Usage of requestPinAppWidget under some uncommon cases

Question

Apps had been allowed to request to pin an app widget on the current launcher since API level 26. As developers, this gave us a chance to make such request in our own Apps. However, the document says "When a request is denied by the user, the caller app will NOT get any response." Sometimes when there isn't enough room for a widget on the current launcher, the caller app will NOT get any response either.
How to differentiate between these two scenarios? Is there any callback function I can use? Is there any way I can get how much space left on the current launcher in my APP?

Answer 1

 private fun pickWidget()
    {
        
        val component = ComponentName(applicationContext,MyWidget::class.java)
        val manager = AppWidgetManager.getInstance(applicationContext)
        val widgetId = (1..999999).random()
        val intent = Intent(applicationContext,MyReceiver::class.java)
        val b = Bundle()
        intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,widgetId)
        val successCallback = PendingIntent.getBroadcast(applicationContext,101,intent,PendingIntent.FLAG_UPDATE_CURRENT)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            manager.requestPinAppWidget(component,b,successCallback)
        }

    }


class MyReceiver : BroadcastReceiver() {

    override fun onReceive(context: Context, intent: Intent) {
        Log.e(TAG, "onReceive: ")
        val b= intent.extras
        b?.let {
        val widgetId = b.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID,AppWidgetManager.INVALID_APPWIDGET_ID)
        if(widgetId!=AppWidgetManager.INVALID_APPWIDGET_ID) {

          //if widget is placed succssfully
        }

        }
    }
}