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 com.android.setupwizardlib.template;
18
19import android.support.annotation.NonNull;
20import android.support.annotation.Nullable;
21import android.util.Log;
22import android.widget.ScrollView;
23
24import com.android.setupwizardlib.template.RequireScrollMixin.ScrollHandlingDelegate;
25import com.android.setupwizardlib.view.BottomScrollView;
26import com.android.setupwizardlib.view.BottomScrollView.BottomScrollListener;
27
28/**
29 * {@link ScrollHandlingDelegate} which analyzes scroll events from {@link BottomScrollView} and
30 * notifies {@link RequireScrollMixin} about scrollability changes.
31 */
32public class ScrollViewScrollHandlingDelegate
33        implements ScrollHandlingDelegate, BottomScrollListener {
34
35    private static final String TAG = "ScrollViewDelegate";
36
37    @NonNull
38    private final RequireScrollMixin mRequireScrollMixin;
39
40    @Nullable
41    private final BottomScrollView mScrollView;
42
43    public ScrollViewScrollHandlingDelegate(
44            @NonNull RequireScrollMixin requireScrollMixin,
45            @Nullable ScrollView scrollView) {
46        mRequireScrollMixin = requireScrollMixin;
47        if (scrollView instanceof BottomScrollView) {
48            mScrollView = (BottomScrollView) scrollView;
49        } else {
50            Log.w(TAG, "Cannot set non-BottomScrollView. Found=" + scrollView);
51            mScrollView = null;
52        }
53    }
54
55    @Override
56    public void onScrolledToBottom() {
57        mRequireScrollMixin.notifyScrollabilityChange(false);
58    }
59
60    @Override
61    public void onRequiresScroll() {
62        mRequireScrollMixin.notifyScrollabilityChange(true);
63    }
64
65    @Override
66    public void startListening() {
67        if (mScrollView != null) {
68            mScrollView.setBottomScrollListener(this);
69        } else {
70            Log.w(TAG, "Cannot require scroll. Scroll view is null.");
71        }
72    }
73
74    @Override
75    public void pageScrollDown() {
76        if (mScrollView != null) {
77            mScrollView.pageScroll(ScrollView.FOCUS_DOWN);
78        }
79    }
80}
81