RE: [gef-dev] ChopboxAnchor/AutomaticRouter bug?

[Sapna George <sgeorge@xxxxxx>]

Yup!!! It works like a charm with the latest build !! :-))

But, I sure learned a lot about Anchors and Routers through that exercise!

thanks. 
Sapna

>===== Original Message From Randy Hudson <hudsonr@xxxxxxxxxx> =====
>The problem you are seeing is fixed in more recent builds.  It is related
>to a ListenerList removing the wrong listener because it was removing
>using .equals() instead of ==. The equals() for ChopBoxAnchor is working
>properly.
>
>
>
>
>Sapna George <sgeorge@xxxxxx>
>Sent by: gef-dev-admin@xxxxxxxxxxx
>02/18/2005 04:33 PM
>Please respond to
>gef-dev
>
>
>To
>gef-dev@xxxxxxxxxxx
>cc
>
>Subject
>[gef-dev] ChopboxAnchor/AutomaticRouter bug?
>
>
>
>
>
>
>My problem:
>
>"My polyline connection uses ChopboxAnchors and
>FanRouter+BendpointConnectionRouter like in the Logic example. However, if
>i
>move a node with two or more connections, one one of the connections move
>along with the node. The others stay hanging in the original place. If i
>click on any of these dangling connections, they refresh and fix
>themselves
>to the node automatically."
>
>I debugged a little and found that ChopboxAnchor and AutomaticRouter have
>certain behaviors that might be leading to the above problem:
>1. The automatic router (FanRouter in my case) groups together all anchors
>on
>mulitple connections that are at the same "location" using a HashKey. This
>is
>so that it can take approriate handleCollision action. In the case of
>FanRouter, it inserts an additional bendpoint inorder to fan out. It order
>to
>find out if 2 anchors on different connections are at the same location,
>the
>router expexts the Anchor class to implement the equals method and the
>getHashCode method.
>2. The equals method in ChopboxAnchor returns true if the two chopbox
>anchors
>belong to the same figure irrespective of the location of the anchor on
>the
>figure.So, two anchors may be at opposite sides of the figure, but will
>still
>return true. This should not be the case, in my opinion. Only a new anchor
>
>that is at the exact location as an exisiting one should return true. A
>new
>anchor at the opposite side of the figure should return false.
>
>So, I modified ChopboxAnchor behavior to as follows and there is some
>improvement:
>
>protected Point locationPoint; // new variable to store anchor location.
>
>public Point getLocation(Point reference) { // super class is
>ChopboxAnchor
>  locationPoint = super.getLocation(reference);
>  return locationPoint;
> }
>
>public boolean equals(Object obj) { // returns true only if the location
>of
>both anchors
>                                                    // is exactly the
>same.
>  if (obj instanceof MyChopboxAnchor ) {
>   MyChopboxAnchor other = (MyChopboxAnchor )obj;
>   if (getLocationPoint() != null && other.getLocationPoint() != null)
>    return other.getOwner() == getOwner() &&
>other.getLocationPoint().equals(getLocationPoint());
>  }
>  return false;
> }
>
>After implementing this, the above dangling problem is not caused for ALL
>connections on a node. It is caused for ONLY those connections using
>anchors
>at the same location on the node boundary. i.e. if the node has 2
>connections
>on two opposite sides, moving the node WILL NOT leave some connections
>dangling.
>
>For those connections that DO have anchors at the exact same location,
>Here's
>what is causing the dangling problem. But i have no idea where it is being
>
>caused and how to fix it:
>
>At some point, by some class, the connection figures get removed from the
>list
>of AnchorListeners in the ChopboxAnchor. This occurs for all connections
>except the last one added to the figure. I found this by moving the node
>figure and debugging ancestorMoved(IFigure figure) method in
>AbstractConnectionAnchor class. Inspecting the variables in the class
>shows
>that all anchors except one, on the figure had AnchorListener = null even
>though they have connections associated with them. Therefore if the node
>figure is moved, the connections do not receive anchorMoved events and the
>
>connections are left dangling!
>
>I tried a lot to find out where this was occuring, but i was unsuccesful.
>Can
>any of the experts help?
>
>thanks
>
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