1 files changed, 29 insertions, 0 deletions
diff --git a/app/src/main/java/com/wireguard/android/widget/fab/FloatingActionsMenuRecyclerViewScrollListener.java b/app/src/main/java/com/wireguard/android/widget/fab/FloatingActionsMenuRecyclerViewScrollListener.java
new file mode 100644
index 00000000..f526d6e8
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/widget/fab/FloatingActionsMenuRecyclerViewScrollListener.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright © 2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.widget.fab;
+
+import android.support.v7.widget.RecyclerView;
+
+import com.wireguard.android.R;
+
+public class FloatingActionsMenuRecyclerViewScrollListener extends RecyclerView.OnScrollListener {
+    private static final float SCALE_FACTOR = 1.5f;
+    private final FloatingActionsMenu menu;
+
+    public FloatingActionsMenuRecyclerViewScrollListener(final FloatingActionsMenu menu) {
+        this.menu = menu;
+    }
+
+    private static float bound(float min, float proposal, float max) {
+        return Math.min(max, Math.max(min, proposal));
+    }
+
+    @Override
+    public void onScrolled(final RecyclerView recyclerView, final int dx, final int dy) {
+        super.onScrolled(recyclerView, dx, dy);
+        menu.setScrollYTranslation(bound(0, menu.getScrollYTranslation() + dy * SCALE_FACTOR, menu.getMeasuredHeight() - menu.getTranslationY()));
+    }
+}