Move bookmark status into its own ViewModel controlled by the activity and integrate a bottom app bar with a floating action button to manage bookmark status.

Auto-hide the top toolbar on scroll in event details screens
Remove legacy UnderlinePageIndicator. Swiping is still possible.

app/src/main/AndroidManifest.xml

@@ -53,11 +53,13 @@
             android:theme="@style/AppTheme.NoActionBar"/>
         <activity
             android:name=".activities.TrackScheduleEventActivity"
-            android:label="@string/event_details"/>
+            android:label="@string/event_details"
+            android:theme="@style/AppTheme.NoActionBar"/>
         <activity
             android:name=".activities.EventDetailsActivity"
             android:label="@string/event_details"
-            android:parentActivityName=".activities.TrackScheduleActivity">
+            android:parentActivityName=".activities.TrackScheduleActivity"
+            android:theme="@style/AppTheme.NoActionBar">
             <intent-filter>
                 <action android:name="android.nfc.action.NDEF_DISCOVERED"/>
 

app/src/main/java/be/digitalia/fosdem/activities/EventDetailsActivity.java

@@ -1,15 +1,19 @@
 package be.digitalia.fosdem.activities;
 
 import android.content.Intent;
+import android.content.res.ColorStateList;
 import android.nfc.NdefRecord;
 import android.os.Bundle;
+import android.view.View;
+import android.widget.ImageButton;
 import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
 import androidx.core.app.NavUtils;
 import androidx.core.app.TaskStackBuilder;
+import androidx.core.content.ContextCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.Observer;
@@ -17,10 +21,15 @@ import androidx.lifecycle.ViewModelProviders;
 import be.digitalia.fosdem.R;
 import be.digitalia.fosdem.fragments.EventDetailsFragment;
 import be.digitalia.fosdem.model.Event;
+import be.digitalia.fosdem.model.Track;
 import be.digitalia.fosdem.utils.NfcUtils;
 import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
 import be.digitalia.fosdem.utils.ThemeUtils;
+import be.digitalia.fosdem.viewmodels.BookmarkStatusViewModel;
 import be.digitalia.fosdem.viewmodels.EventViewModel;
+import be.digitalia.fosdem.widgets.BookmarkStatusAdapter;
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.bottomappbar.BottomAppBar;
 
 /**
  * Displays a single event passed either as a complete Parcelable object in extras or as an id in data.
@@ -31,16 +40,25 @@ public class EventDetailsActivity extends AppCompatActivity implements Observer<
 
 	public static final String EXTRA_EVENT = "event";
 
+	private AppBarLayout appBarLayout;
+	private Toolbar toolbar;
+	private BottomAppBar bottomAppBar;
+
+	private BookmarkStatusViewModel bookmarkStatusViewModel;
 	private Event event;
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
-		setContentView(R.layout.content);
+		setContentView(R.layout.single_event);
+		appBarLayout = findViewById(R.id.appbar);
+		toolbar = findViewById(R.id.toolbar);
+		bottomAppBar = findViewById(R.id.bottom_appbar);
+		setSupportActionBar(bottomAppBar);
 
-		ActionBar bar = getSupportActionBar();
-		bar.setDisplayHomeAsUpEnabled(false);
-		bar.setDisplayShowTitleEnabled(false);
+		ImageButton floatingActionButton = findViewById(R.id.fab);
+		bookmarkStatusViewModel = ViewModelProviders.of(this).get(BookmarkStatusViewModel.class);
+		BookmarkStatusAdapter.setupWithImageButton(bookmarkStatusViewModel, this, floatingActionButton);
 
 		Event event = getIntent().getParcelableExtra(EXTRA_EVENT);
 
@@ -94,14 +112,28 @@ public class EventDetailsActivity extends AppCompatActivity implements Observer<
 	private void initEvent(@NonNull Event event) {
 		this.event = event;
 		// Enable up navigation only after getting the event details
-		getSupportActionBar().setDisplayHomeAsUpEnabled(true);
-		ThemeUtils.setActionBarTrackColor(this, event.getTrack().getType());
+		toolbar.setNavigationIcon(R.drawable.abc_ic_ab_back_material);
+		toolbar.setNavigationContentDescription(R.string.abc_action_bar_up_description);
+		toolbar.setNavigationOnClickListener(new View.OnClickListener() {
+			@Override
+			public void onClick(View v) {
+				navigateUp();
+			}
+		});
+
+		final Track.Type trackType = event.getTrack().getType();
+		ThemeUtils.setStatusBarTrackColor(this, trackType);
+		final ColorStateList trackColor = ContextCompat.getColorStateList(this, trackType.getColorResId());
+		appBarLayout.setBackgroundColor(trackColor.getDefaultColor());
+		bottomAppBar.setBackgroundTint(trackColor);
+
+		bookmarkStatusViewModel.setEvent(event);
+
 		// Enable Android Beam
 		NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
 	}
 
-	@Override
-	public boolean onSupportNavigateUp() {
+	void navigateUp() {
 		// Navigate up to the track associated with this event
 		Intent upIntent = new Intent(this, TrackScheduleActivity.class);
 		upIntent.putExtra(TrackScheduleActivity.EXTRA_DAY, event.getDay());
@@ -121,7 +153,6 @@ public class EventDetailsActivity extends AppCompatActivity implements Observer<
 			startActivity(upIntent);
 			finish();
 		}
-		return true;
 	}
 
 	// CreateNfcAppDataCallback

app/src/main/java/be/digitalia/fosdem/activities/TrackScheduleActivity.java

@@ -3,13 +3,15 @@ package be.digitalia.fosdem.activities;
 import android.content.Intent;
 import android.nfc.NdefRecord;
 import android.os.Bundle;
-import android.widget.ImageView;
+import android.widget.ImageButton;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
+import androidx.core.content.ContextCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
+import androidx.lifecycle.ViewModelProviders;
 import be.digitalia.fosdem.R;
 import be.digitalia.fosdem.fragments.EventDetailsFragment;
 import be.digitalia.fosdem.fragments.RoomImageDialogFragment;
@@ -20,6 +22,8 @@ import be.digitalia.fosdem.model.Track;
 import be.digitalia.fosdem.utils.NfcUtils;
 import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
 import be.digitalia.fosdem.utils.ThemeUtils;
+import be.digitalia.fosdem.viewmodels.BookmarkStatusViewModel;
+import be.digitalia.fosdem.widgets.BookmarkStatusAdapter;
 
 /**
  * Track Schedule container, works in both single pane and dual pane modes.
@@ -27,9 +31,7 @@ import be.digitalia.fosdem.utils.ThemeUtils;
  * @author Christophe Beyls
  */
 public class TrackScheduleActivity extends AppCompatActivity
-		implements TrackScheduleListFragment.Callbacks,
-		EventDetailsFragment.FloatingActionButtonProvider,
-		CreateNfcAppDataCallback {
+		implements TrackScheduleListFragment.Callbacks, CreateNfcAppDataCallback {
 
 	public static final String EXTRA_DAY = "day";
 	public static final String EXTRA_TRACK = "track";
@@ -41,15 +43,14 @@ public class TrackScheduleActivity extends AppCompatActivity
 	private boolean isTabletLandscape;
 	private Event lastSelectedEvent;
 
