much refactoring:

-move event formatting logic to event class
-disable editing of event output, it's available in the calendar app
-replace string datetimes with ZonedDateZime
-move uri checking logic to scraper
-update exception handling and error messages
-reformatting and renaming
-fix messy xml layouts
-update tests
-add comments

app/build.gradle

@@ -40,6 +40,6 @@ dependencies {
     implementation 'com.squareup.picasso:picasso:2.71828'
 
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.2'
-    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
 }

app/src/androidTest/java/com/akdev/nofbeventscraper/MainActivityUnitTest.java

@@ -1,110 +0,0 @@
-package com.akdev.nofbeventscraper;
-
-import android.app.Activity;
-import android.app.Instrumentation;
-import android.content.Context;
-import android.content.Intent;
-
-import androidx.test.ext.junit.runners.AndroidJUnit4;
-import androidx.test.platform.app.InstrumentationRegistry;
-
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
-import static org.junit.Assert.assertEquals;
-
-@RunWith(AndroidJUnit4.class)
-public class MainActivityUnitTest {
-
-    @Test
-    public void TestSubdomainUrl() {
-
-
-        Instrumentation mInstrumentation = getInstrumentation();
-        // We register our interest in the activity
-        Instrumentation.ActivityMonitor monitor = mInstrumentation.addMonitor(MainActivity.class.getName(), null, false);
-        // We launch it
-        Intent intent = new Intent(Intent.ACTION_MAIN);
-        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-        intent.setClassName(mInstrumentation.getTargetContext(), MainActivity.class.getName());
-        mInstrumentation.startActivitySync(intent);
-
-        MainActivity mainActivity = (MainActivity) getInstrumentation().waitForMonitor(monitor);
-
-        // We register our interest in the next activity from the sequence in this use case
-        mInstrumentation.removeMonitor(monitor);
-
-
-        final String exp = "https://m.facebook.com/events/261145401687844";
-
-        String url = "https://www.facebook.com/events/261145401687844";
-        String act = mainActivity.checkURI(url);
-        assertEquals(exp, act);
-
-        url = "https://de-de.facebook.com/events/261145401687844";
-        act = mainActivity.checkURI(url);
-        assertEquals(exp, act);
-
-        url = "https://m.facebook.com/events/261145401687844";
-        act = mainActivity.checkURI(url);
-        assertEquals(exp, act);
-
-        url = "https://www.facebook.com/events/261145401687844/?active_tab=discussion";
-        act = mainActivity.checkURI(url);
-        assertEquals(exp, act);
-
-        url = "https://www.facebook.com/events/261145401687844?reflink_something";
-        act = mainActivity.checkURI(url);
-        assertEquals(exp, act);
-    }
-
-    @Test
-    public void TestTimeToEpoch() {
-
-
-        Instrumentation mInstrumentation = getInstrumentation();
-        // We register our interest in the activity
-        Instrumentation.ActivityMonitor monitor = mInstrumentation.addMonitor(MainActivity.class.getName(), null, false);
-        // We launch it
-        Intent intent = new Intent(Intent.ACTION_MAIN);
-        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-        intent.setClassName(mInstrumentation.getTargetContext(), MainActivity.class.getName());
-        mInstrumentation.startActivitySync(intent);
-
-        MainActivity mainActivity = (MainActivity) getInstrumentation().waitForMonitor(monitor);
-
-        // We register our interest in the next activity from the sequence in this use case
-        mInstrumentation.removeMonitor(monitor);
-
-
-        String in = "2020-07-29T12:00:00+00:00";
-
-        Long exp = new Long(1596024000);
-        exp = exp* 1000;
-        Long act = mainActivity.convertTimeToEpoch(in);
-        assertEquals(exp, act);
-
-
-        in = "2020-07-29T12:00:00+02:00";
-        exp = new Long(1596016800);
-        exp = exp* 1000;
-        act = mainActivity.convertTimeToEpoch(in);
-        assertEquals(exp, act);
-
-
-        in = "1970-01-01T00:00:00+00:00";
-        exp = new Long(0);
-        exp = exp* 1000;
-        act = mainActivity.convertTimeToEpoch(in);
-        assertEquals(exp, act);
-
-        in = "1970-01-01T02:00:00+02:00";
-        exp = new Long(0);
-        exp = exp* 1000;
-        act = mainActivity.convertTimeToEpoch(in);
-        assertEquals(exp, act);
-
-    }
-
-}

app/src/androidTest/java/com/akdev/nofbeventscraper/ScraperUnitTest.java

@@ -5,13 +5,19 @@ import androidx.test.ext.junit.runners.AndroidJUnit4;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.net.MalformedURLException;
+import java.net.URISyntaxException;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+
 import static org.junit.Assert.assertEquals;
 
 @RunWith(AndroidJUnit4.class)
 public class ScraperUnitTest {
 
     @Test
-    public void TestLocation() {
+    public void testLocation() {
+
 
         FbScraper scraper = new FbScraper(null, "");
 
@@ -32,37 +38,50 @@ public class ScraperUnitTest {
     }
 
     @Test
-    public void TestTimezone() {
+    public void testTimezone() {
 
         FbScraper scraper = new FbScraper(null, "");
 
-        String exp = "2020-10-23T05:00:00+02:00";
+        String exp = "2020-10-23T05:00+02:00";
         String in = "2020-10-23T05:00:00+0200";
-        String act = scraper.fixTimezone(in);
+        String act = scraper.toZonedDateTime(in).toString();
         assertEquals(exp, act);
 
