/*
* 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 android.content.Context;
import android.content.res.TypedArray;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LayerDrawable;
import android.util.AttributeSet;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import com.android.internal.R;
/**
* 通过一个带有亮度指示同时默认文本为“ON”或“OFF”的按钮显示选中/未选中状态.
* <p>See the <a href="{@docRoot}guide/topics/ui/controls/togglebutton.html">Toggle Buttons</a>
* guide.</p>
*
* @attr ref android.R.styleable#ToggleButton_textOn
* @attr ref android.R.styleable#ToggleButton_textOff
* @attr ref android.R.styleable#ToggleButton_disabledAlpha
* @author translate by 农民伯伯(Android中文翻译组)
* @author convert by cnmahj
*/
public class ToggleButton extends CompoundButton {
private CharSequence mTextOn;
private CharSequence mTextOff;
private Drawable mIndicatorDrawable;
private static final int NO_ALPHA = 0xFF;
private float mDisabledAlpha;
public ToggleButton(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a =
context.obtainStyledAttributes(
attrs, com.android.internal.R.styleable.ToggleButton, defStyle, 0);
mTextOn = a.getText(com.android.internal.R.styleable.ToggleButton_textOn);
mTextOff = a.getText(com.android.internal.R.styleable.ToggleButton_textOff);
mDisabledAlpha = a.getFloat(com.android.internal.R.styleable.ToggleButton_disabledAlpha, 0.5f);
syncTextState();
a.recycle();
}
public ToggleButton(Context context, AttributeSet attrs) {
this(context, attrs, com.android.internal.R.attr.buttonStyleToggle);
}
public ToggleButton(Context context) {
this(context, null);
}
@Override
public void setChecked(boolean checked) {
super.setChecked(checked);
syncTextState();
}
private void syncTextState() {
boolean checked = isChecked();
if (checked && mTextOn != null) {
setText(mTextOn);
} else if (!checked && mTextOff != null) {
setText(mTextOff);
}
}
/**
* 返回按钮选中时的文本.
*
* @return 选中时的文本.
*/
public CharSequence getTextOn() {
return mTextOn;
}
/**
* 设置按钮选中时显示的文本.
*
* @param textOn 要显示的文本.
*/
public void setTextOn(CharSequence textOn) {
mTextOn = textOn;
}
/**
* 返回按钮未选中时的文本.
*
* @return 未选中时的文本.
*/
public CharSequence getTextOff() {
return mTextOff;
}
/**
* 设置按钮未选中时显示的文本.
*
* @param textOff 要显示的文本.
*/
public void setTextOff(CharSequence textOff) {
mTextOff = textOff;
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
updateReferenceToIndicatorDrawable(getBackground());
}
@Override
public void setBackgroundDrawable(Drawable d) {
super.setBackgroundDrawable(d);
updateReferenceToIndicatorDrawable(d);
}
private void updateReferenceToIndicatorDrawable(Drawable backgroundDrawable) {
if (backgroundDrawable instanceof LayerDrawable) {
LayerDrawable layerDrawable = (LayerDrawable) backgroundDrawable;
mIndicatorDrawable =
layerDrawable.findDrawableByLayerId(com.android.internal.R.id.toggle);
} else {
mIndicatorDrawable = null;
}
}
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
if (mIndicatorDrawable != null) {
mIndicatorDrawable.setAlpha(isEnabled() ? NO_ALPHA : (int) (NO_ALPHA * mDisabledAlpha));
}
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(ToggleButton.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(ToggleButton.class.getName());
}
}