Auto-hide FAB on scroll (#435)

* feat(composeButton): hide fab on scroll
* feat(composeButton): hide when scrolling in profile fragment
* refactor(compose-fab): show fab after small scroll distance
* refactor(compose-fab): code cleanup
* feat(composeButton): hide when scrolling in profile
* fix: duplicate fab var
* feat(fab): show when scrolled to top
* add option to turn it off

---------

Co-authored-by: FineFindus <63370021+FineFindus@users.noreply.github.com>

mastodon/src/main/java/org/joinmastodon/android/GlobalUserPreferences.java

@@ -43,6 +43,7 @@ public class GlobalUserPreferences{
 	public static boolean bottomEncoding;
 	public static boolean collapseLongPosts;
 	public static boolean spectatorMode;
+	public static boolean autoHideFab;
 	public static String publishButtonText;
 	public static ThemePreference theme;
 	public static ColorPreference color;
@@ -91,6 +92,7 @@ public class GlobalUserPreferences{
 		bottomEncoding=prefs.getBoolean("bottomEncoding", false);
 		collapseLongPosts=prefs.getBoolean("collapseLongPosts", true);
 		spectatorMode=prefs.getBoolean("spectatorMode", false);
+		autoHideFab=prefs.getBoolean("autoHideFab", true);
 		publishButtonText=prefs.getString("publishButtonText", "");
 		theme=ThemePreference.values()[prefs.getInt("theme", 0)];
 		recentLanguages=fromJson(prefs.getString("recentLanguages", null), recentLanguagesType, new HashMap<>());
@@ -131,6 +133,7 @@ public class GlobalUserPreferences{
 				.putBoolean("prefixRepliesWithRe", prefixRepliesWithRe)
 				.putBoolean("collapseLongPosts", collapseLongPosts)
 				.putBoolean("spectatorMode", spectatorMode)
+				.putBoolean("autoHideFab", autoHideFab)
 				.putString("publishButtonText", publishButtonText)
 				.putBoolean("bottomEncoding", bottomEncoding)
 				.putInt("theme", theme.ordinal())

mastodon/src/main/java/org/joinmastodon/android/fragments/AccountTimelineFragment.java

@@ -3,6 +3,10 @@ package org.joinmastodon.android.fragments;
 import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
+import android.view.animation.TranslateAnimation;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
 
 import org.joinmastodon.android.R;
 import org.joinmastodon.android.api.requests.accounts.GetAccountStatuses;

mastodon/src/main/java/org/joinmastodon/android/fragments/BaseStatusListFragment.java

@@ -13,9 +13,12 @@ import android.text.Layout;
 import android.text.StaticLayout;
 import android.text.TextPaint;
 import android.text.TextUtils;
+import android.util.Log;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.WindowInsets;
+import android.view.animation.TranslateAnimation;
+import android.widget.ImageButton;
 import android.widget.ImageButton;
 import android.widget.Toolbar;
 
@@ -75,10 +78,11 @@ public abstract class BaseStatusListFragment<T extends DisplayItemsParent> exten
 	protected DisplayItemsAdapter adapter;
 	protected String accountID;
 	protected PhotoViewer currentPhotoViewer;
+	protected ImageButton fab;
+	protected int scrollDiff = 0;
 	protected HashMap<String, Account> knownAccounts=new HashMap<>();
 	protected HashMap<String, Relationship> relationships=new HashMap<>();
 	protected Rect tmpRect=new Rect();
-	protected ImageButton fab;
 
 	public BaseStatusListFragment(){
 		super(20);
@@ -285,11 +289,42 @@ public abstract class BaseStatusListFragment<T extends DisplayItemsParent> exten
 	@Override
 	public void onViewCreated(View view, Bundle savedInstanceState){
 		super.onViewCreated(view, savedInstanceState);
+		fab=view.findViewById(R.id.fab);
 		list.addOnScrollListener(new RecyclerView.OnScrollListener(){
 			@Override
 			public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy){
 				if(currentPhotoViewer!=null)
 					currentPhotoViewer.offsetView(-dx, -dy);
+
+				if (fab!=null && GlobalUserPreferences.autoHideFab) {
+					if (dy > 0 && fab.getVisibility() == View.VISIBLE) {
+						TranslateAnimation animate = new TranslateAnimation(
+								0,
+								0,
+								0,
+								fab.getHeight() * 2);
+						animate.setDuration(300);
+						animate.setFillAfter(true);
+						fab.startAnimation(animate);
+						fab.setVisibility(View.INVISIBLE);
+						scrollDiff = 0;
+					} else if (dy < 0 && fab.getVisibility() != View.VISIBLE) {
+						if (list.getChildLayoutPosition(list.getChildAt(0)) == 0 || scrollDiff > 400) {
+							fab.setVisibility(View.VISIBLE);
+							TranslateAnimation animate = new TranslateAnimation(
+									0,
+									0,
+									fab.getHeight() * 2,
+									0);
+							animate.setDuration(300);
+							animate.setFillAfter(true);
+							fab.startAnimation(animate);
+							scrollDiff = 0;
+						} else {
+							scrollDiff += Math.abs(dy);
+						}
+					}
+				}
 			}
 		});
 		list.addItemDecoration(new StatusListItemDecoration());
@@ -327,7 +362,6 @@ public abstract class BaseStatusListFragment<T extends DisplayItemsParent> exten
 		updateToolbar();
 