 
-        exp = "";
+        exp = null;
         in = "";
-        act = scraper.fixTimezone(in);
+        ZonedDateTime act2 = scraper.toZonedDateTime(in);
-        assertEquals(exp, act);
+        assertEquals(exp, act2);
-
     }
 
     @Test
-    public void TestLinks() {
+    public void testDescriptionLinks() {
 
         FbScraper scraper = new FbScraper(null, "");
 
         String in = "foo @[152580919265:274:MagentaMusik 360] bar";
         String exp = "foo MagentaMusik 360 [m.facebook.com/152580919265] bar";
-        String act = scraper.fixLinks(in);
+        String act = scraper.fixDescriptionLinks(in);
         assertEquals(exp, act);
 
         in = "foo @[152580919265:274:MagentaMusik 360] bar @[666666666666:274:NoOfTheBeast]";
         exp = "foo MagentaMusik 360 [m.facebook.com/152580919265] bar NoOfTheBeast [m.facebook.com/666666666666]";
-        act = scraper.fixLinks(in);
+        act = scraper.fixDescriptionLinks(in);
+        assertEquals(exp, act);
+    }
+
+    @Test
+    public void testURI() throws MalformedURLException, URISyntaxException {
+
+        FbScraper scraper = new FbScraper(null, "");
+
+        String in = "https://www.facebook.com/events/1234324522341432?refsomething";
+        String exp = "https://m.facebook.com/events/1234324522341432";
+        String act = scraper.fixURI(in);
         assertEquals(exp, act);
 
+        in = "https://de-de.facebook.com/events/1234324522341432/?active_tab=discussion";
+        act = scraper.fixURI(in);
+        assertEquals(exp, act);
     }
 }

app/src/main/java/com/akdev/nofbeventscraper/FbEvent.java

@@ -1,14 +1,24 @@
 package com.akdev.nofbeventscraper;
 
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
+
 public class FbEvent {
+
+    public String url;
     public String name;
-    public String start_date;
+    public ZonedDateTime start_date;
-    public String end_date;
+    public ZonedDateTime end_date;
     public String description;
     public String location;
     public String image_url;
 
-    public FbEvent (String name, String start_date, String end_date, String description, String location, String image_url) {
+    public FbEvent() {
+
+    }
+
+    public FbEvent(String name, ZonedDateTime start_date, ZonedDateTime end_date, String description, String location, String image_url) {
         this.name = name;
         this.start_date = start_date;
         this.end_date = end_date;
@@ -16,4 +26,21 @@ public class FbEvent {
         this.location = location;
         this.image_url = image_url;
     }
+
+
+    static Long dateTimeToEpoch(ZonedDateTime datetime) {
+        try {
+            return datetime.toEpochSecond() * 1000;
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
+    static String dateTimeToString(ZonedDateTime datetime) {
+        try {
+            return DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM).format(datetime);
+        } catch (Exception e) {
+            return "";
+        }
+    }
 }

app/src/main/java/com/akdev/nofbeventscraper/FbScraper.java

@@ -1,6 +1,5 @@
 package com.akdev.nofbeventscraper;
 
-
 import android.os.AsyncTask;
 import android.text.Editable;
 import android.text.SpannableStringBuilder;
@@ -11,69 +10,100 @@ import org.jsoup.Jsoup;
 import org.jsoup.nodes.Document;
 
 import java.io.IOException;
+import java.lang.ref.WeakReference;
+import java.net.MalformedURLException;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 public class FbScraper extends AsyncTask<Void, Void, Void> {
 
-    private String url;
     private String error;
-    private MainActivity main;
+    private String input_str;
+    private WeakReference<MainActivity> main; // no context leak with WeakReference
     private FbEvent event;
 
-    FbScraper(MainActivity main, String url) {
+    FbScraper(WeakReference<MainActivity> main, String str) {
-        this.url = url;
         this.main = main;
+        this.input_str = str;
+    }
+
+    protected String fixURI(String str) throws URISyntaxException, MalformedURLException {
+
+        // check for url format
+        new URL(str).toURI();
+
+        Pattern pattern = Pattern.compile("(facebook.com/events/[0-9]*)");
+        Matcher matcher = pattern.matcher(str);
+
+        if (matcher.find()) {
+            // rewrite url to m.facebook and dismiss any query strings or referrals
+            return "https://m." + matcher.group(1);
+        } else {
+            throw new URISyntaxException(str, "Does not contain event.");
+        }
 
     }
+
     protected String fixLocation(String location_json) {
 
-        String name = "";
+        String location_name = "";
 
         try {
             JSONObject reader = new JSONObject(location_json);
 
-            name = reader.getString("name");
+            location_name = reader.getString("name");
             JSONObject address = reader.getJSONObject("address");
 
             String type = address.getString("@type");
 
-            if (type.equals("PostalAddress"))
+            if (type.equals("PostalAddress")) {
-            {
                 String postal_code = address.getString("postalCode");
                 String address_locality = address.getString("addressLocality");
-                String address_country = address.getString("addressCountry");
                 String street_address = address.getString("streetAddress");
+                // included in locality
+                //String address_country = address.getString("addressCountry");
 
-                return name + ", " + street_address + ", " + postal_code + " " + address_locality;
-            }
-            else
-            {
-                return name;
-            }
 
+                return location_name + ", "
+                        + street_address + ", "
+                        + postal_code + " "
+                        + address_locality;
+            } else {
+                return location_name;
+            }
 
         } catch (JSONException e) {
             e.printStackTrace();
-            return name;
+            return location_name;
         }
     }
 
