1 files changed, 46 insertions, 0 deletions
diff --git a/cross-tab-drag-and-drop/src/main/java/it/niedermann/android/crosstabdnd/ScrollHelper.java b/cross-tab-drag-and-drop/src/main/java/it/niedermann/android/crosstabdnd/ScrollHelper.java
new file mode 100644
index 000000000..47b1d9b17
--- /dev/null
+++ b/cross-tab-drag-and-drop/src/main/java/it/niedermann/android/crosstabdnd/ScrollHelper.java
@@ -0,0 +1,46 @@
+package it.niedermann.android.crosstabdnd;
+
+import android.os.Handler;
+
+import androidx.recyclerview.widget.RecyclerView;
+
+@SuppressWarnings("WeakerAccess")
+public class ScrollHelper implements Runnable {
+
+    private static final int SROLL_SPEED = 200;
+
+    public enum ScrollDirection {
+        UP,
+        DOWN
+    }
+
+    private boolean shouldScroll = false;
+    private ScrollDirection scrollDirection;
+    private RecyclerView currentRecyclerView;
+    private Handler handler = new Handler();
+
+    public void startScroll(RecyclerView recyclerView, ScrollDirection scrollDirection) {
+        this.scrollDirection = scrollDirection;
+        this.currentRecyclerView = recyclerView;
+        if (!shouldScroll) {
+            this.shouldScroll = true;
+            handler.post(this);
+        }
+    }
+
+    public void stopScroll() {
+        this.shouldScroll = false;
+    }
+
+    @Override
+    public void run() {
+        if (scrollDirection == ScrollDirection.UP) {
+            currentRecyclerView.smoothScrollBy(0, SROLL_SPEED * -1);
+        } else {
+            currentRecyclerView.smoothScrollBy(0, SROLL_SPEED);
+        }
+        if (shouldScroll) {
+            handler.postDelayed(this, 100);
+        }
+    }
+}
+\ No newline at end of file