[leanback] optimize folder ux

app/src/leanback/java/com/fongmi/android/tv/ui/custom/CustomVerticalGridView.java

@@ -19,17 +19,19 @@ import java.util.List;
 public class CustomVerticalGridView extends VerticalGridView {
 
     private List<View> views;
+    private boolean moveTop;
 
     public CustomVerticalGridView(@NonNull Context context) {
-        super(context);
+        this(context, null);
     }
 
     public CustomVerticalGridView(@NonNull Context context, @Nullable AttributeSet attrs) {
-        super(context, attrs);
+        this(context, attrs, 0);
     }
 
     public CustomVerticalGridView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
+        setMoveTop(true);
     }
 
     @Override
@@ -51,10 +53,14 @@ public class CustomVerticalGridView extends VerticalGridView {
         this.views = Arrays.asList(views);
     }
 
+    public void setMoveTop(boolean moveTop) {
+        this.moveTop = moveTop;
+    }
+
     @Override
     public boolean dispatchKeyEvent(KeyEvent event) {
         if (event.getAction() != KeyEvent.ACTION_DOWN) return super.dispatchKeyEvent(event);
-        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) return moveToTop();
+        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK && moveTop) return moveToTop();
         return super.dispatchKeyEvent(event);
     }
 

app/src/leanback/java/com/fongmi/android/tv/ui/fragment/VodFragment.java

@@ -233,12 +233,14 @@ public class VodFragment extends BaseFragment implements CustomScroller.Callback
     }
 
     public void goBack() {
+        if (mPages.size() == 1) mBinding.recycler.setMoveTop(true);
         mPages.remove(mPage = getLastPage());
         onRefresh();
     }
 
     @Override
     public void onItemClick(Vod item) {
+        if (item.isFolder()) mBinding.recycler.setMoveTop(false);
         if (item.isFolder()) mPages.add(Page.get(item.getVodId(), mBinding.recycler.getSelectedPosition()));
         if (item.isFolder()) getVideo(item.getVodId(), "1");
         else DetailActivity.start(getActivity(), getKey(), item.getVodId(), item.getVodName());