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      1 /*
      2  * Copyright (C) 2015 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;
     18 
     19 import android.content.Context;
     20 import android.content.res.Configuration;
     21 import android.os.Bundle;
     22 import android.support.v4.view.ViewPager;
     23 import android.support.v4.view.ViewPager.OnPageChangeListener;
     24 import android.view.LayoutInflater;
     25 import android.view.View;
     26 import android.view.View.OnClickListener;
     27 import android.view.ViewGroup;
     28 import android.view.accessibility.AccessibilityEvent;
     29 import android.widget.SeekBar;
     30 import android.widget.SeekBar.OnSeekBarChangeListener;
     31 import android.widget.TextView;
     32 
     33 import com.android.settings.widget.DotsPageIndicator;
     34 import com.android.settings.widget.LabeledSeekBar;
     35 
     36 /**
     37  * Preference fragment shows a preview and a seek bar to adjust a specific settings.
     38  */
     39 public abstract class PreviewSeekBarPreferenceFragment extends SettingsPreferenceFragment {
     40 
     41     /** List of entries corresponding the settings being set. */
     42     protected String[] mEntries;
     43 
     44     /** Index of the entry corresponding to initial value of the settings. */
     45     protected int mInitialIndex;
     46 
     47     /** Index of the entry corresponding to current value of the settings. */
     48     protected int mCurrentIndex;
     49 
     50     /** Resource id of the layout for this preference fragment. */
     51     protected int mActivityLayoutResId;
     52 
     53     /** Resource id of the layout that defines the contents inside preview screen. */
     54     protected int[] mPreviewSampleResIds;
     55 
     56     private ViewPager mPreviewPager;
     57     private PreviewPagerAdapter mPreviewPagerAdapter;
     58     private DotsPageIndicator mPageIndicator;
     59 
     60     private TextView mLabel;
     61     private View mLarger;
     62     private View mSmaller;
     63 
     64     private class onPreviewSeekBarChangeListener implements OnSeekBarChangeListener {
     65         private boolean mSeekByTouch;
     66 
     67         @Override
     68         public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
     69             setPreviewLayer(progress, true);
     70             if (!mSeekByTouch) {
     71                 commit();
     72             }
     73         }
     74 
     75         @Override
     76         public void onStartTrackingTouch(SeekBar seekBar) {
     77             mSeekByTouch = true;
     78         }
     79 
     80         @Override
     81         public void onStopTrackingTouch(SeekBar seekBar) {
     82             if (mPreviewPagerAdapter.isAnimating()) {
     83                 mPreviewPagerAdapter.setAnimationEndAction(new Runnable() {
     84                     @Override
     85                     public void run() {
     86                         commit();
     87                     }
     88                 });
     89             } else {
     90                 commit();
     91             }
     92             mSeekByTouch = false;
     93         }
     94     }
     95 
     96     @Override
     97     public View onCreateView(LayoutInflater inflater, ViewGroup container,
     98                              Bundle savedInstanceState) {
     99         final View root = super.onCreateView(inflater, container, savedInstanceState);
    100         final ViewGroup listContainer = (ViewGroup) root.findViewById(android.R.id.list_container);
    101         listContainer.removeAllViews();
    102 
    103         final View content = inflater.inflate(mActivityLayoutResId, listContainer, false);
    104         listContainer.addView(content);
    105 
    106         mLabel = (TextView) content.findViewById(R.id.current_label);
    107 
    108         // The maximum SeekBar value always needs to be non-zero. If there's
    109         // only one available value, we'll handle this by disabling the
    110         // seek bar.
    111         final int max = Math.max(1, mEntries.length - 1);
    112 
    113         final LabeledSeekBar seekBar = (LabeledSeekBar) content.findViewById(R.id.seek_bar);
    114         seekBar.setLabels(mEntries);
    115         seekBar.setMax(max);
    116         seekBar.setProgress(mInitialIndex);
    117         seekBar.setOnSeekBarChangeListener(new onPreviewSeekBarChangeListener());
    118 
    119         mSmaller = content.findViewById(R.id.smaller);
    120         mSmaller.setOnClickListener(new OnClickListener() {
    121             @Override
    122             public void onClick(View v) {
    123                 final int progress = seekBar.getProgress();
    124                 if (progress > 0) {
    125                     seekBar.setProgress(progress - 1, true);
    126                 }
    127             }
    128         });
    129 
    130         mLarger = content.findViewById(R.id.larger);
    131         mLarger.setOnClickListener(new OnClickListener() {
    132             @Override
    133             public void onClick(View v) {
    134                 final int progress = seekBar.getProgress();
    135                 if (progress < seekBar.getMax()) {
    136                     seekBar.setProgress(progress + 1, true);
    137                 }
    138             }
    139         });
    140 
    141         if (mEntries.length == 1) {
    142             // The larger and smaller buttons will be disabled when we call
    143             // setPreviewLayer() later in this method.
