如何将@override方法从活动覆盖到另一个类

Question

Hi let's say I have an activity

class AcitivityA {


    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Do something
    }


}

And I have a class name

class myClass {


    private Activity current_activity;


    myClass(Activity activity) {
        current_activity = activity;
    }
}

So my question is, is there a way i can override onConfigurationChanged and put it into my class myClass?

So my goal is that I want to detect if the orientation is change

But I want it to be inside the class myClass

Answer 1

Create a Listener for that.

public interface OnChange() {
  void changed();
}

public class ListenerHolder {
    public static OnChange onChange = new OnChange( ... );
}

MyClass mClass = new MyClass();

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    ListenerHolder.onChange.changed();
}

Take care that the interface should be static somewhere else then the own activity, else it may be destroyed with the activity.

But there are a few better ways solving that. BroadcastReceivers, Deeplinking, Extending, LiveData (Livecycle-aware), RxJava Subjects, ...

It's a bad design pattern to hook into view events outside a class which is not used for that.

Take a look at Android Architecture Components which uses a Mvvm Pattern including ViewModels and LiveData to survive configuration changes.

If you'r new to Android i highly recommend you to take a look at https://developer.android.com/topic/libraries/architecture/index.html for a proper design of your app. You may also start using Kotlin because it will be the maintained language in future for android.