Google Maps API v3: where's my polyline?

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I made an app that uses google maps API v3 opening a HTML with a javascript saved in the assets. I also set the cache of the app to be able to see the maps even offline. It is working fine.

In the map, when ready, I draw a polyline and markers with 2D GPS data from a CSV file. It again works perfectly when online.

However, when offline, "sometimes" the polyline is shown, and sometimes it isn't. Like if the polyline/marks are hidden by the map itself, randomly. What is it happening? How to make this reliable?

About my code: My HTML has the javascript inside. From android, I call the HTML page with a webview (code below). After the page is loaded, I load the track calling a method in the javascript with:

myWebView.loadUrl("javascript:loadtrackfile(\""+TrackFile+"\")");

Through the Internet, the page also works, and I pass the address as:

http://...../map.html?track=TrackFile

(the only way to pass TrackFile to the webview was with a myWebView.setWebViewClient({}). Maybe there is a better way?

My webview code is below.

Any clues??

Thanks!

L

The webview code:

    public void onCreate(final Bundle onOreintChange) {
        super.onCreate(onOreintChange);
        ave_preferences = PreferenceManager.getDefaultSharedPreferences(this);
        if (ave_preferences.getBoolean("fullscreen", false)) setTheme(R.style.MyTheme);
        setContentView(R.layout.viewmap);

        cachedir = AveActivity.DOWNS + "/cache";
        String maphtml = "file:///android_asset/map.html";

        Bundle extras = getIntent().getExtras();
        if (extras != null) TrackFile = extras.getString("track");

        myWebView = (WebView) findViewById(R.id.webviewmap);
        ws = myWebView.getSettings();
        ws.setUserAgentString(ws.getUserAgentString() + " AveWebview");
        ws.setJavaScriptEnabled(true);

        ///// Cache to Internal SD (thanks to AveSetExtCache.java class)
        ws.setAppCacheMaxSize( 500 * 1024 * 1024 ); // 500MB // DEPRECATED IN API 18
        ws.setAllowFileAccess(true);
        ws.setAppCacheEnabled(true);
        ws.setDatabaseEnabled(true);
        ws.setDomStorageEnabled(true);
        boolean online = Downloads.isConnected(this, ave_preferences.getBoolean("wifionly", true));
        ws.setCacheMode((online) ? WebSettings.LOAD_CACHE_ELSE_NETWORK : WebSettings.LOAD_CACHE_ONLY);

        ///// Geolocation and pass TrackFile to the JS (after page is loaded)
        myWebView.setWebViewClient(new WebViewClient() {
            @Override
            public void onPageFinished(WebView view, String url) {
                myWebView.loadUrl("javascript:loadtrackfile(\""+TrackFile+"\")");
            }
        });

        myWebView.loadUrl(maphtml);
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        if (ave_preferences.getBoolean("myposition", false)) {
          ws.setGeolocationEnabled(false);
          myWebView.loadUrl("javascript:toggleGeoLocation()");
        }
        finish();
    }
}

asked 1 min ago

Luis A. Florit

182