-	private ImageView floatingActionButton;
+	private BookmarkStatusViewModel bookmarkStatusViewModel = null;
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 		setContentView(R.layout.track_schedule);
-		setSupportActionBar((Toolbar) findViewById(R.id.toolbar));
-
-		floatingActionButton = findViewById(R.id.fab);
+		Toolbar toolbar = findViewById(R.id.toolbar);
+		setSupportActionBar(toolbar);
 
 		Bundle extras = getIntent().getExtras();
 		day = extras.getParcelable(EXTRA_DAY);
@@ -60,7 +61,9 @@ public class TrackScheduleActivity extends AppCompatActivity
 		bar.setTitle(track.toString());
 		bar.setSubtitle(day.toString());
 		setTitle(String.format("%1$s, %2$s", track.toString(), day.toString()));
-		ThemeUtils.setActionBarTrackColor(this, track.getType());
+		ThemeUtils.setStatusBarTrackColor(this, track.getType());
+		final int trackColor = ContextCompat.getColor(this, track.getType().getColorResId());
+		toolbar.setBackgroundColor(trackColor);
 
 		isTabletLandscape = getResources().getBoolean(R.bool.tablet_landscape);
 
@@ -100,6 +103,12 @@ public class TrackScheduleActivity extends AppCompatActivity
 		}
 
 		if (isTabletLandscape) {
+			ImageButton floatingActionButton = findViewById(R.id.fab);
+			if (floatingActionButton != null) {
+				bookmarkStatusViewModel = ViewModelProviders.of(this).get(BookmarkStatusViewModel.class);
+				BookmarkStatusAdapter.setupWithImageButton(bookmarkStatusViewModel, this, floatingActionButton);
+			}
+
 			// Enable Android Beam
 			NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
 		}
@@ -128,6 +137,10 @@ public class TrackScheduleActivity extends AppCompatActivity
 					fm.beginTransaction().remove(currentFragment).commitAllowingStateLoss();
 				}
 			}
+
+			if (bookmarkStatusViewModel != null) {
+				bookmarkStatusViewModel.setEvent(event);
+			}
 		} else {
 			// Classic mode: Show event details in a new activity
 			Intent intent = new Intent(this, TrackScheduleEventActivity.class);
@@ -138,13 +151,6 @@ public class TrackScheduleActivity extends AppCompatActivity
 		}
 	}
 
-	// EventDetailsFragment.FloatingActionButtonProvider
-
-	@Override
-	public ImageView getActionButton() {
-		return floatingActionButton;
-	}
-
 	// CreateNfcAppDataCallback
 
 	@Override

app/src/main/java/be/digitalia/fosdem/activities/TrackScheduleEventActivity.java

@@ -1,10 +1,12 @@
 package be.digitalia.fosdem.activities;
 
+import android.content.res.ColorStateList;
 import android.nfc.NdefRecord;
 import android.os.Bundle;
 import android.view.View;
-import androidx.appcompat.app.ActionBar;
+import android.widget.ImageButton;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
 import androidx.core.content.ContextCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
@@ -21,9 +23,12 @@ import be.digitalia.fosdem.model.Track;
 import be.digitalia.fosdem.utils.NfcUtils;
 import be.digitalia.fosdem.utils.NfcUtils.CreateNfcAppDataCallback;
 import be.digitalia.fosdem.utils.ThemeUtils;
+import be.digitalia.fosdem.viewmodels.BookmarkStatusViewModel;
 import be.digitalia.fosdem.viewmodels.TrackScheduleViewModel;
+import be.digitalia.fosdem.widgets.BookmarkStatusAdapter;
 import be.digitalia.fosdem.widgets.ContentLoadingProgressBar;
-import com.viewpagerindicator.UnderlinePageIndicator;
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.bottomappbar.BottomAppBar;
 
 import java.util.List;
 
@@ -41,14 +46,18 @@ public class TrackScheduleEventActivity extends AppCompatActivity implements Obs
 	private int initialPosition = -1;
 	private ContentLoadingProgressBar progress;
 	private ViewPager pager;
-	private UnderlinePageIndicator pageIndicator;
-	private TrackScheduleEventAdapter adapter;
+	TrackScheduleEventAdapter adapter;
+
+	BookmarkStatusViewModel bookmarkStatusViewModel;
 
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
-
 		setContentView(R.layout.track_schedule_event);
+		AppBarLayout appBarLayout = findViewById(R.id.appbar);
+		Toolbar toolbar = findViewById(R.id.toolbar);
+		BottomAppBar bottomAppBar = findViewById(R.id.bottom_appbar);
+		setSupportActionBar(bottomAppBar);
 
 		Bundle extras = getIntent().getExtras();
 		final Day day = extras.getParcelable(EXTRA_DAY);
@@ -57,26 +66,45 @@ public class TrackScheduleEventActivity extends AppCompatActivity implements Obs
 		progress = findViewById(R.id.progress);
 		pager = findViewById(R.id.pager);
 		adapter = new TrackScheduleEventAdapter(getSupportFragmentManager());
-		pageIndicator = findViewById(R.id.indicator);
-		pageIndicator.setSelectedColor(ContextCompat.getColor(this, track.getType().getColorResId()));
 
 		if (savedInstanceState == null) {
 			initialPosition = extras.getInt(EXTRA_POSITION, -1);
 		}
 
-		ActionBar bar = getSupportActionBar();
-		bar.setDisplayHomeAsUpEnabled(true);
-		bar.setTitle(track.toString());
-		bar.setSubtitle(day.toString());
-		ThemeUtils.setActionBarTrackColor(this, track.getType());
+		toolbar.setNavigationIcon(R.drawable.abc_ic_ab_back_material);
+		toolbar.setNavigationContentDescription(R.string.abc_action_bar_up_description);
+		toolbar.setNavigationOnClickListener(new View.OnClickListener() {
+			@Override
+			public void onClick(View v) {
+				finish();
+			}
+		});
+		toolbar.setTitle(track.toString());
+		toolbar.setSubtitle(day.toString());
+		setTitle(String.format("%1$s, %2$s", track.toString(), day.toString()));
+		ThemeUtils.setStatusBarTrackColor(this, track.getType());
+		final ColorStateList trackColor = ContextCompat.getColorStateList(this, track.getType().getColorResId());
+		appBarLayout.setBackgroundColor(trackColor.getDefaultColor());
+		bottomAppBar.setBackgroundTint(trackColor);
 
