1 /* 2 * Copyright (C) 2022 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.settings.accessibility; 18 19 import android.content.Context; 20 import android.util.AttributeSet; 21 import android.view.View; 22 23 import androidx.preference.Preference; 24 import androidx.preference.PreferenceViewHolder; 25 import androidx.viewpager.widget.ViewPager; 26 27 import com.android.internal.util.Preconditions; 28 import com.android.settings.R; 29 import com.android.settings.display.PreviewPagerAdapter; 30 import com.android.settings.widget.DotsPageIndicator; 31 32 /** 33 * A {@link Preference} that could show the preview related to the text and reading options. 34 */ 35 public class TextReadingPreviewPreference extends Preference { 36 private int mCurrentItem; 37 private int mLastLayerIndex; 38 private PreviewPagerAdapter mPreviewAdapter; 39 TextReadingPreviewPreference(Context context)40 TextReadingPreviewPreference(Context context) { 41 super(context); 42 init(); 43 } 44 TextReadingPreviewPreference(Context context, AttributeSet attrs)45 public TextReadingPreviewPreference(Context context, AttributeSet attrs) { 46 super(context, attrs); 47 init(); 48 } 49 TextReadingPreviewPreference(Context context, AttributeSet attrs, int defStyleAttr)50 TextReadingPreviewPreference(Context context, AttributeSet attrs, int defStyleAttr) { 51 super(context, attrs, defStyleAttr); 52 init(); 53 } 54 TextReadingPreviewPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)55 TextReadingPreviewPreference(Context context, AttributeSet attrs, int defStyleAttr, 56 int defStyleRes) { 57 super(context, attrs, defStyleAttr, defStyleRes); 58 init(); 59 } 60 61 @Override onBindViewHolder(PreferenceViewHolder holder)62 public void onBindViewHolder(PreferenceViewHolder holder) { 63 super.onBindViewHolder(holder); 64 65 final ViewPager viewPager = (ViewPager) holder.findViewById(R.id.preview_pager); 66 final DotsPageIndicator pageIndicator = 67 (DotsPageIndicator) holder.findViewById(R.id.page_indicator); 68 updateAdapterIfNeeded(viewPager, pageIndicator, mPreviewAdapter); 69 updatePagerAndIndicator(viewPager, pageIndicator); 70 } 71 setPreviewAdapter(PreviewPagerAdapter previewAdapter)72 void setPreviewAdapter(PreviewPagerAdapter previewAdapter) { 73 if (previewAdapter != mPreviewAdapter) { 74 mPreviewAdapter = previewAdapter; 75 notifyChanged(); 76 } 77 } 78 setCurrentItem(int currentItem)79 void setCurrentItem(int currentItem) { 80 Preconditions.checkNotNull(mPreviewAdapter, 81 "Preview adapter is null, you should init the preview adapter first"); 82 83 if (currentItem != mCurrentItem) { 84 mCurrentItem = currentItem; 85 notifyChanged(); 86 } 87 } 88 getCurrentItem()89 int getCurrentItem() { 90 return mCurrentItem; 91 } 92 updateAdapterIfNeeded(ViewPager viewPager, DotsPageIndicator pageIndicator, PreviewPagerAdapter previewAdapter)93 private void updateAdapterIfNeeded(ViewPager viewPager, DotsPageIndicator pageIndicator, 94 PreviewPagerAdapter previewAdapter) { 95 if (viewPager.getAdapter() == previewAdapter) { 96 return; 97 } 98 99 viewPager.setAdapter(previewAdapter); 100 101 if (previewAdapter != null) { 102 pageIndicator.setViewPager(viewPager); 103 } else { 104 mCurrentItem = 0; 105 } 106 } 107 updatePagerAndIndicator(ViewPager viewPager, DotsPageIndicator pageIndicator)108 private void updatePagerAndIndicator(ViewPager viewPager, DotsPageIndicator pageIndicator) { 109 if (viewPager.getAdapter() == null) { 110 return; 111 } 112 113 if (viewPager.getCurrentItem() != mCurrentItem) { 114 viewPager.setCurrentItem(mCurrentItem); 115 } 116 117 pageIndicator.setVisibility( 118 viewPager.getAdapter().getCount() > 1 ? View.VISIBLE : View.GONE); 119 } 120 init()121 private void init() { 122 setLayoutResource(R.layout.accessibility_text_reading_preview); 123 } 124 notifyPreviewPagerChanged(int pagerIndex)125 void notifyPreviewPagerChanged(int pagerIndex) { 126 Preconditions.checkNotNull(mPreviewAdapter, 127 "Preview adapter is null, you should init the preview adapter first"); 128 129 if (pagerIndex != mLastLayerIndex) { 130 mPreviewAdapter.setPreviewLayer(pagerIndex, mLastLayerIndex, getCurrentItem(), 131 /* animate= */ false); 132 } 133 134 mLastLayerIndex = pagerIndex; 135 } 136 } 137