1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14
15package android.support.v17.leanback.app;
16
17import android.content.Context;
18import android.graphics.Color;
19import android.graphics.drawable.Drawable;
20import android.graphics.drawable.GradientDrawable;
21import android.os.Bundle;
22import android.support.v17.leanback.R;
23import android.support.v17.leanback.widget.FocusHighlightHelper;
24import android.support.v17.leanback.widget.ItemBridgeAdapter;
25import android.support.v17.leanback.widget.PresenterSelector;
26import android.support.v17.leanback.widget.OnItemViewSelectedListener;
27import android.support.v17.leanback.widget.Row;
28import android.support.v17.leanback.widget.RowHeaderPresenter;
29import android.support.v17.leanback.widget.SinglePresenterSelector;
30import android.support.v17.leanback.widget.VerticalGridView;
31import android.support.v7.widget.RecyclerView;
32import android.util.TypedValue;
33import android.view.View;
34import android.view.ViewGroup;
35import android.view.View.OnLayoutChangeListener;
36import android.widget.FrameLayout;
37
38/**
39 * An internal fragment containing a list of row headers.
40 */
41public class HeadersFragment extends BaseRowFragment {
42
43    interface OnHeaderClickedListener {
44        void onHeaderClicked();
45    }
46
47    interface OnHeaderViewSelectedListener {
48        void onHeaderSelected(RowHeaderPresenter.ViewHolder viewHolder, Row row);
49    }
50
51    private OnHeaderViewSelectedListener mOnHeaderViewSelectedListener;
52    private OnHeaderClickedListener mOnHeaderClickedListener;
53    private boolean mHeadersEnabled = true;
54    private boolean mHeadersGone = false;
55    private int mBackgroundColor;
56    private boolean mBackgroundColorSet;
57
58    private static final PresenterSelector sHeaderPresenter = new SinglePresenterSelector(
59            new RowHeaderPresenter(R.layout.lb_header));
60
61    public HeadersFragment() {
62        setPresenterSelector(sHeaderPresenter);
63    }
64
65    public void setOnHeaderClickedListener(OnHeaderClickedListener listener) {
66        mOnHeaderClickedListener = listener;
67    }
68
69    public void setOnHeaderViewSelectedListener(OnHeaderViewSelectedListener listener) {
70        mOnHeaderViewSelectedListener = listener;
71    }
72
73    @Override
74    VerticalGridView findGridViewFromRoot(View view) {
75        return (VerticalGridView) view.findViewById(R.id.browse_headers);
76    }
77
78    @Override
79    void onRowSelected(RecyclerView parent, RecyclerView.ViewHolder viewHolder,
80            int position, int subposition) {
81        if (mOnHeaderViewSelectedListener != null) {
82            if (viewHolder != null && position >= 0) {
83                Row row = (Row) getAdapter().get(position);
84                ItemBridgeAdapter.ViewHolder vh = (ItemBridgeAdapter.ViewHolder) viewHolder;
85                mOnHeaderViewSelectedListener.onHeaderSelected(
86                        (RowHeaderPresenter.ViewHolder) vh.getViewHolder(), row);
87            } else {
88                mOnHeaderViewSelectedListener.onHeaderSelected(null, null);
89            }
90        }
91    }
92
93    private final ItemBridgeAdapter.AdapterListener mAdapterListener =
94            new ItemBridgeAdapter.AdapterListener() {
95        @Override
96        public void onCreate(ItemBridgeAdapter.ViewHolder viewHolder) {
97            View headerView = viewHolder.getViewHolder().view;
98            headerView.setOnClickListener(new View.OnClickListener() {
99                @Override
100                public void onClick(View v) {
101                    if (mOnHeaderClickedListener != null) {
102                        mOnHeaderClickedListener.onHeaderClicked();
103                    }
104                }
105            });
106            headerView.setFocusable(true);
107            headerView.setFocusableInTouchMode(true);
108            if (mWrapper != null) {
109                viewHolder.itemView.addOnLayoutChangeListener(sLayoutChangeListener);
110            } else {
111                headerView.addOnLayoutChangeListener(sLayoutChangeListener);
112            }
113        }
114
115    };
116
117    private static OnLayoutChangeListener sLayoutChangeListener = new OnLayoutChangeListener() {
118        @Override
119        public void onLayoutChange(View v, int left, int top, int right, int bottom,
120            int oldLeft, int oldTop, int oldRight, int oldBottom) {
121            v.setPivotX(v.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL ? v.getWidth() : 0);
122            v.setPivotY(v.getMeasuredHeight() / 2);
123        }
124    };
125
126    @Override
127    int getLayoutResourceId() {
128        return R.layout.lb_headers_fragment;
129    }
130
131    @Override
132    public void onViewCreated(View view, Bundle savedInstanceState) {
133        super.onViewCreated(view, savedInstanceState);
134        final VerticalGridView listView = getVerticalGridView();
135        if (listView == null) {
136            return;
137        }
138        if (getBridgeAdapter() != null) {
139            FocusHighlightHelper.setupHeaderItemFocusHighlight(listView);
