* merged from 1.0.x

fcl/db/datasource.inc

@@ -0,0 +1,497 @@
+{ ---------------------------------------------------------------------
+    TDatalink
+  ---------------------------------------------------------------------}
+
+Constructor TDataLink.Create;
+
+begin
+  Inherited Create;
+  FBufferCount:=1;
+  FDatasourceFixed:=False;
+end;
+
+
+Destructor TDataLink.Destroy; 
+
+begin
+  Factive:=False;
+  FEditing:=False;
+  FDataSourceFixed:=False;
+  DataSource:=Nil;
+  Inherited Destroy;
+end;
+
+  
+Procedure TDataLink.ActiveChanged; 
+
+begin
+end;
+
+Procedure TDataLink.CheckActiveAndEditing;
+
+Var
+  B : Boolean;
+
+begin
+  B:=Assigned(DataSource) and (DataSource.State<>dsInactive);
+  If B<>FActive then
+    begin
+    FActive:=B;
+    ActiveChanged;
+    end;
+  B:=Assigned(DataSource) and (DataSource.State in dsEditModes) and Not FReadOnly;
+  If B<>FEditing Then
+    begin
+    FEditing:=B;
+    EditingChanged;
+    end;
+end;
+
+
+Procedure TDataLink.CheckBrowseMode; 
+
+begin
+end;
+
+Function TDataLink.CalcFirstRecord(Index : Integer) : Integer;
+
+{ recalculates index of first record in buffer, 
+  and returns number of record scrolled.}
+
+Var 
+   A,              // Index of active record in buffer
+   F,              // Index of current first record in buffer 
+   L : Integer;    // index of Last (for us) record in buffer;
+ 
+begin
+  A:=DataSource.DataSet.FActiveRecord;
+  F:=FFirstRecord+Index;
+  L:=F+FBufferCount-1;
+  If A>L Then
+    Result:=A-L
+  else If A<F Then
+    Result:=A-F;
+  FFirstRecord:=F+Result;
+end;
+
+
+Procedure TDataLink.DataEvent(Event: TDataEvent; Info: Longint); 
+
+
+begin
+  Case Event of
+    deFieldChange, 
+    deRecordChange : 
+      If Not FUpdatingRecord then
+        RecordChanged(TField(Info));
+    deDataSetChange: 
+      begin
+      CalcFirstRecord(Info);
+      DatasetChanged;
+      end;
+    deDataSetScroll: 
+      DatasetScrolled(CalcFirstRecord(Info));
+    deLayoutChange: 
+      begin
+      CalcFirstRecord(Info);
+      LayoutChanged;
+      end;
+    deUpdateRecord: 
+      UpdateRecord;
+    deUpdateState: 
+      CheckActiveAndEditing;
+    deCheckBrowseMode:
+      CheckBrowseMode;
+    deFocusControl: 
+      FocusControl(TFieldRef(Info));
+  end;     
+end;
+
+
+Procedure TDataLink.DataSetChanged; 
+
+begin
+  RecordChanged(Nil);
+end;
+
+
+Procedure TDataLink.DataSetScrolled(Distance: Integer); 
+
+begin
+  DataSetChanged;
+end;
+
+
+Procedure TDataLink.EditingChanged; 
+
+begin
+end;
+
+
+Procedure TDataLink.FocusControl(Field: TFieldRef); 
+
+begin
+end;
+
+
+Function TDataLink.GetActiveRecord: Integer; 
+
+begin
+  Result:=Dataset.FActiveRecord;
+end;
+
+Function TDatalink.GetDataSet : TDataset;
+
+begin
+  Result:=FDataSource.DataSet
+end;
+
+
+Function TDataLink.GetBOF: Boolean; 
+
+begin
+  Result:=DataSet.BOF
+end;
+
+
+Function TDataLink.GetBufferCount: Integer; 
+
+begin
+  Result:=FBufferCount;
+end;
+
+
+Function TDataLink.GetEOF: Boolean; 
+
+begin
+  Result:=DataSet.EOF
