Actions should avoid to install listeners which are not needed

[GerdP]

A lot of actions use a constructor which calls JosmAction.installAdapters() by default. Some of these actions don't care about layer changes or selection changes and thus should not install the listeners.

[GerdP]

work in progress patch, probably more actions can be changed

[stoecker]

I don't think you need to provide such patches for review. It seems obvious. Simply fix it as you find it.

[GerdP]

In 16505/josm:

see #19296: Actions should avoid to install listeners which are not needed
tbc

[GerdP]

We have a lot of actions which only need the ActiveLayerChangeAdapter but not the SelectionChangeAdapter.
IIGTR actions should overwrite method listenToSelectionChange() to return false when they only need the ActiveLayerChangeAdapter?

[GerdP]

In 16509/josm:

see #19296: Actions should avoid to install listeners which are not needed

• either don't call installAdapters() or overwrite listenToSelectionChange()
• partly reverts previous changes so that installAdapters() is not overwritten

One has to be careful because installAdapters() also calls initEnabledState()

[stoecker]

Replying to GerdP:

We have a lot of actions which only need the ActiveLayerChangeAdapter but not the SelectionChangeAdapter.
IIGTR actions should overwrite method listenToSelectionChange() to return false when they only need the ActiveLayerChangeAdapter?

That sounds like a lot of code. I'd assume some way telling this via the constructor would be better, like changing bool to an enum which can transport multiple states?

[stoecker]

Looking at the patch it's not so much code :-) Maybe that's ok...

[GerdP]

And it's difficult to change something because some plugins use the existing methods. I've added some more in [o35472:35475]

[simon04]

When starting JOSM, I get the following messages:

2020-05-29 20:14:47.470 INFO: Toolbar action without name: org.openstreetmap.josm.actions.ChangesetManagerToggleAction
2020-05-29 20:14:47.804 INFO: Toolbar action without name: org.openstreetmap.josm.actions.ChangesetManagerToggleAction

[GerdP]

In 16522/josm:

see #19296: fix Toolbar action without name: org.openstreetmap.josm.actions.ChangesetManagerToggleAction
regression of r16509

[GerdP]

@Simon: Thanks for the hint, didn't see that difference in the two constructors.

[simon04]

@GerdP, is anything left to be done?

[GerdP]

I thought of this as a task. I've changed almost all core actions, but only a few plugins.
I kept Undo/Redo action as is because they might be needed for #17196.

[GerdP]

In 17414/josm:

see #19296: Actions should avoid to install listeners which are not needed

• both Note actions don't use SelectionChangeListener or LayerChangeListener

[GerdP]

In 17419/josm:

see #19296: Actions should avoid to install listeners which are not needed

• DownloadAlongAction doesn't use the listeners but is created for each right click on a GPX layer, stores a ref to GpxData and blocks GC