带有 actionLayout 的 NavigationView 菜单项。 如何为每个项目设置这些动作布局的属性？

Question

Following this answer , I learned how to add extra views to the NavigationView 's menu items, by adding an action layout . My question is, esentially, how can I tweak each of those individual actionLayout s dinamically, through Java?

In my case, instead of adding a "switch" to the menu items, I used actionLayout s to add a extra icon, that will show a state for that item. It's a boolean state, so I want to show the difference either by changing the extra icon dinamically, or either toggling visibility.

So, I have a menu.xml like this one for my NavigationView :

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:showIn="navigation_view">

    <group android:id="@+id/menu_group"
        android:checkableBehavior="single" >
        <item
            android:id="@+id/menu_item1"
            android:icon="@drawable/some_main_icon"
            app:actionLayout="@layout/myflag_actionlayout"
            android:title="OPTION 1" />
        <item
            android:id="@+id/menu_item2"
            android:icon="@drawable/some_main_icon"
            app:actionLayout="@layout/myflag_actionlayout"
            android:title="OPTION 2" />
        <!-- etc. -->
    </group>
</menu>

...and my myflag_actionlayout.xml file:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:background="#444444"
    android:layout_width="wrap_content"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/lockedIcon"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        app:srcCompat="@android:drawable/ic_lock_idle_lock" />
</LinearLayout>

So, it looks like this more or less:

Now I wonder: how can I get each of those menu item's instances, access to their <ImageView> instance from Java and change each lockedIcon 's ImageView depending on a boolean variable? (For instance, toggling the ImageView 's visible attribute, or changing the image for app:srcCompat attribute) Should I use some findViewById(R.id.lockedIcon) for this task, or is it a bad idea and I should do it another way?

EDIT:

Just now I recall, I already did something similar to access those " NavigationView items" by Java, and add a string to the counter editing the title:

NavigationView nav_v = findViewById(R.id.navigation_view);
MenuItem nav_option1 = nav_v.getMenu().findItem(R.id.menu_item1);
nav_option1.setTitle(getString(R.string.nav_option1_title) + " -> " + some_counter);

Maybe i can from nav_option1 invoke some method to access it's action layout?

Answer 1

Good. @ianhanniballake 's suggested method worked like a charm: If I do this:

NavigationView nav_v = findViewById(R.id.navigation_view);
MenuItem nav_option1 = nav_v.getMenu().findItem(R.id.menu_item1);
ImageView option1_lock_icon = nav_option1.getActionView().findViewById(R.id.lockedIcon);

And from there, I could do whatever I want with this ImageView :

// Toggle visibility approach
if (item_locked) {
    option1_lock_icon.setVisibility(View.VISIBLE);
} else {
    option1_lock_icon.setVisibility(View.INVISIBLE);
}

// Change icon approach
string uri = "";
if (item_locked) {
    uri = "@android:drawable/ic_lock_idle_lock";
} else {
    uri = "@android:drawable/ic_menu_view";
}
int imageResource = getResources()
      .getIdentifier(uri,
                     null,
                     getPackageName()
      );
option1_lock_icon.setImageDrawable(
       getResources().getDrawable(imageResource)
);

Also, it looks like I can do more or less the same with any object I add to those "action layouts". :-)