[josm-dev] How to update changes in dataSet ?

[Dirk Stöcker]

On Tue, 4 Jan 2011, Flávio Henrique wrote:

> I thought the combineWayWorker method would take care of point 2 (removing
> the original way and adding the new one), as the sequenceCommand returned
> has the commands to delete ways. So, after calling Main.main.undoRedo.add(new
> SequenceCommand(tr("Your job"), cmds)), the command to delete the original
> way would be executed. I'm wrong here?

Correct. All dataset stay localto your function until you pass the command 
to the command stack. Only afterwards the are executed "really". Otherwise 
a proper undo would be impossible. You need to group changes, so they can 
be undone in one step.

[ code snipped ]

Notes:

1) You don't use the returned way of a combine, so your code wont 
find all possibilities. I don't know what you final goal is, but I would
make a loop around

changed = true;
while(changed)
{
   changed = false;
   for ...
     changed = true in case combine worked at least once
}

and integrate the combined ways in subsequent calls and dropping the used 
ones.

2) Only adding the first way to usedWays is wrong. Both ways are unusable 
after combining and only the new returned one is to be used instead. It 
may seem to work, but I doubt it is correct and probably leads to hard to 
detect bugs.

Ciao
-- 
http://www.dstoecker.eu/ (PGP key available)