Scroll list on overscolling web view

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -1907,6 +1907,14 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                                 properties.setPosition(message.id, new Pair<Integer, Integer>(scrollX, scrollY));
                             }
 
+                            @Override
+                            public void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {
+                                if (clampedY) {
+                                    int dy = context.getResources().getDisplayMetrics().heightPixels / 50;
+                                    properties.scrollBy(0, scrollY == 0 ? -dy : dy);
+                                }
+                            }
+
                             @Override
                             public boolean onOpenLink(String url) {
                                 if (parentFragment == null)
@@ -5760,6 +5768,8 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
 
         void scrollTo(int pos, int y);
 
+        void scrollBy(int x, int y);
+
         void move(long id, String type);
 
         void reply(TupleMessageEx message, String selected, View anchor);

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -1700,6 +1700,16 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
             });
         }
 
+        @Override
+        public void scrollBy(int x, int y) {
+            new Handler().post(new Runnable() {
+                @Override
+                public void run() {
+                    rvMessage.scrollBy(x, y);
+                }
+            });
+        }
+
         @Override
         public void move(long id, String type) {
             Bundle args = new Bundle();

app/src/main/java/eu/faircode/email/WebViewEx.java

@@ -145,6 +145,13 @@ public class WebViewEx extends WebView implements DownloadListener, View.OnLongC
         this.intf.onSizeChanged(w, h, ow, oh);
     }
 
+    @Override
+    protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {
+        super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);
+        Log.i("Over scrolled=" + scrollX + "/" + scrollY + " clamped=" + clampedX + "/" + clampedY);
+        intf.onOverScrolled(scrollX, scrollY, clampedX, clampedY);
+    }
+
     @Override
     public void onDownloadStart(
             String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
@@ -208,6 +215,8 @@ public class WebViewEx extends WebView implements DownloadListener, View.OnLongC
 
         void onScrollChange(int scrollX, int scrollY);
 
+        void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY);
+
         boolean onOpenLink(String url);
     }
 }