fixed scroll behavior for payment selection

Author: ajungg

ui/src/main/java/io/snabble/sdk/ui/checkout/PaymentMethodView.java

@@ -4,13 +4,15 @@
 import android.content.res.Resources;
 import android.graphics.drawable.ColorDrawable;
 import android.support.v4.content.res.ResourcesCompat;
+import android.support.v4.widget.NestedScrollView;
 import android.support.v7.widget.DividerItemDecoration;
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.ViewTreeObserver;
 import android.widget.FrameLayout;
 import android.widget.ImageView;
 import android.widget.TextView;
@@ -40,6 +42,7 @@ class PaymentMethodView extends FrameLayout {
 
     private Checkout checkout;
     private List<PaymentMethod> availablePaymentMethods;
+    private RecyclerView recyclerView;
 
     public PaymentMethodView(Context context) {
         super(context);
@@ -74,16 +77,34 @@ private void inflateView() {
             }
         }
 
-        RecyclerView recyclerView = findViewById(R.id.payment_methods);
+        recyclerView = findViewById(R.id.payment_methods);
         recyclerView.setAdapter(new Adapter());
 
-        LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
-        layoutManager.setStackFromEnd(true);
-        layoutManager.scrollToPosition(0);
+        LinearLayoutManager layoutManager = new LinearLayoutManager(getContext()) {
+            @Override
+            public boolean canScrollVertically() {
+                return false;
+            }
+        };
+
+        final NestedScrollView scrollView = findViewById(R.id.scroller);
 
         recyclerView.setLayoutManager(layoutManager);
         recyclerView.setItemAnimator(null);
 
+        scrollView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
+            @Override
+            public void onGlobalLayout() {
+                scrollView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
+
+                scrollView.post(new Runnable() {
+                    public void run() {
+                        scrollView.fullScroll(View.FOCUS_DOWN);
+                    }
+                });
+            }
+        });
+
         DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(getContext(), DividerItemDecoration.VERTICAL);
         int dividerColor = ResourcesCompat.getColor(getResources(), R.color.snabble_dividerColor, null);
         dividerItemDecoration.setDrawable(new ColorDrawable(dividerColor));

ui/src/main/res/layout/view_payment_method.xml

@@ -18,13 +18,15 @@
 
     <android.support.v4.widget.NestedScrollView
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true"
+        android:layout_marginTop="64dp"
+        android:scrollbars="none"
         android:padding="16dp"
-        android:layout_below="@+id/choose_payment_title">
+        android:id="@+id/scroller">
         <android.support.v7.widget.CardView
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:layout_gravity="bottom"
             app:cardCornerRadius="15dp"
             app:cardElevation="3dp"
             app:cardUseCompatPadding="true">