    144             seekBar.setEnabled(false);
    145         }
    146 
    147         final Context context = getContext();
    148         final Configuration origConfig = context.getResources().getConfiguration();
    149         final boolean isLayoutRtl = origConfig.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL;
    150         Configuration[] configurations = new Configuration[mEntries.length];
    151         for (int i = 0; i < mEntries.length; ++i) {
    152             configurations[i] = createConfig(origConfig, i);
    153         }
    154 
    155         mPreviewPager = (ViewPager) content.findViewById(R.id.preview_pager);
    156         mPreviewPagerAdapter = new PreviewPagerAdapter(context, isLayoutRtl,
    157                 mPreviewSampleResIds, configurations);
    158         mPreviewPager.setAdapter(mPreviewPagerAdapter);
    159         mPreviewPager.setCurrentItem(isLayoutRtl ? mPreviewSampleResIds.length - 1 : 0);
    160         mPreviewPager.addOnPageChangeListener(mPreviewPageChangeListener);
    161 
    162         mPageIndicator = (DotsPageIndicator) content.findViewById(R.id.page_indicator);
    163         if (mPreviewSampleResIds.length > 1) {
    164             mPageIndicator.setViewPager(mPreviewPager);
    165             mPageIndicator.setVisibility(View.VISIBLE);
    166             mPageIndicator.setOnPageChangeListener(mPageIndicatorPageChangeListener);
    167         } else {
    168             mPageIndicator.setVisibility(View.GONE);
    169         }
    170 
    171         setPreviewLayer(mInitialIndex, false);
    172         return root;
    173     }
    174 
    175     /**
    176      * Creates new configuration based on the current position of the SeekBar.
    177      */
    178     protected abstract Configuration createConfig(Configuration origConfig, int index);
    179 
    180     /**
    181      * Persists the selected value and sends a configuration change.
    182      */
    183     protected abstract void commit();
    184 
    185     private void setPreviewLayer(int index, boolean animate) {
    186         mLabel.setText(mEntries[index]);
    187         mSmaller.setEnabled(index > 0);
    188         mLarger.setEnabled(index < mEntries.length - 1);
    189         setPagerIndicatorContentDescription(mPreviewPager.getCurrentItem());
    190         mPreviewPagerAdapter.setPreviewLayer(index, mCurrentIndex,
    191                 mPreviewPager.getCurrentItem(), animate);
    192 
    193         mCurrentIndex = index;
    194     }
    195 
    196     private void setPagerIndicatorContentDescription(int position) {
    197         mPageIndicator.setContentDescription(
    198                 getPrefContext().getString(R.string.preview_page_indicator_content_description,
    199                         position + 1, mPreviewSampleResIds.length));
    200     }
    201 
    202     private OnPageChangeListener mPreviewPageChangeListener = new OnPageChangeListener() {
    203         @Override
    204         public void onPageScrollStateChanged(int state) {
    205             // Do nothing.
    206         }
    207 
    208         @Override
    209         public void onPageScrolled(int position, float positionOffset,
    210                 int positionOffsetPixels) {
    211             // Do nothing.
    212         }
    213 
    214         @Override
    215         public void onPageSelected(int position) {
    216             mPreviewPager.sendAccessibilityEvent(AccessibilityEvent.TYPE_ANNOUNCEMENT);
    217         }
    218     };
    219 
    220     private OnPageChangeListener mPageIndicatorPageChangeListener = new OnPageChangeListener() {
    221         @Override
    222         public void onPageScrollStateChanged(int state) {
    223             // Do nothing.
    224         }
    225 
    226         @Override
    227         public void onPageScrolled(int position, float positionOffset,
    228                 int positionOffsetPixels) {
    229             // Do nothing.
    230         }
    231 
    232         @Override
    233         public void onPageSelected(int position) {
    234             setPagerIndicatorContentDescription(position);
    235         }
    236     };
    237 }
    238