Paste is not working on Oncreate? Android Clipboard

Question

There is a strange behavior of Android copy paste. If I use handler paste is working but on oncreate and onstart it is not.

Activity

  @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_verify_files);
    initView();

    Log.e("TAG", "onCreate1: " + C.paste(Verify_files.this) );
    new Handler(getMainLooper()).postDelayed(new Runnable() {
        @Override
        public void run() {

            Log.e("TAG", "onCreate2: " + C.paste(Verify_files.this) );
        }
    },400);

Logs are here. primary clip is false then it becomes true

E/##CC: paste: false
E/TAG: onCreate1: 
E/##CC: paste: true
E/TAG: onCreate2: THIS IS TEXT TO PASTE

Copy() Paste()

    public static void copy(Context context , String text){
    Log.e(TAG, "copy: "+text );

    ClipboardManager clipboard = (ClipboardManager) context.getSystemService( CLIPBOARD_SERVICE);
    ClipData clip = ClipData.newPlainText("label", "THIS IS TEXT TO PASTE");
    clipboard.setPrimaryClip(clip);

    Toast.makeText(context,text+"",Toast.LENGTH_SHORT).show();
}

public static String paste(Context context  ){
    ClipboardManager clipboard= (ClipboardManager) context.getSystemService(CLIPBOARD_SERVICE);

    Log.e(TAG, "paste: "  +clipboard.hasPrimaryClip() );

    if(clipboard.hasPrimaryClip()) {
        ClipData clip = clipboard.getPrimaryClip();
         if (clip != null) {
            ClipData.Item item = clipboard.getPrimaryClip().getItemAt(0);
            return item.getText() + "";
        }
    }
    return  "";

}

Could you try onResume? [getPrimaryClip](https://developer.android.com/reference/android/content/ClipboardManager#getPrimaryClip()) returns false when the window is not in focus, and I think the activity is still in background untill it finishes loading. — IamFr0ssT, Jun 17 '22 at 11:56

Ticherhaz FreePalestine · Accepted Answer · 2022-06-17T12:27:18.160

There are a few approached you can do here.

First, by using ViewTreeObserver. Refer: https://stackoverflow.com/a/8741821/9346054

private void listenToViewTreeObserver(){
    final ViewTreeObserver vto = findViewById(R.id.text_view_something).getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            // do something now when the object is loaded
            // e.g. find the real size of it etc
            Log.e("TAG", "onCreate: onGlobalLayout: " + paste(MainActivity.this) );
            findViewById(R.id.text_view_something).getViewTreeObserver().removeOnGlobalLayoutListener(this);
        }
    });
}

Second, by using MessageQueue. https://stackoverflow.com/a/41276825/9346054

private void listenToMessageQueue(){
   final MessageQueue.IdleHandler handler = () -> {
        Log.e("TAG", "onCreate: IdleHandler: " + paste(MainActivity.this) );
        return false;
    };
    Looper.myQueue().addIdleHandler(handler);
}

At your onCreate.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    copy(MainActivity.this,"Here");

    listenToMessageQueue();
    listenToViewTreeObserver();
}

Your answer has improved my knowledge. Do you know why clipboard doesn't have primary clip on oncreate onstart onresume..? but later it can be accessed? is it because of activity context? — Rohaitas Tanoli, Jun 17 '22 at 18:15
@RohaitasTanoli it can be only access when the view is fully complete. — Ticherhaz FreePalestine, Jun 18 '22 at 00:16

Paste is not working on Oncreate? Android Clipboard

1 Answers1