Android中CheckBox与CompoundButton源码解析

经历过了前面一系列的讲解，下面我们直接来看看系统里面的CheckBox与CompoundButton类的源码文件。你肯定会发现很多熟悉的地方。
结合下面源码，我们对它们进行解析解析，它里面使用的就是自定义drawable state。

我们首先直接看CheckBox的源码

public class CheckBox extends CompoundButton {    public CheckBox(Context context) {        this(context, null);    }    public CheckBox(Context context, AttributeSet attrs) {        this(context, attrs, com.android.internal.R.attr.checkboxStyle);    }    public CheckBox(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }    @Override    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {        super.onInitializeAccessibilityEvent(event);        event.setClassName(CheckBox.class.getName());    }    @Override    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {        super.onInitializeAccessibilityNodeInfo(info);        info.setClassName(CheckBox.class.getName());    }}

我们可以看到，它里面并没有做什么，因为它的操作都是继承自CompoundButton.

我们先来看看下面一个普通的布局文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    android:paddingBottom="@dimen/activity_vertical_margin"    tools:context=".MainActivity">    <CheckBox        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="CheckBox"/></RelativeLayout>

在上面的这个相对布局中，就写了一个CheckBox，我们什么都不做，直接运行代码，就会看到下面的运行界面：

当我们单击这个CheckBox,我们发现他会被选中，那么它内部到底是怎么实现的呢？
其实使用过drawable state的人应该对这个并不陌生，我们经常这样做：

1、在res/drawable文件下创建selector.xml，示例代码如下：

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <item        android:state_pressed="false"        android:drawable="@drawable/title_button_back">    </item>    <item        android:state_pressed="true"        android:drawable="@drawable/title_button_back_h">    </item>    <item        android:state_window_focused="false"        android:drawable="@drawable/title_button_back">    </item></selector>

2、编写布局文件，为布局文件中的ImageButton设置selector，示例代码如下：

<?xml version="1.0" encoding="utf-8"?>  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_height="wrap_content"     android:layout_width="fill_parent">      <ImageButton         android:id="@+id/title_IB"        android:layout_height="wrap_content"         android:layout_width="wrap_content"         android:background="#00000000"         android:layout_marginRight="4dp"         android:layout_centerVertical="true"         android:src="@drawable/selector">    </ImageButton>  </RelativeLayout>

当我们单击这个图片按钮的时候，图片按钮的图片就会发生变化，其实CheckBox也是这样做的，只是这些系统为我们做了。

下面我们来看看系统实现源码：
上面在布局文件中直接写了一个CheckBox,布局文件被解析后就会实例化这个CheckBox对象，就会执行CheckBox的构造函数：

public CheckBox(Context context, AttributeSet attrs) {    this(context, attrs, com.android.internal.R.attr.checkboxStyle);}public CheckBox(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);}

从上面我们可以知道两点：
1、CheckBox的默认样式是com.android.internal.R.attr.checkboxStyle
2、最终执行的时候CompoundButton的构造函数

在frameworks/base/core/res/res/values/themes.xml文件中，已经初始化了checkBoxStyle样式：

<item name="checkboxStyle">@android:style/Widget.CompoundButton.CheckBox</item>

在frameworks/base/core/res/res/values/styles.xml文件，我们来看看它的样式是什么：

<style name="Widget.CompoundButton.CheckBox">    <item name="android:button">?android:attr/listChoiceIndicatorMultiple</item></style>

