bsdbgrids.pas

一套及时通讯的原码

    if Assigned(Field) then
    begin
      RestoreCanvas := not HandleAllocated;
      if RestoreCanvas then
        Canvas.Handle := GetDC(0);
      try
        Canvas.Font := Self.Font;
        GetTextMetrics(Canvas.Handle, TM);
        Result := Field.DisplayWidth * (Canvas.TextWidth('0') - TM.tmOverhang)
          + TM.tmOverhang + 4;
        if dgTitles in Options then
        begin
          Canvas.Font := Title.Font;
          W := Canvas.TextWidth(Title.Caption) + 4;
          if Result < W then
            Result := W;
        end;
      finally
        if RestoreCanvas then
        begin
          ReleaseDC(0,Canvas.Handle);
          Canvas.Handle := 0;
        end;
      end;
    end
    else
      Result := DefaultColWidth;
  end;
end;

procedure TbsColumn.FontChanged;
begin
  Include(FAssignedValues, cvFont);
  Title.RefreshDefaultFont;
  Changed(False);
end;

function TbsColumn.GetAlignment: TAlignment;
begin
  if cvAlignment in FAssignedValues then
    Result := FAlignment
  else
    Result := DefaultAlignment;
end;

function TbsColumn.GetColor: TColor;
begin
  if cvColor in FAssignedValues then
    Result := FColor
  else
    Result := DefaultColor;
end;

function TbsColumn.GetExpanded: Boolean;
begin
  Result := FExpanded and Expandable;
end;

function TbsColumn.GetField: TField;
var
  Grid: TbsSkinCustomDBGrid;
begin    { Returns Nil if FieldName can't be found in dataset }
  Grid := GetGrid;
  if (FField = nil) and (Length(FFieldName) > 0) and Assigned(Grid) and
    Assigned(Grid.DataLink.DataSet) then
  with Grid.Datalink.Dataset do
    if Active or (not DefaultFields) then
      SetField(FindField(FieldName));
  Result := FField;
end;

function TbsColumn.GetFont: TFont;
var
  Save: TNotifyEvent;
begin
  if not (cvFont in FAssignedValues) and (FFont.Handle <> DefaultFont.Handle) then
  begin
    Save := FFont.OnChange;
    FFont.OnChange := nil;
    FFont.Assign(DefaultFont);
    FFont.OnChange := Save;
  end;
  Result := FFont;
end;

function TbsColumn.GetGrid: TbsSkinCustomDBGrid;
begin
  if Assigned(Collection) and (Collection is TbsDBGridColumns) then
    Result := TbsDBGridColumns(Collection).Grid
  else
    Result := nil;
end;

function TbsColumn.GetDisplayName: string;
begin
  Result := FFieldName;
  if Result = '' then Result := inherited GetDisplayName;
end;

function TbsColumn.GetImeMode: TImeMode;
begin
  if cvImeMode in FAssignedValues then
    Result := FImeMode
  else
    Result := DefaultImeMode;
end;

function TbsColumn.GetImeName: TImeName;
begin
  if cvImeName in FAssignedValues then
    Result := FImeName
  else
    Result := DefaultImeName;
end;

function TbsColumn.GetParentColumn: TbsColumn;
var
  Col: TbsColumn;
  Fld: TField;
  I: Integer;
begin
  Result := nil;
  Fld := Field;
  if (Fld <> nil) and (Fld.ParentField <> nil) and (Collection <> nil) then
    for I := Index - 1 downto 0 do
    begin
      Col := TbsColumn(Collection.Items[I]);
      if Fld.ParentField = Col.Field then
      begin
        Result := Col;
        Exit;
      end;
    end;
end;

function TbsColumn.GetPickList: TStrings;
begin
  if FPickList = nil then FPickList := TStringList.Create;
  Result := FPickList;
end;

function TbsColumn.GetReadOnly: Boolean;
begin
  if cvReadOnly in FAssignedValues then
    Result := FReadOnly
  else
    Result := DefaultReadOnly;
end;

