Lab.5.2

{$R *.dfm}

uses UnitAbout, UnitError, UnitExit, UnitDrawTree, UnitNodesAndLeaves,
  UnitInstruction_5_2, UnitTask_5_2;

const
    MAX_DATA = 99;
    MIN_DATA = -99;
    SIZE_NODE = 28;
    HALF_SIZE_NODE = 14;
    TEXT_INDENT = 6;

type
    TPointer = ^TElement;
    TElement = record
        Data: Integer;
        NextLeft: TPointer;
        NextRight: TPointer;
    end;

procedure AddElement(var Curr: TPointer; Data: Integer); stdcall; external 'Lab_5_2_Lib';
procedure DeleteElement(var Curr: TPointer; Data: Integer); stdcall; external 'Lab_5_2_Lib';
function Power(Numb, Pow: Integer): Integer; stdcall; external 'Lab_5_2_Lib';
function SearchElementInTree(Curr: TPointer; Numb: Integer): TPointer; stdcall; external 'Lab_5_2_Lib';
procedure CountInTree(Curr: TPointer; var Nodes: Integer; var Leaves: Integer); stdcall; external 'Lab_5_2_Lib';

var
    Head: TPointer;

procedure TFormMain.ButtonAddElementClick(Sender: TObject);
var
    IsCorrect: Boolean;
    Error: String;
    Data: Integer;
    Elem: TPointer;
begin
    IsCorrect := true;
    ButtonAddElement.Enabled := false;
    try
         Data := StrToInt(EditChangeTree.Text);
         if (Data < MIN_DATA) or (Data > MAX_DATA) then
         begin
            IsCorrect := false;
            Error := 'Значение элемента находится вне допустимого диапазона. ';
         end;
    except
        IsCorrect := false;
        Error := 'Введено некорректное значение элемента. ';
    end;
    if (IsCorrect) then
    begin
        AddElement(Head, Data);
        EditChangeTree.Text := '';
    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;
    Error: String;
    Data: Integer;
    Elem: TPointer;
begin
    IsCorrect := true;
    ButtonDeleteElement.Enabled := false;
    try
         Data := StrToInt(EditChangeTree.Text);
         if (Data < MIN_DATA) or (Data > MAX_DATA) then
         begin
            IsCorrect := false;
            Error := 'Значение элемента находится вне допустимого диапазона. ';
         end;
    except
        IsCorrect := false;
        Error := 'Введено некорректное значение элемента. ';
    end;
    if (IsCorrect) then
    begin
        if (SearchElementInTree(Head, Data) <> nil) then
            DeleteElement(Head, Data)
        else
        begin
            Error := 'Данный элемент не найден в дереве.';
            UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
            UnitError.FormError.ShowModal();
            UnitError.FormError.LabelError.Caption := '';
        end;
        EditChangeTree.Text := '';
    end
    else
    begin
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;

procedure DrawNode(Curr: TPointer; Level: Integer; IsLeft: Boolean; X, Y: Integer);
var
    m, l, i: Integer; //m - середина, l - ширина, i - отступ
    CurrX, CurrY: Integer;
begin
    if Curr <> nil then
    begin
        l := UnitDrawTree.FormTree.ImageTree.Width;
        m := l div 2;
        i := m div Power(2, Level + 1);
        with (UnitDrawTree.FormTree.ImageTree.Canvas) do
        begin
            CurrX := X - HALF_SIZE_NODE;
            CurrY := Y;
            //Rectangle(CurrX, CurrY, CurrX + SIZE_NODE, CurrY + SIZE_NODE);
            Ellipse(CurrX, CurrY, CurrX + SIZE_NODE, CurrY + SIZE_NODE);
            TextOut(CurrX + TEXT_INDENT, CurrY + TEXT_INDENT, IntToStr(Curr^.Data));
            CurrX := X;
            CurrY := Y + SIZE_NODE;
            MoveTo(CurrX, CurrY);
            if (IsLeft) and (Curr^.NextLeft <> nil) then
            begin
                LineTo(CurrX - i, CurrY + HALF_SIZE_NODE);
            end;
            if not(IsLeft) and (Curr^.NextLeft <> nil) then
            begin
                LineTo(CurrX - i, CurrY + HALF_SIZE_NODE);
            end;
            DrawNode(Curr^.NextLeft, (Level + 1), True, CurrX - i, CurrY + HALF_SIZE_NODE);
            MoveTo(CurrX, CurrY);
            if (Curr^.NextRight <> nil) then
            begin
                LineTo(CurrX + i, CurrY + HALF_SIZE_NODE);
            end;
            DrawNode(Curr^.NextRight, (Level + 1), false, CurrX + i, CurrY + HALF_SIZE_NODE);
            MoveTo(CurrX - 2 * i, CurrY - HALF_SIZE_NODE - SIZE_NODE);
        end;
    end;
end;

