/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.settings.accessibility;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.res.TypedArray;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import com.android.settings.CustomDialogPreference;
/**
* Abstract dialog preference that displays a set of values and optional titles.
*/
public abstract class ListDialogPreference extends CustomDialogPreference {
private CharSequence[] mEntryTitles;
private int[] mEntryValues;
private OnValueChangedListener mOnValueChangedListener;
/** The layout resource to use for grid items. */
private int mListItemLayout;
/** The current value of this preference. */
private int mValue;
/** The index within the value set of the current value. */
private int mValueIndex;
/** Whether the value had been set using {@link #setValue}. */
private boolean mValueSet;
public ListDialogPreference(Context context, AttributeSet attrs) {
super(context, attrs);
}
/**
* Sets a listened to invoke when the value of this preference changes.
*
* @param listener the listener to invoke
*/
public void setOnValueChangedListener(OnValueChangedListener listener) {
mOnValueChangedListener = listener;
}
/**
* Sets the layout to use for grid items.
*
* @param layoutResId the layout to use for displaying grid items
*/
public void setListItemLayoutResource(int layoutResId) {
mListItemLayout = layoutResId;
}
/**
* Sets the list of item values. Values must be distinct.
*
* @param values the list of item values
*/
public void setValues(int[] values) {
mEntryValues = values;
if (mValueSet && mValueIndex == AbsListView.INVALID_POSITION) {
mValueIndex = getIndexForValue(mValue);
}
}
/**
* Sets the list of item titles. May be null if no titles are specified, or
* may be shorter than the list of values to leave some titles unspecified.
*
* @param titles the list of item titles
*/
public void setTitles(CharSequence[] titles) {
mEntryTitles = titles;
}
/**
* Populates a list item view with data for the specified index.
*
* @param view the view to populate
* @param index the index for which to populate the view
* @see #setListItemLayoutResource(int)
* @see #getValueAt(int)
* @see #getTitleAt(int)
*/
protected abstract void onBindListItem(View view, int index);
/**
* @return the title at the specified index, or null if none specified
*/
protected CharSequence getTitleAt(int index) {
if (mEntryTitles == null || mEntryTitles.length <= index) {
return null;
}
return mEntryTitles[index];
}
/**
* @return the value at the specified index
*/
protected int getValueAt(int index) {
return mEntryValues[index];
}
@Override
public CharSequence getSummary() {
if (mValueIndex >= 0) {
return getTitleAt(mValueIndex);
}
return null;
}
@Override
protected void onPrepareDialogBuilder(AlertDialog.Builder builder,
DialogInterface.OnClickListener listener) {
super.onPrepareDialogBuilder(builder, listener);
final Context context = getContext();
final int dialogLayout = getDialogLayoutResource();
final View picker = LayoutInflater.from(context).inflate(dialogLayout, null);
final ListPreferenceAdapter adapter = new ListPreferenceAdapter();
final AbsListView list = (AbsListView) picker.findViewById(android.R.id.list);
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapter, View v, int position, long id) {
if (callChangeListener((int) id)) {
setValue((int) id);
}
final Dialog dialog = getDialog();
if (dialog != null) {
dialog.dismiss();
}
}
});
// Set initial selection.
final int selectedPosition = getIndexForValue(mValue);
if (selectedPosition != AbsListView.INVALID_POSITION) {
list.setSelection(selectedPosition);
}
builder.setView(picker);
builder.setPositiveButton(null, null);
}
/**
* @return the index of the specified value within the list of entry values,
* or {@link AbsListView#INVALID_POSITION} if not found
*/
protected int getIndexForValue(int value) {
final int[] values = mEntryValues;
if (values != null) {
final int count = values.length;
for (int i = 0; i < count; i++) {
if (values[i] == value) {
return i;
}
}
}
return AbsListView.INVALID_POSITION;
}
/**
* Sets the current value. If the value exists within the set of entry
* values, updates the selection index.
*
* @param value the value to set
*/
public void setValue(int value) {
final boolean changed = mValue != value;
if (changed || !mValueSet) {
mValue = value;
mValueIndex = getIndexForValue(value);
mValueSet = true;
persistInt(value);
if (changed) {
notifyDependencyChange(shouldDisableDependents());
notifyChanged();
}
if (mOnValueChangedListener != null) {
mOnValueChangedListener.onValueChanged(this, value);
}
}
}
/**
* @return the current value
*/
public int getValue() {
return mValue;
}
@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
return a.getInt(index, 0);
}
@Override
protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
setValue(restoreValue ? getPersistedInt(mValue) : (Integer) defaultValue);
}
@Override
protected Parcelable onSaveInstanceState() {
final Parcelable superState = super.onSaveInstanceState();
if (isPersistent()) {
// No need to save instance state since it's persistent
return superState;
}
final SavedState myState = new SavedState(superState);
myState.value = getValue();
return myState;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state == null || !state.getClass().equals(SavedState.class)) {
// Didn't save state for us in onSaveInstanceState
super.onRestoreInstanceState(state);
return;
}
SavedState myState = (SavedState) state;
super.onRestoreInstanceState(myState.getSuperState());
setValue(myState.value);
}
private class ListPreferenceAdapter extends BaseAdapter {
private LayoutInflater mInflater;
@Override
public int getCount() {
return mEntryValues.length;
}
@Override
public Integer getItem(int position) {
return mEntryValues[position];
}
@Override
public long getItemId(int position) {
return mEntryValues[position];
}
@Override
public boolean hasStableIds() {
return true;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
if (mInflater == null) {
mInflater = LayoutInflater.from(parent.getContext());
}
convertView = mInflater.inflate(mListItemLayout, parent, false);
}
onBindListItem(convertView, position);
return convertView;
}
}
private static class SavedState extends BaseSavedState {
public int value;
public SavedState(Parcel source) {
super(source);
value = source.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(value);
}
public SavedState(Parcelable superState) {
super(superState);
}
@SuppressWarnings({ "hiding", "unused" })
public static final Creator<SavedState> CREATOR = new Creator<SavedState>() {
@Override
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
public interface OnValueChangedListener {
public void onValueChanged(ListDialogPreference preference, int value);
}
}