1/*
2 * Copyright (C) 2009 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.camera;
18
19import android.content.Context;
20import android.content.SharedPreferences;
21import android.content.res.TypedArray;
22import android.util.AttributeSet;
23import android.util.Log;
24import android.util.TypedValue;
25
26import java.util.ArrayList;
27import java.util.List;
28
29/**
30 * A type of <code>CameraPreference</code> whose number of possible values
31 * is limited.
32 */
33public class ListPreference extends CameraPreference {
34    private final String TAG = "ListPreference";
35    private final String mKey;
36    private String mValue;
37    private final CharSequence[] mDefaultValues;
38
39    private CharSequence[] mEntries;
40    private CharSequence[] mEntryValues;
41    private boolean mLoaded = false;
42
43    public ListPreference(Context context, AttributeSet attrs) {
44        super(context, attrs);
45
46        TypedArray a = context.obtainStyledAttributes(
47                attrs, R.styleable.ListPreference, 0, 0);
48
49        mKey = Util.checkNotNull(
50                a.getString(R.styleable.ListPreference_key));
51
52        // We allow the defaultValue attribute to be a string or an array of
53        // strings. The reason we need multiple default values is that some
54        // of them may be unsupported on a specific platform (for example,
55        // continuous auto-focus). In that case the first supported value
56        // in the array will be used.
57        int attrDefaultValue = R.styleable.ListPreference_defaultValue;
58        TypedValue tv = a.peekValue(attrDefaultValue);
59        if (tv != null && tv.type == TypedValue.TYPE_REFERENCE) {
60            mDefaultValues = a.getTextArray(attrDefaultValue);
61        } else {
62            mDefaultValues = new CharSequence[1];
63            mDefaultValues[0] = a.getString(attrDefaultValue);
64        }
65
66        setEntries(a.getTextArray(R.styleable.ListPreference_entries));
67        setEntryValues(a.getTextArray(
68                R.styleable.ListPreference_entryValues));
69        a.recycle();
70    }
71
72    public String getKey() {
73        return mKey;
74    }
75
76    public CharSequence[] getEntries() {
77        return mEntries;
78    }
79
80    public CharSequence[] getEntryValues() {
81        return mEntryValues;
82    }
83
84    public void setEntries(CharSequence entries[]) {
85        mEntries = entries == null ? new CharSequence[0] : entries;
86    }
87
88    public void setEntryValues(CharSequence values[]) {
89        mEntryValues = values == null ? new CharSequence[0] : values;
90    }
91
92    public String getValue() {
93        if (!mLoaded) {
94            mValue = getSharedPreferences().getString(mKey,
95                    findSupportedDefaultValue());
96            mLoaded = true;
97        }
98        return mValue;
99    }
100
101    // Find the first value in mDefaultValues which is supported.
102    private String findSupportedDefaultValue() {
103        for (int i = 0; i < mDefaultValues.length; i++) {
104            for (int j = 0; j < mEntryValues.length; j++) {
105                // Note that mDefaultValues[i] may be null (if unspecified
106                // in the xml file).
107                if (mEntryValues[j].equals(mDefaultValues[i])) {
108                    return mDefaultValues[i].toString();
109                }
110            }
111        }
112        return null;
113    }
114
115    public void setValue(String value) {
116        if (findIndexOfValue(value) < 0) throw new IllegalArgumentException();
117        mValue = value;
118        persistStringValue(value);
119    }
120
121    public void setValueIndex(int index) {
122        setValue(mEntryValues[index].toString());
123    }
124
125    public int findIndexOfValue(String value) {
126        for (int i = 0, n = mEntryValues.length; i < n; ++i) {
127            if (Util.equals(mEntryValues[i], value)) return i;
128        }
129        return -1;
130    }
131
132    public String getEntry() {
133        return mEntries[findIndexOfValue(getValue())].toString();
134    }
135
136    protected void persistStringValue(String value) {
137        SharedPreferences.Editor editor = getSharedPreferences().edit();
138        editor.putString(mKey, value);
139        editor.apply();
140    }
141
142    @Override
143    public void reloadValue() {
144        this.mLoaded = false;
145    }
146
147    public void filterUnsupported(List<String> supported) {
148        ArrayList<CharSequence> entries = new ArrayList<CharSequence>();
149        ArrayList<CharSequence> entryValues = new ArrayList<CharSequence>();
150        for (int i = 0, len = mEntryValues.length; i < len; i++) {
151            if (supported.indexOf(mEntryValues[i].toString()) >= 0) {
152                entries.add(mEntries[i]);
153                entryValues.add(mEntryValues[i]);
154            }
155        }
156        int size = entries.size();
157        mEntries = entries.toArray(new CharSequence[size]);
158        mEntryValues = entryValues.toArray(new CharSequence[size]);
159    }
160
161    public void print() {
162        Log.v(TAG, "Preference key=" + getKey() + ". value=" + getValue());
163        for (int i = 0; i < mEntryValues.length; i++) {
164            Log.v(TAG, "entryValues[" + i + "]=" + mEntryValues[i]);
165        }
166    }
167}
168