1/*
2 * Copyright (C) 2011 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 android.preference;
18
19import android.content.Context;
20import android.content.res.TypedArray;
21import android.os.Parcel;
22import android.os.Parcelable;
23import android.util.AttributeSet;
24import android.view.KeyEvent;
25import android.view.View;
26import android.widget.SeekBar;
27import android.widget.SeekBar.OnSeekBarChangeListener;
28
29/**
30 * @hide
31 */
32public class SeekBarPreference extends Preference
33        implements OnSeekBarChangeListener {
34
35    private int mProgress;
36    private int mMax;
37    private boolean mTrackingTouch;
38
39    public SeekBarPreference(
40            Context context, AttributeSet attrs, int defStyle) {
41        super(context, attrs, defStyle);
42        TypedArray a = context.obtainStyledAttributes(attrs,
43                com.android.internal.R.styleable.ProgressBar, defStyle, 0);
44        setMax(a.getInt(com.android.internal.R.styleable.ProgressBar_max, mMax));
45        a.recycle();
46        setLayoutResource(com.android.internal.R.layout.preference_widget_seekbar);
47    }
48
49    public SeekBarPreference(Context context, AttributeSet attrs) {
50        this(context, attrs, 0);
51    }
52
53    public SeekBarPreference(Context context) {
54        this(context, null);
55    }
56
57    @Override
58    protected void onBindView(View view) {
59        super.onBindView(view);
60        SeekBar seekBar = (SeekBar) view.findViewById(
61                com.android.internal.R.id.seekbar);
62        seekBar.setOnSeekBarChangeListener(this);
63        seekBar.setMax(mMax);
64        seekBar.setProgress(mProgress);
65        seekBar.setEnabled(isEnabled());
66    }
67
68    @Override
69    public CharSequence getSummary() {
70        return null;
71    }
72
73    @Override
74    protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
75        setProgress(restoreValue ? getPersistedInt(mProgress)
76                : (Integer) defaultValue);
77    }
78
79    @Override
80    protected Object onGetDefaultValue(TypedArray a, int index) {
81        return a.getInt(index, 0);
82    }
83
84    @Override
85    public boolean onKey(View v, int keyCode, KeyEvent event) {
86        if (event.getAction() != KeyEvent.ACTION_UP) {
87            if (keyCode == KeyEvent.KEYCODE_PLUS
88                    || keyCode == KeyEvent.KEYCODE_EQUALS) {
89                setProgress(getProgress() + 1);
90                return true;
91            }
92            if (keyCode == KeyEvent.KEYCODE_MINUS) {
93                setProgress(getProgress() - 1);
94                return true;
95            }
96        }
97        return false;
98    }
99
100    public void setMax(int max) {
101        if (max != mMax) {
102            mMax = max;
103            notifyChanged();
104        }
105    }
106
107    public void setProgress(int progress) {
108        setProgress(progress, true);
109    }
110
111    private void setProgress(int progress, boolean notifyChanged) {
112        if (progress > mMax) {
113            progress = mMax;
114        }
115        if (progress < 0) {
116            progress = 0;
117        }
118        if (progress != mProgress) {
119            mProgress = progress;
120            persistInt(progress);
121            if (notifyChanged) {
122                notifyChanged();
123            }
124        }
125    }
126
127    public int getProgress() {
128        return mProgress;
129    }
130
131    /**
132     * Persist the seekBar's progress value if callChangeListener
133     * returns true, otherwise set the seekBar's progress to the stored value
134     */
135    void syncProgress(SeekBar seekBar) {
136        int progress = seekBar.getProgress();
137        if (progress != mProgress) {
138            if (callChangeListener(progress)) {
139                setProgress(progress, false);
140            } else {
141                seekBar.setProgress(mProgress);
142            }
143        }
144    }
145
146    @Override
147    public void onProgressChanged(
148            SeekBar seekBar, int progress, boolean fromUser) {
149        if (fromUser && !mTrackingTouch) {
150            syncProgress(seekBar);
151        }
152    }
153
154    @Override
155    public void onStartTrackingTouch(SeekBar seekBar) {
156        mTrackingTouch = true;
157    }
158
159    @Override
160    public void onStopTrackingTouch(SeekBar seekBar) {
161        mTrackingTouch = false;
162        if (seekBar.getProgress() != mProgress) {
163            syncProgress(seekBar);
164        }
165    }
166
167    @Override
168    protected Parcelable onSaveInstanceState() {
169        /*
170         * Suppose a client uses this preference type without persisting. We
171         * must save the instance state so it is able to, for example, survive
172         * orientation changes.
173         */
174
175        final Parcelable superState = super.onSaveInstanceState();
176        if (isPersistent()) {
177            // No need to save instance state since it's persistent
178            return superState;
179        }
180
181        // Save the instance state
182        final SavedState myState = new SavedState(superState);
183        myState.progress = mProgress;
184        myState.max = mMax;
185        return myState;
186    }
187
188    @Override
189    protected void onRestoreInstanceState(Parcelable state) {
190        if (!state.getClass().equals(SavedState.class)) {
191            // Didn't save state for us in onSaveInstanceState
192            super.onRestoreInstanceState(state);
193            return;
194        }
195
196        // Restore the instance state
197        SavedState myState = (SavedState) state;
198        super.onRestoreInstanceState(myState.getSuperState());
199        mProgress = myState.progress;
200        mMax = myState.max;
201        notifyChanged();
202    }
203
204    /**
205     * SavedState, a subclass of {@link BaseSavedState}, will store the state
206     * of MyPreference, a subclass of Preference.
207     * <p>
208     * It is important to always call through to super methods.
209     */
210    private static class SavedState extends BaseSavedState {
211        int progress;
212        int max;
213
214        public SavedState(Parcel source) {
215            super(source);
216
217            // Restore the click counter
218            progress = source.readInt();
219            max = source.readInt();
220        }
221
222        @Override
223        public void writeToParcel(Parcel dest, int flags) {
224            super.writeToParcel(dest, flags);
225
226            // Save the click counter
227            dest.writeInt(progress);
228            dest.writeInt(max);
229        }
230
231        public SavedState(Parcelable superState) {
232            super(superState);
233        }
234
235        @SuppressWarnings("unused")
236        public static final Parcelable.Creator<SavedState> CREATOR =
237                new Parcelable.Creator<SavedState>() {
238            public SavedState createFromParcel(Parcel in) {
239                return new SavedState(in);
240            }
241
242            public SavedState[] newArray(int size) {
243                return new SavedState[size];
244            }
245        };
246    }
247}
248