procedure TFormMain.ButtonDrawTreeClick(Sender: TObject);
var
    Temp: TPointer;
begin
    UnitDrawTree.FormTree.ImageTree.Canvas.Pen.Color := clWhite;
    UnitDrawTree.FormTree.ImageTree.Canvas.Brush.Color := clSkyBlue;
    UnitDrawTree.FormTree.ImageTree.Canvas.Font.Color := clWhite;
    UnitDrawTree.FormTree.ImageTree.Canvas.Font.Name := 'Century Gothic';
    UnitDrawTree.FormTree.ImageTree.Canvas.Font.Style := [fsBold];
    UnitDrawTree.FormTree.ImageTree.Canvas.Rectangle(0, 0, UnitDrawTree.FormTree.ImageTree.Width, UnitDrawTree.FormTree.ImageTree.Height);
    DrawNode(Head, 0, True, (UnitDrawTree.FormTree.ImageTree.Width div 2), HALF_SIZE_NODE);
    UnitDrawTree.FormTree.ShowModal();
end;

procedure TFormMain.ButtonFindAnswerClick(Sender: TObject);
var
    Error: String;
    CountNode, CountLeaf: Integer;
begin
    CountNode := 0;
    CountLeaf := 0;
    if Head <> nil then
    begin
        CountInTree(Head, CountNode, CountLeaf);
        UnitNodesAndLeaves.FormNodesAndLeaves.LabelNodes.Caption := IntToStr(CountNode);
        UnitNodesAndLeaves.FormNodesAndLeaves.LabelLeaves.Caption := IntToStr(CountLeaf);
        UnitNodesAndLeaves.FormNodesAndLeaves.ShowModal();
        UnitNodesAndLeaves.FormNodesAndLeaves.LabelNodes.Caption := '';
        UnitNodesAndLeaves.FormNodesAndLeaves.LabelLeaves.Caption := '';
    end
    else
    begin
        Error := 'Дерево пустое. ';
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;

procedure TFormMain.ButtonTaskClick(Sender: TObject);
begin
    UnitTask_5_2.FormTask.ShowModal();
end;

procedure TFormMain.EditChangeTreeChange(Sender: TObject);
begin
    if (EditChangeTree.Text <> '') and (EditChangeTree.Text <> '-') then
    begin
        ButtonAddElement.Enabled := true;
        ButtonDeleteElement.Enabled := true;
    end
    else
    begin
        ButtonAddElement.Enabled := false;
        ButtonDeleteElement.Enabled := false;
    end;
end;

procedure TFormMain.EditChangeTreeKeyPress(Sender: TObject; var Key: Char);
begin
    if not(Key in ['0'..'9', #8, '-']) then
        Key := #0;
    if (Length(EditChangeTree.Text) > 0) and (EditChangeTree.Text[1] = '-') then
        EditChangeTree.MaxLength := 3
    else
        EditChangeTree.MaxLength := 2;
    if (Length(EditChangeTree.Text) > 0) and (Key = '-') then
        Key := #0;
    if (Length(EditChangeTree.Text) = 1) and (EditChangeTree.Text[1] = '-') and (Key = '0') then
        Key := #0;
    if (Length(EditChangeTree.Text) = 1) and (EditChangeTree.Text[1] = '0') and not(Length(EditChangeTree.SelText) > 0) and not(Key = #8) then
        Key := #0;
end;

procedure TFormMain.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
    If UnitExit.FormExit.ShowModal() = mrOk Then
        CanClose := True
    Else
        CanClose := False;
end;


procedure TFormMain.FormCreate(Sender: TObject);
begin
    Head := nil;
end;

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

procedure TFormMain.NInstructionClick(Sender: TObject);
begin
    UnitInstruction_5_2.FormInstruction.ShowModal();
end;

procedure TFormMain.NOpenFileClick(Sender: TObject);
var
    Path, Error, InputStr: String;
    IsCorrect, IsEmpty: Boolean;
    F: TextFile;
    Element: Integer;
begin
    IsCorrect := true;
    Error := '';
    IsEmpty := true;
    if (OpenDialog.Execute) then
    begin
        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_DATA) or (Element > MAX_DATA) then
                            begin
                                IsCorrect := false;
                                Error := 'Найден элемент, не входящий в допустимый диапазон. ';
                            end
                            else
                            begin
                                AddElement(Head, Element);
                                IsEmpty := false;
                            end;
                        except
                            IsCorrect := false;
                            Error := 'Найден некорректный элемент списка. ';
                        end;
                    end;
                end;
                if (IsCorrect) then
                begin
                    if (IsEmpty) then
                    begin
                        IsCorrect := false;
                        Error := 'В файле не найдено элементов. ';
                    end;
                end;
            finally
                CloseFile(F);
            end;
        except
            IsCorrect := false;
            Error := 'Ошибка при считывании данных из файла. ';
        end;
    end;
    if not(IsCorrect) then
    begin
        Head := nil;
        UnitError.FormError.LabelError.Caption := 'Ошибка! ' + Error;
        UnitError.FormError.ShowModal();
        UnitError.FormError.LabelError.Caption := '';
    end;
end;