/*
* 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>
* 一个包含选中/未选中两个状态的按钮.当按钮按下或单击时自动改变状态.
* </p>
*
* <p><strong>XML 属性</strong></p>
* <p>
* 参见 {@link android.R.styleable#CompoundButton
* CompoundButton 属性}、{@link android.R.styleable#Button Button
* 属性}、{@link android.R.styleable#TextView TextView 属性} 和 {@link
* android.R.styleable#View View 属性}.
* </p>
* @author translate by 德罗德
* @author convert by cnmahj
*/
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>改变按钮的选中状态.</p>
*
* @param checked true 选中按钮，false 取消选中.
*/
public void setChecked(boolean checked) {
if (mChecked != checked) {
mChecked = checked;
refreshDrawableState();
notifyAccessibilityStateChanged();
// 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;
}
}
/**
* 注册一个在按钮状态发生改变时执行的回调函数
*
* @param listener 当选中状态改变时调用的回调函数
*/
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;
}
/**
* 定义了一个在按钮的选中状态改变时要调用的回调函数的接口.
*/
public static interface OnCheckedChangeListener {
/**
* 在按钮选中状态发生改变时被调用.
* @param buttonView 选中状态发生改变的那个按钮.
* @param isChecked 按钮的选中状态.
*/
void onCheckedChanged(CompoundButton buttonView, boolean isChecked);
}
/**
* 通过资源 ID 给按钮背景设置一个可绘制对象.
* @param resid 作为背景可绘制对象的资源 ID.
*/
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);
}
/**
* 通过资源 ID 给按钮背景设置一个可绘制对象.
*
* @param d 作为背景的可绘制对象
*/
public void setButtonDrawable(Drawable d) {
if (d != null) {
if (mButtonDrawable != null) {
mButtonDrawable.setCallback(null);
unscheduleDrawable(mButtonDrawable);
}
d.setCallback(this);
d.setState(getDrawableState());
d.setVisible(getVisibility() == VISIBLE, false);
mButtonDrawable = d;
mButtonDrawable.setState(null);
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();
}
}