-    protected String fixTimezone(String time_in) {
+    protected ZonedDateTime toZonedDateTime(String time_in) {
 
         try {
-
+            // time in is missing a : in the timezone offset
             Editable editable = new SpannableStringBuilder(time_in);
+            String time_str = editable.insert(22, ":").toString();
 
-            return editable.insert(22, ":").toString();
+            // parse e.g. 2011-12-03T10:15:30+01:00
+            return ZonedDateTime.parse(time_str, DateTimeFormatter.ISO_OFFSET_DATE_TIME);
 
         } catch (Exception e) {
             e.printStackTrace();
-            return "";
+            return null;
         }
     }
 
-    protected String fixLinks(String description_in) {
+    protected String fixDescriptionLinks(String description_in) {
         try {
-            // @[152580919265:274:MagentaMusik 360] -> m.facebook.com/152580919265
+            /* @[152580919265:274:SiteDescription]
+             * to
+             * SiteDescription [m.facebook.com/152580919265] */
+
             return description_in.replaceAll("@\\[([0-9]{10,}):[0-9]{3}:([^]]*)]",
                     "$2 [m.facebook.com/$1]");
 
@@ -86,60 +116,45 @@ public class FbScraper extends AsyncTask<Void, Void, Void> {
     private String readFromJson(JSONObject reader, String field) {
         try {
             return reader.getString(field);
-        }
+        } catch (Exception e) {
-        catch (Exception e) {
             e.printStackTrace();
             return "";
         }
     }
+
     @Override
     protected Void doInBackground(Void... voids) {
 
-        Document document = null;
-
         try {
-            document = Jsoup.connect(url).userAgent("Mozilla").get();
+            String url = fixURI(input_str);
+            // useragent needed with Jsoup > 1.12
+            Document document = Jsoup.connect(url).userAgent("Mozilla").get();
+            String json = document
+                    .select("script[type = application/ld+json]")
+                    .first().data();
 
-            try {
+            JSONObject reader = new JSONObject(json);
-                String json = document.select("script[type = application/ld+json]").first().data();
 
-                JSONObject reader = new JSONObject(json);
+            event = new FbEvent();
+            event.url = url;
+            event.name = readFromJson(reader, "name");
+            event.start_date = toZonedDateTime(readFromJson(reader, "startDate"));
+            event.end_date = toZonedDateTime(readFromJson(reader, "endDate"));
+            event.description = fixDescriptionLinks(readFromJson(reader, "description"));
+            event.location = fixLocation(readFromJson(reader, "location"));
+            event.image_url = readFromJson(reader, "image");
 
-                String event_name = readFromJson(reader, "name");
+        } catch (URISyntaxException | MalformedURLException e) {
-                String event_start = fixTimezone(readFromJson(reader, "startDate"));
-                String event_end = fixTimezone(readFromJson(reader, "endDate"));
-
-                String event_description = fixLinks(readFromJson(reader, "description"));
-                String location = fixLocation(readFromJson(reader, "location"));
-
-                String image_url = "";
-
-                try {
-                    image_url = readFromJson(reader, "image"); // get from json
-
-                    // get from event header
-                    image_url = document.getElementsByClass("scaledImageFitWidth").first().attr("src");
-                } catch (Exception e) {
-                    e.printStackTrace();
-                    this.error = "Error: no image found";
-                }
-
-                if (event_name == null) {
-                    this.event = null;
-                    throw new Exception();
-                } else {
-                    this.event = new FbEvent(event_name, event_start, event_end, event_description, location, image_url);
-                    //this.event = new FbEvent("", "", "", "", "", "");
-                }
-
-            } catch (Exception e) {
-                e.printStackTrace();
-                this.error = "Error: Scraping event data failed";
-            }
-        } catch (Exception e) {
             e.printStackTrace();
-            this.error = "Error: URL not available";
+            this.error = "Error: URL invalid.";
+        } catch (JSONException e) {
+            e.printStackTrace();
+            this.error = "Error: Scraping event data failed";
+        } catch (IOException e) {
+            e.printStackTrace();
+            this.error = "Error: Unable to connect.";
         }
+
         return null;
     }
 
@@ -152,11 +167,10 @@ public class FbScraper extends AsyncTask<Void, Void, Void> {
         super.onPostExecute(aVoid);
 
         if (this.event != null) {
-            this.main.update(event);
+            main.get().update(event);
-        }
+        } else {
-        else {
+            main.get().error(error);
-            main.error(error);
+            main.get().clear(false);
-            this.main.clear(false);
         }
     }
 }

app/src/main/java/com/akdev/nofbeventscraper/MainActivity.java

@@ -5,12 +5,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-
-import com.google.android.material.appbar.AppBarLayout;
-import com.google.android.material.appbar.CollapsingToolbarLayout;
-import com.google.android.material.textfield.TextInputEditText;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
 import android.provider.CalendarContract;
 import android.view.KeyEvent;
 import android.view.Menu;
@@ -19,32 +13,39 @@ import android.view.View;
 import android.widget.Button;
 import android.widget.ImageView;
 
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
+
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.appbar.CollapsingToolbarLayout;
+import com.google.android.material.textfield.TextInputEditText;
 import com.google.android.material.textfield.TextInputLayout;
 import com.squareup.picasso.Picasso;
 
-import java.net.URL;
+import java.lang.ref.WeakReference;
-import java.time.ZonedDateTime;
-import java.time.format.DateTimeFormatter;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
+import static com.akdev.nofbeventscraper.FbEvent.dateTimeToEpoch;
 
 public class MainActivity extends AppCompatActivity {
 
-    private Button paste_button;
+    protected Button ok_button;
-    private Button ok_button;
+    protected Button paste_button;
 
