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#1: Future of SimpleGraph Author: shternlib, Location: Russia

Posted: 28/06/04 07:38
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Hi. Where can I know about your feature plans of TSimpleGraph? Do you plan to make polylines? Thanks.

#2: Author: Kambiz, Location: Tehran, Iran

Posted: 28/06/04 09:24
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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:

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:

TSimpleGraph.Register(TTriangularNode);

That's all.

#3: I mean polyline link Author: shternlib, Location: Russia

Posted: 28/06/04 10:43
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Is it possible to make polyline link? F.e. link from node A to node B and another link from B to A?

#4: Author: Kambiz, Location: Tehran, Iran

Posted: 28/06/04 11:56
—
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. Wink