RE: [Extgraph-developer] TSimplegraph.DrawObjectOrder

[vrecion <pav...@sy...>]

Yeah ZOrder will be usefull.

Pavel

 

  _____  

From: ext...@li...
[mailto:ext...@li...] On Behalf Of Marco
Wobben
Sent: Wednesday, February 23, 2005 9:46 AM
To: ext...@li...
Subject: [Extgraph-developer] TSimplegraph.DrawObjectOrder

 

Hi guys,

My first real need and adjustment to the code is the being able to influence
the drawing order of the GraphObjects. For this to work I've done the
following:

*	Introduced a new TDrawObjectOrder enumeration (ooZOrder,
ooLinksFirst, ooNodesFirst)
*	Added a published property DrawObjectOrder (default value
ooLinksFirst for backward compatible behaviour)
*	Rewritten the TSimpleGraph.Draw method a little.

Below is a small snippet to show you how this influences the drawing of
GraphObjects, you can compare it to the existing code in this method which
always draws links first and the other objects on top of that. However this
ignores the ZOrder and the need for it to happen the other way around (as it
does in my case).

Hope to write about more changes I've made and add even more usable changes
soon...

Regards,
Marco.

procedure TSimpleGraph.Draw(Canvas: TCanvas);
var
  I: Integer;

  (* MW *)
  procedure DrawObjects(aType: TDrawObjects);
  var
    i: integer;
  begin
    for I := 0 to Objects.Count - 1 do
      with Objects[I] do
        if (aType = doAll) or
          (IsLink and (aType = doLinks)) or
          (not IsLink and (aType = doNodes)) then
          Draw(Canvas);
  end;

begin
  (* MW *)
  case DrawObjectOrder of
    ooNodesFirst: DrawObjects(doNodes);
    ooLinksFirst: DrawObjects(doLinks);
  end;

  if Linking and ((State = gsMoveLink) or
    ((CommandMode = cmLinkNodes) and (FirstNodeOfLink <> nil))) then
  begin
    Canvas.Pen.Mode := pmNot;
    Canvas.Pen.Width := 1;
    Canvas.Pen.Style := psSolid;
    DefaultLinkClass.DrawDraft(Canvas,
      Rect(StartPoint.X, StartPoint.Y, StopPoint.X, StopPoint.Y));
  end;

  (* MW *)
  case DrawObjectOrder of
    ooNodesFirst: DrawObjects(doLinks);
    ooLinksFirst: DrawObjects(doNodes);
  else
    DrawObjects(doAll);
  end;

  if Linking and (CommandMode = cmLinkNodes) and (FirstNodeOfLink <> nil)
then
  ...
  ...