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Why do checkable menu items not display checkboxes

Time:10-17

NavigationView Menu:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
   <group android:checkableBehavior="all">
        <item
            android:id="@ id/itemFoo1"
            android:checkable="true"
            android:title="Foo1" />
        <item
            android:id="@ id/itemFoo2"
            android:checkable="true"
            android:title="Foo2" />
    </group>
</menu>

The designer in Android Studio shows checkboxes: enter image description here

However, the app does not display checkboxes:

enter image description here

Could anyone offer a clue about this?

The layout using the menu:

<com.google.android.material.navigation.NavigationView
    android:id="@ id/navigationView"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="end"
    app:menu="@menu/activity_foo_view"/>

CodePudding user response:

The default behavior for the NavigationView is to select an item at a time; this typically picks a fragment in a drawer layout for instance.

And as Mike M pointed out in comments; making an item checkable doesn't mean that it's a CheckBox.

So, you have to add a CheckBox to the menu item, and there are two options to do that:

  • Option 1: Using a CheckBox as app:actionViewClass

  • Option 2: Using a custom layout with app:actionLayout: Check this answer for that

Using a CheckBox as app:actionViewClass:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
   <group android:checkableBehavior="all">
        <item
            android:id="@ id/itemFoo1"
            android:checkable="true"
            app:actionViewClass="android.widget.CheckBox"
            android:title="Foo1" />
        <item
            android:id="@ id/itemFoo2"
            android:checkable="true"
            app:actionViewClass="android.widget.CheckBox"
            android:title="Foo2" />
    </group>
</menu>

Hitting the checkBox will toggle its state, but hitting the item text will not; this can be fixed programmatically by getting the menuItem ActionView and toggle the CheckBox using setChecked():

private final NavigationView.OnNavigationItemSelectedListener navViewlistener = new NavigationView.OnNavigationItemSelectedListener() {
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {

        int id = item.getItemId();

        if (id == R.id.itemFoo1 || id == R.id.itemFoo2) {
            CheckBox actionView = (CheckBox) item.getActionView();
            actionView.setChecked(!actionView.isChecked()); // Toggle the CheckBox
        }

        return true;
    }
};

navView.setNavigationItemSelectedListener(navViewlistener);

UPDATE

I used app:actionViewClass="android.widget.CheckBox" for a while. The main issue is the the checkbox is independent of the item. Clicking it does not trigger NavigationItemSelectedListener. That is the main reason I am seeking a new way.

This is right; we could fix this programmatically by triggering a MenuItem click event whenever the holding CheckBox is checked/unchecked.

But the main issue of that, it can cause infinite loop; as we check/uncheck the CheckBox within onNavigationItemSelected; and that will trigger another MenuItem click and so on.

So, here a mIsCheckBoxClick boolean and also stopping CheckBox listeners before calling setChecked(), and reattaching them after that; all that to avoid the loop:

private boolean mIsCheckBoxClick;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // ....... add your code

    // Enable CheckBox listeners at the NavView menu items by default 
    addFooListeners(navView, true);
}

private void addFooListeners(final NavigationView navView, boolean enabled) {
    adjustNavViewItemListener(navView.getMenu().findItem(R.id.itemFoo1), navView, enabled);
    adjustNavViewItemListener(navView.getMenu().findItem(R.id.itemFoo2), navView, enabled);
}

private void adjustNavViewItemListener(final MenuItem item, final NavigationView navView, boolean enabled) {
    final CheckBox fooChBox = (CheckBox) item.getActionView();
    CompoundButton.OnCheckedChangeListener listener = new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            mIsCheckBoxClick = true;
            navView.getMenu().performIdentifierAction(item.getItemId(), 0); // perform a click on MenuItem to trigger OnNavigationItemSelectedListener
        }
    };
    fooChBox.setOnCheckedChangeListener(enabled ? listener : null);
}


private final NavigationView.OnNavigationItemSelectedListener navViewlistener = new NavigationView.OnNavigationItemSelectedListener() {
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {

        int id = item.getItemId();

        if (id == R.id.itemFoo1 || id == R.id.itemFoo2) {
            
            // Loop prevention check
            if (!mIsCheckBoxClick) {
                CheckBox actionView = (CheckBox) item.getActionView();
            
                // Stop the CheckBox listeners
                addFooListeners(navView, false);
                
                actionView.setChecked(!actionView.isChecked());
                
                // Reattach the CheckBox listeners
                addFooListeners(navView, true);
            }
            mIsCheckBoxClick = false;           
        }

        return true;
    }
};

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