function TbsColumn.GetShowing: Boolean;
var
  Col: TbsColumn;
begin
  Result := not Expanded and Visible;
  if Result then
  begin
    Col := Self;
    repeat
      Col := Col.ParentColumn;
    until (Col = nil) or not Col.Expanded;
    Result := Col = nil;
  end;
end;

function TbsColumn.GetVisible: Boolean;
var
  Col: TbsColumn;
begin
  Result := FVisible;
  if Result then
  begin
    Col := ParentColumn;
    Result := Result and ((Col = nil) or Col.Visible);
  end;
end;

function TbsColumn.GetWidth: Integer;
begin
  if not Showing then
    Result := -1
  else if cvWidth in FAssignedValues then
    Result := FWidth
  else
    Result := DefaultWidth;
end;

function TbsColumn.IsAlignmentStored: Boolean;
begin
  Result := (cvAlignment in FAssignedValues) and (FAlignment <> DefaultAlignment);
end;

function TbsColumn.IsColorStored: Boolean;
begin
  Result := (cvColor in FAssignedValues) and (FColor <> DefaultColor);
end;

function TbsColumn.IsFontStored: Boolean;
begin
  Result := (cvFont in FAssignedValues);
end;

function TbsColumn.IsImeModeStored: Boolean;
begin
  Result := (cvImeMode in FAssignedValues) and (FImeMode <> DefaultImeMode);
end;

function TbsColumn.IsImeNameStored: Boolean;
begin
  Result := (cvImeName in FAssignedValues) and (FImeName <> DefaultImeName);
end;

function TbsColumn.IsReadOnlyStored: Boolean;
begin
  Result := (cvReadOnly in FAssignedValues) and (FReadOnly <> DefaultReadOnly);
end;

function TbsColumn.IsWidthStored: Boolean;
begin
  Result := (cvWidth in FAssignedValues) and (FWidth <> DefaultWidth);
end;

procedure TbsColumn.RefreshDefaultFont;
var
  Save: TNotifyEvent;
begin
  if cvFont in FAssignedValues then Exit;
  Save := FFont.OnChange;
  FFont.OnChange := nil;
  try
    FFont.Assign(DefaultFont);
  finally
    FFont.OnChange := Save;
  end;
end;

procedure TbsColumn.RestoreDefaults;
var
  FontAssigned: Boolean;
begin
  FontAssigned := cvFont in FAssignedValues;
  FTitle.RestoreDefaults;
  FAssignedValues := [];
  RefreshDefaultFont;
  FPickList.Free;
  FPickList := nil;
  ButtonStyle := cbsAuto;
  Changed(FontAssigned);
end;

procedure TbsColumn.SetAlignment(Value: TAlignment);
var
  Grid: TbsSkinCustomDBGrid;
begin
  if IsStored then
  begin
    if (cvAlignment in FAssignedValues) and (Value = FAlignment) then Exit;
    FAlignment := Value;
    Include(FAssignedValues, cvAlignment);
    Changed(False);
  end
  else
  begin
    Grid := GetGrid;
    if Assigned(Grid) and (Grid.Datalink.Active) and Assigned(Field) then
      Field.Alignment := Value;
  end;
end;

procedure TbsColumn.SetButtonStyle(Value: TbsColumnButtonStyle);
begin
  if Value = FButtonStyle then Exit;
  FButtonStyle := Value;
  Changed(False);
end;

procedure TbsColumn.SetColor(Value: TColor);
begin
  if (cvColor in FAssignedValues) and (Value = FColor) then Exit;
  FColor := Value;
  Include(FAssignedValues, cvColor);
  Changed(False);
end;

