation

{$R *.dfm}

uses UnitAbout, UnitError, UnitExit, UnitTask_5_1, UnitInstruction_5_1;

type
    TPointer = ^TElement;
    TElement = record
        Data: Integer;
        Next: TPointer;
    end;

procedure AddElementInList(var Prev: TPointer; Data: Integer); stdcall; external 'Lab_5_1_Lib';
function ChangeList(Start: TPointer): TPointer; stdcall; external 'Lab_5_1_Lib';

const
    MAX_VALUE = 9999;
    MIN_VALUE = -9999;
    MIN_SIZE = 1;

var
    Start: TPointer;
    IsEmpty: Boolean;

procedure TFormMain.ButtonAddElementClick(Sender: TObject);
var
    Data, I: Integer;
    IsCorrect: Boolean;
    Error: String;
begin
    IsCorrect := true;
    try
        Data := StrToInt(EditAddNewElement.Text);
        if (Data > MAX_VALUE) or (Data < MIN_VALUE) then
        begin
            IsCorrect := false;
            Error := 'Значение элемента не входит в допустимый диапазон. ';
        end;
    except
        IsCorrect := false;
        Error := 'Некорректное значение элемента списка. ';
    end;
    if (IsCorrect) then
    begin
        EditAddNewElement.Text := '';
        I := List.ColCount;
        List.ColCount := List.ColCount + 1;
        List.Cells[I, 0] := '№' + IntToStr(I);
        List.Cells[I, 1] := IntToStr(Data);
        ButtonMakeNewList.Enabled := true;
        FormMain.Height := 299;
        NSaveFile.Enabled := false;
    end
    else
    begin
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;

procedure TFormMain.ButtonDeleteElementClick(Sender: TObject);
var
    IsCorrect: Boolean;
    Number, Index, I: Integer;
    Error: String;
begin
    IsCorrect := true;
    try
        Number := StrToInt(EditDeleteElement.Text);
        if (Number > List.ColCount - 1) or (Number < MIN_SIZE) then
        begin
            IsCorrect := false;
            Error := 'Не найдено элемента с таким номером. ';
        end;
        if (List.ColCount = 1) then
        begin
            IsCorrect := false;
            Error := 'В списке нет элементов для удаления. ';
        end;
    except
        IsCorrect := false;
        Error := 'Некорректное значение номера элемента списка. ';
    end;
    if (IsCorrect) then
    begin
        EditDeleteElement.Text := '';
        Index := Number + 1;
        for I := Number to List.ColCount - 2 do
        begin
            List.Cells[I, 0] := '№' + IntToStr(I);
            List.Cells[I, 1] := List.Cells[I + 1, 1];
        end;
        List.ColCount := List.ColCount - 1;
        FormMain.Height := 299;
        NSaveFile.Enabled := false;
    end
    else
    begin
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;

procedure TFormMain.ButtonMakeNewListClick(Sender: TObject);
var
    Temp, NewStart: TPointer;
    IsCorrect: Boolean;
    Error: String;
    Element, I: Integer;
begin
    IsCorrect := true;
    I := 1;
    New(Temp);
    New(NewStart);
    Temp := Start;
    if (List.ColCount = 1) then
    begin
        IsCorrect := false;
        Error := 'Недостаточно элементов в списке. ';
    end;
    while (IsCorrect) and (I < List.ColCount) do
    begin
        try
            Element := StrToInt(List.Cells[I, 1]);
            AddElementInList(Temp, Element);
            Temp := Temp^.Next;
        except
            IsCorrect := false;
            Error := 'Ошибка при добавлении элемента №' + IntToStr(I) + ' в список';
        end;
        Inc(I);
    end;
    if (IsCorrect) then
    begin
        NewList.ColCount := 1;
        NewStart := ChangeList(Start);
        Temp := NewStart^.Next;
        I := 0;
        while (Temp <> nil) do
        begin
            NewList.Cells[I, 0] := IntToStr(Temp^.Data);
            NewList.ColCount := NewList.ColCount + 1;
            Temp := Temp^.Next;
            Inc(I);
        end;
        NewList.ColCount := NewList.ColCount - 1;
        FormMain.Height := 357;
        NSaveFile.Enabled := true;
    end
    else
    begin
        UnitError.FormError.LabelError.Caption := Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;

procedure TFormMain.ButtonShowTaskClick(Sender: TObject);
begin
    UnitTask_5_1.FormTask.ShowModal();
end;

procedure TFormMain.EditAddNewElementChange(Sender: TObject);
begin
    if (EditAddNewElement.Text = '') or (EditAddNewElement.Text = '-') then
        ButtonAddElement.Enabled := false
    else
        ButtonAddElement.Enabled := true;
end;