在frameworks/base/core/res/res/values/themes.xml文件：

<item name="listChoiceIndicatorMultiple">@android:drawable/btn_check</item>

可以看到，CheckBox的默认样式就是给它的button属性赋值了一个btn_check,我们来看看btn_check文件里面的具体内容。

在frameworks/base/core/res/res/drawable/btn_check.xml

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android">    <!-- Enabled states -->    <item android:state_checked="true" android:state_window_focused="false"          android:state_enabled="true"          android:drawable="@drawable/btn_check_on" />    <item android:state_checked="false" android:state_window_focused="false"          android:state_enabled="true"          android:drawable="@drawable/btn_check_off" />    <item android:state_checked="true" android:state_pressed="true"          android:state_enabled="true"          android:drawable="@drawable/btn_check_on_pressed" />    <item android:state_checked="false" android:state_pressed="true"          android:state_enabled="true"          android:drawable="@drawable/btn_check_off_pressed" />    <item android:state_checked="true" android:state_focused="true"          android:state_enabled="true"          android:drawable="@drawable/btn_check_on_selected" />    <item android:state_checked="false" android:state_focused="true"          android:state_enabled="true"          android:drawable="@drawable/btn_check_off_selected" />    <item android:state_checked="false"          android:state_enabled="true"          android:drawable="@drawable/btn_check_off" />    <item android:state_checked="true"          android:state_enabled="true"          android:drawable="@drawable/btn_check_on" />    <!-- Disabled states -->    <item android:state_checked="true" android:state_window_focused="false"          android:drawable="@drawable/btn_check_on_disable" />    <item android:state_checked="false" android:state_window_focused="false"          android:drawable="@drawable/btn_check_off_disable" />    <item android:state_checked="true" android:state_focused="true"          android:drawable="@drawable/btn_check_on_disable_focused" />    <item android:state_checked="false" android:state_focused="true"          android:drawable="@drawable/btn_check_off_disable_focused" />    <item android:state_checked="false" android:drawable="@drawable/btn_check_off_disable" />    <item android:state_checked="true" android:drawable="@drawable/btn_check_on_disable" /></selector>

我们看到，state_checked为true的时候，drawable=”@drawable/btn_check_on”，state_checked为false的时候,drawable=”@drawable/btn_check_off”.
@drawable/btn_check_on图片和@drawable/btn_check_off图片，在frameworks/base/core/res/res/drawable我们可以找到：

我们可以看到，其实就是根据不同的状态，为button属性赋值了不同的图片资源，这就是我们看到的效果。

state_checked这个状态的定义，在下面进行了定义：

<declare-styleable name="DrawableStates">    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when a view has input focus. -->    <attr name="state_focused" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when a view's window has input focus. -->    <attr name="state_window_focused" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when a view is enabled. -->    <attr name="state_enabled" format="boolean" />    <!-- State identifier indicating that the object <var>may</var> display a check mark.         See {@link R.attr#state_checked} for the identifier that indicates whether it is         actually checked. -->    <attr name="state_checkable" format="boolean"/>    <!-- State identifier indicating that the object is currently checked.  See         {@link R.attr#state_checkable} for an additional identifier that can indicate if         any object may ever display a check, regardless of whether state_checked is         currently set. -->    <attr name="state_checked" format="boolean"/>    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when a view (or one of its parents) is currently selected. -->    <attr name="state_selected" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when the user is pressing down in a view. -->    <attr name="state_pressed" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when a view or its parent has been "activated" meaning the user has currently         marked it as being of interest.  This is an alternative representation of         state_checked for when the state should be propagated down the view hierarchy. -->    <attr name="state_activated" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable}.-->    <attr name="state_active" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable}.-->    <attr name="state_single" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable}.-->    <attr name="state_first" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable}.-->    <attr name="state_middle" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable}.-->    <attr name="state_last" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         indicating that the Drawable is in a view that is hardware accelerated.         This means that the device can at least render a full-screen scaled         bitmap with one layer of text and bitmaps composited on top of it         at 60fps.  When this is set, the colorBackgroundCacheHint will be         ignored even if it specifies a solid color, since that optimization         is not needed. -->    <attr name="state_accelerated" format="boolean" />    <!-- State value for {@link android.graphics.drawable.StateListDrawable StateListDrawable},         set when a pointer is hovering over the view. -->    <attr name="state_hovered" format="boolean" />    <!-- State for {@link android.graphics.drawable.StateListDrawable StateListDrawable}         indicating that the Drawable is in a view that is capable of accepting a drop of         the content currently being manipulated in a drag-and-drop operation. -->    <attr name="state_drag_can_accept" format="boolean" />    <!-- State for {@link android.graphics.drawable.StateListDrawable StateListDrawable}         indicating that a drag operation (for which the Drawable's view is a valid recipient)         is currently positioned over the Drawable. -->    <attr name="state_drag_hovered" format="boolean" />    <!-- State for {@link android.graphics.drawable.StateListDrawable StateListDrawable}         indicating that a View has accessibility focus. -->    <attr name="state_accessibility_focused" format="boolean" /></declare-styleable>

