topic Re: Blank MapView when I start the map without WiFi in ArcGIS Runtime SDK for Android Questions

Blank MapView when I start the map without WiFi

JasonChristian — Sun, 12 Dec 2021 02:39:26 GMT

Hi, I am currently building an Android App using ArcGIS runtime SDK for Android. The app has a MapView on the layout and I plan to make it work offline without wifi. Thus, I have provided myself several .tpk files as offline areas. Under working WiFi connection, it worked well (the map is displayed, along with the offline tiles). But, when I turned off the WiFi and restarted the app, it only shows blank (black) map

I used the OnStatusChangedListener to listen to the MapView status. Here is the code snippet

mapView.setOnStatusChangedListener(new OnStatusChangedListener() {
    @Override
    public void onStatusChanged(Object o, STATUS status) {
        //initialization
        if (o == mapView && status == STATUS.INITIALIZED){
            //setup everything, including adding offline maps here
            //...

I was under impression that the INITIALIZED status requires connecting to the internet. That's why I couldn't use the map or anything because I ran it without the WiFi turned on.

If that's the case, how can I use the MapView without using internet connection, when initializing the map itself requires internet connection? Is it actually one of the limitation of the SDK?

THX before

Re: Blank MapView when I start the map without WiFi

AlexanderNohe1 — Mon, 24 Oct 2016 12:31:29 GMT

ihazbackup‌

Are you inflating the MapView from XML or are you creating the MapView dynamically?

If you are inflating from XML can you not include the basemap URL in the XML?

Does this help?

Re: Blank MapView when I start the map without WiFi

JasonChristian — Tue, 25 Oct 2016 07:24:37 GMT

I am inflating the map from XML and I don't include any basemap URL in the XML. It's just a MapView with usual id, width, height, mapOptions set to Street and zoom set to 15. No basemap URL

The STATUS.INITIALIZED is not triggerred on the code. Instead, without internet connection, it will give you something like "Init failed". I am not on my workspace right now. I will provide better explanation once I get there.

Re: Blank MapView when I start the map without WiFi

JasonChristian — Thu, 27 Oct 2016 06:42:48 GMT

I have checked on my code. There's no basemap URL included there. Without Wifi or internet connection, it fails to initialize the map. I put all of the map setup code inside the if (status == STATUS.INITIALIZED) block, so it doesn't load up properly due to the calling IF statement is false.

I have tried moving it out of the IF block (so it will initialize the map regardless of the status change), but it's still the same old black map (doesn't even show the grids).

Re: Blank MapView when I start the map without WiFi

AlexanderNohe1 — Sun, 12 Dec 2021 02:39:29 GMT

package com.arcgis.androidsupportcases.offlinestarter;

import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import com.esri.android.map.MapView;
import com.esri.android.map.ags.ArcGISLocalTiledLayer;

public class MainActivity extends AppCompatActivity implements ActivityCompat.OnRequestPermissionsResultCallback {

    MapView mMapView;

    final static int EXTERNAL_STORAGE_PERMISSION_CODE = 3774;

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

        mMapView = (MapView) findViewById(R.id.map);

        int permissionCheck = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);

        if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
            loadLayer();
        } else {
            requestStorage();
        }


    }

    private void requestStorage() {
        if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            //TODO: Explanation if wanted.
        } else {
            ActivityCompat.requestPermissions(this,
                    new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE},
                    EXTERNAL_STORAGE_PERMISSION_CODE);
        }
    }

    /**
     * Callback for the result from requesting permissions. This method
     * is invoked for every call on {@link #requestPermissions(String[], int)}.
     * <p>
     * <strong>Note:</strong> It is possible that the permissions request interaction
     * with the user is interrupted. In this case you will receive empty permissions
     * and results arrays which should be treated as a cancellation.
     * </p>
     *
     * @param requestCode  The request code passed in {@link #requestPermissions(String[], int)}.
     * @param permissions  The requested permissions. Never null.
     * @param grantResults The grant results for the corresponding permissions
     *                     which is either {@link PackageManager#PERMISSION_GRANTED}
     *                     or {@link PackageManager#PERMISSION_DENIED}. Never null.
     * @see #requestPermissions(String[], int)
     */
    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == EXTERNAL_STORAGE_PERMISSION_CODE) {
            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                loadLayer();
            } else {
                Log.e("ESS", "Permission Denied");
            }
        }
    }

    private void loadLayer() {
        mMapView.addLayer(new ArcGISLocalTiledLayer(Environment.getExternalStorageDirectory().getPath() + "/ArcGIS/" + "custom.tpk"));
    }
}
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I was able to write a really quick sample to test this out. I ignored the check to the initialization and was able to load my TPK without issue.

I am seeing the same behavior that you explained when doing the initialization check.