-		// Enable Android Beam
-		NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
+		// Monitor the currently displayed event to update the bookmark status in FAB
+		ImageButton floatingActionButton = findViewById(R.id.fab);
+		bookmarkStatusViewModel = ViewModelProviders.of(this).get(BookmarkStatusViewModel.class);
+		BookmarkStatusAdapter.setupWithImageButton(bookmarkStatusViewModel, this, floatingActionButton);
+		pager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
+			@Override
+			public void onPageSelected(int position) {
+				bookmarkStatusViewModel.setEvent(adapter.getEvent(position));
+			}
+		});
 
 		setCustomProgressVisibility(true);
 		final TrackScheduleViewModel viewModel = ViewModelProviders.of(this).get(TrackScheduleViewModel.class);
 		viewModel.setTrack(day, track);
 		viewModel.getSchedule().observe(this, this);
+
+		// Enable Android Beam
+		NfcUtils.setAppDataPushMessageCallbackIfAvailable(this, this);
 	}
 
 	private void setCustomProgressVisibility(boolean isVisible) {
@@ -99,12 +127,6 @@ public class TrackScheduleEventActivity extends AppCompatActivity implements Obs
 		return NfcUtils.createEventAppData(this, event);
 	}
 
-	@Override
-	public boolean onSupportNavigateUp() {
-		finish();
-		return true;
-	}
-
 	@Override
 	public void onChanged(List<StatusEvent> schedule) {
 		setCustomProgressVisibility(false);
@@ -117,21 +139,25 @@ public class TrackScheduleEventActivity extends AppCompatActivity implements Obs
 			// to ensure the current position is restored properly
 			if (pager.getAdapter() == null) {
 				pager.setAdapter(adapter);
-				pageIndicator.setViewPager(pager);
-			}
 
-			if (initialPosition != -1) {
-				pager.setCurrentItem(initialPosition, false);
-				initialPosition = -1;
+				if (initialPosition != -1) {
+					pager.setCurrentItem(initialPosition, false);
+					initialPosition = -1;
+				}
+
+				final int currentPosition = pager.getCurrentItem();
+				if (currentPosition >= 0) {
+					bookmarkStatusViewModel.setEvent(adapter.getEvent(currentPosition));
+				}
 			}
 		}
 	}
 
-	public static class TrackScheduleEventAdapter extends FragmentStatePagerAdapter {
+	private static class TrackScheduleEventAdapter extends FragmentStatePagerAdapter {
 
 		private List<StatusEvent> events = null;
 
-		public TrackScheduleEventAdapter(FragmentManager fm) {
+		TrackScheduleEventAdapter(FragmentManager fm) {
 			super(fm);
 		}
 

app/src/main/java/be/digitalia/fosdem/fragments/EventDetailsFragment.java

@@ -1,11 +1,8 @@
 package be.digitalia.fosdem.fragments;
 
-import android.annotation.SuppressLint;
-import android.app.Activity;
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
-import android.graphics.drawable.Animatable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.provider.CalendarContract;
@@ -13,10 +10,8 @@ import android.text.*;
 import android.text.method.LinkMovementMethod;
 import android.text.style.ClickableSpan;
 import android.view.*;
-import android.widget.ImageView;
 import android.widget.TextView;
 import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import androidx.browser.customtabs.CustomTabsIntent;
 import androidx.core.app.ShareCompat;
 import androidx.core.content.ContextCompat;
@@ -40,14 +35,6 @@ import java.util.Map;
 
 public class EventDetailsFragment extends Fragment {
 
-	/**
-	 * Interface implemented by container activities
-	 */
-	public interface FloatingActionButtonProvider {
-		// May return null
-		ImageView getActionButton();
-	}
-
 	static class ViewHolder {
 		LayoutInflater inflater;
 		TextView personsTextView;
@@ -62,9 +49,6 @@ public class EventDetailsFragment extends Fragment {
 	ViewHolder holder;
 	EventDetailsViewModel viewModel;
 
-	private MenuItem bookmarkMenuItem;
-	private ImageView actionButton;
-
 	public static EventDetailsFragment newInstance(Event event) {
 		EventDetailsFragment f = new EventDetailsFragment();
 		Bundle args = new Bundle();
@@ -79,6 +63,7 @@ public class EventDetailsFragment extends Fragment {
 		event = getArguments().getParcelable(ARG_EVENT);
 		viewModel = ViewModelProviders.of(this).get(EventDetailsViewModel.class);
 		viewModel.setEvent(event);
+		setHasOptionsMenu(true);
 	}
 
 	public Event getEvent() {
@@ -181,23 +166,6 @@ public class EventDetailsFragment extends Fragment {
 	public void onActivityCreated(Bundle savedInstanceState) {
 		super.onActivityCreated(savedInstanceState);
 
-		Activity activity = getActivity();
-		if (activity instanceof FloatingActionButtonProvider) {
-			actionButton = ((FloatingActionButtonProvider) activity).getActionButton();
-			if (actionButton != null) {
-				actionButton.setOnClickListener(actionButtonClickListener);
-			}
-		}
-
-		// Ensure the actionButton is initialized before creating the options menu
-		setHasOptionsMenu(true);
-
-		viewModel.getBookmarkStatus().observe(getViewLifecycleOwner(), new Observer<Boolean>() {
-			@Override
-			public void onChanged(@Nullable Boolean isBookmarked) {
-				updateBookmarkMenuItem(isBookmarked, true);
-			}
-		});
 		viewModel.getEventDetails().observe(getViewLifecycleOwner(), new Observer<EventDetails>() {
 			@Override
 			public void onChanged(EventDetails eventDetails) {
@@ -222,34 +190,16 @@ public class EventDetailsFragment extends Fragment {
 		});
 	}
 
-	private final View.OnClickListener actionButtonClickListener = new View.OnClickListener() {
-
-		@Override
-		public void onClick(View view) {
-			viewModel.toggleBookmarkStatus();
-		}
-	};
-
 	@Override
 	public void onDestroyView() {
 		super.onDestroyView();
 		holder = null;
-		if (actionButton != null) {
-			// Clear the reference to this fragment
-			actionButton.setOnClickListener(null);
-			actionButton = null;
-		}
 	}
 
 	@Override
 	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
 		inflater.inflate(R.menu.event, menu);
 		menu.findItem(R.id.share).setIntent(getShareChooserIntent());
-		bookmarkMenuItem = menu.findItem(R.id.bookmark);
-		if (actionButton != null) {
-			bookmarkMenuItem.setEnabled(false).setVisible(false);
-		}
-		updateBookmarkMenuItem(viewModel.getBookmarkStatus().getValue(), false);
 	}
 
 	private Intent getShareChooserIntent() {
@@ -261,67 +211,9 @@ public class EventDetailsFragment extends Fragment {
 				.createChooserIntent();
 	}
 