-    private TextInputEditText field_uri_input;
+    protected TextInputEditText edit_text_uri_input;
-    private TextInputEditText field_event_name;
+    protected TextInputEditText edit_text_event_name;
-    private TextInputEditText field_event_start;
+    protected TextInputEditText edit_text_event_start;
-    private TextInputEditText field_event_end;
+    protected TextInputEditText edit_text_event_end;
-    private TextInputEditText field_event_location;
+    protected TextInputEditText edit_text_event_location;
-    private TextInputEditText field_event_description;
+    protected TextInputEditText edit_text_event_description;
-    private ImageView         toolbar_image_view;
+
-    private CollapsingToolbarLayout toolbar_layout;
+    protected TextInputLayout layout_uri_input;
-    private TextInputLayout   input_layout;
+    protected TextInputLayout layout_event_location;
-    private TextInputLayout   location_layout;
+
-    private FbScraper         scraper;
+    protected ImageView image_view_toolbar;
+    protected CollapsingToolbarLayout layout_toolbar;
+
+    protected FbScraper scraper;
+    protected FbEvent event;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -56,43 +57,52 @@ public class MainActivity extends AppCompatActivity {
         ok_button = (Button) findViewById(R.id.ok_button);
         paste_button = (Button) findViewById(R.id.paste_button);
 
-        field_uri_input = (TextInputEditText) findViewById(R.id.field_uri_input);
+        edit_text_uri_input = (TextInputEditText) findViewById(R.id.edit_text_uri_input);
-        input_layout = (TextInputLayout) findViewById(R.id.textInputLayout);
+        edit_text_event_name = (TextInputEditText) findViewById(R.id.edit_text_event_name);
-        location_layout = (TextInputLayout) findViewById(R.id.location_layout);
+        edit_text_event_start = (TextInputEditText) findViewById(R.id.edit_text_event_start);
-        field_event_name = (TextInputEditText) findViewById(R.id.field_event_name);
+        edit_text_event_end = (TextInputEditText) findViewById(R.id.edit_text_event_end);
-        field_event_start = (TextInputEditText) findViewById(R.id.field_event_start);
+        edit_text_event_location = (TextInputEditText) findViewById(R.id.edit_text_event_location);
-        field_event_end = (TextInputEditText) findViewById(R.id.field_event_end);
+        edit_text_event_description = (TextInputEditText) findViewById(R.id.edit_text_event_description);
-        field_event_location = (TextInputEditText) findViewById(R.id.field_event_location);
+
-        field_event_description = (TextInputEditText) findViewById(R.id.field_event_description);
+        layout_uri_input = (TextInputLayout) findViewById(R.id.layout_uri_input);
-        toolbar_image_view = (ImageView) findViewById(R.id.image_view);
+        layout_event_location = (TextInputLayout) findViewById(R.id.layout_event_location);
-        toolbar_layout = (CollapsingToolbarLayout) findViewById(R.id.toolbar_layout);
+        layout_toolbar = (CollapsingToolbarLayout) findViewById(R.id.layout_toolbar);
+        image_view_toolbar = (ImageView) findViewById(R.id.image_view);
 
 
+        /*
+         * Default view settings
+         */
         ok_button.setEnabled(false);
-        location_layout.setEndIconVisible(false);
+        layout_event_location.setEndIconVisible(false);
-
+        image_view_toolbar.setImageResource(R.drawable.ic_banner_foreground);
-        toolbar_image_view.setImageResource(R.drawable.ic_banner_foreground);
 
+        /*
+         * Display title only when toolbar is collapsed
+         */
         AppBarLayout app_bar_layout = (AppBarLayout) findViewById(R.id.app_bar);
         app_bar_layout.addOnOffsetChangedListener(new AppBarLayout.OnOffsetChangedListener() {
-            boolean isShow = true;
+            boolean show = true;
-            int scrollRange = -1;
+            int scroll_range = -1;
 
             @Override
-            public void onOffsetChanged(AppBarLayout appBarLayout, int verticalOffset) {
+            public void onOffsetChanged(AppBarLayout app_bar_layout, int vertical_offset) {
-                if (scrollRange == -1) {
+                if (scroll_range == -1) {
-                    scrollRange = appBarLayout.getTotalScrollRange();
+                    scroll_range = app_bar_layout.getTotalScrollRange();
                 }
-                if (scrollRange + verticalOffset == 0) {
+                if (scroll_range + vertical_offset == 0) {
-                    toolbar_layout.setTitle(getString(R.string.app_name));
+                    layout_toolbar.setTitle(getString(R.string.app_name));
-                    isShow = true;
+                    show = true;
-                } else if(isShow) {
+                } else if (show) {
-                    toolbar_layout.setTitle(" ");
+                    layout_toolbar.setTitle(" ");
-                    isShow = false;
+                    show = false;
                 }
             }
         });
 
+        /*
+         * Paste button: get last entry from clipboard
+         */
         paste_button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
@@ -102,9 +112,8 @@ public class MainActivity extends AppCompatActivity {
                     String str = clipboard.getPrimaryClip().getItemAt(0).getText().toString();
 
                     clear(true);
-                    field_uri_input.setText(str);
+                    edit_text_uri_input.setText(str);
-                }
+                } catch (NullPointerException e) {
-                catch (NullPointerException e) {
                     e.printStackTrace();
                     error("Error: Clipboard empty");
                 }
@@ -112,71 +121,65 @@ public class MainActivity extends AppCompatActivity {
             }
         });
 
