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
onProgressChanged(SeekBar seekBar, int progress, boolean fromUser)68         public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
69             setPreviewLayer(progress, true);
70             if (!mSeekByTouch) {
71                 commit();
72             }
73         }
74 
75         @Override
onStartTrackingTouch(SeekBar seekBar)76         public void onStartTrackingTouch(SeekBar seekBar) {
77             mSeekByTouch = true;
78         }
79 
80         @Override
onStopTrackingTouch(SeekBar seekBar)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
onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)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      */
createConfig(Configuration origConfig, int index)178     protected abstract Configuration createConfig(Configuration origConfig, int index);
179 
180     /**
181      * Persists the selected value and sends a configuration change.
182      */
commit()183     protected abstract void commit();
184 
setPreviewLayer(int index, boolean animate)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