-	void updateBookmarkMenuItem(Boolean isBookmarked, boolean animate) {
-		if (actionButton != null) {
-			// Action Button is used as bookmark button
-
-			if (isBookmarked == null) {
-				actionButton.setEnabled(false);
-			} else {
-				// Only animate if the button was showing a previous value
-				animate = animate && actionButton.isEnabled();
-				actionButton.setEnabled(true);
-
-				if (isBookmarked) {
-					actionButton.setContentDescription(getString(R.string.remove_bookmark));
-					actionButton.setImageResource(animate ? R.drawable.avd_bookmark_add_24dp : R.drawable.ic_bookmark_white_24dp);
-				} else {
-					actionButton.setContentDescription(getString(R.string.add_bookmark));
-					actionButton.setImageResource(animate ? R.drawable.avd_bookmark_remove_24dp : R.drawable.ic_bookmark_outline_white_24dp);
-				}
-				if (animate) {
-					((Animatable) actionButton.getDrawable()).start();
-				}
-			}
-		} else {
-			// Standard menu item is used as bookmark button
-
-			if (bookmarkMenuItem != null) {
-				if (isBookmarked == null) {
-					bookmarkMenuItem.setEnabled(false);
-				} else {
-					// Only animate if the menu item was showing a previous value
-					animate = animate && bookmarkMenuItem.isEnabled();
-					bookmarkMenuItem.setEnabled(true);
-
-					if (isBookmarked) {
-						bookmarkMenuItem.setTitle(R.string.remove_bookmark);
-						bookmarkMenuItem.setIcon(animate ? R.drawable.avd_bookmark_add_24dp : R.drawable.ic_bookmark_white_24dp);
-					} else {
-						bookmarkMenuItem.setTitle(R.string.add_bookmark);
-						bookmarkMenuItem.setIcon(animate ? R.drawable.avd_bookmark_remove_24dp : R.drawable.ic_bookmark_outline_white_24dp);
-					}
-					if (animate) {
-						((Animatable) bookmarkMenuItem.getIcon()).stop();
-						((Animatable) bookmarkMenuItem.getIcon()).start();
-					}
-				}
-			}
-		}
-	}
-
-	@Override
-	public void onDestroyOptionsMenu() {
-		super.onDestroyOptionsMenu();
-		bookmarkMenuItem = null;
-	}
-
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
 		switch (item.getItemId()) {
-			case R.id.bookmark:
-				viewModel.toggleBookmarkStatus();
-				return true;
 			case R.id.add_to_agenda:
 				addToAgenda();
 				return true;
@@ -329,7 +221,6 @@ public class EventDetailsFragment extends Fragment {
 		return false;
 	}
 
-	@SuppressLint("InlinedApi")
 	private void addToAgenda() {
 		Intent intent = new Intent(Intent.ACTION_EDIT);
 		intent.setType("vnd.android.cursor.item/event");
@@ -344,8 +235,7 @@ public class EventDetailsFragment extends Fragment {
 		EventDetails details = viewModel.getEventDetails().getValue();
 		final int personsCount = (details == null) ? 0 : details.getPersons().size();
 		if (personsCount > 0) {
-			description = String.format("%1$s: %2$s\n\n%3$s", getResources().getQuantityString(R.plurals.speakers, personsCount), event.getPersonsSummary(),
-					description);
+			description = String.format("%1$s: %2$s\n\n%3$s", getResources().getQuantityString(R.plurals.speakers, personsCount), event.getPersonsSummary(), description);
 		}
 		intent.putExtra(CalendarContract.Events.DESCRIPTION, description);
 		Date time = event.getStartTime();

app/src/main/java/be/digitalia/fosdem/model/BookmarkStatus.java

@@ -0,0 +1,20 @@
+package be.digitalia.fosdem.model;
+
+public class BookmarkStatus {
+
+	private final boolean isBookmarked;
+	private final boolean isUpdate;
+
+	public BookmarkStatus(boolean isBookmarked, boolean isUpdate) {
+		this.isBookmarked = isBookmarked;
+		this.isUpdate = isUpdate;
+	}
+
+	public boolean isBookmarked() {
+		return isBookmarked;
+	}
+
+	public boolean isUpdate() {
+		return isUpdate;
+	}
+}

app/src/main/java/be/digitalia/fosdem/utils/ThemeUtils.java

@@ -1,24 +1,17 @@
 package be.digitalia.fosdem.utils;
 
+import android.app.Activity;
 import android.app.ActivityManager;
-import android.graphics.drawable.ColorDrawable;
 import android.os.Build;
-
 import androidx.annotation.NonNull;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.content.ContextCompat;
 import be.digitalia.fosdem.model.Track;
 
 public class ThemeUtils {
 
-	@SuppressWarnings("deprecation")
-	public static void setActionBarTrackColor(@NonNull AppCompatActivity activity, @NonNull Track.Type trackType) {
-		ActionBar actionBar = activity.getSupportActionBar();
-		final int color = ContextCompat.getColor(activity, trackType.getColorResId());
-		actionBar.setBackgroundDrawable(new ColorDrawable(color));
-
+	public static void setStatusBarTrackColor(@NonNull Activity activity, @NonNull Track.Type trackType) {
 		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+			final int color = ContextCompat.getColor(activity, trackType.getColorResId());
 			final int darkColor = ContextCompat.getColor(activity, trackType.getDarkColorResId());
 			activity.getWindow().setStatusBarColor(darkColor);
 			final ActivityManager.TaskDescription taskDescription;

app/src/main/java/be/digitalia/fosdem/viewmodels/BookmarkStatusViewModel.java

@@ -0,0 +1,83 @@
+package be.digitalia.fosdem.viewmodels;
+
+import android.app.Application;
+import android.os.AsyncTask;
+import androidx.annotation.NonNull;
+import androidx.arch.core.util.Function;
+import androidx.core.util.ObjectsCompat;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.Transformations;
+import be.digitalia.fosdem.db.AppDatabase;
+import be.digitalia.fosdem.livedata.ExtraTransformations;
+import be.digitalia.fosdem.model.BookmarkStatus;
+import be.digitalia.fosdem.model.Event;
+
+public class BookmarkStatusViewModel extends AndroidViewModel {
+
+	private final AppDatabase appDatabase = AppDatabase.getInstance(getApplication());
+	private final MutableLiveData<Event> event = new MutableLiveData<>();
+	private final LiveData<BookmarkStatus> bookmarkStatus = Transformations.switchMap(event,
+			new Function<Event, LiveData<BookmarkStatus>>() {
+				@Override
+				public LiveData<BookmarkStatus> apply(Event event) {
+					if (event == null) {
+						MutableLiveData<BookmarkStatus> singleNullResult = new MutableLiveData<>();
+						singleNullResult.setValue(null);
+						return singleNullResult;
+					}
+
+					return Transformations.map(
+							// Prevent updating the UI when a bookmark is added back or removed back
+							ExtraTransformations.distinctUntilChanged(
+									appDatabase.getBookmarksDao().getBookmarkStatus(event)
+							), new Function<Boolean, BookmarkStatus>() {
+								@Override
+								public BookmarkStatus apply(Boolean isBookmarked) {
+									if (isBookmarked == null) {
+										return null;
+									}
+									final boolean isUpdate = firstResultReceived;
+									firstResultReceived = true;
+									return new BookmarkStatus(isBookmarked, isUpdate);
+								}
+							}
+					);
+				}
+			});
+	private boolean firstResultReceived = false;
+
+	public BookmarkStatusViewModel(@NonNull Application application) {
+		super(application);
+	}
+
+	public void setEvent(Event event) {
+		if (!ObjectsCompat.equals(event, this.event.getValue())) {
+			firstResultReceived = false;
+			this.event.setValue(event);
+		}
+	}
+
+	public LiveData<BookmarkStatus> getBookmarkStatus() {
+		return bookmarkStatus;
+	}
+
+	public void toggleBookmarkStatus() {
+		final Event event = this.event.getValue();
+		final BookmarkStatus currentStatus = bookmarkStatus.getValue();
+		// Ignore the action if the status for the current event hasn't been received yet
+		if (event != null && currentStatus != null && firstResultReceived) {
+			AsyncTask.SERIAL_EXECUTOR.execute(new Runnable() {
+				@Override
+				public void run() {
+					if (currentStatus.isBookmarked()) {
+						appDatabase.getBookmarksDao().removeBookmark(event);
+					} else {
+						appDatabase.getBookmarksDao().addBookmark(event);
+					}
+				}
+			});
+		}
+	}
+}