procedure TbsColumn.SetField(Value: TField);
begin
  if FField = Value then Exit;
  if Assigned(FField) and
     (GetGrid <> nil) then
    FField.RemoveFreeNotification(GetGrid);
  FField := Value;
  if Assigned(Value) then
  begin
    if GetGrid <> nil then
      FField.FreeNotification(GetGrid);
    FFieldName := Value.FullName;
  end;
  if not IsStored then
  begin
    if Value = nil then
      FFieldName := '';
    RestoreDefaults;
  end;
  Changed(False);
end;

procedure TbsColumn.SetFieldName(const Value: String);
var
  AField: TField;
  Grid: TbsSkinCustomDBGrid;
begin
  AField := nil;
  Grid := GetGrid;
  if Assigned(Grid) and Assigned(Grid.DataLink.DataSet) and
    not (csLoading in Grid.ComponentState) and (Length(Value) > 0) then
      AField := Grid.DataLink.DataSet.FindField(Value); { no exceptions }
  FFieldName := Value;
  SetField(AField);
  Changed(False);
end;

procedure TbsColumn.SetFont(Value: TFont);
begin
  FFont.Assign(Value);
  Include(FAssignedValues, cvFont);
  Changed(False);
end;

procedure TbsColumn.SetImeMode(Value: TImeMode);
begin
  if (cvImeMode in FAssignedValues) or (Value <> DefaultImeMode) then
  begin
    FImeMode := Value;
    Include(FAssignedValues, cvImeMode);
  end;
  Changed(False);
end;

procedure TbsColumn.SetImeName(Value: TImeName);
begin
  if (cvImeName in FAssignedValues) or (Value <> DefaultImeName) then
  begin
    FImeName := Value;
    Include(FAssignedValues, cvImeName);
  end;
  Changed(False);
end;

procedure TbsColumn.SetIndex(Value: Integer);
var
  Grid: TbsSkinCustomDBGrid;
  Fld: TField;
  I, OldIndex: Integer;
  Col: TbsColumn;
begin
  OldIndex := Index;
  Grid := GetGrid;

  if IsStored then
  begin
    Grid.BeginLayout;
    try
      I := OldIndex + 1;  // move child columns along with parent
      while (I < Collection.Count) and (TbsColumn(Collection.Items[I]).ParentColumn = Self) do
        Inc(I);
      Dec(I);
      if OldIndex > Value then   // column moving left
      begin
        while I > OldIndex do
        begin
          Collection.Items[I].Index := Value;
          Inc(OldIndex);
        end;
        inherited SetIndex(Value);
      end
      else
      begin
        inherited SetIndex(Value);
        while I > OldIndex do
        begin
          Collection.Items[OldIndex].Index := Value;
          Dec(I);
        end;
      end;
    finally
      Grid.EndLayout;
    end;
  end
  else
  begin
    if (Grid <> nil) and Grid.Datalink.Active then
    begin
      if Grid.AcquireLayoutLock then
      try
        Col := Grid.ColumnAtDepth(Grid.Columns[Value], Depth);
        if (Col <> nil) then
        begin
          Fld := Col.Field;
          if Assigned(Fld) then
            Field.Index := Fld.Index;
        end;
      finally
        Grid.EndLayout;
      end;
    end;
    inherited SetIndex(Value);
  end;
end;

procedure TbsColumn.SetPickList(Value: TStrings);
begin
  if Value = nil then
  begin
    FPickList.Free;
    FPickList := nil;
    Exit;
  end;
  PickList.Assign(Value);
end;

procedure TbsColumn.SetPopupMenu(Value: TPopupMenu);
begin
  FPopupMenu := Value;
  if Value <> nil then Value.FreeNotification(GetGrid);
end;

procedure TbsColumn.SetReadOnly(Value: Boolean);
var
  Grid: TbsSkinCustomDBGrid;
begin
  Grid := GetGrid;
  if not IsStored and Assigned(Grid) and Grid.Datalink.Active and Assigned(Field) then
    Field.ReadOnly := Value
  else
  begin
    if (cvReadOnly in FAssignedValues) and (Value = FReadOnly)