/*
* Copyright 2018 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 androidx.preference;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Parcel;
import android.os.Parcelable;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;
import androidx.annotation.ArrayRes;
import androidx.annotation.NonNull;
import androidx.core.content.res.TypedArrayUtils;
/**
* A {@link Preference} that displays a list of entries as a dialog.
*
* <p>This preference saves a string value. This string will be the value from the
* {@link #setEntryValues(CharSequence[])} array.
*
* @attr name android:entries
* @attr name android:entryValues
*/
public class ListPreference extends DialogPreference {
private static final String TAG = "ListPreference";
private CharSequence[] mEntries;
private CharSequence[] mEntryValues;
private String mValue;
private String mSummary;
private boolean mValueSet;
public ListPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
TypedArray a = context.obtainStyledAttributes(
attrs, R.styleable.ListPreference, defStyleAttr, defStyleRes);
mEntries = TypedArrayUtils.getTextArray(a, R.styleable.ListPreference_entries,
R.styleable.ListPreference_android_entries);
mEntryValues = TypedArrayUtils.getTextArray(a, R.styleable.ListPreference_entryValues,
R.styleable.ListPreference_android_entryValues);
if (TypedArrayUtils.getBoolean(a, R.styleable.ListPreference_useSimpleSummaryProvider,
R.styleable.ListPreference_useSimpleSummaryProvider, false)) {
setSummaryProvider(SimpleSummaryProvider.getInstance());
}
a.recycle();
//Retrieve the Preference summary attribute since it's private in the Preference class.
a = context.obtainStyledAttributes(attrs,
R.styleable.Preference, defStyleAttr, defStyleRes);
mSummary = TypedArrayUtils.getString(a, R.styleable.Preference_summary,
R.styleable.Preference_android_summary);
a.recycle();
}
public ListPreference(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
public ListPreference(Context context, AttributeSet attrs) {
this(context, attrs, TypedArrayUtils.getAttr(context, R.attr.dialogPreferenceStyle,
android.R.attr.dialogPreferenceStyle));
}
public ListPreference(Context context) {
this(context, null);
}
/**
* Sets the human-readable entries to be shown in the list. This will be shown in subsequent
* dialogs.
*
* <p>Each entry must have a corresponding index in {@link #setEntryValues(CharSequence[])}.
*
* @param entries The entries
* @see #setEntryValues(CharSequence[])
*/
public void setEntries(CharSequence[] entries) {
mEntries = entries;
}
/**
* @param entriesResId The entries array as a resource
* @see #setEntries(CharSequence[])
*/
public void setEntries(@ArrayRes int entriesResId) {
setEntries(getContext().getResources().getTextArray(entriesResId));
}
/**
* The list of entries to be shown in the list in subsequent dialogs.
*
* @return The list as an array
*/
public CharSequence[] getEntries() {
return mEntries;
}
/**
* The array to find the value to save for a preference when an entry from entries is
* selected. If a user clicks on the second item in entries, the second item in this array
* will be saved to the preference.
*
* @param entryValues The array to be used as values to save for the preference
*/
public void setEntryValues(CharSequence[] entryValues) {
mEntryValues = entryValues;
}
/**
* @param entryValuesResId The entry values array as a resource
* @see #setEntryValues(CharSequence[])
*/
public void setEntryValues(@ArrayRes int entryValuesResId) {
setEntryValues(getContext().getResources().getTextArray(entryValuesResId));
}
/**
* Returns the array of values to be saved for the preference.
*
* @return The array of values
*/
public CharSequence[] getEntryValues() {
return mEntryValues;
}
@Override
public void setSummary(CharSequence summary) {
super.setSummary(summary);
if (summary == null && mSummary != null) {
mSummary = null;
} else if (summary != null && !summary.equals(mSummary)) {
mSummary = summary.toString();
}
}
@SuppressWarnings("unchecked")
@Override
public CharSequence getSummary() {
if (getSummaryProvider() != null) {
return getSummaryProvider().provideSummary(this);
}
final CharSequence entry = getEntry();
CharSequence summary = super.getSummary();
if (mSummary == null) {
return summary;
}
String formattedString = String.format(mSummary, entry == null ? "" : entry);
if (TextUtils.equals(formattedString, summary)) {
return summary;
}
Log.w(TAG,
"Setting a summary with a String formatting marker is no longer supported."
+ " You should use a SummaryProvider instead.");
return formattedString;
}
/**
* Sets the value of the key. This should be one of the entries in {@link #getEntryValues()}.
*
* @param value The value to set for the key
*/
public void setValue(String value) {
// Always persist/notify the first time.
final boolean changed = !TextUtils.equals(mValue, value);
if (changed || !mValueSet) {
mValue = value;
mValueSet = true;
persistString(value);
if (changed) {
notifyChanged();
}
}
}
/**
* Returns the value of the key. This should be one of the entries in {@link #getEntryValues()}.
*
* @return The value of the key
*/
public String getValue() {
return mValue;
}
/**
* Returns the entry corresponding to the current value.
*
* @return The entry corresponding to the current value, or {@code null}
*/
public CharSequence getEntry() {
int index = getValueIndex();
return index >= 0 && mEntries != null ? mEntries[index] : null;
}
/**
* Returns the index of the given value (in the entry values array).
*
* @param value The value whose index should be returned
* @return The index of the value, or -1 if not found
*/
public int findIndexOfValue(String value) {
if (value != null && mEntryValues != null) {
for (int i = mEntryValues.length - 1; i >= 0; i--) {
if (mEntryValues[i].equals(value)) {
return i;
}
}
}
return -1;
}
/**
* Sets the value to the given index from the entry values.
*
* @param index The index of the value to set
*/
public void setValueIndex(int index) {
if (mEntryValues != null) {
setValue(mEntryValues[index].toString());
}
}
private int getValueIndex() {
return findIndexOfValue(mValue);
}
@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
return a.getString(index);
}
@Override
protected void onSetInitialValue(Object defaultValue) {
setValue(getPersistedString((String) 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.mValue = 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.mValue);
}
private static class SavedState extends BaseSavedState {
public static final Parcelable.Creator<SavedState> CREATOR =
new Parcelable.Creator<SavedState>() {
@Override
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
String mValue;
SavedState(Parcel source) {
super(source);
mValue = source.readString();
}
SavedState(Parcelable superState) {
super(superState);
}
@Override
public void writeToParcel(@NonNull Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeString(mValue);
}
}
/**
* A simple {@link androidx.preference.Preference.SummaryProvider} implementation for a
* {@link ListPreference}. If no value has been set, the summary displayed will be 'Not set',
* otherwise the summary displayed will be the entry set for this preference.
*/
public static final class SimpleSummaryProvider implements SummaryProvider<ListPreference> {
private static SimpleSummaryProvider sSimpleSummaryProvider;
private SimpleSummaryProvider() {}
/**
* Retrieve a singleton instance of this simple
* {@link androidx.preference.Preference.SummaryProvider} implementation.
*
* @return a singleton instance of this simple
* {@link androidx.preference.Preference.SummaryProvider} implementation
*/
public static SimpleSummaryProvider getInstance() {
if (sSimpleSummaryProvider == null) {
sSimpleSummaryProvider = new SimpleSummaryProvider();
}
return sSimpleSummaryProvider;
}
@Override
public CharSequence provideSummary(ListPreference preference) {
if (TextUtils.isEmpty(preference.getEntry())) {
return (preference.getContext().getString(R.string.not_set));
} else {
return preference.getEntry();
}
}
}
}