app/src/main/java/be/digitalia/fosdem/viewmodels/EventDetailsViewModel.java

@@ -1,7 +1,6 @@
 package be.digitalia.fosdem.viewmodels;
 
 import android.app.Application;
-import android.os.AsyncTask;
 import androidx.annotation.NonNull;
 import androidx.arch.core.util.Function;
 import androidx.lifecycle.AndroidViewModel;
@@ -9,7 +8,6 @@ import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.Transformations;
 import be.digitalia.fosdem.db.AppDatabase;
-import be.digitalia.fosdem.livedata.ExtraTransformations;
 import be.digitalia.fosdem.model.Event;
 import be.digitalia.fosdem.model.EventDetails;
 
@@ -17,16 +15,6 @@ public class EventDetailsViewModel extends AndroidViewModel {
 
 	private final AppDatabase appDatabase = AppDatabase.getInstance(getApplication());
 	private final MutableLiveData<Event> event = new MutableLiveData<>();
-	private final LiveData<Boolean> bookmarkStatus = Transformations.switchMap(event,
-			new Function<Event, LiveData<Boolean>>() {
-				@Override
-				public LiveData<Boolean> apply(Event event) {
-					// Prevent animating the UI when a bookmark is added back or removed back
-					return ExtraTransformations.distinctUntilChanged(
-							appDatabase.getBookmarksDao().getBookmarkStatus(event)
-					);
-				}
-			});
 	private final LiveData<EventDetails> eventDetails = Transformations.switchMap(event,
 			new Function<Event, LiveData<EventDetails>>() {
 				@Override
@@ -45,27 +33,6 @@ public class EventDetailsViewModel extends AndroidViewModel {
 		}
 	}
 
-	public LiveData<Boolean> getBookmarkStatus() {
-		return bookmarkStatus;
-	}
-
-	public void toggleBookmarkStatus() {
-		final Event event = this.event.getValue();
-		final Boolean isBookmarked = bookmarkStatus.getValue();
-		if (event != null && isBookmarked != null) {
-			AsyncTask.SERIAL_EXECUTOR.execute(new Runnable() {
-				@Override
-				public void run() {
-					if (isBookmarked) {
-						appDatabase.getBookmarksDao().removeBookmark(event);
-					} else {
-						appDatabase.getBookmarksDao().addBookmark(event);
-					}
-				}
-			});
-		}
-	}
-
 	public LiveData<EventDetails> getEventDetails() {
 		return eventDetails;
 	}

app/src/main/java/be/digitalia/fosdem/widgets/BookmarkStatusAdapter.java

@@ -0,0 +1,56 @@
+package be.digitalia.fosdem.widgets;
+
+import android.graphics.drawable.Animatable;
+import android.graphics.drawable.Drawable;
+import android.view.View;
+import android.widget.ImageButton;
+import androidx.annotation.NonNull;
+import androidx.lifecycle.LifecycleOwner;
+import androidx.lifecycle.Observer;
+import be.digitalia.fosdem.R;
+import be.digitalia.fosdem.model.BookmarkStatus;
+import be.digitalia.fosdem.viewmodels.BookmarkStatusViewModel;
+
+public class BookmarkStatusAdapter {
+
+	private BookmarkStatusAdapter() {
+	}
+
+	/**
+	 * Connect an ImageButton to a BookmarkStatusViewModel
+	 * to update its icon according to the current status and trigger a bookmark toggle on click.
+	 */
+	public static void setupWithImageButton(@NonNull final BookmarkStatusViewModel viewModel, @NonNull LifecycleOwner owner,
+											@NonNull final ImageButton imageButton) {
+		imageButton.setOnClickListener(new View.OnClickListener() {
+			@Override
+			public void onClick(View v) {
+				viewModel.toggleBookmarkStatus();
+			}
+		});
+		viewModel.getBookmarkStatus().observe(owner, new Observer<BookmarkStatus>() {
+			@Override
+			public void onChanged(BookmarkStatus bookmarkStatus) {
+				if (bookmarkStatus == null) {
+					imageButton.setEnabled(false);
+					imageButton.setImageResource(R.drawable.ic_bookmark_outline_white_24dp);
+				} else {
+					// Only animate updates, when the button was already enabled
+					final boolean animate = bookmarkStatus.isUpdate() && imageButton.isEnabled();
+					imageButton.setEnabled(true);
+					if (bookmarkStatus.isBookmarked()) {
+						imageButton.setContentDescription(imageButton.getContext().getString(R.string.remove_bookmark));
+						imageButton.setImageResource(animate ? R.drawable.avd_bookmark_add_24dp : R.drawable.ic_bookmark_white_24dp);
+					} else {
+						imageButton.setContentDescription(imageButton.getContext().getString(R.string.add_bookmark));
+						imageButton.setImageResource(animate ? R.drawable.avd_bookmark_remove_24dp : R.drawable.ic_bookmark_outline_white_24dp);
+					}
+					final Drawable drawable = imageButton.getDrawable();
+					if (drawable instanceof Animatable) {
+						((Animatable) drawable).start();
+					}
+				}
+			}
+		});
+	}
+}

app/src/main/java/com/viewpagerindicator/PageIndicator.java

@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2011 Patrik Akerfeldt
- * Copyright (C) 2011 Jake Wharton
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.viewpagerindicator;
-
-import androidx.viewpager.widget.ViewPager;
-
-/**
- * A PageIndicator is responsible to show an visual indicator on the total views
- * number and the current visible view.
- */
-public interface PageIndicator extends ViewPager.OnPageChangeListener {
-    /**
-     * Bind the indicator to a ViewPager.
-     *
-     * @param view
-     */
-    void setViewPager(ViewPager view);
-
-    /**
-     * Bind the indicator to a ViewPager.
-     *
-     * @param view
-     * @param initialPosition
-     */
-    void setViewPager(ViewPager view, int initialPosition);
-
-    /**
-     * <p>Set the current page of both the ViewPager and indicator.</p>
-     *
-     * <p>This <strong>must</strong> be used if you need to set the page before
-     * the views are drawn on screen (e.g., default start page).</p>
-     *
-     * @param item
-     */
-    void setCurrentItem(int item);
-
-    /**
-     * Notify the indicator that the fragment list has changed.
-     */
-    void notifyDataSetChanged();
-}