-
+        /*
-        input_layout.setEndIconOnClickListener(new View.OnClickListener() {
+         * Clear button: delete all text in all fields
+         */
+        View.OnClickListener listener = new View.OnClickListener() {
             @Override
             public void onClick(View view) {
                 clear(true);
             }
-        });
+        };
-        input_layout.setErrorIconOnClickListener(new View.OnClickListener() {
+        layout_uri_input.setEndIconOnClickListener(listener);
+        layout_uri_input.setErrorIconOnClickListener(listener);
+
+        /*
+         * Maps button: launch maps intent
+         */
+        layout_event_location.setEndIconOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
-                clear(true);
+                String map_search = "geo:0,0?q=" + edit_text_event_location.getText();
-            }
-        });
 
-
+                Uri intent_uri = Uri.parse(map_search);
-        location_layout.setEndIconOnClickListener(new View.OnClickListener() {
+                Intent map_intent = new Intent(Intent.ACTION_VIEW, intent_uri);
-            @Override
+                if (map_intent.resolveActivity(getPackageManager()) != null) {
-            public void onClick(View view) {
+                    startActivity(map_intent);
-                String map_search = "geo:0,0?q=" + field_event_location.getText();
-
-                Uri gmmIntentUri = Uri.parse(map_search);
-                Intent mapIntent = new Intent(Intent.ACTION_VIEW, gmmIntentUri);
-                //mapIntent.setPackage("com.google.android.apps.maps");
-                if (mapIntent.resolveActivity(getPackageManager()) != null) {
-                    startActivity(mapIntent);
                 }
-
             }
         });
 
-
+        /*
+         * Add to calendar button: launch calendar application
+         */
         ok_button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View view) {
-                try {
-                    Long start_epoch = convertTimeToEpoch(field_event_start.getText().toString());
-                    Long end_epoch = convertTimeToEpoch(field_event_end.getText().toString());
 
-                    String name = parseField(field_event_name);
+                Long start_epoch = dateTimeToEpoch(event.start_date);
+                Long end_epoch = dateTimeToEpoch(event.end_date);
 
-                    String location = parseField(field_event_location);
+                Intent intent = new Intent(Intent.ACTION_EDIT);
-                    String description = parseField(field_event_description);
+                intent.setType("vnd.android.cursor.item/event");
-                    String uri = parseField(field_uri_input);
+                intent.putExtra(CalendarContract.Events.TITLE, event.name);
-
+                intent.putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, start_epoch);
-                    Intent intent = new Intent(Intent.ACTION_EDIT);
+                intent.putExtra(CalendarContract.EXTRA_EVENT_END_TIME, end_epoch);
-                    intent.setType("vnd.android.cursor.item/event");
+                intent.putExtra(CalendarContract.Events.EVENT_LOCATION, event.location);
-                    intent.putExtra(CalendarContract.Events.TITLE, name);
-                    intent.putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, start_epoch);
-                    intent.putExtra(CalendarContract.EXTRA_EVENT_END_TIME, end_epoch);
-                    intent.putExtra(CalendarContract.Events.EVENT_LOCATION, location);
-                    intent.putExtra(CalendarContract.Events.DESCRIPTION, uri + "\n\n" + description);
-                    startActivity(intent);
-                }
-                catch (Exception e )
-                {
-                    e.printStackTrace();
-                }
 
+                // prepend url in description
+                String desc = event.url + "\n\n" + event.description;
+                intent.putExtra(CalendarContract.Events.DESCRIPTION, desc);
+                startActivity(intent);
             }
         });
 
-        field_uri_input.setOnKeyListener(new View.OnKeyListener() {
+        /*
-            public boolean onKey(View view, int keyCode, KeyEvent keyevent) {
+         * Enter button in uri input: start scraping
-                //If the keyevent is a key-down event on the "enter" button
+         */
-                if ((keyevent.getAction() == KeyEvent.ACTION_DOWN) && (keyCode == KeyEvent.KEYCODE_ENTER)) {
+        edit_text_uri_input.setOnKeyListener(new View.OnKeyListener() {
+            public boolean onKey(View view, int keycode, KeyEvent keyevent) {
+                //If the key event is a key-down event on the "enter" button
+                if ((keyevent.getAction() == KeyEvent.ACTION_DOWN) && (keycode == KeyEvent.KEYCODE_ENTER)) {
                     startScraping();
                     return true;
                 }
@@ -184,175 +187,122 @@ public class MainActivity extends AppCompatActivity {
             }
         });
 
-        //get data from deep link
+
+        /*
+         * Get data from intent: if launched by other application
+         * via "share to" or "open with"
+         */
         Intent intent = getIntent();
         Uri data = intent.getData();
         String shared_text = intent.getStringExtra(Intent.EXTRA_TEXT);
 
         if (data != null) {
             // opening external fb link
-            field_uri_input.setText(data.toString());
+            edit_text_uri_input.setText(data.toString());
             startScraping();
-        }
+        } else if (shared_text != null) {
-        else if (shared_text != null) {
             //share to nofb
-            field_uri_input.setText(shared_text);
+            edit_text_uri_input.setText(shared_text);
             startScraping();
         }
 