procedure TFormMain.EditAddNewElementKeyPress(Sender: TObject; var Key: Char);
begin
    if not(Key in ['0'..'9', '-', #8, #13]) then
        Key := #0;
    if (Length(EditAddNewElement.Text) > 0) and (EditAddNewElement.Text[1] = '-') then
        EditAddNewElement.MaxLength := 5
    else
        EditAddNewElement.MaxLength := 4;
    if (Length(EditAddNewElement.Text) > 0) and (EditAddNewElement.Text[1] = '0') and not(Key in [#8, #13]) and not(Length(EditAddNewElement.SelText) > 0) then
        Key := #0;
    if (Length(EditAddNewElement.Text) > 0) and (Key = '-') and not(Length(EditAddNewElement.SelText) > 0) then
        Key := #0;
    if (Length(EditAddNewElement.Text) = 1) and (EditAddNewElement.Text[1] = '-') and (Key = '0') then
        Key := #0;
    if (Length(EditAddNewElement.Text) > 0) and (Key = #13) then
        ButtonAddElementClick(Sender);
end;

procedure TFormMain.EditDeleteElementChange(Sender: TObject);
begin
    if (EditDeleteElement.Text = '') or (EditDeleteElement.Text = '-') then
        ButtonDeleteElement.Enabled := false
    else
        ButtonDeleteElement.Enabled := true;
end;

procedure TFormMain.EditDeleteElementKeyPress(Sender: TObject; var Key: Char);
begin
    if not(Key in ['0'..'9', #8, #13]) then
        Key := #0;
    if (Length(EditDeleteElement.Text) > 0) and (EditDeleteElement.Text[1] = '0') and not(Key in [#8, #13]) and not(Length(EditDeleteElement.SelText) > 0) then
        Key := #0;
    if (Length(EditDeleteElement.Text) > 0) and (Key = #13) then
        ButtonDeleteElementClick(Sender);
end;

procedure TFormMain.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
var
    Res: Integer;
begin
    Res := UnitExit.FormExit.ShowModal();
    if Res = mrOk then
        CanClose := true
    else
        CanClose := false;
end;

procedure TFormMain.FormCreate(Sender: TObject);
begin
    New(Start);
    Start.Next := nil;
    List.ColWidths[0] := 80;
    List.RowHeights[0] := 20;
    List.Cells[0, 0] := '№ элемента';
    List.Cells[0, 1] := 'Элемент';
    FormMain.Height := 299;
end;

procedure TFormMain.NAboutClick(Sender: TObject);
begin
    UnitAbout.FormAbout.ShowModal();
end;

procedure TFormMain.NInstructionClick(Sender: TObject);
begin
    UnitInstruction_5_1.FormInstruction.ShowModal();
end;

procedure TFormMain.NOpenFileClick(Sender: TObject);
var
    Path, Error, InputStr: String;
    IsCorrect: Boolean;
    F: TextFile;
    Element, I: Integer;
begin
    IsCorrect := true;
    Error := '';
    if (OpenDialog.Execute) then
    begin
        List.ColCount := 1;
        Path := OpenDialog.FileName;
        AssignFile(F, Path);
        try
            Reset(F);
            try
                while not(EoF(F)) and (IsCorrect) do
                begin
                    Readln(F, InputStr);
                    if not(InputStr.IsEmpty) then
                    begin
                        try
                            Element := StrToInt(InputStr);
                            if (Element < MIN_VALUE) or (Element > MAX_VALUE) then
                            begin
                                IsCorrect := false;
                                Error := 'Найден элемент, не входящий в допустимый диапазон. ';
                            end
                            else
                            begin
                                I := List.ColCount;
                                List.ColCount := List.ColCount + 1;
                                List.Cells[I, 0] := '№' + IntToStr(I);
                                List.Cells[I, 1] := IntToStr(Element);
                            end;
                        except
                            IsCorrect := false;
                            Error := 'Найден некорректный элемент списка. ';
                        end;
                    end;
                end;
                if (IsCorrect) then
                begin
                    if (List.ColCount = 1) then
                    begin
                        IsCorrect := false;
                        Error := 'В файле не найдено элементов. ';
                        ButtonMakeNewList.Enabled := false;
                    end
                    else
                    begin
                        ButtonMakeNewList.Enabled := true;
                        FormMain.Height := 299;
                        NSaveFile.Enabled := false;
                    end;
                end;
            finally
                CloseFile(F);
            end;
        except
            IsCorrect := false;
            Error := 'Ошибка при считывании данных из файла. ';
        end;
    end;
    if not(IsCorrect) then
    begin
        List.ColCount := 1;
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;

procedure TFormMain.NSaveFileClick(Sender: TObject);
var
    IsCorrect: Boolean;
    Error, Path: String;
    I: Integer;
    F: TextFile;
begin
    IsCorrect := true;
    Error := '';
    if (SaveDialog.Execute) then
    begin
        Path := SaveDialog.FileName;
        AssignFile(F, Path);
        try
            Rewrite(F);
            I := 0;
            try
                Writeln(F, 'Полученный список: ');
                while (I < NewList.ColCount) do
                begin
                    Write(F, NewList.Cells[I, 0], ' ');
                    Inc(I);
                end;
            finally
                CloseFile(F);
            end;
        except
            IsCorrect := false;
            Error := 'Оишбка открытия файла для записи. ';
        end;
    end;
    if not(IsCorrect) then
    begin
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := ''
    end;
end;