app/src/main/java/com/viewpagerindicator/UnderlinePageIndicator.java

@@ -1,377 +0,0 @@
-/*
- * Copyright (C) 2012 Jake Wharton
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.viewpagerindicator;
-
-import android.content.Context;
-import android.content.res.TypedArray;
-import android.graphics.Canvas;
-import android.graphics.Paint;
-import android.graphics.drawable.Drawable;
-import android.os.Parcel;
-import android.os.Parcelable;
-import android.util.AttributeSet;
-import android.view.MotionEvent;
-import android.view.View;
-import android.view.ViewConfiguration;
-
-import androidx.annotation.NonNull;
-import androidx.core.view.ViewCompat;
-import androidx.viewpager.widget.ViewPager;
-import be.digitalia.fosdem.R;
-
-/**
- * Draws a line for each page. The current page line is colored differently
- * than the unselected page lines.
- */
-public class UnderlinePageIndicator extends View implements PageIndicator {
-    private static final int INVALID_POINTER = -1;
-    static final int FADE_FRAME_MS = 30;
-
-    final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
-
-    boolean mFades;
-    private int mFadeDelay;
-    private int mFadeLength;
-    int mFadeBy;
-
-    private ViewPager mViewPager;
-    private int mScrollState;
-    private int mCurrentPage;
-    private float mPositionOffset;
-
-    private int mTouchSlop;
-    private float mLastMotionX = -1;
-    private int mActivePointerId = INVALID_POINTER;
-    private boolean mIsDragging;
-
-    final Runnable mFadeRunnable = new Runnable() {
-      @Override public void run() {
-        if (!mFades) return;
-
-        final int alpha = Math.max(mPaint.getAlpha() - mFadeBy, 0);
-        mPaint.setAlpha(alpha);
-        invalidate();
-        if (alpha > 0) {
-          postDelayed(this, FADE_FRAME_MS);
-        }
-      }
-    };
-
-    public UnderlinePageIndicator(Context context) {
-        this(context, null);
-    }
-
-    public UnderlinePageIndicator(Context context, AttributeSet attrs) {
-        this(context, attrs, R.attr.vpiUnderlinePageIndicatorStyle);
-    }
-
-    public UnderlinePageIndicator(Context context, AttributeSet attrs, int defStyle) {
-        super(context, attrs, defStyle);
-        if (isInEditMode()) return;
-
-        //Retrieve styles attributes
-        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.UnderlinePageIndicator, defStyle, R.style.UnderlinePageIndicator);
-
-        setFades(a.getBoolean(R.styleable.UnderlinePageIndicator_fades, false));
-        setSelectedColor(a.getColor(R.styleable.UnderlinePageIndicator_selectedColor, 0));
-        setFadeDelay(a.getInteger(R.styleable.UnderlinePageIndicator_fadeDelay, 0));
-        setFadeLength(a.getInteger(R.styleable.UnderlinePageIndicator_fadeLength, 0));
-
-        Drawable background = a.getDrawable(R.styleable.UnderlinePageIndicator_android_background);
-        if (background != null) {
-            ViewCompat.setBackground(this, background);
-        }
-
-        a.recycle();
-
-        mTouchSlop = ViewConfiguration.get(context).getScaledPagingTouchSlop();
-    }
-
-    public boolean getFades() {
-        return mFades;
-    }
-
-    public void setFades(boolean fades) {
-        if (fades != mFades) {
-            mFades = fades;
-            if (fades) {
-                post(mFadeRunnable);
-            } else {
-                removeCallbacks(mFadeRunnable);
-                mPaint.setAlpha(0xFF);
-                invalidate();
-            }
-        }
-    }
-
-    public int getFadeDelay() {
-        return mFadeDelay;
-    }
-
-    public void setFadeDelay(int fadeDelay) {
-        mFadeDelay = fadeDelay;
-    }
-
-    public int getFadeLength() {
-        return mFadeLength;
-    }
-
-    public void setFadeLength(int fadeLength) {
-        mFadeLength = fadeLength;
-        mFadeBy = 0xFF / (mFadeLength / FADE_FRAME_MS);
-    }
-
-    public int getSelectedColor() {
-        return mPaint.getColor();
-    }
-
-    public void setSelectedColor(int selectedColor) {
-        mPaint.setColor(selectedColor);
-        invalidate();
-    }
-
-    @Override
-    protected void onDraw(Canvas canvas) {
-        super.onDraw(canvas);
-
-        if (mViewPager == null) {
-            return;
-        }
-        final int count = mViewPager.getAdapter().getCount();
-        if (count == 0) {
-            return;
-        }
-
-        if (mCurrentPage >= count) {
-            setCurrentItem(count - 1);
-            return;
-        }
-
-        final int paddingLeft = getPaddingLeft();
-        final float pageWidth = (getWidth() - paddingLeft - getPaddingRight()) / (1f * count);
-        final float left = paddingLeft + pageWidth * (mCurrentPage + mPositionOffset);
-        final float right = left + pageWidth;
-        final float top = getPaddingTop();
-        final float bottom = getHeight() - getPaddingBottom();
-        canvas.drawRect(left, top, right, bottom, mPaint);
-    }
-
-    @Override
-	public boolean onTouchEvent(@NonNull MotionEvent ev) {
-        if (super.onTouchEvent(ev)) {
-            return true;
-        }
-        if ((mViewPager == null) || (mViewPager.getAdapter().getCount() == 0)) {
-            return false;
-        }
-
-        final int action = ev.getAction() & MotionEvent.ACTION_MASK;
-        switch (action) {
-            case MotionEvent.ACTION_DOWN:
-                mActivePointerId = ev.getPointerId(0);
-                mLastMotionX = ev.getX();
-                break;
-
-            case MotionEvent.ACTION_MOVE: {
-                final int activePointerIndex = ev.findPointerIndex(mActivePointerId);
-                final float x = ev.getX(activePointerIndex);
-                final float deltaX = x - mLastMotionX;
-
-                if (!mIsDragging) {
-                    if (Math.abs(deltaX) > mTouchSlop) {
-                        mIsDragging = true;
-                    }
-                }
-
-                if (mIsDragging) {
-                    mLastMotionX = x;
-                    if (mViewPager.isFakeDragging() || mViewPager.beginFakeDrag()) {
-                        mViewPager.fakeDragBy(deltaX);
-                    }
-                }
-
-                break;
-            }
-
-            case MotionEvent.ACTION_CANCEL:
-            case MotionEvent.ACTION_UP:
-                if (!mIsDragging) {
-                    final int count = mViewPager.getAdapter().getCount();
-                    final int width = getWidth();
-                    final float halfWidth = width / 2f;
-                    final float sixthWidth = width / 6f;
-
-                    if ((mCurrentPage > 0) && (ev.getX() < halfWidth - sixthWidth)) {
-                        if (action != MotionEvent.ACTION_CANCEL) {
-                            mViewPager.setCurrentItem(mCurrentPage - 1);
-                        }
-                        return true;
-                    } else if ((mCurrentPage < count - 1) && (ev.getX() > halfWidth + sixthWidth)) {
-                        if (action != MotionEvent.ACTION_CANCEL) {
-                            mViewPager.setCurrentItem(mCurrentPage + 1);
-                        }
-                        return true;
-                    }
-                }
-
-                mIsDragging = false;
-                mActivePointerId = INVALID_POINTER;
-                if (mViewPager.isFakeDragging()) mViewPager.endFakeDrag();
-                break;
-
-            case MotionEvent.ACTION_POINTER_DOWN: {
-                final int index = ev.getActionIndex();
-                mLastMotionX = ev.getX(index);
-                mActivePointerId = ev.getPointerId(index);
-                break;
-            }
-
-            case MotionEvent.ACTION_POINTER_UP:
-                final int pointerIndex = ev.getActionIndex();
-                final int pointerId = ev.getPointerId(pointerIndex);
-                if (pointerId == mActivePointerId) {
-                    final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
-                    mActivePointerId = ev.getPointerId(newPointerIndex);
-                }
-                mLastMotionX = ev.getX(ev.findPointerIndex(mActivePointerId));
-                break;
-        }
-
-        return true;
-    }
-
-    @Override
-    public void setViewPager(ViewPager viewPager) {
-        if (mViewPager == viewPager) {
-            return;
-        }
-        if (mViewPager != null) {
-            //Clear us from the old pager.
-            mViewPager.removeOnPageChangeListener(this);
-        }
-        if (viewPager.getAdapter() == null) {
-            throw new IllegalStateException("ViewPager does not have adapter instance.");
-        }
-        mViewPager = viewPager;
-        mViewPager.addOnPageChangeListener(this);
-        invalidate();
-        post(new Runnable() {
-            @Override public void run() {
-                if (mFades) {
-                    post(mFadeRunnable);
-                }
-            }
-        });
-    }
-
-    @Override
-    public void setViewPager(ViewPager view, int initialPosition) {
-        setViewPager(view);
-        setCurrentItem(initialPosition);
-    }
-
-    @Override
-    public void setCurrentItem(int item) {
-        if (mViewPager == null) {
-            throw new IllegalStateException("ViewPager has not been bound.");
-        }
-        mViewPager.setCurrentItem(item);
-        mCurrentPage = item;
-        invalidate();
-    }
-
-    @Override
-    public void notifyDataSetChanged() {
-        invalidate();
-    }
-
-    @Override
-    public void onPageScrollStateChanged(int state) {
-        mScrollState = state;
-    }
-
-    @Override
-    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
-        mCurrentPage = position;
-        mPositionOffset = positionOffset;
-        if (mFades) {
-            if (positionOffsetPixels > 0) {
-                removeCallbacks(mFadeRunnable);
-                mPaint.setAlpha(0xFF);
-            } else if (mScrollState != ViewPager.SCROLL_STATE_DRAGGING) {
-                postDelayed(mFadeRunnable, mFadeDelay);
-            }
-        }
-        invalidate();
-    }
-
-    @Override
-    public void onPageSelected(int position) {
-        if (mScrollState == ViewPager.SCROLL_STATE_IDLE) {
-            mCurrentPage = position;
-            mPositionOffset = 0;
-            invalidate();
-            mFadeRunnable.run();
-        }
-    }
-
-    @Override
-    public void onRestoreInstanceState(Parcelable state) {
-        SavedState savedState = (SavedState)state;
-        super.onRestoreInstanceState(savedState.getSuperState());
-        mCurrentPage = savedState.currentPage;
-        requestLayout();
-    }
-
-    @Override
-    public Parcelable onSaveInstanceState() {
-        Parcelable superState = super.onSaveInstanceState();
-        SavedState savedState = new SavedState(superState);
-        savedState.currentPage = mCurrentPage;
-        return savedState;
-    }
-
-    static class SavedState extends BaseSavedState {
-        int currentPage;
-
-        public SavedState(Parcelable superState) {
-            super(superState);
-        }
-
-        SavedState(Parcel in) {
-            super(in);
-            currentPage = in.readInt();
-        }
-
-        @Override
-        public void writeToParcel(@NonNull Parcel dest, int flags) {
-            super.writeToParcel(dest, flags);
-            dest.writeInt(currentPage);
-        }
-
-        public static final Creator<SavedState> CREATOR = new Creator<SavedState>() {
-            @Override
-            public SavedState createFromParcel(Parcel in) {
-                return new SavedState(in);
-            }
-
-            @Override
-            public SavedState[] newArray(int size) {
-                return new SavedState[size];
-            }
-        };
-    }
-}

