Future of SimpleGraph

[shternlib]

Hi. Where can I know about your feature plans of TSimpleGraph? Do you plan to make polylines? Thanks.

[Kambiz]

Frankly, no future plan!

Defining a new polyline node is very easy. You just need to subclass a new class from TPloygonalNode and override two simple methods.

For example here is the definitian of TTriangularNode:

Code: Select all

TTriangularNode = class(TPolygonalNode)
  protected
    function GetMaxTextRect: TRect; override;
    class procedure DefineVertices(const ARect: TRect; var Points: TPointArray); override;
  end;

class procedure TTriangularNode.DefineVertices(const ARect: TRect;
  var Points: TPointArray);
begin
  SetLength(Points, 3);
  with ARect do
  begin
    with Points[0] do
    begin
      X := (Left + Right) div 2;
      Y := Top;
    end;
    with Points[1] do
    begin
      X := Right;
      Y := Bottom;
    end;
    with Points[2] do
    begin
      X := Left;
      Y := Bottom;
    end;
  end;
end;

function TTriangularNode.GetMaxTextRect: TRect;
begin
  with Result do
  begin
    Left := (Vertices[0].X + Vertices[2].X) div 2;
    Top := (Vertices[0].Y + Vertices[2].Y) div 2;
    Right := (Vertices[0].X + Vertices[1].X) div 2;
    Bottom := Vertices[1].Y;
  end;
  OffsetRect(Result, -Left, -Top);
  IntersectRect(Result, Result, inherited GetMaxTextRect);
end;

By the way, to be able to read a newly defined node from a stream, you have to register its class to SimpleGraph as follow:

Code: Select all

TSimpleGraph.Register(TTriangularNode);

That's all.

[shternlib]

Is it possible to make polyline link? F.e. link from node A to node B and another link from B to A?

[Kambiz]

For this purpose you have to subclass TGraphLink, and add some intermediate points to the link. Also, the new link class should be registered to the SimpleGraph, as same as node classes.

To be honest, it's lot of work and because of that I didn't implement it myself. Who knows, maybe in future I do it.

[shternlib]

And what is needed to make this moment closure?

[Kambiz]

(Motivation + Spare Time) . (a lot)

[shternlib]

Motivation is what? If I understand you correct, spare time is consequence of motivation

[Kambiz]

Currently I have three open projects in my hands. When I finished them, I may improve TGraphLink class to fit in your needs.

[shternlib]

Does anything can change the priority of your projects? I mean making TSimpleGraph before those three projects

[Kambiz]

Two of them are contracted projects and I cannot postpone them.