The grids seem to only appear when a dataset is loaded. Are you loading any datasets when you see the black map? (I have only tested with a TPK thus far)

Re: Blank MapView when I start the map without WiFi

JasonChristian — Thu, 27 Oct 2016 16:04:28 GMT

I have some .tpk files that I manage to load by selecting them from a list. Whenever the map is blank (no internet connection), the .tpk file was not shown on the map. If it has internet connection, the grid shows up and the selected .tpk file can be shown correctly.

What kind of datasets are we talking about?

The stuff I did after the initialization (which is now moved outside the OnStatusChangedListener), which is related to the MapView, is just adding Graphics Layer for marker and regions, and turning on the location listener.

EDIT: Can u also provide me the XML file you use for that example? Thank you

Re: Blank MapView when I start the map without WiFi

AlexanderNohe1 — Thu, 27 Oct 2016 16:08:02 GMT

Any offline datasets should be available. TPK's, offline features, etc...

If you follow the sample from above, are you able to see your TPK loaded? Are you getting any errors when loading your TPK? At this point, I would like to know how testing outside of the mapViews statusChanges listener worked for you.

Re: Blank MapView when I start the map without WiFi

AlexanderNohe1 — Thu, 27 Oct 2016 16:55:58 GMT

Better yet, could you share your TPK with me and I can test with my sample and see if I reproduce the same issue that you are experiencing?

Re: Blank MapView when I start the map without WiFi

JasonChristian — Thu, 27 Oct 2016 17:03:43 GMT

I will try this tomorrow, as I am currently not on my workspace. I'll also provide a sample tpk I used for this

EDIT:

I tried loading the .tpk directly when offline and not using the OnStatusChangeListener. It shows the grid and offline map without internet connection.

I cannot help but wonder, that u need to load any offline features just to get the map started. In my opinion, it should have started regardless whether you have any offline features or not (and by then you can dynamically add more offline features on the run, not adding 1 or all of them on first init).

EDIT2:

Now came another problem. I have some TPK files that are spread across a country. The problem is, I cannot pan the map to other location other than my location.

E.g. My last position is at Kansas and I have 3 TPK files for Colorado, Oklahoma, and Arizona. I cannot scroll or pan my map to Oklahoma or Arizona because it's quite far from my current position. It seems that there's this invisible boundary that limits my panning

EDIT3:

last edit. Finally got it working. I just need to programamtically set the max extent of the map using MapView.setMaxExtent(). I took the (xmin,ymin) and (xmax, ymax) from ArcGIS street map's REST API and now I could navigate to any location on the map

Re: Blank MapView when I start the map without WiFi

ShellyGill1 — Fri, 28 Oct 2016 09:48:10 GMT

> It's just a MapView with usual id, width, height, mapOptions set to Street and zoom set to 15. No basemap URL

You dont need an internet connection to initialize a MapView. However, if you have used the mapOptions attribute, then the map view will be initialized using one of the Esri default basemap map services - so would require an internet connection. I would remove the mapOptions attribute (you can leave the MapView definition there). Then in your code, check if you have an internet connection - if so, you can programmatically add one of the services (Folder: / ) to your map as the base layer, which will initialize the map. If you dont have a connection, then you can go ahead and programmatically add your local data layers.

Hope this helps,

Shelly

Re: Blank MapView when I start the map without WiFi

JasonChristian — Fri, 28 Oct 2016 10:59:17 GMT

The MapOptions is actually still there. But I got everything working now. You just need to check if the internet connection is not available, then add offline features (e.g. tpk files) and it will initialize itself (Don't check for status INIT_SUCCESS). The MapOptions attribute is still useful for when I have slow/unreliable connection, so I don't have to programmatically change the basemap

The solution is to always add any offline features to actually initialize the map when offline (kudos to Alexander)

Thank you for the reply.

Re: Blank MapView when I start the map without WiFi

AlexanderNohe1 — Sun, 12 Dec 2021 02:39:32 GMT

Hey Shelly Gill‌,

I am on Runtime 10.2.8-1.

I went ahead and attempted to do this in a quick sample.

My MapView object looks like this (I dropped all mapOptions attributes):

<com.esri.android.map.MapView
    android:id="@+id/map"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

and my mMapView initialization check looks like this:

mMapView = (MapView) findViewById(R.id.map);

mMapView.setOnStatusChangedListener(new OnStatusChangedListener() {
    @Override
    public void onStatusChanged(Object o, STATUS status) {
        Log.e("ESS", "STATUS");
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
            loadLayer();
        } else {
            requestStorage();
        }
    }
});

I am not seeing the following:

        Log.e("ESS", "STATUS");

in LogCat, nor is my code running the permission check or the load layer. I am thinking I might be missing something. Can you confirm that I might have missed something?

Thanks,

Alexander

Re: Blank MapView when I start the map without WiFi

ShellyGill1 — Fri, 28 Oct 2016 12:36:01 GMT

If the map doesn't have any layers or spatial reference, it won't initialize, so you'd need something to trigger that status changed listener.

Re: Blank MapView when I start the map without WiFi

AlexanderNohe1 — Fri, 28 Oct 2016 12:43:23 GMT

Got yah. Thank you for that information! This is helpful!