 		if (withComposeButton()) {
-			fab = view.findViewById(R.id.fab);
 			fab.setVisibility(View.VISIBLE);
 			fab.setOnClickListener(this::onFabClick);
 			fab.setOnLongClickListener(this::onFabLongClick);

mastodon/src/main/java/org/joinmastodon/android/fragments/ProfileFragment.java

@@ -19,11 +19,13 @@ import android.os.Bundle;
 import android.text.SpannableStringBuilder;
 import android.text.TextUtils;
 import android.text.style.ImageSpan;
+import android.util.Log;
 import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
+import android.view.MotionEvent;
 import android.view.SubMenu;
 import android.view.View;
 import android.view.ViewGroup;
@@ -31,9 +33,11 @@ import android.view.ViewOutlineProvider;
 import android.view.ViewTreeObserver;
 import android.view.WindowInsets;
 import android.view.inputmethod.InputMethodManager;
+import android.view.animation.TranslateAnimation;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.FrameLayout;
+import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.ProgressBar;
 import android.widget.RelativeLayout;
@@ -144,10 +148,11 @@ public class ProfileFragment extends LoaderFragment implements OnBackPressedList
 	private Uri editNewAvatar, editNewCover;
 	private String profileAccountID;
 	private boolean refreshing;
-	private View fab;
+	private ImageButton fab;
 	private WindowInsets childInsets;
 	private PhotoViewer currentPhotoViewer;
 	private boolean editModeLoading;
+	protected int scrollDiff = 0;
 
 	private static final int MAX_FIELDS=4;
 
@@ -749,6 +754,10 @@ public class ProfileFragment extends LoaderFragment implements OnBackPressedList
 		notifyButton.setContentDescription(getString(relationship.notifying ? R.string.sk_user_post_notifications_on : R.string.sk_user_post_notifications_off, '@'+account.username));
 	}
 
+	public ImageButton getFab() {
+		return fab;
+	}
+
 	private void onScrollChanged(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY){
 		int topBarsH=getToolbar().getHeight()+statusBarHeight;
 		if(scrollY>avatarBorder.getTop()-topBarsH){
@@ -779,6 +788,37 @@ public class ProfileFragment extends LoaderFragment implements OnBackPressedList
 		if(currentPhotoViewer!=null){
 			currentPhotoViewer.offsetView(0, oldScrollY-scrollY);
 		}
+
+		if (GlobalUserPreferences.autoHideFab) {
+			int dy = scrollY - oldScrollY;
+			if (dy > 0 && fab.getVisibility() == View.VISIBLE) {
+				TranslateAnimation animate = new TranslateAnimation(
+						0,
+						0,
+						0,
+						fab.getHeight() * 2);
+				animate.setDuration(300);
+				animate.setFillAfter(true);
+				fab.startAnimation(animate);
+				fab.setVisibility(View.INVISIBLE);
+				scrollDiff = 0;
+			} else if (dy < 0 && fab.getVisibility() != View.VISIBLE) {
+				if (v.getScrollY() == 0 || scrollDiff > 400) {
+					fab.setVisibility(View.VISIBLE);
+					TranslateAnimation animate = new TranslateAnimation(
+							0,
+							0,
+							fab.getHeight() * 2,
+							0);
+					animate.setDuration(300);
+					animate.setFillAfter(true);
+					fab.startAnimation(animate);
+					scrollDiff = 0;
+				} else {
+					scrollDiff += Math.abs(dy);
+				}
+			}
+		}
 	}
 
 	private Fragment getFragmentForPage(int page){

mastodon/src/main/java/org/joinmastodon/android/fragments/SettingsFragment.java

@@ -248,6 +248,11 @@ public class SettingsFragment extends MastodonToolbarFragment{
 			GlobalUserPreferences.save();
 			needAppRestart=true;
 		}));
+		items.add(new SwitchItem(R.string.sk_settings_hide_fab, R.drawable.ic_fluent_edit_24_regular, GlobalUserPreferences.autoHideFab, i->{
+			GlobalUserPreferences.autoHideFab=i.checked;
+			GlobalUserPreferences.save();
+			needAppRestart=true;
+		}));
 		items.add(new SwitchItem(R.string.sk_settings_translate_only_opened, R.drawable.ic_fluent_translate_24_regular, GlobalUserPreferences.translateButtonOpenedOnly, i->{
 			GlobalUserPreferences.translateButtonOpenedOnly=i.checked;
 			GlobalUserPreferences.save();

mastodon/src/main/res/values/strings_sk.xml

@@ -261,4 +261,5 @@
     <string name="sk_settings_hide_interaction">Hide interaction buttons</string>
     <string name="sk_follow_as">Follow from other account</string>
     <string name="sk_followed_as">Followed from %s</string>
+    <string name="sk_settings_hide_fab">Auto-hide Compose button</string>
 </resources>