我们可以看到<attr name="state_checked" format="boolean"/>

下面我们看看CompoundButton的构造函数，因为CheckBox最终执行的是它的构造函数。

public CompoundButton(Context context, AttributeSet attrs, int defStyle) {    super(context, attrs, defStyle);    TypedArray a =            context.obtainStyledAttributes(                    attrs, com.android.internal.R.styleable.CompoundButton, defStyle, 0);    Drawable d = a.getDrawable(com.android.internal.R.styleable.CompoundButton_button);    if (d != null) {        setButtonDrawable(d);    }    boolean checked = a            .getBoolean(com.android.internal.R.styleable.CompoundButton_checked, false);    setChecked(checked);    a.recycle();}

我们可以知道CompoundButton自定义了两个属性，进入frameworks/base/core/res/res/values/attrs.xml文件：

<declare-styleable name="CompoundButton">    <!-- Indicates the initial checked state of this button. -->    <attr name="checked" format="boolean" />    <!-- Drawable used for the button graphic (e.g. checkbox, radio button, etc). -->    <attr name="button" format="reference"/></declare-styleable>

我们可以看到它定义了两个属性：checked，button，一个存放的是一个boolean类型的值，表示是否被选中，一个存放的是引用类型，对应的是一个图片。
在构造函数中，我们获取到了这两个属性值。上面就是对button这个属性进行了默认赋值，然后我们这里就可以获取到上面的btn_check这个xml文件的drawable。
也就是说Drawable d = a.getDrawable(com.android.internal.R.styleable.CompoundButton_button)中的d的到的就是btn_check这个xml文件的drawable。

然后分别调用了setButtonDrawable(d)和setChecked(checked)来对我们自定义的控件进行了设置。

我们来看看setButtonDrawable(d)函数：

public void setButtonDrawable(Drawable d) {    if (d != null) {        if (mButtonDrawable != null) {            mButtonDrawable.setCallback(null);            unscheduleDrawable(mButtonDrawable);        }        //这里设置Callback的原因就是refreshDrawableState刷新的时候可以回调到invalidateDrawable        //这样就可以重绘，这个我们在#详解refreshDrawableList()的执行流程#这篇文件讲过        d.setCallback(this);        d.setVisible(getVisibility() == VISIBLE, false);        mButtonDrawable = d;        setMinHeight(mButtonDrawable.getIntrinsicHeight());    }    refreshDrawableState();}

最后调用了refreshDrawableState这个方法，这个执行过程我们也分析过，整个执行思路都是一样，不过不同的是，里面的很多方法都被覆盖了。

这里我们再来把整个思路走一走。

refreshDrawableState执行的还是View里面的这个方法，直接看源码。

public void refreshDrawableState() {    //首先把标志设置为PFLAG_DRAWABLE_STATE_DIRTY    mPrivateFlags |= PFLAG_DRAWABLE_STATE_DIRTY;    drawableStateChanged();    ViewParent parent = mParent;    if (parent != null) {        parent.childDrawableStateChanged(this);    }}

drawableStateChanged这个方法不在执行View里面的这个方法，因为CompoundButton里面有这个方法，我们看看CompoundButton的这个方法。

@Overrideprotected void drawableStateChanged() {    super.drawableStateChanged();    if (mButtonDrawable != null) {        int[] myDrawableState = getDrawableState();        // Set the state of the Drawable        mButtonDrawable.setState(myDrawableState);        invalidate();    }}

getDrawableState这个函数还是调用的View的这个函数。

public final int[] getDrawableState() {    //PFLAG_DRAWABLE_STATE_DIRTY是前面refreshDrawableState设置的    //如果mDrawableState不为空，并且不需要刷新状态，则直接返回，否则重新进行获取    if ((mDrawableState != null) && ((mPrivateFlags & PFLAG_DRAWABLE_STATE_DIRTY) == 0)) {        return mDrawableState;    } else {        //这里就是重新得到视图状态，并将其返回        mDrawableState = onCreateDrawableState(0);        //清除前面refreshDrawableState设置的标识        mPrivateFlags &= ~PFLAG_DRAWABLE_STATE_DIRTY;        return mDrawableState;    }}

下面调用到了onCreateDrawableState这个方法，这个方法也不在是执行View里面的这个方法，因为CompoundButton里面也有这个方法。

@Overrideprotected int[] onCreateDrawableState(int extraSpace) {    final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);    if (isChecked()) {        mergeDrawableStates(drawableState, CHECKED_STATE_SET);    }    return drawableState;}

