1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.tv.menu;
18 
19 import android.content.Context;
20 import android.content.res.Resources;
21 import android.graphics.Rect;
22 import android.support.annotation.NonNull;
23 import android.util.AttributeSet;
24 import android.util.Log;
25 import android.util.TypedValue;
26 import android.view.View;
27 import android.view.ViewGroup;
28 import android.view.accessibility.AccessibilityEvent;
29 import android.widget.LinearLayout;
30 import android.widget.TextView;
31 import com.android.tv.R;
32 import com.android.tv.menu.Menu.MenuShowReason;
33 
34 public abstract class MenuRowView extends LinearLayout {
35     private static final String TAG = "MenuRowView";
36     private static final boolean DEBUG = false;
37 
38     private TextView mTitleView;
39     private View mContentsView;
40 
41     private final float mTitleViewAlphaDeselected;
42     private final float mTitleViewScaleSelected;
43 
44     /**
45      * The lastly focused view. It is used to keep the focus while navigating the menu rows and
46      * reset when the menu is popped up.
47      */
48     private View mLastFocusView;
49 
50     private MenuRow mRow;
51 
52     private final OnFocusChangeListener mOnFocusChangeListener =
53             new OnFocusChangeListener() {
54                 @Override
55                 public void onFocusChange(View v, boolean hasFocus) {
56                     onChildFocusChange(v, hasFocus);
57                 }
58             };
59 
60     /** Returns the alpha value of the title view when it's deselected. */
getTitleViewAlphaDeselected()61     public float getTitleViewAlphaDeselected() {
62         return mTitleViewAlphaDeselected;
63     }
64 
65     /** Returns the scale value of the title view when it's selected. */
getTitleViewScaleSelected()66     public float getTitleViewScaleSelected() {
67         return mTitleViewScaleSelected;
68     }
69 
MenuRowView(Context context)70     public MenuRowView(Context context) {
71         this(context, null);
72     }
73 
MenuRowView(Context context, AttributeSet attrs)74     public MenuRowView(Context context, AttributeSet attrs) {
75         this(context, attrs, 0);
76     }
77 
MenuRowView(Context context, AttributeSet attrs, int defStyleAttr)78     public MenuRowView(Context context, AttributeSet attrs, int defStyleAttr) {
79         this(context, attrs, defStyleAttr, 0);
80     }
81 
MenuRowView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)82     public MenuRowView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
83         super(context, attrs, defStyleAttr, defStyleRes);
84         Resources res = context.getResources();
85         TypedValue outValue = new TypedValue();
86         res.getValue(R.dimen.menu_row_title_alpha_deselected, outValue, true);
87         mTitleViewAlphaDeselected = outValue.getFloat();
88         float textSizeSelected =
89                 res.getDimensionPixelSize(R.dimen.menu_row_title_text_size_selected);
90         float textSizeDeselected =
91                 res.getDimensionPixelSize(R.dimen.menu_row_title_text_size_deselected);
92         mTitleViewScaleSelected = textSizeSelected / textSizeDeselected;
93         this.setAccessibilityDelegate(
94                 new AccessibilityDelegate() {
95                     @Override
96                     public void sendAccessibilityEvent(View host, int eventType) {
97                         super.sendAccessibilityEvent(host, eventType);
98                         if (eventType == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED &&
99                                 !mRow.isReselected()) {
100                             requestChildFocus();
101                         }
102                     }
103                 }
104         );
105     }
106 
107     @Override
onFinishInflate()108     protected void onFinishInflate() {
109         super.onFinishInflate();
110         mTitleView = (TextView) findViewById(R.id.title);
111         mContentsView = findViewById(getContentsViewId());
112         if (mContentsView.isFocusable()) {
113             mContentsView.setOnFocusChangeListener(mOnFocusChangeListener);
114         }
115         if (mContentsView instanceof ViewGroup) {
116             setOnFocusChangeListenerToChildren((ViewGroup) mContentsView);
117         }
118         // Make contents view invisible in order that the view participates in the initial layout.
119         // The visibility is set to GONE after the first layout finishes.
120         // If not, we can't see the contents view animation for the first time it is shown.
121         // TODO: Find a better way to resolve this issue.