     }
-    private String parseField(TextInputEditText field) {
-        try {
-            return field.getText().toString();
-        }
-        catch (Exception e) {
-            return null;
-        }
-    }
-
-
-    Long convertTimeToEpoch(String time_str) {
-        try {
-            ZonedDateTime datetime = ZonedDateTime.parse(time_str, DateTimeFormatter.ISO_DATE_TIME);
-
-            return datetime.toEpochSecond() * 1000;
-        } catch (Exception e)
-        {
-            e.printStackTrace();
-        }
-        return null;
-    }
-
-    String checkURI(String str)
-    {
-        try {
-
-            // check for a valid uri
-            new URL(str).toURI();
-
-            Pattern pattern = Pattern.compile("(facebook.com/events/[0-9]*)");
-            Matcher matcher = pattern.matcher(str);
-
-            if (matcher.find())
-            {
-                return "https://m." + matcher.group(1);
-            }
-            else
-            {
-                error("Error: Invalid URL");
-                clear(false);
-                return "";
-            }
-
-        }
-        catch (Exception e) {
-            e.printStackTrace();
-            error("Error: Invalid URL");
-            clear(false);
-            return "";
-        }
-    }
 
     public void startScraping() {
 
         error(null);
 
         try {
-            String str = checkURI(field_uri_input.getText().toString());
+            String url = edit_text_uri_input.getText().toString();
+            scraper = new FbScraper(new WeakReference<>(this), url);
+            scraper.execute();
 
-
+        } catch (Exception e) {
-            if (!str.equals(""))
-            {
-                field_uri_input.setText(str);
-                scraper = new FbScraper(this, field_uri_input.getText().toString());
-                scraper.execute();
-            }
-
-        }
-        catch (Exception e) {
             e.printStackTrace();
             error("Error: Invalid URL");
         }
 
-
     }
+
     public void error(String str) {
-        //Toast.makeText(this, str, Toast.LENGTH_SHORT).show();
+        layout_uri_input.setError(str);
-        input_layout.setError(str);
-    }
-    public void clear(boolean clearUri) {
-        if (clearUri) {
-            field_uri_input.setText("");
-        }
-        field_event_name.setText("");
-        field_event_name.setError(null);
-        field_event_start.setText("");
-        field_event_start.setError(null);
-        field_event_end.setText("");
-        field_event_end.setError(null);
-        field_event_location.setText("");
-        field_event_location.setError(null);
-        field_event_description.setText("");
-        field_event_description.setError(null);
-        toolbar_image_view.setImageDrawable(null);
-
-        if (scraper!=null)
-        {
-            scraper.cancel(true);
-            scraper = null;
-        }
-        ok_button.setEnabled(false);
-        location_layout.setEndIconVisible(false);
-        toolbar_image_view.setImageResource(R.drawable.ic_banner_foreground);
     }
 
-    public void update(FbEvent event) {
+    public void clear(boolean clear_uri) {
-        field_event_name.setText(event.name);
-        input_layout.setError(null);
 
-        if (event.name.equals(""))
+        if (clear_uri) {
-        {
+            edit_text_uri_input.setText("");
-            field_event_name.setError("no event name detected");
+            layout_uri_input.setError(null);
-        }
-        field_event_start.setText(event.start_date);
-
-        if (event.start_date.equals(""))
-        {
-            field_event_start.setError("no event start date detected");
-        }
-        field_event_end.setText(event.end_date);
-
-        if (event.end_date.equals(""))
-        {
-            field_event_end.setError("no event end date detected");
-        }
-
-        field_event_location.setText(event.location);
-
-        if (event.location.equals(""))
-        {
-            field_event_location.setError("no event location detected");
-        }
-        else
-        {
-            location_layout.setEndIconVisible(true);
-            field_event_location.setError(null);
-        }
-        field_event_description.setText(event.description);
-
-        if (event.description.equals(""))
-        {
-            field_event_description.setError("no event description detected");
         }
+        edit_text_event_name.setText("");
+        edit_text_event_start.setText("");
+        edit_text_event_end.setText("");
+        edit_text_event_location.setText("");
+        edit_text_event_description.setText("");
 
+        edit_text_event_name.setError(null);
+//        edit_text_event_start.setError(null);
+        edit_text_event_end.setError(null);
+        edit_text_event_location.setError(null);
+        edit_text_event_description.setError(null);
 
         try {
-            Picasso.get().load(event.image_url).into(toolbar_image_view);
+            scraper.cancel(true);
-        } catch (Exception e)
+            scraper = null;
-        {
+        } catch (Exception e) {
             e.printStackTrace();
         }
 
+
+        ok_button.setEnabled(false);
+        layout_event_location.setEndIconVisible(false);
+        image_view_toolbar.setImageResource(R.drawable.ic_banner_foreground);
+    }
+
+    public void update(FbEvent scraped_event) {
+
+        this.event = scraped_event;
+
+        edit_text_uri_input.setText(event.url);
+
+        if (event.name.equals("")) {
+            edit_text_event_name.setError("no event name detected");
+        } else {
+            edit_text_event_name.setText(event.name);
+        }
+
+        if (event.start_date == null) {
+            edit_text_event_start.setError("no event start date detected");
+        } else {
+            String str = FbEvent.dateTimeToString(event.start_date);
+            edit_text_event_start.setText(str);
+        }
+
+        if (event.end_date == null) {
+            edit_text_event_end.setError("no event end date detected");
+        } else {
+            String str = FbEvent.dateTimeToString(event.end_date);
+            edit_text_event_end.setText(str);
+        }
+
+        if (event.location.equals("")) {
+            edit_text_event_location.setError("no event location detected");
+        } else {
+            edit_text_event_location.setText(event.location);
+            layout_event_location.setEndIconVisible(true);
+        }
+
+        if (event.description.equals("")) {
+            edit_text_event_description.setError("no event description detected");
+        } else {
+            edit_text_event_description.setText(event.description);
+        }
+
+        Picasso.get()
+                .load(event.image_url)
+                .placeholder(R.drawable.ic_banner_foreground)
+                .into(image_view_toolbar);
+
         ok_button.setEnabled(true);
     }
 

app/src/main/res/layout/activity_main.xml

@@ -3,6 +3,7 @@
 <androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/coordinator_layout"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
@@ -16,7 +17,7 @@
         android:theme="@style/AppTheme.AppBarOverlay">
 
