Java VerticalGridView.requestFocus方法代码示例

import android.support.v17.leanback.widget.VerticalGridView; //导入方法依赖的package包/类
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    if (sRecycledViewPool == null) {
        // sRecycledViewPool should be initialized by calling preloadRecycledViews()
        // before the entering animation of this fragment starts,
        // because it takes long time and if it is called after the animation starts (e.g. here)
        // it can affect the animation.
        throw new IllegalStateException("The RecyclerView pool has not been initialized.");
    }
    View view = inflater.inflate(getFragmentLayoutResourceId(), container, false);

    TextView textView = (TextView) view.findViewById(R.id.side_panel_title);
    textView.setText(getTitle());

    mListView = (VerticalGridView) view.findViewById(R.id.side_panel_list);
    mListView.setRecycledViewPool(sRecycledViewPool);

    mAdapter = new ItemAdapter(inflater, getItemList());
    mListView.setAdapter(mAdapter);
    mListView.requestFocus();

    return view;
}
 

import android.support.v17.leanback.widget.VerticalGridView; //导入方法依赖的package包/类
@Override
void onTransitionStart() {
    super.onTransitionStart();
    if (!mHeadersEnabled) {
        // When enabling headers fragment,  the RowHeaderView gets a focus but
        // isShown() is still false because its parent is INVSIBILE, accessibility
        // event is not sent.
        // Workaround is: prevent focus to a child view during transition and put
        // focus on it after transition is done.
        final VerticalGridView listView = getVerticalGridView();
        if (listView != null) {
            listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
            if (listView.hasFocus()) {
                listView.requestFocus();
            }
        }
    }
}
 

import android.support.v17.leanback.widget.VerticalGridView; //导入方法依赖的package包/类
@Override
void onTransitionEnd() {
    if (mHeadersEnabled) {
        final VerticalGridView listView = getVerticalGridView();
        if (listView != null) {
            listView.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
            if (listView.hasFocus()) {
                listView.requestFocus();
            }
        }
    }
    super.onTransitionEnd();
}