current/DataAccess/ConnectionManager.pas

unit ConnectionManager;
interface

uses TypeDefs, DataAccess, Access_OniArchive, Access_OUP_ADB;

type
  TConnections = array of TDataAccess;

  TConnectionListChangedEvent = procedure of object;

  
  TConnectionManager = class
  private
    FConnections: TConnections;
    FLastID:      Integer;
    FConnectionListChanged: TConnectionListChangedEvent;
    function GetConnectionCount: Integer;
    function GetConnection(ConnectionID: Integer): TDataAccess;
    function GetConnectionByIndex(Index: Integer): TDataAccess;
    procedure RemoveConnection(ArrayIndex: Integer);
  protected
  public
    property Count: Integer read GetConnectionCount;
    property Connection[ConnectionID: Integer]: TDataAccess read GetConnection;
    property ConnectionByIndex[Index: Integer]: TDataAccess read GetConnectionByIndex;
    property OnCoonnectionListChanged: TConnectionListChangedEvent read FConnectionListChanged write FConnectionListChanged;

    constructor Create;
    function Close: Boolean;

    function OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
    function CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean; overload;
    function CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean; overload;
    function CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean; overload;
  published
  end;


implementation
uses
  SysUtils, Dialogs;

(*
 Implementation of TConnectionManager
*)


function TConnectionManager.GetConnectionCount: Integer;
begin
  Result := Length(FConnections);
end;

function TConnectionManager.GetConnection(ConnectionID: Integer): TDataAccess;
var
  i: Integer;
begin
  Result := nil;
  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].ConnectionID = ConnectionID then
      begin
        Result := FConnections[i];
        Break;
      end;
    end;
    if i = Length(FConnections) then
      ShowMessage('Couldn''t find specified ConnectionID (' +
          IntToStr(ConnectionID) + '). Please contact developer!!!');
  end;
end;


function TConnectionManager.GetConnectionByIndex(Index: Integer): TDataAccess;
begin
  Result := nil;
  if index < Length(FConnections) then
  begin
    Result := FConnections[index];
  end;
end;

constructor TConnectionManager.Create;
begin
  inherited;
  FLastID := 0;
end;

function TConnectionManager.Close: Boolean;
begin
  Result := False;
  if Length(FConnections) > 0 then
    Exit;

  inherited;
end;


function TConnectionManager.OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
var
  i: Integer;
  ext: String;
  backend: TDataBackend;
  CreateMsg: TStatusMessages;
begin
  Msg := SM_UnknownError;
  Result := -1;

  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].FileName = FileName then
      begin
        Result := FConnections[i].ConnectionID;
        Msg := SM_AlreadyOpened;
        Exit;
      end;
    end;
  end;

  if not FileExists(FileName) then
  begin
    Msg := SM_FileNotFound;
    Exit;
  end;

  ext := UpperCase(ExtractFileExt(FileName));

  if ext = 'ODB' then
    backend := DB_ADB
  else if ext = 'DAT' then
    backend := DB_ONI
  else
  begin
    Msg := SM_UnknownExtension;
    Exit;
  end;

  SetLength(FConnections, Length(FConnections) + 1);
  i := High(FConnections);
  case backend of
    DB_ONI:
      FConnections[i] := TAccess_OniArchive.Create(FileName, FLastID + 1, CreateMsg);
    DB_ADB:
      FConnections[i] := TAccess_OUP_ADB.Create(FileName, FLastID + 1, CreateMsg);
  end;

  if CreateMsg = SM_OK then
  begin
    FLastID := FConnections[i].ConnectionID;
    Result := FLastID;
  end
  else
  begin
    FConnections[i].Close;
    FConnections[i].Free;
    FConnections[i] := nil;
    SetLength(FConnections, Length(FConnections) - 1);
    Msg := SM_UnknownError;
  end;
end;


procedure TConnectionManager.RemoveConnection(ArrayIndex: Integer);
var
  i: Integer;
begin
  if Length(FConnections) > 1 then
  begin
    for i := ArrayIndex to High(FConnections) - 1 do
    begin
      FConnections[i] := FConnections[i + 1];
    end;
  end;
  SetLength(FConnections, Length(FConnections) - 1);
end;

function TConnectionManager.CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean;
begin
  Msg := SM_UnknownError;
  Result := False;

  if Index < Length(FConnections) then
  begin
    FConnections[Index].Close;
    RemoveConnection(Index);
    Msg := SM_OK;
    Result := True;
  end;
end;

function TConnectionManager.CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean;
var
  i: Integer;
begin
  Msg := SM_UnknownError;
  Result := False;

