1/*
2 * Copyright (C) 2017 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
17package android.support.wear.internal.widget.drawer;
18
19import android.graphics.drawable.Drawable;
20import android.support.annotation.Nullable;
21import android.support.annotation.RestrictTo;
22import android.support.annotation.RestrictTo.Scope;
23import android.support.wear.widget.drawer.WearableNavigationDrawerView;
24import android.support.wear.widget.drawer.WearableNavigationDrawerView.WearableNavigationDrawerAdapter;
25
26/**
27 * Provides a {@link WearableNavigationDrawerPresenter} implementation that is designed for the
28 * single page navigation drawer.
29 *
30 * @hide
31 */
32@RestrictTo(Scope.LIBRARY_GROUP)
33public class SinglePagePresenter extends WearableNavigationDrawerPresenter {
34
35    private static final long DRAWER_CLOSE_DELAY_MS = 500;
36
37    private final Ui mUi;
38    private final boolean mIsAccessibilityEnabled;
39    @Nullable
40    private WearableNavigationDrawerAdapter mAdapter;
41    private int mCount = 0;
42    private int mSelected = 0;
43
44    /**
45     * Controls the user interface of a single-page {@link WearableNavigationDrawerView}.
46     */
47    public interface Ui {
48
49        /**
50         * Associates a {@link WearableNavigationDrawerPresenter} with this {@link Ui}.
51         */
52        void setPresenter(WearableNavigationDrawerPresenter presenter);
53
54        /**
55         * Initializes the {@link Ui} with {@code count} items.
56         */
57        void initialize(int count);
58
59        /**
60         * Sets the item's {@link Drawable} icon and its {@code contentDescription}.
61         */
62        void setIcon(int index, Drawable drawable, CharSequence contentDescription);
63
64        /**
65         * Displays {@code itemText} in a {@link android.widget.TextView} used to indicate which
66         * item is selected. When the {@link Ui} doesn't have space, it should show a {@link
67         * android.widget.Toast} if {@code showToastIfNoTextView} is {@code true}.
68         */
69        void setText(CharSequence itemText, boolean showToastIfNoTextView);
70
71        /**
72         * Indicates that the item at {@code index} has been selected.
73         */
74        void selectItem(int index);
75
76        /**
77         * Removes the indication that the item at {@code index} has been selected.
78         */
79        void deselectItem(int index);
80
81        /**
82         * Closes the drawer after the given delay.
83         */
84        void closeDrawerDelayed(long delayMs);
85
86        /**
87         * Peeks the {@link WearableNavigationDrawerView}.
88         */
89        void peekDrawer();
90    }
91
92    public SinglePagePresenter(Ui ui, boolean isAccessibilityEnabled) {
93        if (ui == null) {
94            throw new IllegalArgumentException("Received null ui.");
95        }
96
97        mIsAccessibilityEnabled = isAccessibilityEnabled;
98        mUi = ui;
99        mUi.setPresenter(this);
100        onDataSetChanged();
101    }
102
103    @Override
104    public void onDataSetChanged() {
105        if (mAdapter == null) {
106            return;
107        }
108        int count = mAdapter.getCount();
109        if (mCount != count) {
110            mCount = count;
111            mSelected = Math.min(mSelected, count - 1);
112            mUi.initialize(count);
113        }
114        for (int i = 0; i < count; i++) {
115            mUi.setIcon(i, mAdapter.getItemDrawable(i), mAdapter.getItemText(i));
116        }
117
118        mUi.setText(mAdapter.getItemText(mSelected), false /* showToastIfNoTextView */);
119        mUi.selectItem(mSelected);
120    }
121
122    @Override
123    public void onNewAdapter(WearableNavigationDrawerAdapter adapter) {
124        if (adapter == null) {
125            throw new IllegalArgumentException("Received null adapter.");
126        }
127        mAdapter = adapter;
128        mAdapter.setPresenter(this);
129        onDataSetChanged();
130    }
131
132    @Override
133    public void onSelected(int index) {
134        mUi.deselectItem(mSelected);
135        mUi.selectItem(index);
136        mSelected = index;
137        if (mIsAccessibilityEnabled) {
138            // When accessibility gestures are enabled, the user can't access a closed nav drawer,
139            // so peek it instead.
140            mUi.peekDrawer();
141        } else {
142            mUi.closeDrawerDelayed(DRAWER_CLOSE_DELAY_MS);
143        }
144
145        if (mAdapter != null) {
146            mUi.setText(mAdapter.getItemText(index), true /* showToastIfNoTextView */);
147        }
148        notifyItemSelectedListeners(index);
149    }
150
151    @Override
152    public void onSetCurrentItemRequested(int index, boolean smoothScrollTo) {
153        mUi.deselectItem(mSelected);
154        mUi.selectItem(index);
155        mSelected = index;
156        if (mAdapter != null) {
157            mUi.setText(mAdapter.getItemText(index), false /* showToastIfNoTextView */);
158        }
159        notifyItemSelectedListeners(index);
160    }
161
162    @Override
163    public boolean onDrawerTapped() {
164        // Do nothing. Use onSelected as our tap trigger so that we get which index was tapped on.
165        return false;
166    }
167}
168