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{
fpGUI - Free Pascal GUI Library
Database support classes
Copyright (C) 2000 - 2006 See the file AUTHORS.txt, included in this
distribution, for details of the copyright.
See the file COPYING.modifiedLGPL, included in this distribution,
for details about redistributing fpGUI.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
}
unit fpGUI_DB;
{$IFDEF Debug}
{$ASSERTIONS On}
{$ENDIF}
interface
uses Classes, fpGUI, DB;
type
TFieldDataLink = class(TDataLink)
private
FWidget: TWidget;
FField: TField;
FFieldName: String;
FOnDataChange: TNotifyEvent;
procedure SetFieldName(const AFieldName: String);
procedure UpdateField;
protected
procedure ActiveChanged; override;
procedure RecordChanged(AField: TField); override;
public
constructor Create(AWidget: TWidget);
property Field: TField read FField;
property FieldName: String read FFieldName write SetFieldName;
property OnDataChange: TNotifyEvent read FOnDataChange write FOnDataChange;
end;
TDBText = class(TFCustomLabel)
private
FDataLink: TFieldDataLink;
function GetDataField: String;
procedure SetDataField(const ADataField: String);
function GetDataSource: TDataSource;
procedure SetDataSource(ADataSource: TDataSource);
procedure DataChange(Sender: TObject);
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
published
property Text;
property DataField: String read GetDataField write SetDataField;
property DataSource: TDataSource read GetDataSource write SetDataSource;
end;
// ===================================================================
// ===================================================================
implementation
constructor TFieldDataLink.Create(AWidget: TWidget);
begin
inherited Create;
FWidget := AWidget;
end;
procedure TFieldDataLink.ActiveChanged;
begin
UpdateField;
end;
procedure TFieldDataLink.RecordChanged(AField: TField);
begin
if Assigned(OnDataChange) then
OnDataChange(Self);
end;
procedure TFieldDataLink.SetFieldName(const AFieldName: String);
begin
if AFieldName <> FieldName then
begin
FFieldName := AFieldName;
UpdateField;
end;
end;
procedure TFieldDataLink.UpdateField;
begin
WriteLn('##############UpdateField. DataSet: ', DataSource.DataSet.ClassName);
FField := DataSource.DataSet.FindField(FieldName);
if Assigned(OnDataChange) then
OnDataChange(Self);
end;
constructor TDBText.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FDataLink := TFieldDataLink.Create(Self);
FDataLink.OnDataChange := @DataChange;
end;
destructor TDBText.Destroy;
begin
FDataLink.Free;
inherited Destroy;
end;
function TDBText.GetDataField: String;
begin
Result := FDataLink.FieldName;
end;
procedure TDBText.SetDataField(const ADataField: String);
begin
FDataLink.FieldName := ADataField;
end;
function TDBText.GetDataSource: TDataSource;
begin
Result := FDataLink.DataSource;
end;
procedure TDBText.SetDataSource(ADataSource: TDataSource);
begin
FDataLink.DataSource := ADataSource;
end;
procedure TDBText.DataChange(Sender: TObject);
begin
Write('TDBText.DataChange');
if Assigned(FDataLink.Field) then
begin
Text := FDataLink.Field.DisplayText;
WriteLn(' new text: "', Text, '"');
end else
begin
Text := '';
WriteLn('DataLink has no data');
end;
end;
end.
{
$Log: fpgui_db.pp,v $
Revision 1.2 2001/01/17 21:36:26 sg
* Updating fixes
Revision 1.1 2000/12/23 23:20:16 sg
* First public CVS version...
}
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