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 17 package com.android.setupwizardlib.template; 18 19 import android.support.annotation.NonNull; 20 import android.support.annotation.Nullable; 21 import android.util.Log; 22 import android.widget.ScrollView; 23 24 import com.android.setupwizardlib.template.RequireScrollMixin.ScrollHandlingDelegate; 25 import com.android.setupwizardlib.view.BottomScrollView; 26 import 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 */ 32 public 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