结合之前我们详解refreshDrawableList()的执行流程的分析。这个方法就是在之前的基础上加入了一个判断，如果isChekced为真，就把我们自定义的这个状态加进去，这样当前状态里面就有我们的自定义的状态，后面在状态二维数组中查询的时候，就可以找到对应的drawable图片进行设置了。

这个函数执行完了就会回到上面的getDrawableState函数，然后把当前的状态返回到drawableStateChanged函数中，接着看里面的代码。

接着执行mButtonDrawable.setState(myDrawableState)，把得到的当前状态数组设置进去。里面的执行过去前面详解refreshDrawableList()的执行流程的分析也说过，是完全一样的，我们就省略,不明白就再看看，最后会执行invalidateSelf函数。

这个函数就会得到前面我们设置的Callback回调，调用它的invalidateDrawable方法。

public void invalidateSelf() {    final Callback callback = getCallback();    if (callback != null) {        callback.invalidateDrawable(this);    }}

跟前面一样，因为View实现了这个回调，所以它执行的是View里面的实现方法。在这个方法里面执行了invalidate函数，所以会执行onDraw方法.
在CompoundButton里面实现了这个方法，它不再直接执行View里面的这个方法了。

protected void onDraw(Canvas canvas) {    super.onDraw(canvas);    final Drawable buttonDrawable = mButtonDrawable;    if (buttonDrawable != null) {        final int verticalGravity = getGravity() & Gravity.VERTICAL_GRAVITY_MASK;        final int drawableHeight = buttonDrawable.getIntrinsicHeight();        final int drawableWidth = buttonDrawable.getIntrinsicWidth();        int top = 0;        switch (verticalGravity) {            case Gravity.BOTTOM:                top = getHeight() - drawableHeight;                break;            case Gravity.CENTER_VERTICAL:                top = (getHeight() - drawableHeight) / 2;                break;        }        int bottom = top + drawableHeight;        int left = isLayoutRtl() ? getWidth() - drawableWidth : 0;        int right = isLayoutRtl() ? getWidth() : drawableWidth;        buttonDrawable.setBounds(left, top, right, bottom);        buttonDrawable.draw(canvas);    }}

这样这个图片就绘制出来了，从btn_check里面我们可以看到最开始显示的图片是btn_check_off，当我们单击这个CheckBox的时候，会执行performClick函数。

@Overridepublic boolean performClick() {    /*     * XXX: These are tiny, need some surrounding 'expanded touch area',     * which will need to be implemented in Button if we only override     * performClick()     */    /* When clicked, toggle the state */    toggle();    return super.performClick();}

接着执行toggle函数。

public void toggle() {    setChecked(!mChecked);}

这里面就把当前的状态设置为与之前相反的状态，刚开始为false,这个时候就为true.

接着我们看看setChecked函数。

public void setChecked(boolean checked) {    if (mChecked != checked) {        mChecked = checked;        refreshDrawableState();        notifyViewAccessibilityStateChangedIfNeeded(                AccessibilityEvent.CONTENT_CHANGE_TYPE_UNDEFINED);        // Avoid infinite recursions if setChecked() is called from a listener        if (mBroadcasting) {            return;        }        mBroadcasting = true;        if (mOnCheckedChangeListener != null) {            mOnCheckedChangeListener.onCheckedChanged(this, mChecked);        }        if (mOnCheckedChangeWidgetListener != null) {            mOnCheckedChangeWidgetListener.onCheckedChanged(this, mChecked);        }        mBroadcasting = false;                }}

在这个里面又执行了refreshDrawableState函数，同样把上面的refreshDrawableState过程又执行了一遍，执行在到onCreateDrawableState就不一样了。
我们在来看看这个函数：

protected int[] onCreateDrawableState(int extraSpace) {    final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);    if (isChecked()) {        mergeDrawableStates(drawableState, CHECKED_STATE_SET);    }    return drawableState;}

第一次执行的时候isChecked为false,自定义的这个状态没有合进去，这次就把自定义的这个状态合进去，这样就可以查询到我们的状态，所以就可以找到定义的drawable,所以图片发生改变为btn_check_on。

最后把完整的CompoundButton源码贴出来，可以对照上面将的，然后再根据前面讲的详解refreshDrawableList()的执行流程这个过程理解理解。

