[Extgraph-developer] ScrollInView and DoCanMoveResizeNode

[Marco W. <in...@ca...>]

Pavel,

Since you're the first merging developer at this moment, perhaps you can 
find some space and time to insert this routine. It's been posted 
earlier in an email to Stefan (I think), and has been extended a little 
so that if a node is scrolled to the right or bottom the scrollbars move 
with it, keeping it visible. The same goes for dragging it to the top or 
left, than it moves all other controls to the bottom right...

Marco.

There you go:

procedure TSimpleGraph.DoCanMoveResizeNode(Node: TGraphNode; var aLeft,
  aTop, aWidth, aHeight: Integer; var CanMove, CanResize: Boolean);
var
  i: integer;
  Delta: TPoint;
  R: TRect;
begin
  if FreezeTopLeft then
  begin
    if aLeft < 0 then aLeft := 0;
    if aTop < 0 then aTop := 0;
  end
  else
  begin
    { MeW: scroll other nodes to the bottom right
           if a node is scrolled beyond the topleft }
    if (aLeft < Left) or (aTop < Top) then
    begin
      Delta := Point(0,0);
      if (aLeft < Left) then Delta.X := -aLeft;
      if (aTop < Top) then Delta.Y := -aTop;
      BeginUpdate;
      try
        for i:=0 to ObjectsCount-1 do
        begin
          if (not Objects.Items[i].Selected) and
            (Objects.Items[i] <> Node) and
            (TGraphNodeExt(Objects.Items[i]).Parent = nil) then
          begin
            R := Objects[i].BoundsRect;
            OffsetRect(R, Delta.X, Delta.Y);
            Objects[i].BoundsRect := R;
          end;
        end;
        if (aLeft < Left) then aLeft := 0;
        if (aTop < Top) then aTop := 0;
      finally
        EndUpdate;
      end;
    end;
    { MeW:  scroll right and/or bottom if required }
    if (aLeft + Width > VisibleBounds.Right) or
      (aTop + Height > VisibleBounds.Bottom) then
      ScrollInView(Node);
  end;
  if Assigned(OnCanMoveResizeNode) then
    OnCanMoveResizeNode(Self, Node, aLeft, aTop, aWidth, aHeight, 
CanMove, CanResize);
end;