122         mContentsView.setVisibility(INVISIBLE);
123     }
124 
setOnFocusChangeListenerToChildren(ViewGroup parent)125     private void setOnFocusChangeListenerToChildren(ViewGroup parent) {
126         int childCount = parent.getChildCount();
127         for (int i = 0; i < childCount; ++i) {
128             View child = parent.getChildAt(i);
129             if (child.isFocusable()) {
130                 child.setOnFocusChangeListener(mOnFocusChangeListener);
131             }
132             if (child instanceof ViewGroup) {
133                 setOnFocusChangeListenerToChildren((ViewGroup) child);
134             }
135         }
136     }
137 
getContentsViewId()138     protected abstract int getContentsViewId();
139 
140     /** Returns the title view. */
getTitleView()141     public final TextView getTitleView() {
142         return mTitleView;
143     }
144 
145     /** Returns the contents view. */
getContentsView()146     public final View getContentsView() {
147         return mContentsView;
148     }
149 
150     /**
151      * Initialize this view. e.g. Set the initial selection. This method is called when the main
152      * menu is visible. Subclass of {@link MenuRowView} should override this to set correct
153      * mLastFocusView.
154      *
155      * @param reason A reason why this is initialized. See {@link MenuShowReason}
156      */
initialize(@enuShowReason int reason)157     public void initialize(@MenuShowReason int reason) {
158         mLastFocusView = null;
159     }
160 
getMenu()161     protected Menu getMenu() {
162         return mRow == null ? null : mRow.getMenu();
163     }
164 
onBind(MenuRow row)165     public void onBind(MenuRow row) {
166         if (DEBUG) Log.d(TAG, "onBind: row=" + row);
167         mRow = row;
168         mTitleView.setText(row.getTitle());
169     }
170 
171     @Override
onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect)172     protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
173         // Expand view here so initial focused item can be shown.
174         return getInitialFocusView().requestFocus();
175     }
176 
177     @NonNull
getInitialFocusView()178     private View getInitialFocusView() {
179         if (mLastFocusView == null) {
180             return mContentsView;
181         }
182         return mLastFocusView;
183     }
184 
185     /**
186      * Sets the view which needs to have focus when this row appears. Subclasses should call this in
187      * {@link #initialize} if needed.
188      */
setInitialFocusView(@onNull View v)189     protected void setInitialFocusView(@NonNull View v) {
190         mLastFocusView = v;
191     }
192 
193     /** Subclasses should implement this to request focus on child. */
requestChildFocus()194     protected abstract void requestChildFocus();
195 
196     /**
197      * Called when the focus of a child view is changed. The inherited class should override this
198      * method instead of calling {@link
199      * android.view.View#setOnFocusChangeListener(android.view.View.OnFocusChangeListener)}.
200      */
onChildFocusChange(View v, boolean hasFocus)201     protected void onChildFocusChange(View v, boolean hasFocus) {
202         if (hasFocus) {
203             mLastFocusView = v;
204         }
205     }
206 
207     /** Returns the ID of row object bound to this view. */
getRowId()208     public String getRowId() {
209         return mRow == null ? null : mRow.getId();
210     }
211 
212     /**
213      * Called when this row is selected.
214      *
215      * @param showTitle If {@code true}, the title is not hidden immediately after the row is
216      *     selected even though hideTitleWhenSelected() is {@code true}.
217      */
onSelected(boolean showTitle)218     public void onSelected(boolean showTitle) {
219         if (mRow.hideTitleWhenSelected() && !showTitle) {
220             // Title view should participate in the layout even though it is not visible.
221             mTitleView.setVisibility(INVISIBLE);
222         } else {
223             mTitleView.setVisibility(VISIBLE);
224             mTitleView.setAlpha(1.0f);
225             mTitleView.setScaleX(mTitleViewScaleSelected);
226             mTitleView.setScaleY(mTitleViewScaleSelected);
227         }
228         // Making the content view visible will cause it to set a focus item
229         // So we store mLastFocusView and reset it
230         View lastFocusView = mLastFocusView;
231         mContentsView.setVisibility(VISIBLE);
232         mLastFocusView = lastFocusView;
233     }
234 
235     /** Called when this row is deselected. */
onDeselected()236     public void onDeselected() {
237         mTitleView.setVisibility(VISIBLE);
238         mTitleView.setAlpha(mTitleViewAlphaDeselected);
239         mTitleView.setScaleX(1.0f);
240         mTitleView.setScaleY(1.0f);
241         mContentsView.setVisibility(GONE);
242     }
243 
244     /** Returns the preferred height of the contents view. The top/bottom padding is excluded. */
getPreferredContentsHeight()245     public int getPreferredContentsHeight() {
246         return mRow.getHeight();
247     }
248 }
249