         <com.google.android.material.appbar.CollapsingToolbarLayout
-            android:id="@+id/toolbar_layout"
+            android:id="@+id/layout_toolbar"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:background="@color/colorPrimary"
@@ -63,7 +64,7 @@
     <include layout="@layout/content_main" />
 
     <com.google.android.material.bottomappbar.BottomAppBar
-        android:id="@+id/bottomButtonLayout"
+        android:id="@+id/bottom_appbar"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_gravity="bottom"

app/src/main/res/layout/content_main.xml

@@ -1,59 +1,50 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.core.widget.NestedScrollView
+    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/nested_scroll_view"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:animateLayoutChanges="false"
     app:layout_behavior="@string/appbar_scrolling_view_behavior"
     tools:context=".MainActivity"
-    tools:showIn="@layout/activity_main"
+    tools:showIn="@layout/activity_main">
-    android:id="@+id/nested_scroll_view" >
 
-    <androidx.constraintlayout.widget.ConstraintLayout
+
-        android:id="@+id/constraint_layout"
+    <LinearLayout
+        android:id="@+id/linear_layout"
         android:layout_width="match_parent"
-        android:layout_height="match_parent">
+        android:layout_height="wrap_content"
+        android:layout_marginStart="16dp"
+        android:layout_marginEnd="16dp"
+        android:layout_marginTop="32dp"
+        android:layout_marginBottom="64dp"
 
-        <LinearLayout
+        android:divider="@drawable/divider"
-            android:id="@+id/linearLayout4"
+        android:orientation="vertical"
-            android:layout_width="0dp"
+        android:showDividers="middle">
-            android:layout_height="wrap_content"
-            android:layout_marginStart="16dp"
-            android:layout_marginTop="16dp"
-            android:layout_marginEnd="16dp"
-            android:gravity="center"
-            android:orientation="vertical"
-            app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toTopOf="parent">
 
-        </LinearLayout>
 
         <com.google.android.material.textfield.TextInputLayout
-            android:id="@+id/textInputLayout"
+            android:id="@+id/layout_uri_input"
-            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
+            style="@style/Widget.MaterialComponents.TextInputLayout.FilledBox"
-            android:layout_width="0dp"
+            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
+            android:layout_height="match_parent"
-            android:layout_marginStart="16dp"
-            android:layout_marginTop="16dp"
 
-            android:layout_marginEnd="16dp"
             app:endIconCheckable="false"
             app:endIconDrawable="@drawable/ic_backspace_black"
-            app:endIconMode="custom"
             app:errorIconDrawable="@drawable/ic_backspace_black"
+            app:endIconMode="custom"
+
             app:helperText="@string/add_link_helper"
-            app:helperTextEnabled="true"
+            app:helperTextEnabled="true">
-            app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@+id/linearLayout4">
 
             <com.google.android.material.textfield.TextInputEditText
-                android:id="@+id/field_uri_input"
+                android:id="@+id/edit_text_uri_input"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:autoLink="web"
-                android:clickable="true"
                 android:cursorVisible="true"
                 android:hint="@string/add_link_hint"
                 android:inputType="textNoSuggestions"
@@ -61,127 +52,94 @@
                 android:textColorLink="@color/material_on_background_emphasis_high_type" />
         </com.google.android.material.textfield.TextInputLayout>
 
-        <LinearLayout
+        <com.google.android.material.textfield.TextInputLayout
-            android:id="@+id/scrollView"
+            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
             android:layout_width="match_parent"
-            android:layout_height="wrap_content"
+            android:layout_height="match_parent">
-            android:layout_marginStart="16dp"
-            android:layout_marginTop="16dp"
-            android:layout_marginEnd="16dp"
-            android:layout_marginBottom="16dp"
-            app:layout_constraintBottom_toTopOf="@+id/spacer"
-            app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@+id/textInputLayout">
 
-            <LinearLayout
+            <com.google.android.material.textfield.TextInputEditText
+                android:id="@+id/edit_text_event_name"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                android:divider="@drawable/divider"
+                android:focusable="false"
-                android:orientation="vertical"
+                android:cursorVisible="false"
-                android:showDividers="middle">
+                android:hint="Event name"
+                android:inputType="textNoSuggestions"
+                android:singleLine="true"
+                android:textColorLink="@color/material_on_background_emphasis_high_type" />
+        </com.google.android.material.textfield.TextInputLayout>
 
-                <com.google.android.material.textfield.TextInputLayout
+        <com.google.android.material.textfield.TextInputLayout
-                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
+            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
-                    android:layout_width="match_parent"
+            android:layout_width="match_parent"
-                    android:layout_height="match_parent">
+            android:layout_height="match_parent">
 