  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].ConnectionID = ID then
      begin
        FConnections[i].Close;
        RemoveConnection(i);
        Msg := SM_OK;
        Result := True;
        Exit;
      end;
    end;
  end;
end;

function TConnectionManager.CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean;
var
  i: Integer;
begin
  Msg := SM_UnknownError;
  Result := False;

  if Length(FConnections) > 0 then
  begin
    for i := 0 to High(FConnections) do
    begin
      if FConnections[i].FileName = FileName then
      begin
        FConnections[i].Close;
        RemoveConnection(i);
        Msg := SM_OK;
        Result := True;
        Exit;
      end;
    end;
  end;
end;


end.
Revision:	93
Committed:	Thu Jan 18 17:15:59 2007 UTC (18 years, 9 months ago) by alloc
Content type:	text/x-pascal
Original Path:	*oup/rewrite/DataAccess/ConnectionManager.pas*
File size:	5754 byte(s)
Log Message:
#	Content
1	unit ConnectionManager;
2	interface
3
4	uses TypeDefs, DataAccess, Access_OniArchive, Access_OUP_ADB;
5
6	type
7	TConnections = array of TDataAccess;
8
9	TConnectionListChangedEvent = procedure of object;
10
11
12	TConnectionManager = class
13	private
14	FConnections: TConnections;
15	FLastID: Integer;
16	FConnectionListChanged: TConnectionListChangedEvent;
17	function GetConnectionCount: Integer;
18	function GetConnection(ConnectionID: Integer): TDataAccess;
19	function GetConnectionByIndex(Index: Integer): TDataAccess;
20	procedure RemoveConnection(ArrayIndex: Integer);
21	protected
22	public
23	property Count: Integer read GetConnectionCount;
24	property Connection[ConnectionID: Integer]: TDataAccess read GetConnection;
25	property ConnectionByIndex[Index: Integer]: TDataAccess read GetConnectionByIndex;
26	property OnCoonnectionListChanged: TConnectionListChangedEvent read FConnectionListChanged write FConnectionListChanged;
27
28	constructor Create;
29	function Close: Boolean;
30
31	function OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
32	function CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean; overload;
33	function CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean; overload;
34	function CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean; overload;
35	published
36	end;
37
38
39	implementation
40	uses
41	SysUtils, Dialogs;
42
43	(*
44	Implementation of TConnectionManager
45	*)
46
47
48	function TConnectionManager.GetConnectionCount: Integer;
49	begin
50	Result := Length(FConnections);
51	end;
52
53	function TConnectionManager.GetConnection(ConnectionID: Integer): TDataAccess;
54	var
55	i: Integer;
56	begin
57	Result := nil;
58	if Length(FConnections) > 0 then
59	begin
60	for i := 0 to High(FConnections) do
61	begin
62	if FConnections[i].ConnectionID = ConnectionID then
63	begin
64	Result := FConnections[i];
65	Break;
66	end;
67	end;
68	if i = Length(FConnections) then
69	ShowMessage('Couldn''t find specified ConnectionID (' +
70	IntToStr(ConnectionID) + '). Please contact developer!!!');
71	end;
72	end;
73
74
75	function TConnectionManager.GetConnectionByIndex(Index: Integer): TDataAccess;
76	begin
77	Result := nil;
78	if index < Length(FConnections) then
79	begin
80	Result := FConnections[index];
81	end;
82	end;
83
84	constructor TConnectionManager.Create;
85	begin
86	inherited;
87	FLastID := 0;