app/src/main/res/layout-sw600dp-land/track_schedule.xml

@@ -18,7 +18,7 @@
         style="@style/Toolbar.Fosdem"
         android:layout_width="match_parent"
         android:layout_height="128dp"
-        android:elevation="4dp"
+        android:elevation="@dimen/toolbar_elevation"
         android:gravity="top" />
 
     <androidx.cardview.widget.CardView
@@ -36,15 +36,12 @@
 
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/fab"
+        style="@style/FloatingActionButton.BookmarkStatus"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginEnd="@dimen/detail_fab_margin_end"
         android:layout_marginRight="@dimen/detail_fab_margin_end"
-        android:contentDescription="@string/add_bookmark"
-        android:theme="@style/ThemeOverlay.AppCompat.Dark"
-        app:fabSize="normal"
         app:layout_anchor="@+id/toolbar"
-        app:layout_anchorGravity="bottom|end"
-        app:srcCompat="@drawable/ic_bookmark_outline_white_24dp" />
+        app:layout_anchorGravity="bottom|end" />
 
 </androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -1,15 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
-<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
-            xmlns:tools="http://schemas.android.com/tools"
-            android:id="@+id/scroll_view"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            tools:context=".activities.EventDetailsActivity">
+<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/scroll_view"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:scrollbars="vertical"
+    tools:context=".activities.EventDetailsActivity">
 
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:orientation="vertical">
+        android:orientation="vertical"
+        android:paddingBottom="@dimen/detail_bottom_padding">
 
         <LinearLayout
             android:layout_width="match_parent"
@@ -144,4 +146,4 @@
             android:visibility="gone"/>
     </LinearLayout>
 
-</ScrollView>
+</androidx.core.widget.NestedScrollView>

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

@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/main_content"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/appbar"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <androidx.appcompat.widget.Toolbar
+            android:id="@+id/toolbar"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+            app:layout_scrollFlags="scroll|enterAlways"
+            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
+
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <FrameLayout
+        android:id="@+id/content"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_marginBottom="?attr/actionBarSize"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior" />
+
+    <com.google.android.material.bottomappbar.BottomAppBar
+        android:id="@+id/bottom_appbar"
+        android:layout_width="match_parent"
+        android:layout_height="?attr/actionBarSize"
+        android:layout_gravity="bottom"
+        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+        app:backgroundTint="?attr/colorPrimary"
+        app:fabAlignmentMode="end" />
+
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/fab"
+        style="@style/FloatingActionButton.BookmarkStatus"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_anchor="@id/bottom_appbar" />
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

