Added keybindings to move the maven dependency graph with cursor keys around and zoom in and out.

[JoachimRohde]

Also added keybindings and mouse wheel listener to zoom in (CTRL + +) and zoom out (CTRL + -).

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[mbien]

this is probably an area which can be improved but the current PR has a few problems and overwrites existing functionality you might not be aware of.

zoom:

Mouse wheel zoom is already implemented (ctrl+wheel). It is zooms to the mouse pointer location commonly seen on maps/graphs etc. This PR overwrites this functionality and makes it worse since it doesn't take the mouse pointer as zoom point into account.

navigation:

Once a tree component had focus, arrow keys will move the item selection around, I couldn't get the focus back to the graph to move it with arrow keys.

Middle mouse drag is also already implemented btw

UI:

The tool tips should use the same format used for other actions. They usually follow the Name [hotkey] pattern like:

instead of

There is also a utility which can generate the hotkey text, it might work here too, example:

netbeans/platform/favorites/src/org/netbeans/modules/favorites/Tab.java

Lines 242 to 247 in 2fba977

	String hotkey = ""; // NOI18N
	Action action = org.openide.awt.Actions.forID("Window/SelectDocumentNode", "org.netbeans.modules.favorites.Select"); // NOI18N
	if (action != null && action.getValue(Action.ACCELERATOR_KEY) instanceof KeyStroke ks) {
	hotkey = org.openide.awt.Actions.keyStrokeToString(ks);
	}
	setToolTipText(NbBundle.getMessage(Tab.class, "TT_Favorites", hotkey)); //NOI18N

[neilcsmith-net]

Agree with @mbien that there are a number of issues that need addressing here.

Moving the scene by arrow keys should work using the bindings in the scroll pane UI, as long as the scene view has focus. The request focus call here is probably all that is needed for that to work. At least, it's working in a platform application.

Should add the wheel pan action too - https://bits.netbeans.org/29/javadoc/org-netbeans-api-visual/org/netbeans/api/visual/action/ActionFactory.html#createWheelPanAction()

Zoom actions are better registered globally somewhere IMO using callback action registrations. This would allow better integration with the shortcuts system, and we can look to migrate other internal uses (eg. image viewer). I did this recently in a platform application - see praxis-live/praxis-live@ded66c8

Also, CTRL should never be hardcoded as a shortcut trigger due to macOS.

[JoachimRohde]

I was indeed neither aware of mouse wheel zoom nor middle mouse dragging.
I removed the mouse listener and also the cursor key shortcuts because, as Neil mentioned, the request focus call was all that was needed.

The shortcut for zooming in and out was changed from CTRL+[+/-] to Alt+[+/-]. My question is: is this okay or should I use another shortcut (or should I also remove this part)?
Another question: I added in the tooltip a hint that CTRL+mousewheel is an alternative to the provided shortcuts. Is this okay or is it cumbersome and should be removed?

"Once a tree component had focus, arrow keys will move the item selection around, I couldn't get the focus back to the graph to move it with arrow keys."

I could not reproduce this behavior. Even though I select a node and press then a cursor key the whole graph is moved, not a single node.