mruunit.pas

一个漂亮的电子书籍阅读管理器

//---------------------------------------------------------------------------
//(R)CopyRight KivenSoft International ,inc 1999
//单元名称：最近开启文件列表类
//程序名称：电子书库
//作    者：李会文
//开始时间：1999.07.06
//最后修改：1999.07.06
//备注：此单元定义了最近开启的文件列表类
//---------------------------------------------------------------------------
unit MruUnit;

interface
uses
  Menus;

type
  TMru=class
  private
    FFileList:array[0..4]of string;
    FListIndex:array[0..4]of integer;
    FParentMenu:TMenuItem;
    FPosition:integer;
    FVisible:boolean;
    function GetFileList(index:integer):string;
    procedure SetFileList(index:integer;Value:string);
    procedure SetVisible(Value:boolean);
  public
    constructor Create;
    destructor Destroy;override;
    procedure Add(Fn:string);
    property FileList[index:integer]:string read GetFileList write SetFileList;default;
    property ParentMenu:TMenuItem read FParentMenu write FParentMenu;
    property Position:integer read FPosition write FPosition;
    property Visible:boolean read FVisible write SetVisible;
  end;

var
  Mru:TMru;
  
implementation

constructor TMru.Create;
var
  i:integer;
begin
  for i:=0 to 4 do
  begin
    FFileList[i]:='';
    FListIndex[i]:=i;
  end;
  FParentMenu:=nil;
  FPosition:=0;
  FVisible:=true;
end;

destructor TMru.Destroy;
begin
  inherited Destroy;
end;

procedure TMru.Add(Fn:string);
var
  i,j,k:integer;
begin
  {$ifdef debug}
    if FParentMenu=nil then raise Exception.Create('Error in TMru.InsertToMenu');
  {$endif}
  if FFileList[FListIndex[0]]=Fn then exit;
  j:=-1;
  for i:=1 to 4 do
    if FFileList[FListIndex[i]]=Fn then j:=i;
  if j=-1 then
  begin
    k:=FListIndex[4];   //保存最后串索引
    FFileList[k]:=Fn; //更新最后串
    for i:=4 downto 1 do FListIndex[i]:=FListIndex[i-1];
    FListIndex[0]:=k;   //置最后串到最前
  end
  else
  begin
    k:=FListIndex[j];
    for i:=j downto 1 do FListIndex[i]:=FListIndex[i-1];
    FListIndex[0]:=k;
  end;
  if FVisible then
    for i:=0 to 4 do
      with FParentMenu do
      begin
        if FFileList[FListIndex[i]]<>'' then
        begin
          Items[Position+i].Caption:='&1 '+FFileList[FListIndex[i]];
          Items[Position+i].Visible:=true;
        end
        else
        begin
          Items[Position+i].Visible:=false;
        end;
      end;
end;

function TMru.GetFileList(index:integer):string;
begin
  Result:=FFileList[FListIndex[index]];
end;

procedure TMru.SetFileList(index:integer;Value:string);
begin
  FFileList[FListIndex[index]]:=Value;
end;

procedure TMru.SetVisible(Value:boolean);
var
  i:integer;
begin
  FVisible:=Value;
  with FParentMenu do
  begin
    if Value then
    begin
      for i:=0 to 4 do
        if FFileList[FListIndex[i]]<>'' then Items[Position+i].Visible:=true
        else Items[Position+i].Visible:=false;
    end
    else
    begin
      for i:=0 to 4 do Items[Position+i].Visible:=Value;
    end;
    Items[Position+5].Visible:=Value;
  end;
end;

end.