+end;
+
+
+Function TDataLink.GetRecordCount: Integer; 
+
+Var D : TDataSet;
+
+begin
+  Result:=Dataset.RecordCount;
+  If Result>BufferCount then
+    Result:=BufferCount;
+end;
+
+
+Procedure TDataLink.LayoutChanged; 
+
+begin
+  DataSetChanged;
+end;
+
+
+Function TDataLink.MoveBy(Distance: Integer): Integer; 
+
+begin
+  DataSet.MoveBy(Distance);
+end;
+
+
+Procedure TDataLink.RecordChanged(Field: TField); 
+
+begin
+end;
+
+
+Procedure TDataLink.SetActiveRecord(Value: Integer); 
+
+begin
+  Dataset.FActiveRecord:=Value;
+end;
+
+
+Procedure TDataLink.SetBufferCount(Value: Integer); 
+
+begin
+  If FBUfferCount<>Value then
+    begin
+    FBufferCount:=Value;
+    Dataset.SetBufListSize(Value);
+    end;
+end;
+
+Procedure TDataLink.SetDataSource(Value : TDatasource);
+
+begin
+  if not FDataSourceFixed then
+  begin
+    if Assigned(DataSource) then
+      DataSource.UnregisterDatalink(Self);
+    FDataSource := Value;
+    if Assigned(DataSource) then
+      DataSource.RegisterDatalink(Self);
+  end;
+end;
+
+Procedure TDatalink.SetReadOnly(Value : Boolean); 
+
+begin
+  If FReadOnly<>Value then
+    begin
+    FReadOnly:=Value;
+    CheckActiveAndEditing;
+    end;
+end;
+
+Procedure TDataLink.UpdateData; 
+
+begin
+end;
+
+
+
+Function TDataLink.Edit: Boolean;
+
+begin
+  If Not FReadOnly then
+    DataSource.Edit;
+  // Triggered event will set FEditing
+  Result:=FEditing;  
+end;
+
+
+Procedure TDataLink.UpdateRecord;
+
+begin
+  FUpdatingRecord:=True;
+  Try
+    UpdateData;
+  finally
+   FUpdatingRecord:=False;
+  end;
+end;
+
+
+
+{ ---------------------------------------------------------------------
+    TDetailDataLink
+  ---------------------------------------------------------------------}
+  
+Function TDetailDataLink.GetDetailDataSet: TDataSet; 
+
+begin
+end;
+
+
+{ ---------------------------------------------------------------------
+    TMasterDataLink
+  ---------------------------------------------------------------------}
+
+constructor TMasterDataLink.Create(ADataSet: TDataSet);
+
+begin
+end;
+
+
+destructor TMasterDataLink.Destroy; 
+
+begin
+  inherited Destroy;
+end;
+  
+
+Procedure TMasterDataLink.ActiveChanged; 
+
+begin
+end;
+
+
+Procedure TMasterDataLink.CheckBrowseMode; 
+
+begin
+end;
+
+
+Function TMasterDataLink.GetDetailDataSet: TDataSet; 
+
+begin
+end;
+
+
+Procedure TMasterDataLink.LayoutChanged; 
+
+begin
+end;
+
+
+Procedure TMasterDataLink.RecordChanged(Field: TField); 
+
+begin
+end;
+
+procedure TMasterDatalink.SetFieldNames(const Value: string);
+
+begin
+end;
+
+
+{ ---------------------------------------------------------------------
+    TDatasource
+  ---------------------------------------------------------------------}
+    
+Constructor TDataSource.Create(AOwner: TComponent); 
+
+begin
+  Inherited Create(AOwner);
+  FDatalinks:=TList.Create;
+  FEnabled:=True;
+  FAutoEdit:=True;
+end;
+
+
+Destructor TDataSource.Destroy; 
+
+begin
+  FOnStateCHange:=Nil;
+  Dataset:=Nil;
