SwitchPreference Listener with Custom Layout

Question

I\'m trying to use a SwitchPreference in my Settings page, but i can\'t get the listener to work. I am using a custom widget layout in order to style the switch, as I cannot

Answer 1

I ran into the same issue, my solution is similar to the followings:

1. In your custom switch layout, add following code. This "uncovers" the preference, and makes the whole block clickable. That's why the listener is not triggered at all.

   android:clickable="false" android:focusable="false"

2. Extend "SwitchPreference", and in "onBindView" class, get states from SharedPreferences, and handle switch states change there.

   public class MySwitchPreference extends SwitchPreference {
   
       public MySwitchPreference(Context context) {
           super(context, null);
       }
   
       public MySwitchPreference(Context context, AttributeSet attrs) {
           super(context, attrs);
       }
       public MySwitchPreference(Context context, AttributeSet attrs, int defStyle) {
           super(context, attrs, defStyle);
       }
   
       protected void onBindView(View view) {
           // Clean listener before invoke SwitchPreference.onBindView
           ViewGroup viewGroup= (ViewGroup)view;
           clearListenerInViewGroup(viewGroup);
           super.onBindView(view);
   
           final Switch mySwitch = (Switch) view.findViewById(R.id.custom_switch_item);
           Boolean initVal = this.getPersistedBoolean(false);
           if (initVal) {
               mySwitch.setChecked(true);
           }
           this.setOnPreferenceChangeListener(new OnPreferenceChangeListener() {
               @Override
               public boolean onPreferenceChange(Preference preference, Object newValue) {
                   //Do your things here, toggling the switch and so on
                   return true;
               }
           });
       }
   
       private void clearListenerInViewGroup(ViewGroup viewGroup) {
           if (null == viewGroup) {
               return;
           }
   
           int count = viewGroup.getChildCount();
           for(int n = 0; n < count; ++n) {
               View childView = viewGroup.getChildAt(n);
               if(childView instanceof Switch) {
                   final Switch switchView = (Switch) childView;
                   switchView.setOnCheckedChangeListener(null);
                   return;
               } else if (childView instanceof ViewGroup){
                   ViewGroup childGroup = (ViewGroup)childView;
                   clearListenerInViewGroup(childGroup);
               }
           }
       }
   }
   

Hopefully this can help you. I was not able to find any solution for my case until I figured it out this way.

Answer 2

The id of SwitchView should be @android:id/switch_widget instead of @+id/custom_switch_item or any other custom id.

In the source of SwitchPreference class, we can find the code:

View switchView = view.findViewById(AndroidResources.ANDROID_R_SWITCH_WIDGET);

and in AndroidResources:

static final int ANDROID_R_SWITCH_WIDGET = android.R.id.switch_widget;

so only id = @android:id/switch_widget can be found correctly.

Here's a demo about SwitchPreference's widgetLayout:

<Switch xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/switch_widget"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center_vertical" />

Answer 3

Solution – based on @RickCase answer, but works with both Switch and SwitchCompat.