Move the wallet floating button away when scroll gets to the bottom at FileViewFragment (#1155)

app/src/main/java/io/lbry/browser/MainActivity.java

@@ -1,5 +1,6 @@
 package io.lbry.browser;
 
+import android.animation.ObjectAnimator;
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.app.ActivityManager;
@@ -824,6 +825,20 @@ public class MainActivity extends AppCompatActivity implements SdkStatusListener
         walletBalanceListeners.remove(listener);
     }
 
+    public void restoreWalletContainerPosition() {
+        View floatingBalance = findViewById(R.id.floating_balance_main_container);
+
+        ObjectAnimator animation = ObjectAnimator.ofFloat(floatingBalance, "translationY", 0f);
+        animation.setDuration(250).start();
+    }
+
+    public void translateFloatingWallet(float initialY) {
+        if (findViewById(R.id.floating_balance_main_container).getY() == initialY) {
+            ObjectAnimator animation = ObjectAnimator.ofFloat(findViewById(R.id.floating_balance_main_container), "translationY", 2 * findViewById(R.id.floating_balance_main_container).getHeight());
+            animation.setDuration(300).start();
+        }
+    }
+
     public void removeNavFragment(Class fragmentClass, int navItemId) {
         String key = buildNavFragmentKey(fragmentClass, navItemId, null);
         if (openNavFragments.containsKey(key)) {

app/src/main/java/io/lbry/browser/ui/findcontent/FileViewFragment.java

@@ -247,6 +247,8 @@ public class FileViewFragment extends BaseFragment implements
     // if this is set, scroll to the specific comment on load
     private String commentHash;
 
+    private float floatingWalletPositionY;
+
     public View onCreateView(@NonNull LayoutInflater inflater,
                              ViewGroup container, Bundle savedInstanceState) {
         View root = inflater.inflate(R.layout.fragment_file_view, container, false);
@@ -802,6 +804,7 @@ public class FileViewFragment extends BaseFragment implements
             activity.removeSdkStatusListener(this);
             activity.removeStoragePermissionListener(this);
             activity.removeWalletBalanceListener(this);
+            activity.restoreWalletContainerPosition();
             activity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
         }
 
@@ -1282,6 +1285,27 @@ public class FileViewFragment extends BaseFragment implements
         buttonUnfollow.setOnClickListener(followUnfollowListener);
         buttonBell.setOnClickListener(bellIconListener);
 
+        NestedScrollView scrollView = root.findViewById(R.id.file_view_scroll_view);
+
+        // Store floating wallet balance vertical position when fragment was created
+        // This is used for animate it when user scrolls to the bottom of the screen
+        View floatingBalance = getActivity().findViewById(R.id.floating_balance_main_container);
+        floatingWalletPositionY = floatingBalance.getY();
+
+        scrollView.setOnScrollChangeListener(new NestedScrollView.OnScrollChangeListener() {
+            @Override
+            public void onScrollChange(NestedScrollView v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
+                Context ctx = getContext();
+                if (scrollY < oldScrollY && ctx instanceof MainActivity) {
+                    // User has scrolled upwards
+                    ((MainActivity) ctx).restoreWalletContainerPosition();
+                } else if (scrollY == (v.getChildAt(0).getMeasuredHeight() - v.getMeasuredHeight()) && ctx instanceof MainActivity) {
+                    // User is at the bottom of the screen
+                    ((MainActivity) ctx).translateFloatingWallet(floatingWalletPositionY);
+                }
+            }
+        });
+
         commentChannelSpinnerAdapter = new InlineChannelSpinnerAdapter(getContext(), R.layout.spinner_item_channel, new ArrayList<>());
         commentChannelSpinnerAdapter.addPlaceholder(false);