+  With FDataLinks do 
+    While Count>0 do
+      TDatalink(Items[Count - 1]).DataSource:=Nil;
+  FDatalinks.Free;
+  inherited Destroy;
+end;
+
+
+Procedure TDatasource.Edit;
+
+begin
+  If (State=dsBrowse) and AutoEdit Then
+    Dataset.Edit;
+end;
+
+
+Function TDataSource.IsLinkedTo(ADataSet: TDataSet): Boolean;
+
+begin
+  Result:=False;
+end;
+
+
+procedure TDatasource.DistributeEvent(Event: TDataEvent; Info: Longint);
+
+
+Var 
+  i : Longint;
+
+begin
+  With FDatalinks do
+    begin
+    For I:=0 to Count-1 do
+      With TDatalink(Items[i]) do
+        If Not VisualControl Then
+          DataEvent(Event,Info); 
+    For I:=0 to Count-1 do
+      With TDatalink(Items[i]) do
+        If VisualControl Then
+          DataEvent(Event,Info); 
+    end;
+end;
+
+procedure TDatasource.RegisterDataLink(DataLink: TDataLink);
+
+begin
+  FDatalinks.Add(DataLink);
+  If DataSet<>Nil then 
+    Dataset.SetBufListSize(Datalink.BufferCount);
+end;
+
+
+procedure TDatasource.SetDataSet(ADataSet: TDataSet);
+
+begin
+  If FDataset<>Nil Then
+    FDataset.UnRegisterDataSource(Self);
+  If ADataset<>Nil Then
+    ADataset.RegisterDatasource(Self);
+  FDataSet:=ADAtaset;  
+  ProcessEvent(deUpdateState,0);
+end;
+
+
+procedure TDatasource.SetEnabled(Value: Boolean);
+
+begin
+  FEnabled:=Value;
+end;
+
+
+Procedure TDatasource.DoDataChange (Info : Pointer);
+
+begin
+  If Assigned(OnDataChange) Then
+    OnDataChange(Self,TField(Info));
+end;
+
+Procedure TDatasource.DoStateChange;
+
+begin
+  If Assigned(OnStateChange) Then 
+    OnStateChange(Self);
+end;
+
+
+Procedure TDatasource.DoUpdateData;
+
+begin
+  If Assigned(OnUpdateData) Then 
+    OnUpdateData(Self);
+end;
+
+
+procedure TDatasource.UnregisterDataLink(DataLink: TDataLink);
+
+begin
+  FDatalinks.Remove(Datalink);
+  If Dataset<>Nil then 
+    Dataset.SetBufListSize(DataLink.BufferCount);
+end;
+
+
+procedure TDataSource.ProcessEvent(Event : TDataEvent; Info : longint);
+
+Const 
+  OnDataChangeEvents = [deRecordChange, deDataSetChange, 
+                           deDataSetScroll, 
+                           deLayoutChange,deUpdateState];
+
+Var
+  NeedDataChange : Boolean;
+  FLastState : TdataSetState;
+  
+begin
+  // Special UpdateState handling.
+  If Event=deUpdateState then
+    begin
+    NeedDataChange:=(FState=dsInactive);
+    FLastState:=FState;
+    If Assigned(Dataset) then
+      FState:=Dataset.State
+    else
+      FState:=dsInactive;  
+    // Don't do events if nothing changed.  
+    If FState<>FlastState then 
+      exit;  
+    end
+  else
+    NeedDataChange:=True;  
+  DistributeEvent(Event,Info);
+  // Extra handlers
+  If Not (csDestroying in ComponentState) then
+    begin
+    If (Event=deUpdateState) then
+      DoStateChange;
+    If (Event in OnDataChangeEvents) and 
+       NeedDataChange Then
+      DoDataChange(Nil);
+    If (Event = deFieldChange) Then
+      DoDataCHange(Pointer(Info));
+    If (Event=deUpdateRecord) then
+      DoUpdateData;
+    end;
+ end;