Correctly sort all menu entries (alphabetically by default)

[imagejan]

Currently, legacy-compatible IJ2 commands end up in a menu group separate from IJ1 plugins, e.g. the Debug, Sandbox, AutoRun, Kymograph and Scripting submenus of the Plugins menu are in a separate section.

Let's merge them all and sort them alphabetically.

See also https://github.com/PreibischLab/BigStitcher/issues/7#issuecomment-342518669.

The adding and sorting is supposed to happen in IJ1Helper#addMenuItems() method:

https://github.com/imagej/imagej-legacy/blob/dd36b3ffd2d8c8cc392a7ade88e2edd87e172175/src/main/java/net/imagej/legacy/IJ1Helper.java#L775-L850

[imagejan]

I created a small test project (https://github.com/imagejan/test-menu-path), containing:

• an IJ1 plugin,
• an IJ2 command, and
• an IJ2 script

in the same submenu Plugins > ASubmenu.

When placing the project's jar file (Test_Menu_Path-0.1.0-SNAPSHOT.jar) in ./Fiji.app/plugins/, all three menu entries appear in ASubmenu in the upper part of the Plugins menu.

However, when the jar file is placed in ./Fiji.app/jars/ (where the IJ1 plugin isn't recognized), the ASubmenu entry ends up being in the lower part of Plugins, below the separator.

[imagejan]

Menu entries are sorted alphabetically if and only if their menu weight is the same.

• By default, IJ2 commands that don't define their own menu weight will have a weight of DEFAULT_WEIGHT = Double.POSITIVE_INFINITY.
• Legacy commands however seem to have their weight generated here:

https://github.com/imagej/imagej-legacy/blob/dd36b3ffd2d8c8cc392a7ade88e2edd87e172175/src/main/java/net/imagej/legacy/IJ1Helper.java#L907-L922

So in order to unify menus of Legacy and IJ2 commands, we need to either:

• Specify a weight for each IJ2 command (and possibly make clear in the javadoc that new commands will always be added at the end of the menu unless a weight is specified
• Remove the specified weight from legacy commands (at least in the lowest-level menus) such that they're always sorted alphabetically, possibly disturbing the (current) menu order of some of them.
• Auto-generate weights for IJ2 commands at the same time as legacy commands (?)

(Maybe I'm missing something here.)

[imagejan]

For the record: here's a script I used to display the menu weights for each menu entry:

#@ MenuService menus

def printMenu(menu, prefix) {
    entry = menu.getMenuEntry()
    if(entry!=null) println "${prefix}[${entry.getWeight()}] ${entry.getName()}"
    if (!menu.isLeaf()) {
        menu.getChildren().each {
            printMenu(it, prefix+"   ")
        }
    }
}

printMenu(menus.getMenu(), "")