DDM 2021-12-21

package com.joythis.android.receiverandasync;

import androidx.appcompat.app.AppCompatActivity;
import androidx.loader.content.AsyncTaskLoader;

import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    Context mContext;
    TextView mTvReceivedText;

    class MyTaskToPost extends AsyncTask<String, Void, String>{

        @Override
        protected String doInBackground(String... strings) {
            String url = strings[0];
            String when = strings[1];
            String what = strings[2];
            String strJsonReply = AmIoHttp.postShare(url , when, what);
            return strJsonReply;
        }//doInBackground

        @Override
        protected void onPostExecute(String s) {
            displayTextOnTv(
                mTvReceivedText,
                s
            );
            super.onPostExecute(s);
        }//onPostExecute
    }//MyTaskToPost

    class MyAsyncTaskForWebTraffic extends AsyncTask<
            String, //input data type , a string, e.g. URL
            Void, //no progress indicator
            String//ouput data type, a string, the source code at URL
        >{

        /*
        the code in doInBackground will happen on a separate thread (of the main UI thread)
        doInBackground receives an arbitrary number of params
        the corresponding args are sent upon calling the "execute" method of the object MyAsyncTaskForWebTraffic
         */
        @Override
        protected String doInBackground(String... strings) {
            //return null;
            String url = strings[0];
            String strHtmlSourceCode = AmIoHttp.io_https_ReadAll(url);
            return strHtmlSourceCode;
        }

        /*
        when the code in doInBackground ends, onPostExecute will be automatically called
        receiving, as an argument, the return of doInBackground
         */
        @Override
        protected void onPostExecute(String s) {
            displayTextOnTv(mTvReceivedText, s);
            super.onPostExecute(s);
        }
    }

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

        init();
    }//onCreate

    void init(){
        mContext = this;
        mTvReceivedText = findViewById(R.id.idTvReceivedText);

        receiveTextFromSharedOtherApps(); //demo1 - receive text from other apps

        readSourceCodeAtUrl("https://arturmarques.com/"); //demo2 - async reading external contents

        writeToExternalService(
            "https://arturmarques.com/edu/ddm/files/w12/receiver.php",
            "2021-12-21 12:17:00",
            "okay"
        );
    }//init

    void writeToExternalService(
        String pUrl,
        String pWhen,
        String pWhat
    ){
        //IMPOSSIBLE! Because it would work on the main UI main thread
        //AmIoHttp.postShare(pUrl , pWhen, pWhat);

        //POSSIBLE!
        MyTaskToPost t = new MyTaskToPost();
        t.execute(pUrl , pWhen, pWhat);
    }//writeToExternalService

    void readSourceCodeAtUrl(String pUrl){
        //IMPOSSIBLE => can NOT happen on the main thread
        //String strHtmlSourceCode = AmIoHttp.io_https_ReadAll(pUrl);
        //displayTextOnTv(mTvReceivedText, strHtmlSourceCode);

        //POSSIBLE => must happen on a separate thread
        //via AsyncTask
        MyAsyncTaskForWebTraffic myTask = new MyAsyncTaskForWebTraffic();
        myTask.execute("https://arturmarques.com/");
    }//readSourceCodeAtUrl

    void receiveTextFromSharedOtherApps(){
        Intent whoCalledMe = this.getIntent();

        if (whoCalledMe!=null){
            String strAction = whoCalledMe.getAction();
            boolean bInternalStart = strAction == Intent.ACTION_MAIN;
            boolean bExternalStart = strAction == Intent.ACTION_SEND;

            //an external app is sharing data
            if (bExternalStart){
                String strType = whoCalledMe.getType();
                boolean bIsSomeOtherAppSharingTextWithMe = strType.startsWith("text/");
                if (bIsSomeOtherAppSharingTextWithMe){
                    //a string named "EXTRA_TEXT" transports text between apps
                    String strTheSharedText =
                        whoCalledMe.getStringExtra(
                            Intent.EXTRA_TEXT
                        );

                    displayTextOnTv (mTvReceivedText, strTheSharedText);
                }//if
            }//bExternalStart
        }//if
    }//receiveTextFromSharedOtherApps

    void displayTextOnTv(
        TextView pTv,
        String pS
    )
    {
        pTv.setText(pS+"\n"+pTv.getText().toString());
    }//displayTextOnTv
}