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.support.annotation.Nullable;
20import android.support.annotation.RestrictTo;
21import android.support.annotation.RestrictTo.Scope;
22import android.support.wear.widget.drawer.WearableNavigationDrawerView;
23import android.support.wear.widget.drawer.WearableNavigationDrawerView.WearableNavigationDrawerAdapter;
24
25/**
26 * Provides a {@link WearableNavigationDrawerPresenter} implementation that is designed for the
27 * multi-page navigation drawer.
28 *
29 * @hide
30 */
31@RestrictTo(Scope.LIBRARY_GROUP)
32public class MultiPagePresenter extends WearableNavigationDrawerPresenter {
33
34    private final Ui mUi;
35    private final WearableNavigationDrawerView mDrawer;
36    private final boolean mIsAccessibilityEnabled;
37    @Nullable private WearableNavigationDrawerAdapter mAdapter;
38
39    /**
40     * Controls the user interface of a multi-page {@link WearableNavigationDrawerView}.
41     */
42    public interface Ui {
43
44        /**
45         * Initializes the {@code Ui}.
46         */
47        void initialize(WearableNavigationDrawerView drawer,
48                WearableNavigationDrawerPresenter presenter);
49
50        /**
51         * Should notify the {@code NavigationPagerAdapter} that the underlying data has changed.
52         */
53        void notifyNavigationPagerAdapterDataChanged();
54
55        /**
56         * Should notify the Page Indicator that the underlying data has changed.
57         */
58        void notifyPageIndicatorDataChanged();
59
60        /**
61         * Associates the given {@code adapter} with this {@link Ui}.
62         */
63        void setNavigationPagerAdapter(WearableNavigationDrawerAdapter adapter);
64
65        /**
66         * Sets which item is selected and optionally smooth scrolls to it.
67         */
68        void setNavigationPagerSelectedItem(int index, boolean smoothScrollTo);
69    }
70
71    public MultiPagePresenter(WearableNavigationDrawerView drawer, Ui ui,
72            boolean isAccessibilityEnabled) {
73        if (drawer == null) {
74            throw new IllegalArgumentException("Received null drawer.");
75        }
76        if (ui == null) {
77            throw new IllegalArgumentException("Received null ui.");
78        }
79        mDrawer = drawer;
80        mUi = ui;
81        mUi.initialize(drawer, this);
82        mIsAccessibilityEnabled = isAccessibilityEnabled;
83    }
84
85    @Override
86    public void onDataSetChanged() {
87        mUi.notifyNavigationPagerAdapterDataChanged();
88        mUi.notifyPageIndicatorDataChanged();
89    }
90
91    @Override
92    public void onNewAdapter(WearableNavigationDrawerAdapter adapter) {
93        if (adapter == null) {
94            throw new IllegalArgumentException("Received null adapter.");
95        }
96        mAdapter = adapter;
97        mAdapter.setPresenter(this);
98        mUi.setNavigationPagerAdapter(adapter);
99    }
100
101    @Override
102    public void onSelected(int index) {
103        notifyItemSelectedListeners(index);
104    }
105
106    @Override
107    public void onSetCurrentItemRequested(int index, boolean smoothScrollTo) {
108        mUi.setNavigationPagerSelectedItem(index, smoothScrollTo);
109    }
110
111    @Override
112    public boolean onDrawerTapped() {
113        if (mDrawer.isOpened()) {
114            if (mIsAccessibilityEnabled) {
115                // When accessibility gestures are enabled, the user can't access a closed nav
116                // drawer, so peek it instead.
117                mDrawer.getController().peekDrawer();
118            } else {
119                mDrawer.getController().closeDrawer();
120            }
121            return true;
122        }
123        return false;
124    }
125}
126