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package com.example.checkableviews;
* Copyright 2013 Chris Banes.
* 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
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.Checkable;
import android.widget.LinearLayout;
public class CheckableLinearLayout extends LinearLayout implements Checkable {
* Interface definition for a callback to be invoked when the checked state of this View is
* changed.
public static interface OnCheckedChangeListener {
* Called when the checked state of a compound button has changed.
* @param checkableView The view whose state has changed.
* @param isChecked The new checked state of checkableView.
void onCheckedChanged(View checkableView, boolean isChecked);
private static final int[] CHECKED_STATE_SET = {android.R.attr.state_checked};
private boolean mChecked = false;
private OnCheckedChangeListener mOnCheckedChangeListener;
public CheckableLinearLayout(Context context, AttributeSet attrs) {
super(context, attrs);
public boolean isChecked() {
return mChecked;
public void setChecked(boolean b) {
if (b != mChecked) {
mChecked = b;
if (mOnCheckedChangeListener != null) {
mOnCheckedChangeListener.onCheckedChanged(this, mChecked);
public void toggle() {
public int[] onCreateDrawableState(int extraSpace) {
final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
if (isChecked()) {
mergeDrawableStates(drawableState, CHECKED_STATE_SET);
return drawableState;
* Register a callback to be invoked when the checked state of this view changes.
* @param listener the callback to call on checked state change
public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
mOnCheckedChangeListener = listener;

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@dubiao dubiao commented Jan 13, 2015

int[] onCreateDrawableState(int extraSpace)
Is it this method that make the key impact?

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