140        }
141        view.setBackgroundColor(getBackgroundColor());
142        updateFadingEdgeToBrandColor(getBackgroundColor());
143        updateListViewVisibility();
144    }
145
146    private void updateListViewVisibility() {
147        final VerticalGridView listView = getVerticalGridView();
148        if (listView != null) {
149            getView().setVisibility(mHeadersGone ? View.GONE : View.VISIBLE);
150            if (!mHeadersGone) {
151                if (mHeadersEnabled) {
152                    listView.setChildrenVisibility(View.VISIBLE);
153                } else {
154                    listView.setChildrenVisibility(View.INVISIBLE);
155                }
156            }
157        }
158    }
159
160    void setHeadersEnabled(boolean enabled) {
161        mHeadersEnabled = enabled;
162        updateListViewVisibility();
163    }
164
165    void setHeadersGone(boolean gone) {
166        mHeadersGone = gone;
167        updateListViewVisibility();
168    }
169
170    static class NoOverlappingFrameLayout extends FrameLayout {
171
172        public NoOverlappingFrameLayout(Context context) {
173            super(context);
174        }
175
176        /**
177         * Avoid creating hardware layer for header dock.
178         */
179        @Override
180        public boolean hasOverlappingRendering() {
181            return false;
182        }
183    }
184
185    // Wrapper needed because of conflict between RecyclerView's use of alpha
186    // for ADD animations, and RowHeaderPresnter's use of alpha for selected level.
187    private final ItemBridgeAdapter.Wrapper mWrapper = new ItemBridgeAdapter.Wrapper() {
188        @Override
189        public void wrap(View wrapper, View wrapped) {
190            ((FrameLayout) wrapper).addView(wrapped);
191        }
192
193        @Override
194        public View createWrapper(View root) {
195            return new NoOverlappingFrameLayout(root.getContext());
196        }
197    };
198    @Override
199    void updateAdapter() {
200        super.updateAdapter();
201        ItemBridgeAdapter adapter = getBridgeAdapter();
202        if (adapter != null) {
203            adapter.setAdapterListener(mAdapterListener);
204            adapter.setWrapper(mWrapper);
205        }
206        if (adapter != null && getVerticalGridView() != null) {
207            FocusHighlightHelper.setupHeaderItemFocusHighlight(getVerticalGridView());
208        }
209    }
210
211    void setBackgroundColor(int color) {
212        mBackgroundColor = color;
213        mBackgroundColorSet = true;
214
215        if (getView() != null) {
216            getView().setBackgroundColor(mBackgroundColor);
217            updateFadingEdgeToBrandColor(mBackgroundColor);
218        }
219    }
220
221    private void updateFadingEdgeToBrandColor(int backgroundColor) {
222        View fadingView = getView().findViewById(R.id.fade_out_edge);
223        Drawable background = fadingView.getBackground();
224        if (background instanceof GradientDrawable) {
225            background.mutate();
226            ((GradientDrawable) background).setColors(
227                    new int[] {Color.TRANSPARENT, backgroundColor});
228        }
229    }
230
231    int getBackgroundColor() {
232        if (getActivity() == null) {
233            throw new IllegalStateException("Activity must be attached");
234        }
235
236        if (mBackgroundColorSet) {
237            return mBackgroundColor;
238        }
239
240        TypedValue outValue = new TypedValue();
241        if (getActivity().getTheme().resolveAttribute(R.attr.defaultBrandColor, outValue, true)) {
242            return getResources().getColor(outValue.resourceId);
243        }
244        return getResources().getColor(R.color.lb_default_brand_color);
245    }
246
247    @Override
248    void onTransitionStart() {
249        super.onTransitionStart();
250        if (!mHeadersEnabled) {
251            // When enabling headers fragment,  the RowHeaderView gets a focus but
252            // isShown() is still false because its parent is INVSIBILE, accessibility
253            // event is not sent.
254            // Workaround is: prevent focus to a child view during transition and put
255            // focus on it after transition is done.
256            final VerticalGridView listView = getVerticalGridView();
257            if (listView != null) {
258                listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
259                if (listView.hasFocus()) {
260                    listView.requestFocus();
261                }
262            }
263        }
264    }
265
266    @Override
267    void onTransitionEnd() {
268        if (mHeadersEnabled) {
269            final VerticalGridView listView = getVerticalGridView();
270            if (listView != null) {
271                listView.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
272                if (listView.hasFocus()) {
273                    listView.requestFocus();
274                }
275            }
276        }
277        super.onTransitionEnd();
278    }
279}
280