CODEWITHSUNDEEP
androidmultithreadingitext
Javallion
Javallion

Reputation: 23

Creating PDF in separate thread STILL making main thread unresponsive

I am not sure what I am doing wrong here but my main thread is blocked (as per Android studio's message : I/Choreographer: Skipped 1009 frames! The application may be doing too much work on its main thread.) although I am using a seperate thread to create my PDF using itext.

+

My spinner class, my toast do not show as well, both are written in main thread (perhaps because of main thread being unresponsive as per the message). Once the PDF is created, the dialog shows up as normal and everything starts working as expected.

val bmap = BitmapFactory.decodeResource([email protected],R.drawable.camera_item_center)
                val threadPDF = Thread(object : Runnable {
                    override fun run() {
                        CreatePDF(file, site, bmap).makePDF()
                    }
                })
                threadPDF.start()
                spinner.setVisibility(View.VISIBLE)
                Toast.makeText(this@SiteItemsActivity,"Please wait....",Toast.LENGTH_SHORT).show()
                while (threadPDF.isAlive){
 //Thread.sleep(1) 
    }
                        spinner.setVisibility(View.GONE);
                        showDialog()

Upvotes: 0

Views: 324

Answers (1)

CommonsWare
CommonsWare

Reputation: 1007276

although I am using a seperate thread to create my PDF using itext

But then you are tying up the main application thread with an continuous loop (while (threadPDF.isAlive)).

Delete that while loop. Use other solutions for updating your UI when the work is done. For example, you could:

  • replace your thread with an AsyncTask and update your UI in onPostExecute()

  • have your thread post() a Runnable (using your Spinner) to have that Runnable be run on the main application thread after your thread's work is done

  • replace your thread with an RxJava Observable, where you schedule its work a background thread (e.g., Schedulers.io()) and observe it on the main application thread (AndroidSchedulers.mainThread())

  • wrap your thread in a LiveData object and have your UI code observe that LiveData for the completion of the work

  • and so on

Upvotes: 1

Related Questions