/*
* Copyright (C) 2007 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.example.android.apis.preference;
import com.example.android.apis.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Parcel;
import android.os.Parcelable;
import android.preference.Preference;
import android.util.AttributeSet;
import android.view.View;
import android.widget.TextView;
/**
* This is an example of a custom preference type. The preference counts the
* number of clicks it has received and stores/retrieves it from the storage.
*/
public class MyPreference extends Preference {
private int mClickCounter;
// This is the constructor called by the inflater
public MyPreference(Context context, AttributeSet attrs) {
super(context, attrs);
setWidgetLayoutResource(R.layout.preference_widget_mypreference);
}
@Override
protected void onBindView(View view) {
super.onBindView(view);
// Set our custom views inside the layout
final TextView myTextView = (TextView) view.findViewById(R.id.mypreference_widget);
if (myTextView != null) {
myTextView.setText(String.valueOf(mClickCounter));
}
}
@Override
protected void onClick() {
int newValue = mClickCounter + 1;
// Give the client a chance to ignore this change if they deem it
// invalid
if (!callChangeListener(newValue)) {
// They don't want the value to be set
return;
}
// Increment counter
mClickCounter = newValue;
// Save to persistent storage (this method will make sure this
// preference should be persistent, along with other useful checks)
persistInt(mClickCounter);
// Data has changed, notify so UI can be refreshed!
notifyChanged();
}
@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
// This preference type's value type is Integer, so we read the default
// value from the attributes as an Integer.
return a.getInteger(index, 0);
}
@Override
protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
if (restoreValue) {
// Restore state
mClickCounter = getPersistedInt(mClickCounter);
} else {
// Set state
int value = (Integer) defaultValue;
mClickCounter = value;
persistInt(value);
}
}
@Override
protected Parcelable onSaveInstanceState() {
/*
* Suppose a client uses this preference type without persisting. We
* must save the instance state so it is able to, for example, survive
* orientation changes.
*/
final Parcelable superState = super.onSaveInstanceState();
if (isPersistent()) {
// No need to save instance state since it's persistent
return superState;
}
// Save the instance state
final SavedState myState = new SavedState(superState);
myState.clickCounter = mClickCounter;
return myState;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (!state.getClass().equals(SavedState.class)) {
// Didn't save state for us in onSaveInstanceState
super.onRestoreInstanceState(state);
return;
}
// Restore the instance state
SavedState myState = (SavedState) state;
super.onRestoreInstanceState(myState.getSuperState());
mClickCounter = myState.clickCounter;
notifyChanged();
}
/**
* SavedState, a subclass of {@link BaseSavedState}, will store the state
* of MyPreference, a subclass of Preference.
*
* It is important to always call through to super methods.
*/
private static class SavedState extends BaseSavedState {
int clickCounter;
public SavedState(Parcel source) {
super(source);
// Restore the click counter
clickCounter = source.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
// Save the click counter
dest.writeInt(clickCounter);
}
public SavedState(Parcelable superState) {
super(superState);
}
public static final Parcelable.Creator CREATOR =
new Parcelable.Creator() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
}
//layout/preference_widget_mypreference.xml
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_marginRight="6sp"
android:focusable="false"
android:clickable="false" />