-                    <com.google.android.material.textfield.TextInputEditText
+            <com.google.android.material.textfield.TextInputEditText
-                        android:id="@+id/field_event_name"
+                android:id="@+id/edit_text_event_start"
-                        android:layout_width="match_parent"
+                android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
+                android:layout_height="wrap_content"
-                        android:clickable="true"
+                android:focusable="false"
-                        android:cursorVisible="true"
+                android:cursorVisible="false"
-                        android:hint="Event name"
+                android:hint="Event start"
-                        android:inputType="textNoSuggestions"
+                android:inputType="textNoSuggestions"
-                        android:singleLine="true"
+                android:singleLine="true" />
-                        android:textColorLink="@color/material_on_background_emphasis_high_type" />
+        </com.google.android.material.textfield.TextInputLayout>
-                </com.google.android.material.textfield.TextInputLayout>
 
-                <com.google.android.material.textfield.TextInputLayout
+        <com.google.android.material.textfield.TextInputLayout
-                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
+            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
-                    android:layout_width="match_parent"
+            android:layout_width="match_parent"
-                    android:layout_height="match_parent">
+            android:layout_height="match_parent">
 
-                    <com.google.android.material.textfield.TextInputEditText
+            <com.google.android.material.textfield.TextInputEditText
-                        android:id="@+id/field_event_start"
+                android:id="@+id/edit_text_event_end"
-                        android:layout_width="match_parent"
+                android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
+                android:layout_height="wrap_content"
-                        android:clickable="true"
+                android:focusable="false"
-                        android:cursorVisible="true"
+                android:cursorVisible="false"
-                        android:inputType="textNoSuggestions"
+                android:hint="Event end"
-                        android:hint="Event start"
+                android:inputType="textNoSuggestions"
-                        android:singleLine="true" />
+                android:singleLine="true" />
-                </com.google.android.material.textfield.TextInputLayout>
+        </com.google.android.material.textfield.TextInputLayout>
-
-                <com.google.android.material.textfield.TextInputLayout
-                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
-                    android:layout_width="match_parent"
-                    android:layout_height="match_parent">
-
-                    <com.google.android.material.textfield.TextInputEditText
-                        android:id="@+id/field_event_end"
-                        android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
-                        android:clickable="true"
-                        android:cursorVisible="true"
-                        android:inputType="textNoSuggestions"
-                        android:hint="Event end"
-                        android:singleLine="true" />
-                </com.google.android.material.textfield.TextInputLayout>
 
 
-                <com.google.android.material.textfield.TextInputLayout
+        <com.google.android.material.textfield.TextInputLayout
-                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
+            android:id="@+id/layout_event_location"
-                    android:id="@+id/location_layout"
+            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
-                    android:layout_width="match_parent"
+            android:layout_width="match_parent"
-                    android:layout_height="match_parent"
+            android:layout_height="match_parent"
-                    app:endIconDrawable="@drawable/ic_add_location"
+            app:endIconDrawable="@drawable/ic_add_location"
-                    app:endIconMode="custom">
+            app:endIconMode="custom">
 
-                    <com.google.android.material.textfield.TextInputEditText
+            <com.google.android.material.textfield.TextInputEditText
-                        android:id="@+id/field_event_location"
+                android:id="@+id/edit_text_event_location"
-                        android:layout_width="match_parent"
+                android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
+                android:layout_height="wrap_content"
-                        android:autoLink="map"
+                android:autoLink="map"
-                        android:clickable="true"
+                android:focusable="false"
-                        android:cursorVisible="true"
+                android:cursorVisible="false"
-                        android:hint="Event location"
+                android:hint="Event location"
-                        android:inputType="textNoSuggestions"
+                android:inputType="textNoSuggestions"
-                        android:singleLine="true" />
+                android:singleLine="true" />
-                </com.google.android.material.textfield.TextInputLayout>
+        </com.google.android.material.textfield.TextInputLayout>
 
-                <com.google.android.material.textfield.TextInputLayout
+        <com.google.android.material.textfield.TextInputLayout
-                    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
+            style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
-                    android:layout_width="match_parent"
+            android:layout_width="match_parent"
-                    android:layout_height="match_parent">
+            android:layout_height="match_parent">
 
-                    <com.google.android.material.textfield.TextInputEditText
+            <com.google.android.material.textfield.TextInputEditText
-                        android:id="@+id/field_event_description"
+                android:id="@+id/edit_text_event_description"
-                        android:layout_width="match_parent"
+                android:layout_width="match_parent"
-                        android:layout_height="wrap_content"
+                android:layout_height="wrap_content"
-                        android:autoLink="web"
+                android:autoLink="web"
-                        android:clickable="true"
+                android:focusable="false"
-                        android:cursorVisible="true"
+                android:cursorVisible="false"
-                        android:hint="Event description"
+                android:hint="Event description"
-                        android:inputType="textNoSuggestions|textMultiLine"
+                android:inputType="textNoSuggestions|textMultiLine"
-                        android:singleLine="false"
+                android:singleLine="false"
-                        android:textColorLink="@color/material_on_background_emphasis_high_type" />
+                android:textColorLink="@color/material_on_background_emphasis_high_type" />
-                </com.google.android.material.textfield.TextInputLayout>
+        </com.google.android.material.textfield.TextInputLayout>
 
-            </LinearLayout>
+    </LinearLayout>
-        </LinearLayout>
-
-        <Space
-            android:id="@+id/spacer"
-            android:layout_width="wrap_content"
-            android:layout_height="48dp"
-            android:layout_marginStart="16dp"
-            android:layout_marginEnd="16dp"
-            app:layout_constraintBottom_toBottomOf="@id/constraint_layout"
-            app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintStart_toStartOf="parent" />
-
-    </androidx.constraintlayout.widget.ConstraintLayout>
 
 </androidx.core.widget.NestedScrollView>