/* * 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 android.widget;import com.android.internal.R;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.drawable.Drawable;import android.os.Parcel;import android.os.Parcelable;import android.util.AttributeSet;import android.view.Gravity;import android.view.ViewDebug;import android.view.accessibility.AccessibilityEvent;import android.view.accessibility.AccessibilityNodeInfo;/** * <p> * A button with two states, checked and unchecked. When the button is pressed * or clicked, the state changes automatically. * </p> * * <p><strong>XML attributes</strong></p> * <p> * See {@link android.R.styleable#CompoundButton * CompoundButton Attributes}, {@link android.R.styleable#Button Button * Attributes}, {@link android.R.styleable#TextView TextView Attributes}, {@link * android.R.styleable#View View Attributes} * </p> */public abstract class CompoundButton extends Button implements Checkable {    private boolean mChecked;    private int mButtonResource;    private boolean mBroadcasting;    private Drawable mButtonDrawable;    private OnCheckedChangeListener mOnCheckedChangeListener;    private OnCheckedChangeListener mOnCheckedChangeWidgetListener;    private static final int[] CHECKED_STATE_SET = {        R.attr.state_checked    };    public CompoundButton(Context context) {        this(context, null);    }    public CompoundButton(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public CompoundButton(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        TypedArray a =                context.obtainStyledAttributes(                        attrs, com.android.internal.R.styleable.CompoundButton, defStyle, 0);        Drawable d = a.getDrawable(com.android.internal.R.styleable.CompoundButton_button);        if (d != null) {            setButtonDrawable(d);        }        boolean checked = a                .getBoolean(com.android.internal.R.styleable.CompoundButton_checked, false);        setChecked(checked);        a.recycle();    }    public void toggle() {        setChecked(!mChecked);    }    @Override    public boolean performClick() {        /*         * XXX: These are tiny, need some surrounding 'expanded touch area',         * which will need to be implemented in Button if we only override         * performClick()         */        /* When clicked, toggle the state */        toggle();        return super.performClick();    }    @ViewDebug.ExportedProperty    public boolean isChecked() {        return mChecked;    }    /**     * <p>Changes the checked state of this button.</p>     *     * @param checked true to check the button, false to uncheck it     */    public void setChecked(boolean checked) {        if (mChecked != checked) {            mChecked = checked;            refreshDrawableState();            notifyViewAccessibilityStateChangedIfNeeded(                    AccessibilityEvent.CONTENT_CHANGE_TYPE_UNDEFINED);            // Avoid infinite recursions if setChecked() is called from a listener            if (mBroadcasting) {                return;            }            mBroadcasting = true;            if (mOnCheckedChangeListener != null) {                mOnCheckedChangeListener.onCheckedChanged(this, mChecked);            }            if (mOnCheckedChangeWidgetListener != null) {                mOnCheckedChangeWidgetListener.onCheckedChanged(this, mChecked);            }            mBroadcasting = false;                    }    }    /**     * Register a callback to be invoked when the checked state of this button     * changes.     *     * @param listener the callback to call on checked state change     */    public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {        mOnCheckedChangeListener = listener;    }    /**     * Register a callback to be invoked when the checked state of this button     * changes. This callback is used for internal purpose only.     *     * @param listener the callback to call on checked state change     * @hide     */    void setOnCheckedChangeWidgetListener(OnCheckedChangeListener listener) {        mOnCheckedChangeWidgetListener = listener;    }    /**     * Interface definition for a callback to be invoked when the checked state     * of a compound button changed.     */    public static interface OnCheckedChangeListener {        /**         * Called when the checked state of a compound button has changed.         *         * @param buttonView The compound button view whose state has changed.         * @param isChecked  The new checked state of buttonView.         */        void onCheckedChanged(CompoundButton buttonView, boolean isChecked);    }    /**     * Set the background to a given Drawable, identified by its resource id.     *     * @param resid the resource id of the drawable to use as the background      */    public void setButtonDrawable(int resid) {        if (resid != 0 && resid == mButtonResource) {            return;        }        mButtonResource = resid;        Drawable d = null;        if (mButtonResource != 0) {            d = getResources().getDrawable(mButtonResource);        }        setButtonDrawable(d);    }    /**     * Set the background to a given Drawable     *     * @param d The Drawable to use as the background     */    public void setButtonDrawable(Drawable d) {        if (d != null) {            if (mButtonDrawable != null) {                mButtonDrawable.setCallback(null);                unscheduleDrawable(mButtonDrawable);            }            d.setCallback(this);            d.setVisible(getVisibility() == VISIBLE, false);            mButtonDrawable = d;            setMinHeight(mButtonDrawable.getIntrinsicHeight());        }        refreshDrawableState();    }    @Override    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {        super.onInitializeAccessibilityEvent(event);        event.setClassName(CompoundButton.class.getName());        event.setChecked(mChecked);    }    @Override    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {        super.onInitializeAccessibilityNodeInfo(info);        info.setClassName(CompoundButton.class.getName());        info.setCheckable(true);        info.setChecked(mChecked);    }    @Override    public int getCompoundPaddingLeft() {        int padding = super.getCompoundPaddingLeft();        if (!isLayoutRtl()) {            final Drawable buttonDrawable = mButtonDrawable;            if (buttonDrawable != null) {                padding += buttonDrawable.getIntrinsicWidth();            }        }        return padding;    }    @Override    public int getCompoundPaddingRight() {        int padding = super.getCompoundPaddingRight();        if (isLayoutRtl()) {            final Drawable buttonDrawable = mButtonDrawable;            if (buttonDrawable != null) {                padding += buttonDrawable.getIntrinsicWidth();            }        }        return padding;    }    /**     * @hide     */    @Override    public int getHorizontalOffsetForDrawables() {        final Drawable buttonDrawable = mButtonDrawable;        return (buttonDrawable != null) ? buttonDrawable.getIntrinsicWidth() : 0;    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        final Drawable buttonDrawable = mButtonDrawable;        if (buttonDrawable != null) {            final int verticalGravity = getGravity() & Gravity.VERTICAL_GRAVITY_MASK;            final int drawableHeight = buttonDrawable.getIntrinsicHeight();            final int drawableWidth = buttonDrawable.getIntrinsicWidth();            int top = 0;            switch (verticalGravity) {                case Gravity.BOTTOM:                    top = getHeight() - drawableHeight;                    break;                case Gravity.CENTER_VERTICAL:                    top = (getHeight() - drawableHeight) / 2;                    break;            }            int bottom = top + drawableHeight;            int left = isLayoutRtl() ? getWidth() - drawableWidth : 0;            int right = isLayoutRtl() ? getWidth() : drawableWidth;            buttonDrawable.setBounds(left, top, right, bottom);            buttonDrawable.draw(canvas);        }    }    @Override    protected int[] onCreateDrawableState(int extraSpace) {        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);        if (isChecked()) {            mergeDrawableStates(drawableState, CHECKED_STATE_SET);        }        return drawableState;    }    @Override    protected void drawableStateChanged() {        super.drawableStateChanged();        if (mButtonDrawable != null) {            int[] myDrawableState = getDrawableState();            // Set the state of the Drawable            mButtonDrawable.setState(myDrawableState);            invalidate();        }    }    @Override    protected boolean verifyDrawable(Drawable who) {        return super.verifyDrawable(who) || who == mButtonDrawable;    }    @Override    public void jumpDrawablesToCurrentState() {        super.jumpDrawablesToCurrentState();        if (mButtonDrawable != null) mButtonDrawable.jumpToCurrentState();    }    static class SavedState extends BaseSavedState {        boolean checked;        /**         * Constructor called from {@link CompoundButton#onSaveInstanceState()}         */        SavedState(Parcelable superState) {            super(superState);        }        /**         * Constructor called from {@link #CREATOR}         */        private SavedState(Parcel in) {            super(in);            checked = (Boolean)in.readValue(null);        }        @Override        public void writeToParcel(Parcel out, int flags) {            super.writeToParcel(out, flags);            out.writeValue(checked);        }        @Override        public String toString() {            return "CompoundButton.SavedState{"                    + Integer.toHexString(System.identityHashCode(this))                    + " checked=" + checked + "}";        }        public static final Parcelable.Creator<SavedState> CREATOR                = new Parcelable.Creator<SavedState>() {            public SavedState createFromParcel(Parcel in) {                return new SavedState(in);            }            public SavedState[] newArray(int size) {                return new SavedState[size];            }        };    }    @Override    public Parcelable onSaveInstanceState() {        // Force our ancestor class to save its state        setFreezesText(true);        Parcelable superState = super.onSaveInstanceState();        SavedState ss = new SavedState(superState);        ss.checked = isChecked();        return ss;    }    @Override    public void onRestoreInstanceState(Parcelable state) {        SavedState ss = (SavedState) state;        super.onRestoreInstanceState(ss.getSuperState());        setChecked(ss.checked);        requestLayout();    }}