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

@@ -1,7 +1,24 @@
 <?xml version="1.0" encoding="utf-8"?>
-<merge xmlns:android="http://schemas.android.com/apk/res/android"
-       android:layout_width="match_parent"
-       android:layout_height="match_parent">
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/main_content"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:id="@+id/appbar"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <androidx.appcompat.widget.Toolbar
+            android:id="@+id/toolbar"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+            app:layout_scrollFlags="scroll|enterAlways"
+            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
+
+    </com.google.android.material.appbar.AppBarLayout>
 
     <be.digitalia.fosdem.widgets.ContentLoadingProgressBar
         android:id="@+id/progress"
@@ -9,18 +26,30 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_gravity="center"
-        android:visibility="gone"/>
+        android:visibility="gone" />
 
     <androidx.viewpager.widget.ViewPager
         android:id="@+id/pager"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:visibility="gone"/>
+        android:layout_marginBottom="?attr/actionBarSize"
+        android:visibility="gone"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior" />
 
-    <com.viewpagerindicator.UnderlinePageIndicator
-        android:id="@+id/indicator"
+    <com.google.android.material.bottomappbar.BottomAppBar
+        android:id="@+id/bottom_appbar"
         android:layout_width="match_parent"
-        android:layout_height="2dp"
-        android:layout_gravity="bottom"/>
+        android:layout_height="?attr/actionBarSize"
+        android:layout_gravity="bottom"
+        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
+        app:backgroundTint="?attr/colorPrimary"
+        app:fabAlignmentMode="end" />
 
-</merge>
+    <com.google.android.material.floatingactionbutton.FloatingActionButton
+        android:id="@+id/fab"
+        style="@style/FloatingActionButton.BookmarkStatus"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        app:layout_anchor="@id/bottom_appbar" />
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>

app/src/main/res/menu/event.xml

@@ -1,21 +1,16 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
-      xmlns:app="http://schemas.android.com/apk/res-auto">
+    xmlns:app="http://schemas.android.com/apk/res-auto">
 
-    <item
-        android:id="@+id/bookmark"
-        android:icon="@drawable/ic_bookmark_outline_white_24dp"
-        android:title="@string/add_bookmark"
-        app:showAsAction="ifRoom"/>
     <item
         android:id="@+id/share"
         android:icon="@drawable/ic_share_white_24dp"
         android:title="@string/share"
-        app:showAsAction="ifRoom"/>
+        app:showAsAction="ifRoom" />
     <item
         android:id="@+id/add_to_agenda"
         android:icon="@drawable/ic_event_add_white_24dp"
         android:title="@string/add_to_agenda"
-        app:showAsAction="ifRoom"/>
+        app:showAsAction="ifRoom" />
 
 </menu>

app/src/main/res/values-sw600dp-land/dimens.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <dimen name="detail_bottom_padding">0dp</dimen>
+
+</resources>

app/src/main/res/values/dimens.xml

@@ -6,8 +6,9 @@
     <dimen name="main_menu_footer_height">32dp</dimen>
     <dimen name="list_item_padding">8dp</dimen>
     <dimen name="content_margin">16dp</dimen>
-    <dimen name="toolbar_elevation">8dp</dimen>
+    <dimen name="toolbar_elevation">4dp</dimen>
     <dimen name="schedule_column_width">360dp</dimen>
+    <dimen name="detail_bottom_padding">12dp</dimen>
     <dimen name="detail_card_view_elevation">6dp</dimen>
     <!-- Enlarge the card view by 6dp left & right and 9dp top & bottom
          to compensate for the compatibility padding of the elevation -->

app/src/main/res/values/styles.xml

@@ -70,6 +70,14 @@
         <item name="tabIndicatorColor">@android:color/white</item>
     </style>
 
+    <style name="FloatingActionButton.BookmarkStatus" parent="Widget.Design.FloatingActionButton">
+        <item name="android:contentDescription">@string/add_bookmark</item>
+        <item name="android:enabled">false</item>
+        <item name="android:theme">@style/ThemeOverlay.AppCompat.Dark</item>
+        <item name="fabSize">normal</item>
+        <item name="srcCompat">@drawable/ic_bookmark_outline_white_24dp</item>
+    </style>
+
     <style name="SeparatorLine">
         <item name="android:layout_width">match_parent</item>
         <item name="android:layout_height">1dp</item>

app/src/main/res/values/vpi__attrs.xml

@@ -1,46 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-     Copyright (C) 2012 Jake Wharton
-     Copyright (C) 2011 Patrik Åkerfeldt
-
-     Licensed under the Apache License, Version 2.0 (the "License");
-     you may not use this file except in compliance with the License.
-     You may obtain a copy of the License at
-
-          http://www.apache.org/licenses/LICENSE-2.0
-
-     Unless required by applicable law or agreed to in writing, software
-     distributed under the License is distributed on an "AS IS" BASIS,
-     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-     See the License for the specific language governing permissions and
-     limitations under the License.
--->
-
-<resources>
-
-    <declare-styleable name="ViewPagerIndicator">
-
-        <!-- Style of the underline indicator. -->
-        <attr name="vpiUnderlinePageIndicatorStyle" format="reference" />
-    </declare-styleable>
-
-    <attr name="centered" format="boolean" />
-    <attr name="selectedColor" format="color" />
-    <attr name="strokeWidth" format="dimension" />
-    <attr name="unselectedColor" format="color" />
-
-    <declare-styleable name="UnderlinePageIndicator">
-
-        <!-- Whether or not the selected indicator fades. -->
-        <attr name="fades" format="boolean" />
-        <!-- Length of the delay to fade the indicator. -->
-        <attr name="fadeDelay" format="integer" />
-        <!-- Length of the indicator fade to transparent. -->
-        <attr name="fadeLength" format="integer" />
-        <!-- Color of the selected line that represents the current page. -->
-        <attr name="selectedColor" />
-        <!-- View background -->
-        <attr name="android:background" />
-    </declare-styleable>
-
-</resources>

app/src/main/res/values/vpi__defaults.xml

@@ -1,27 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<!--
-     Copyright (C) 2012 Jake Wharton
-
-     Licensed under the Apache License, Version 2.0 (the "License");
-     you may not use this file except in compliance with the License.
-     You may obtain a copy of the License at
-
-          http://www.apache.org/licenses/LICENSE-2.0
-
-     Unless required by applicable law or agreed to in writing, software
-     distributed under the License is distributed on an "AS IS" BASIS,
-     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-     See the License for the specific language governing permissions and
-     limitations under the License.
--->
-
-<resources>
-
-    <style name="UnderlinePageIndicator" parent="android:Widget">
-        <item name="fades">true</item>
-        <item name="fadeDelay">300</item>
-        <item name="fadeLength">400</item>
-        <item name="selectedColor">?attr/colorPrimary</item>
-    </style>
-
-</resources>