88	end;
89
90	function TConnectionManager.Close: Boolean;
91	begin
92	Result := False;
93	if Length(FConnections) > 0 then
94	Exit;
95
96	inherited;
97	end;
98
99
100
101	function TConnectionManager.OpenConnection(FileName: String; var Msg: TStatusMessages): Integer;
102	var
103	i: Integer;
104	ext: String;
105	backend: TDataBackend;
106	CreateMsg: TStatusMessages;
107	begin
108	Msg := SM_UnknownError;
109	Result := -1;
110
111	if Length(FConnections) > 0 then
112	begin
113	for i := 0 to High(FConnections) do
114	begin
115	if FConnections[i].FileName = FileName then
116	begin
117	Result := FConnections[i].ConnectionID;
118	Msg := SM_AlreadyOpened;
119	Exit;
120	end;
121	end;
122	end;
123
124	if not FileExists(FileName) then
125	begin
126	Msg := SM_FileNotFound;
127	Exit;
128	end;
129
130	ext := UpperCase(ExtractFileExt(FileName));
131
132	if ext = 'ODB' then
133	backend := DB_ADB
134	else if ext = 'DAT' then
135	backend := DB_ONI
136	else
137	begin
138	Msg := SM_UnknownExtension;
139	Exit;
140	end;
141
142	SetLength(FConnections, Length(FConnections) + 1);
143	i := High(FConnections);
144	case backend of
145	DB_ONI:
146	FConnections[i] := TAccess_OniArchive.Create(FileName, FLastID + 1, CreateMsg);
147	DB_ADB:
148	FConnections[i] := TAccess_OUP_ADB.Create(FileName, FLastID + 1, CreateMsg);
149	end;
150
151	if CreateMsg = SM_OK then
152	begin
153	FLastID := FConnections[i].ConnectionID;
154	Result := FLastID;
155	end
156	else
157	begin
158	FConnections[i].Close;
159	FConnections[i].Free;
160	FConnections[i] := nil;
161	SetLength(FConnections, Length(FConnections) - 1);
162	Msg := SM_UnknownError;
163	end;
164	end;
165
166
167	procedure TConnectionManager.RemoveConnection(ArrayIndex: Integer);
168	var
169	i: Integer;
170	begin
171	if Length(FConnections) > 1 then
172	begin
173	for i := ArrayIndex to High(FConnections) - 1 do
174	begin
175	FConnections[i] := FConnections[i + 1];
176	end;
177	end;
178	SetLength(FConnections, Length(FConnections) - 1);
179	end;
180
181	function TConnectionManager.CloseConnectionByIndex(Index: Integer; var Msg: TStatusMessages): Boolean;
182	begin
183	Msg := SM_UnknownError;
184	Result := False;
185
186	if Index < Length(FConnections) then
187	begin
188	FConnections[Index].Close;
189	RemoveConnection(Index);
190	Msg := SM_OK;
191	Result := True;
192	end;
193	end;
194
195	function TConnectionManager.CloseConnection(ID: Integer; var Msg: TStatusMessages): Boolean;
196	var
197	i: Integer;
198	begin
199	Msg := SM_UnknownError;
200	Result := False;
201
202	if Length(FConnections) > 0 then
203	begin
204	for i := 0 to High(FConnections) do
205	begin
206	if FConnections[i].ConnectionID = ID then
207	begin
208	FConnections[i].Close;
209	RemoveConnection(i);
210	Msg := SM_OK;
211	Result := True;
212	Exit;
213	end;
214	end;
215	end;
216	end;
217
218	function TConnectionManager.CloseConnection(FileName: String; var Msg: TStatusMessages): Boolean;
219	var
220	i: Integer;
221	begin
222	Msg := SM_UnknownError;
223	Result := False;
224
225	if Length(FConnections) > 0 then
226	begin
227	for i := 0 to High(FConnections) do
228	begin
229	if FConnections[i].FileName = FileName then
230	begin
231	FConnections[i].Close;
232	RemoveConnection(i);
233	Msg := SM_OK;
234	Result := True;
235	Exit;
236	end;
237	end;
238	end;
239	end;
240
241
242	end.