Android: changing drawable states of option menu items seems to have side-effects

Question

In my onCreateOptionsMenu() I have basically the following:

public boolean onCreateOptionsMenu(Menu menu) {

        menu.add(Menu.NONE, MENU_ITEM_INSERT, Menu.NONE, R.string.item_menu_insert).setShortcut('3',
                'a').setIcon(android.R.drawable.ic_menu_add);

        PackageManager pm = getPackageManager();
        if(pm.hasSystemFeature(PackageManager.FEATURE_CAMERA) && pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_AUTOFOCUS)){
            menu.add(Menu.NONE, MENU_ITEM_SCAN_ADD, Menu.NONE, ((Collectionista.DEBUG)?"DEBUG Scan and add item":getString(R.string.item_menu_scan_add))).setShortcut('4',
                    'a').setIcon(android.R.drawable.ic_menu_add);
        }
        ...
}

And in onPrepareOptionsMenu among others the following:

final boolean scanAvailable = ScanIntent.isInstalled(this);
final MusicCDItemScanAddTask task = new MusicCDItemScanAddTask(this);          
menu.findItem(MENU_ITEM_SCAN_ADD).setEnabled(scanAvailable && (tasks == null || !existsTask(task)));

As you see, two options items have the same drawable set (android.R.drawable.ic_menu_add). Now, if in onPrepareOptionsMenu the second menu item gets disabled, its label and icon become gray, but also the icon of the first menu item becomes gray, while the label of that first menu item stays black and it remains clickable. What is causing this crosstalk between the two icons/drawables? Shouldn't the system handle things like mutate() in this case?

I've included a screenshot:

Answer 1

http://www.curious-creature.org/2009/05/02/drawable-mutations/

The above article by Romain Guy explains this very situation and provides a work around.

Answer 2

Yes, this looks odd. I can not explain why this is as it is, however I can propose a workaround - instead of using internal drawable resourse, you could put the same image in your app drawable resourse dir AND you could duplicate the add image, so you have 2 images - add_for_menu_item_1.png and add_for_menu_item_2.png named differently, but having the same visual representation. I am sure this would do the trick.

Answer 3

可能是两个菜单项共享相同的alphaChar导致第二个menuItem被禁用？