With the error Cordova-> Looper.prepare ()

I often get angry with Thread while using Cordova.framework, so I'll take a note of myself with a commandment.

error contents

adb.logcat

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

It happens when you create a View in a background thread.

Cause

Cordova isn't basically because it uses a Web engine, but ... there are times when I have to use NativeView, so that's when.

For example

test.Java

@Override
public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
    cordova.getActivity().runOnUiThread(new Runnable() {
        public void run() {
            ...
            timerView = view.findViewById(R.id.hogeview);

            //No good point! !! !!
            mHandler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    mRootView.addView(timerView);
                },200);
            }
        }
    });
    return true;
}

This is an example of what I did because View generation was heavy + screen transition was sandwiched. Further delay processing is written in the thread processing of cordova. Looper basically runs on the UI thread, so if you change the thread with Handler, Looper will not work.

Since the creation of View is heavy this time, it is called by cordova.getActivity (). RunOnUiThread (), so mHandler (). PostDelayed (new Runnable () { Will get rid of.

Easy solution

test.Java

@Override
public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
    cordova.getActivity().runOnUiThread(new Runnable() {
        public void run() {
            ...
            timerView = view.findViewById(R.id.hogeview);
            mRootView.addView(timerView);
        }
    });
    return true;
}

Or there is a way to implement Looper yourself. However, basically, it is a method called by Framework, so it is forbidden.

I often do such simple things ...